Climate Risk and Vulnerability Assessment

Home , Kumarapuram, Ottapidaram, Velankanni

Chennai-Kanyakumari Industrial Corridor: Power Sector Investment Project (RRP IND 51308-001)

Document Stage: Final Project Number: 51308-001 March 2019

India: Chennai-Kanyakumari Industrial Corridor : Power Sector Investment Project

Asian Development Bank

TABLE OF CONTENTS

LIST OF FIGURES II LIST OF TABLES IV INDEX OF TERMS V UNITS VI CLIMATE GLOSSARY VI EXECUTIVE SUMMARY 1 1. INTRODUCTION 4 1.1 Brief Project Description 4 1.2 Project Information 4 1.3 Concept of Risk and Vulnerability 6 1.4 Sector Climate Risk and Vulnerability 7 1.5 Sector’s Regulatory, Legal, Institutional and Policy Frameworks Related to Climate Change 7 1.6 Data Sources 7 1.7 Structure of the Climate Risk and Vulnerability Assessment 8

2. PROJECT DESCRIPTION 9 2.1 Project Profile 9 2.2 Objective/s of the CRVA or Rationale 12 2.3 Methodology, scope and limitations 12

3. GOVERNMENT STRATEGY FOR COPING WITH CLIMATE CHANGE 13 3.1 Impact of Climate Change in Tamil Nadu 13 3.2 Tamil Nadu Government Strategy for Climate Change 14 3.3 Summary 16

4. CLIMATE CHANGE IMPACTS THAT CAN AFFECT PROJECT COMPONENTS 16 4.1 Temperature 16 4.1.1 Temperature – Past Trends 16 4.1.2 Change in Temperature (Increase) 17 4.1.3 Temperature Projections 17 4.1.4 Minimum temperature projections: 18 4.1.5 Risk Management within sub-project 20 4.2 Change in Precipitation 20 4.2.1 Rainfall - Observed Pattern 20 4.2.2 Rainfall Projections 22 4.2.3 Risk Management Response/ Recommendation 29 4.3 Cyclones/ Storm Surge – Observed Trends 29 4.3.1 Existing Cyclonic Activity Profile 29 4.3.2 Impact of Tsunami 31 4.3.3 Impact of Cyclone 32 4.3.4 Coastal inundation and damages 32 4.3.5 Projected Cyclonic Activity/Trend 33 4.3.6 Risk Management Response 34 4.4 Sea Level Rise 34 4.4.1 Sea Level Rise – Past Trend 34 4.4.2 Sea Level Rise – Projections 34 4.4.3 Risk Management Response 36 4.5 Other Climate Change Impacts 36 4.5.1 Impact of Climate Change on Avian Central Asian Flyway 36 4.5.2 Risk Management Measures 36

5. CLIMATE RISK AND VULNERABILITY ASSESSMENT 37

5.1 Methodology 37 5.1.1 Projection Horizon 37 5.1.2 Hazard Characterization 37 5.2. Sensitivity and Exposure Impact Assessment 38 5.2.1 Calculating risk 38 5.2.2 Vulnerability and adaptive capacity Assessment - Score/Ranking 38 5.3 Influence of Climate Change on Project Components 41 5.3.1 Region Specific designs 41 5.4 Sub-Project Level Vulnerability Risk Ranking 42 5.5 Hazard-Exposure-Sensitivity & Vulnerability Ranking/Scoring 45 5.6 Overall Project Ranking 47

6. PROPOSED MANAGEMENT AND ADAPTATION ACTIONS 48 6.1 Adaptation Measures and Recommendations 48 6.2 Proposed Adaptation Measures 53 6.3 Overall Likely Climate Change Impacts 55 6.4 Climate Adaptation Measures within the Project Design 56 6.4.1 Design items 56 6.4.2 Cost Benefit Analysis of Extra cost items 57 6.4.3 Social and Political acceptability 58

7. STAKEHOLDER CONSULTATION AND GROUND VALIDATION 59 7.1 Building State Level Capacities to enhance energy efficiency 59 7.1.1 National Action Plan on Climate Change (NAPCC) 59 7.1.2 Tamil Nadu State Action Plan on Climate Change (TNSAPCC) 59 7.1.3 Tamil Nadu State Climate Change Cell (TNSCCC) 60 7.1.4 Flood Management Programme in Tamil Nadu 60 7.2 Institutions involved in the management of Coastal Zone 60

REFERENCES 62 APPENDICES 63 Appendix A: Relevant Technical Specifications 63

LIST OF FIGURES

Figure 1.1: Geographic Locations of Substations and Transmission Lines to be Built 5 under the Project

Figure 1.2: Climate Risk and Vulnerability Assessment – Process Flow 6

Figure 2.1: Location of Substations and Illustrative Lines Routes (bee line) 10

Figure 4.1: Change in Maximum Temperature (ºC) Projections for 2010-2040, 2040- 19 2070, 2070-2100 with Reference to Baseline (1970-2000)

Figure 4.2: Change in Minimum Temperature (ºC) Projections for 2010-2040, 2040- 20 2070, 2070-2100 Reference to Baseline (1970-2000)

Figure 4.3: Rainfall (mm) over Tamil Nadu during (a) Oct; (b) Nov; (c) Dec; and (d) NE 23 Monsoon

Figure 4.4: Change in Annual Rainfall (mm) Projections for 2010-2040, 2040-2070 and 25 2070-2100 with Reference to Baseline (1970-2000)

Figure 4.5: Stations with Significant Increasing/Decreasing Trends in One Day Extreme 26 Rainfall ii

Figure 4.6: Boundary of the Cauvery River Basin 27

Figure 4.7: Annual Rainfall - Baseline and Projections 28

Figure 4.8: Annual Rainfall Days in Baseline and End Century Scenario 28

Figure 4.9: Average rainfall intensity 29

Figure 4.10: Average rainfall intensity during south west monsoon (JJAS) 29

Figure 4.11: Average rainfall intensity during north east monsoon (ONDJ) 29

Figure 4.12: Wind and Cyclone Hazard Map of Tamil Nadu 32

Figure 4.13: Probable Maximum Surge Heights (m) of Surges with a 50-year Return 34 Period Figure 4.14: Trends of Sea Level Between 1989 and 2009 Observed in Specific Areas 36 Along the Coast Line in Tamil Nadu

Figure 5.1: Illustrates the CRVA Methodology and its Key Factors 39

Figure 6.1: Design Wind Speed Map of India 51

Figure 6.2: India Wind and Cyclone Zone Map 52

Figure 6.3: Wind and Cyclone Hazard Map of Tamil Nadu 53

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LIST OF TABLES

Table 2.1: List of Subprojects in CKIC Power Sector Investment Project 9

Table 2.2: Location of Substations and Termination Points of Transmission Lines 11

Table 3.1: Key Strategies to Address Climate Concerns for the Energy Sector 15

Table 4.1: District-wise Projected Change in Maximum Temperature in 0C with 18 Reference to 1970-2000

Table 4.2: District-wise Change in Minimum Temperature in ºC with Reference to 1970- 20 2000

Table 4.3: Seasonal Rainfall of Selected Stations in Tamil Nadu (Rainfall in cm) 21

Table 4.4: Percentage Changes in Annual and Seasonal Rainfall and in Number of Rainy 22 Days in the Last 100 Years

Table 4.5: District-wise Percentage Change in Annual Rainfall with Reference to 1970- 24 2000

Table 4.6: Changes in Precipitation in Mid-century (2021-2050) in the Cauvery Basin with 30 respect to Baseline (1961-1990)

Table 4.7: Return Periods of Storm Surges of Different Strengths 34

Table 4.8: Projection of Sea Level Rise Based on Different IPCC SRES Scenarios 35

Table 5.1: Hazard Characterization and Vulnerability Ranking Criteria 41

Table 5.2: Meteorological Data used for Design 44

Table 5.3: Vulnerability Assessment of Sub-Project areas – Ranking 45

Table 5.4: Summary Table of Vulnerability Ranking for Sub-project Components 47

Table 5.5: Sub-project Overall Vulnerability Ranking 48

Table 6.1: Design Wind Speed Zones 51

Table 6.2: Design Wind Pressure Pd in N/m2 54

Table 6.3: Soil Properties to be Considered in Foundation Designs for Relevant Types of 54 Soil

Table 6.4: Climate Adaptation in Design by TANTRANSCO 56

Table 6.5: Climate Change Adaptation Measures within the Project 58

Table 7.1: Institutions Involved in Management of Various Aspects in the Coastal Zone 63 Area in Tamil Nadu and Interactions with TANTRANSCO

INDEX OF TERMS ADB Asian Development Bank CC Climate Change CEIG Chief Electrical Inspector to Government CKIC Chennai-Kanyakumari Industrial Corridor CMFRI Central Marine Fisheries Research Institute CPCB Central Pollution Control Board CRA&MR Climate Risk Assessment & Management Reporting CRVA Climate Risk & Vulnerability Assessment CRZ Coastal Regulation Zone Notification DC Direct Current DPR Detailed Project Reports EHV Extra High Voltage EIA Environment Impact Assessment ERS Earthquake Resistant Structures GCM Global Circulation Models GHG Greenhouse emissions GoI Government of India GoTN Government of Tamil Nadu GPRS General Packet Radio Service HFL High Flood Level IEC Information, Education & Communication IMD Indian Meteorological Department INCCA Indian Network for Climate Change Assessment IPCC Intergovernmental Panel on Climate Change IT Information Technology MoEFCC Ministry of Environment, Forests and Climate Change NAPCC National Action Plan on Climate Change NDMA National Disaster Management Authority NH National Highway NIO National Institute of Oceanography O&M Operation & Maintenance PGCIL Power Grid Corporation of India Limited PRECIS Providing Regional Climates for Impact Studies PSP Private Sector Participation SAP-CC State Action Plan on Climate Change (Tamil Nadu) SCADA Supervisory Control and Data Acquisition (Systems) SH State Highway SLR Sea Level Rise SOR Schedule of Rates UNFCCC United Nations Framework Convention on Climate Change WG Working Group

UNITS bcm Billion cubic metre mg/l Milligram per litre bgl below ground level m.ha.m. Million hectare metre cm Centimetre mcm Million cubic metre cu.m. Cubic metre per mg/kg Milligram per kilogram second cusec Cubic feet per second mg/l Milligram per litre deg. C Degree m ha Million hectare (°C) Centigrade/Celsius g gram MKWH Million kilowatt hour ha Hectare MGD Million Gallons per day HFL High Flood Level ML Million Litres HHWL Highest High-Water MLD Million litres per day Level HWL High Water Level mm Millimetre INR/ Rs. Indian Rupees mm/yr Millimetre per year INR Indian Rupees Million MPN Most Probable Number Million kg/m3 Kilogram per cubic MSL Mean Sea Level metre KLD Kilo litres per day MT Metric Ton Km Kilometre MTA Metric Ton per annum Sq.km. Square kilometre MT/day Metric Ton per day km3 Cubic kilometre MWL Maximum Water Level Kmph Kilometre per hour LWL Low Water Level Lpcd Litres per capita per NTU Natural Turbidity Unit day cu.m. Cubic metre PSU Practical Salinity Unit mcm Million cubic metre ppm parts per million m/day Metre per day rm running metre (length in m) m2/day Square metre per day sq km Square kilometre m2/sec Square metre per sec T or t Ton m3/hr Cubic metre per hour

CLIMATE GLOSSARY Terms Definitions Adaptation The process of adjustment to actual or expected climate and its effects. In human systems, adaptation seeks to moderate harm or exploit beneficial opportunities. In natural systems, human intervention may facilitate adjustment to expected climate and its effects. Adaptive capacity The pre-existing and inherent attribute or capacity (financial, technological, knowledge or institutional) of a system or population to cope with climate impacts or climate change by changing processes, practices or governance structures in order to moderate or offset the potential damages associated with climate change. AOGCM Atmospheric Ocean General Circulation Models Asset(s) Something that has potential or actual value to an organization AMSL Average mean sea level Climate Average weather based on the statistical description in terms of the mean and variability of relevant quantities, such as temperature, precipitation and wind, over an extended period of time Climate change A statistically significant variation in either the mean state of the climate or in its variability, persisting for an extended period (typically decades or longer)

Terms Definitions Climate change Difference between a climate scenario and the current climate scenario Coping capacity The ability of people, organizations and systems to face and manage adverse conditions, emergencies or disasters using available skills and resources, Consequence Outcome of a hazard event that affects objectives. Consequences are qualitative and quantitative impacts to exposed and vulnerable people, buildings, or infrastructure, and many can be communicated in terms of economic losses. Consequences can be certain or uncertain and can have positive or negative effects. May be expressed quantitatively or qualitatively. Emissions GHG emissions Exposure Exposure signifies people, buildings, infrastructure, and other resources (assets) that are within areas that are most likely to experience hazard impacts GCM Global Circulation Model GHG Greenhouse gas Impact A threat or an opportunity that may arise as a result of either the weather or climate change both in the short and long term, and represents the fact that the issue is one that is constantly evolving Infrastructure The assets and systems of assets required to support the functioning of a community, city and associated region, such as transportation and communications systems, water and power lines, and public institutions. IPCC AR5 Intergovernmental Panel on Climate Change Fifth Assessment Report (2014) Isoceraunic Representation of equal thunderstorm intensity or frequency LAT Lowest Astronomical Tide Level of risk Magnitude of a risk or combination of risks, expressed in terms of the combination of consequences and their likelihood Life cycle Time interval that commences with the identification of the need for an asset and terminates with the decommissioning of the asset or any associated liabilities Likelihood Chance of something happening In risk management terminology, the word ‘likelihood’ is used to refer to the chance of something happening, whether defined, measured or determined objectively or subjectively, qualitatively or quantitatively, and described using general terms or mathematically (such as a probability or a frequency over a given time period). Mean Higher High Inundation caused by storm surge and sea level is calculated above Water (MHHW) the Mean Higher High Water (MHHW) level, which is the mean of all the highest daily tides in a location over a year, and defines the high tide levels Mitigation An intervention to reduce the sources or enhance the sinks of greenhouse gases (GHGs). Climate change mitigation generally involves reductions in human (anthropogenic) emissions of greenhouse gases (GHGs). Mitigation may also be achieved by increasing the capacity of carbon sinks, e.g., through reforestation Monitoring Continual checking, supervising, critically observing or determining the status in order to identify change from the performance level required or expected MSL Mean Sea Level PMSS Probable maximum storm surge

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Terms Definitions Representative A Representative Concentration Pathway (RCP) is a greenhouse Concentration gas concentration (not emissions) trajectory adopted by the IPCC for Pathway (RCP)1 its fifth Assessment Report (AR5) in 2014. Four pathways have been selected for climate modeling and research, which describe different climate futures, all of which are considered possible depending on how much greenhouse gases are emitted in the years to come. It supersedes Special Report on Emissions Scenarios (SRES) projections published in 2000. Residual risk Risk remaining after risk treatment Resilience The ability of a system and its component parts to anticipate, absorb, accommodate, or recover from the effects of a hazardous event in a timely and efficient manner, including through ensuring the preservation, restoration, or improvement of its essential basic structures and functions Risk The effect of uncertainty on objectives The combination of the probability of an event and its negative consequences. Conventionally risk is expressed with the equation Risk = Hazards * Exposure * Vulnerability / Capacity. Risk analysis Process to comprehend the nature of risk and to determine the level of risk Risk assessment Overall process of risk identification, risk analysis and risk evaluation Risk management Coordinated activities to direct and control an organization with regard to risk Risk management framework Set of components that provides the foundations and organizational arrangements for designing, implementing, monitoring, reviewing and continually improving risk management throughout the organization Sensitivity The results mainly from high level of dependency on environmental services for livelihoods, food, energy and shelter; lack of human, social, natural, physical, financial, cultural, and technological assets. Trigger levels Identified points at which climate change impacts are beginning to be experienced at site level. Once the project or site-specific trigger level has been reached, management response is initiated Vulnerability Degree to which a system is susceptible to, or unable to cope with, adverse effects of climate change, including climate variability and extremes Structural This term made popular in Canada and Australia to identify adaptation infrastructure-based adaptation measures such as weirs, revetments, embankments, as a separate approach from adaptation derived from non-structural and ‘soft’ processes

1 Source: Wikipedia viii

Terms Definitions Systemic The ability to utilize a backup system for failure of critical parts of the redundancy system. It is a common approach to improve the reliability and availability of a system. It is also considered extremely important for the development of emergency response and recovery. Redundancy increases system dependability since the required operation can be carried out by the redundant system, as a failure of a single component will not affect all operations. Additionally, redundancy provides multiple locations for yielding to occur, increasing the probability that damages will be constrained and limiting the progression of failure under extreme conditions. The existence of redundancy assists in: (1) Enhancing the safety margin/reliability of a system in its intact state; and (2) Mitigating the sensitivity/vulnerability of the system to localized damage. Systemic The simultaneous interplay of at least three separate factors: capacity vulnerability related obligations, scarce resource endowments and severe (climate) threats. Heat island effect Refers to any area, populated or not, which is consistently hotter than the surrounding area. Vulnerability Vulnerability refers to extent (how and why) people or assets could be affected by a hazard and their predisposition to be adversely affected Vulnerability encompasses a variety of concepts including sensitivity or susceptibility to harm and lack of capacity to cope and adapt

EXECUTIVE SUMMARY

Climate Risk & Vulnerability Assessment (CRVA) has been performed for sub-projects under Chennai-Kanyakumari Industrial Corridor Power Transmission Improvement Project. The project entails investment of approximately $645.7 million in power transmission assets in the State of Tamil Nadu. It is proposed a loan of $451.0 million from the Asian Development Bank (ADB) to finance the project including technical assistance (TASF-others) of $0.5 million. The transmission assets to be financed under the project comprises of two new substations, five new transmission lines of voltage ranging from 110 kV to 765 kV, six items of reconfiguration of existing lines, and addition of bays at three associated substations. These transmission assets are required to meet the expected growth in demand in Tamil Nadu through integration of renewable and other generation sources to the transmission network.

Past trends of climate events such as temperature, rainfall, cyclones, storm surge and projections of future events from the analysis provided in the Tamil Nadu State Action Plan for Climate Change and other relevant documentation have been reviewed. Mean annual temperature in the sub- project region of Tamil Nadu is projected to increase by up to 2ºC by the 2030s and by up to 4.3ºC by the end of the century (2100) respectively with reference to the baseline 1970-2000 (SRES A1B scenario2). Past trends of rainfall in Tamil Nadu indicate a generally decreasing amount of average precipitation coupled with high spatial variation. However, the projections indicate higher possibility of extreme rainfall events in the northern coastal areas and lower level of rainfall in the inland southern and western regions with risk of prolonged drought conditions. South India is projected to experience increased frequency of tropical cyclones with increasing average wind speeds. Projected Sea Level Rise along the eastern coast of India is likely to increase coastal flooding and salinity ingress in surface waters.

Climate change and related adverse weather events can impact power transmission assets. Transmission lines are sensitive to increase in temperature. Transmission assets in inland areas can also be affected by spatial variability and changes in rainfall distribution and prolonged flooding conditions. Transmission assets in coastal t areas can be impacted from storm surges linked to cyclones and long-term effects of sea level rise.

Based on past trends and projections, vulnerability assessment performed at a sub-project level indicates overall project level ranking of “Medium” with Virudhunagar and Ottapidaram substation areas ranked as “Medium to High” while the transmission lines also ranked as “Medium” due to some transmission lines passing through coastal areas.

In 2013, the Intergovernmental Panel on Climate Change projected that global sea levels could rise anywhere between 0.3 meters and 0.6 meters by 2100. This prediction was based on a scenario of relatively ambitious emission reductions. It assumes that with effective climate policies and strong afforestation programs, global GHG emissions will increase only slightly before declining post-2040.

Primary climate change risks in “short” to “medium” term are temperature increase, spatial variability in precipitation and prolonged drought conditions in both coastal and inland areas. Long term climate change risks that could impact sub-projects are flooding from extreme rainfall events and storm surge coupled with sea level rise in coastal areas. Adaptation measures such as elevating electrical and instrumentation/ control equipment above the flood levels in coastal and inundation prone areas; use of more cyclone resilient designs of transmission lines, substation etc. and raising awareness on climate risks among project beneficiaries. These non-engineering adaptation measures have been incorporated in commercial sections of awards and engineering measures are covered in Technical Specification. Due consideration as per relevant standards has

2 Although Representative Concentration Pathway (RCP) supersedes Special Report on Emissions Scenarios (SRES) projections published in 2000, the government data “Tamil Nadu State Action Plan for Climate Change document prepared by Government of Tamil Nadu” is quoted.

been given for Flooding Risk Management, Lightning, Thunderstorm/ Cyclones etc. Following is the brief detail:

No. Description Standards Followed by Status of Tolerances and TANTRANSCO Inclusion Particulars in Design 1. Special Foundations for towers and its Bidding a) Grade M-15 having Designs of protection works are being designed Docume strength of 15N/mm2 Foundations as per CBIP3 Manual publication No. nts and b) Grade M-20 having (i.e.) to avoid 323, 2014 and relevant Indian Technica strength of 20 N.mm2 failure due to Standards for foundation design. l c) Grade M 30 having excessive Indian Standards IS 456 – 1978 Specifica strength of 32 N/mm2 (IS winds and also (Concrete) under Provision of E-1 of tions 456:2000 Table 3- to adapt high Appendix-E regarding Tower Condition iii) Severe salinity foundation base. IS: 1786-1976 for Concrete surfaces conditions of RCC. exposed to severe rain, the soil. Indian standards IS: 1893 (Part – I) alternate wetting and latest being used for earthquake drying or occasional resistant design of different freezing whilst wet or infrastructures. severe condensation. Table 5 shows the types of concrete to be used). d) Density of concrete for RCC is 2400/kg/m3 e) If required, special type of cement can be used for saline soils (that can withstand high alkalinity). 2. Design of Additional terrain roughness co- Bidding Terrain Category 2: Open towers to efficient of 1.0 for calculating wind Docume terrain with well scattered include pressure has been considered for nts and obstructions having height excessive wind coastal area in Transmission Lines as Technica generally between 1.5m loads during per IS: 802 (Part – I) 1985 for the l to 10 m. Withstand cyclones specific wind zones. Specifica cyclonic force winds (at a tions minimum for winds and impacts consistent with a Category 4 cyclone) in 90 km for 765 km long transmission line segment. 3. Other aspects Substations are being protected from Bidding The climatic conditions at related to lightning and thunderstorms by Docume site under which the substation providing high mast lighting system in nts and equipment shall operate design for yard and by providing shield wire Technica satisfactorily, are: lightning and /spikes on the substation towers. l (a) Atmosphere: Highly thunderstorms Protection of buildings in the Specifica polluted etc. switchyard area is being done by tions (b) Maximum ambient air providing spikes and MS Flat as per temperature: 45 °C relevant standards IS: 2309. As per (c) Minimum ambient air IS:2309 annual average thunderstorm temperature 5 °C days have been considered 65 days (d) Maximum daily per annum as per site climatic average ambient air conditions in the design. Very high temperature 40 °C

3 Central Board of Irrigation and Power, a government supported think tank.

No. Description Standards Followed by Status of Tolerances and TANTRANSCO Inclusion Particulars in Design creepage distance i.e. 31 mm per kV (e) Maximum yearly and Short Circuit Time Rating has average ambient air been considered 2 seconds in the temperature: 32 °C design of substations. The rated peak (f) Maximum Humidity: short circuit current shall be 2.5 times 95% the rated short time withstand current. (g) Average thunder storm For the protection of Transmission days per annum: 65 Lines, shielding angle upto 220 kV is (h) Average dust storm 30 degrees and for 400 kV days per annum: Transmission Lines it is 20 degrees. Occasional For 400 kV, two earth-wire/ OPGW (i) Average rainy day per are being used as per CBIP annum: 65 days Guidelines. For 765 kV line all (j) Average annual rainfall: standards used as per Power Grid 100 cm Corporation of India Limited (PGCIL) (k) Number of months shall be used. during which tropical 4. Metrological Climatic and Isoceraunic / Bidding monsoon conditions (rainfall, floods, atmospheric conditions have been Docume prevails: 5 etc.) obtained from the Metrological nts and (l) Maximum wind history/projecti Department of India which cater major Technica pressure: 150kgf/sq.m. ons, parameters shown as per 3. above. l (m) Altitude above M.S.L: hydrological Secondary Information from various Specifica <1000m data of the Tamil Nadu state sources will be used tions subject areas for any future monitoring.

Suitable risk management options and climate change adaptation measures have been made in project design by TANTRANSCO. The cost tables being utilized in the project already incorporates these adaptation measures and the incremental cost of these adaptation measures is considered to be cost of climate change adaptation.

It is further confirmed that infrastructure design of substations and transmission lines is flood, earthquake, climatic resilient - wind and cyclone proof (Wind zone 2 and 4 in some areas) and TANTRANSCO design standards follow the standards being followed by PGCIL and Central Electricity Authority (CEA) for coastal area Transmission Lines and substations.

1. INTRODUCTION

1.1 Brief Project Description

1. The Government of Tamil Nadu (GoTN) with assistance from the Asian Development Bank (ADB) proposed to invest in power transmission assets to meet the expected demand in Chennai Kanyakumari Industrial Corridor (CKIC) and to provide connectivity to proposed renewable and thermal power plants in southern section of CKIC and load centers in northern section of CKIC. The Tamil Nadu Transmission Company Ltd (TANTRANSCO) is the implementing agency of the project.

2. As per the 2018 Statistic data4, Tamil Nadu with a population of 76.67 million represents 5.83% of India’s total population (1,316 million). It is the most urbanized state in India, and has a population density of 586 persons/sq.km, significantly higher than the Indian average of 400 persons/sq.km. Like many other Indian States, Tamil Nadu is highly dependent on natural resources and can be impacted by climate change.

1.2 Project Information Project Title : Chennai Kanyakumari Industrial Corridor (CKIC) Location : Tamil Nadu, India Sectors : Energy Sub-sector : Electricity transmission and distribution Strategic : Inclusive economic growth - Economic opportunities, including jobs, Agenda: crested and expanded.

3. The proposed project will strengthen the transmission network by improving the transmission connectivity at extra high voltage 765 kV level between the proposed energy hub in Madurai-Thoothukudi sector located in the southeast region of Tamil Nadu and demand centres in the northern sector of CKIC (i.e., Chennai-Madurai) and Coimbatore. In addition, the proposed project will connect the renewable energy hubs in Thoothukudi region to the 765 kV network through pooling substations at 400 kV level. Figure 1.1 shows location of substations.

4 Central Statistics Office

Source: Anna University under ADB Funding Figure 1.1: Geographic Locations of Substations and Transmission Lines to be Built Under the Project

1.3 Concept of Risk and Vulnerability Climate Risk & Vulnerability Assessment (CRVA) has been performed for first two subproject involving construction of physical assets. Objective of the CRVA is to provide sufficient information on climate related risks to assess the extent of in-built adaptation already available in the sub- project elements and the additional adaptation measures that may require to be incorporated to mitigate climate change risks to achieve intended outcomes of the planned investment. Recommendations are made to incorporate suitable climate change adaption measures into the detailed design, installation and operation & maintenance of sub project components vulnerable to climate risks.

4. Since 2014, ADB has required all investment projects to consider climate risk and incorporate adaptation measures in projects at risk from climate change impacts. This is consistent with ADB’s commitment to scale up support for adaptation and climate resilience in project design and implementation, articulated in the Midterm Review of Strategy 2020: Meeting the Challenges of a Transforming Asia and Pacific (ADB, 2014a5).

5. ADB has an established Risk Management Framework aimed at reducing risks associated with climate change on investment projects by providing for climate risk assessments and the inclusion of adaptation measures into projects at the design phase. The process, undertaken on a project-by-project basis, is illustrated in Figure 1.2.

Source: ADB (2014b) Figure 1.2: Climate Risk and Vulnerability Assessment – Process Flow

6. The first stage in the Climate Risk Management Framework is the initial screening of the

5 Asia Development Bank (ADB) Makes Climate Change Core to Operations through Series of Strategy and PolicyChanges. Details online at https://www.mainstreamingclimate.org/

project that aims to identify whether the project may be vulnerable to climate change hazards. If the risk screening identifies any medium or high risks, a CRVA is required.

7. Risk screening was undertaken for the proposed project as per the CRS methodology. and the overall climate related risk was rated as “Medium”.

1.4 Sector Climate Risk and Vulnerability

8. Outputs of the CRVA, especially the adaptation measures, is used to finalize the detailed design and technical specification of the subprojects. Power sector's regulatory, legal, and institutional and policy frameworks applicable to the Tamil Nadu state for environment protection are discussed in detail in the IEE for CKIC.

9. The physical vulnerability of electricity transmission facilities can be directly linked to damage from extreme weather events: • Substations and underground electricity networks could be inundated during floods, which shall lead to short circuiting of cables, explosions and fires. Excessive precipitation could lead to flooding/other mass movements. • The overhead cables and transmission towers could be destroyed in violent storms due to extreme wind speeds. • Hot temperatures, such as drought or extreme temperatures, could lead to equipment failure, excessive sag and short circuits. • Mass movements due to earthquakes: The transmission towers and the substation sites fall in Seismic Zone I&II area6 (Low Damage Risk Zone MSK7 VI zone which indicates a very moderate damage risk zone as per the project IEE.

10. On the Risk scale, the CRS identified that the sub-project areas are at risk from climate change impacts: • Climate impacts were deemed to be low to medium risk from higher temperatures, water scarcity, increased rainfall intensity and variability, increased cyclonic activity and storm surges and long-term risk of coastal flooding due to sea level rise; • Climate change impacts were deemed to be at medium risk from change in precipitation (decrease) and risk of prolonged drought conditions. • In land subproject areas are identified to be at low to medium risk from increase in temperature, change in precipitation (decrease) and prolonged drought conditions; and • Low-lying areas along the rivers / waterways along the transmission lines were identified to be at medium risk for localized or riverine flooding due to extreme rainfall events • Coastal areas are deemed to be at a medium to high level risk of flooding due to cyclone linked storm surge and tsunamis.

1.5 Sector’s Regulatory, Legal, Institutional and Policy Frameworks Related to Climate Change

• Tamil Nadu State Groundwater Development and Management Act, 2003 • State Water Policy, 1994 • National Action Plan on Climate Change for Cauvery delta • Flood Management Programme in Tamil Nadu

1.6 Data Sources 11. The primary objective of this section is to provide information on baseline parameters and

6 The latest version of seismic zoning map of India given in the earthquake resistant design code of India [IS 1893 (Part 1) 2002] assigns four levels of seismicity for India in terms of zone factors. 7 Medvedev-Sponheuer-Karnik (MSK) intensity broadly associated with the various seismic zones is VI (or less), VII, VIII and IX (and above) for Zones II, III, IV and V, respectively.

how some of these are predicted to change in the future. The goal is to determine how these changes will impact the transmission infrastructure in the sub-project areas and which element or climate variable will have the greatest impact on vulnerability of infrastructure components.

12. The key resources consulted for information on existing and potential future climate for the State of Tamil Nadu include: • Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC AR5) 2014; • India’s Second National Communication to the United Nations Framework Convention on Climate Change; • Tamil Nadu State Action Plan for Climate Change; and • Sea Level Rise: Impact on Major Infrastructure, Land and Ecosystems along the Tamil Nadu Coast8

13. This climate overview is consistent with the findings of the preliminary screening of risks conducted for the project in the initial Climate Risk Assessment.

1.7 Structure of the Climate Risk and Vulnerability Assessment

14. Section 2 describes the project scope including specific information about the power transmission project sector being assessed; Section 3 about climate change impacts on power transmission sector; Section 4 on Climate Risk and Vulnerability Assessment through impact modelling/descriptive impact matrix and hazard characterization; Section 5 on proposed management and adaptation actions and Section 6 on stakeholder consultation and ground validation.

15. The CRVA has been structured as follows: • Section 1 – Introduction; • Section 2 – Project description; • Section 3 – Climate Change Impacts in Tamil Nadu • Section 3 – Climate overview, including historical climate change observations and relevant climate change projections; • Section 4 – Describes the risk assessment methodology and risk assessment findings; vulnerability assessment/ ranking and adaptation measures • Section 5 – Medium- and long-term planning for climate change; • Section 6 – Stakeholder and Ground Validation

16. Appendix A gives the list of some relevant technical specification criteria of equipment listed by TANTRANSCO for Bidding Documents that consist of relevant climate resilience measures in conformance with Indian Standards (IS) codes.

8 S. Byravan and R. Rangarajan, Center for Development Finance, IFMR, Chennai & S. C. Rajan, Humanities & Social Sciences, Indian Institute of Technology, Madras; “Sea Level Rise: Impact on Major Infrastructure, Land and Ecosystems along the Tamil Nadu Coast”.

2. PROJECT DESCRIPTION

2.1 Project Profile 17. The proposed project will strengthen the transmission network by improving the transmission connectivity at extra high voltage 765 kilovolt (kV) level between the proposed energy hub in Madurai-Thoothukudi sector located in the southeast region of Tamil Nadu and demand centers in the northern sector of CKIC (i.e., Chennai-Madurai) and Coimbatore. In addition, the proposed project will connect the renewable energy hubs in Thoothukudi region to the 765 kV network through pooling substations at 400 kV level. The project would develop a transmission link from the energy hub in southern CKIC to load centers in northern CKIC and establishing pooling substation for renewable energy established in southern CKIC. The project’s impact is aligned with the enhancement of industrial development and renewable energy generation in Tamil Nadu and expected to improve the power supply to industrial demand centers in CKIC.

18. The project proposes to finance the construction of the following transmission assets in the state of Tamil Nadu. The assets comprise two new substations, five new transmission lines of voltage ranging from 110 kV to 765 kV, six items of reconfiguration of existing lines, and addition of bays at three associated substations. Table 2.1 list sub-projects being considered for investment under the ADB funded CKIC power investment program.

Table 2.1: List of Subprojects in CKIC Power Sector Investment Project S. Substation Operating voltages (kV) 1 Virudhunagar (2x1500MVA) 765/400 2 Ottapidaram (2x500MVA) + (2x200MVA) 400/230/110 T1. Transmission lines associated with Virudhunagar Approximate Route substation Length (km) 1.1 765 kV double circuit line Virudhunagar – Coimbatore 242 1.2 400 kV double circuit line Virudhunagar – Kayathar 72 1.3 400 kV double circuit line in and out at Virudhunagar for Kamuthi 5 to Thappagundu (proposed) line T2. Transmission lines associated with Ottapidaram substation Approximate Route Length (km) 2.1 400 kV double circuit line Ottapidaram – Udangudi 68 2.2 400 kV double circuit line Ottapidaram – Kamuthi 71 2.3 230 kV double circuit line in and out at Ottapidaram for Sipcot – 10 Kavanoor line 2.4 230 kV double circuit line in and out at Ottapidaram for Sipcot – 6 Savasapuram line 2.5 110 kV double circuit line in and out at Ottapidaram for 4 Ottapidaram – Eppothumvendran 2.6 110 kV single circuit line Ottapidaram – Vijayapuri 34 2.7 110 kV double circuit line in and out at Ottapidaram for TTN Auto 10 – T-off Sipcot line New bays at associated substations Quantity 3.1 400 kV bays at Kamuthi substation 2 3.2 400 kV bays at Kayathar substation 2 3.3 110 kV bay provisions at Vijayapuri substation 1

Figure 2.1: Location of Substations and Illustrative Lines Routes (bee line)

Table 2.2: Location of Substations and Termination Points of Transmission Lines Sno Description Length Starting Point Ending Point in km Village Name Latitude Longitude Village Name Latitude Longitude 1. Transmission lines associated with Virudhunagar substation 765/400 KV SS T1.1 765 KV DC TL from 242 Mannarkottai & 9° 26’ 41.827” N 77° 59’ 52.876” E Near 11° 14’ 51.796” N 77° 26’ 58.672” E Virudhunagar 765 KV SS to Valayapatti Koundampalayam Coimbatore 765 KV SS Village T1.2 400 KV DC TL from 73 Mannarkottai & 9° 26’ 41.827” N 77° 59’ 52.876” E Ayyanar Uthu 8° 57’ 27.872” N 77° 43’ 29.739” E Virudhunagar 765 KV SS to Valayapatti Village Kayathar 400 KV SS Village T1.3 400 KV DC TL (line in and 4 Mannarkottai & 9° 26’ 41.827” N 77° 59’ 52.876” E Malaipatty village 9° 29’ 1.892” N 78° 1’ 9.807” E Line out) at Virudhunagar for Valayapatti Kamuthi to Thappagundu Village (proposed line) 2. Transmission lines associated with Ottapidaram substation 400/230/110 T2.1 400 KV DC TL from 68 Swaminatham 8° 53’ 39.695” N 78° 2’ 53.010” E Udangudi 8° 26’ 3.205” N 78° 3’ 30.103” E Ottapidaram 400 KV SS to Udangudi Switch Yard T2.2 400 KV DC TL from 72 Swaminatham 8° 53’ 39.695” N 78° 2’ 53.010” E Kamuthi 9° 20’ 57.983” N 78° 23’ 50.9832” E Ottapidaram 400 KV SS to Kamudhi Switch Yard T2.3 230 KV TL LILO 10 Swaminatham 8° 53’ 39.695” N 78° 2’ 53.010” E Kumarapuram 8° 54’ 42.540” N 78° 7’ 54.380” E Ottapidaram-Sipcot and Kavanoor T2.4 230 KV TL LILO 6 Swaminatham 8° 53’ 39.695” N 78° 2’ 53.010” E Venkatachalpura 8° 54’ 15.770” N 78° 5’ 47.240” E Ottapidaram-Sipcot and m Savaspuram T2.5 110 KV Double circuit line in 4 Swaminatham 8° 53’ 39.695” N 78° 2’ 53.010” E Sinthalakattai 8° 53’ 41.320” N 78° 4’ 48.410” E and Line out at Ottapidaram- For Ottapidaram- Eppothumventran T2.6 110 KV TL Ottapidaram- 35 Swaminatham 8° 53’ 39.695” N 78° 2’ 53.010” E Vijayapuri 9° 8’ 12.820” N 77° 53’ 56.840” E Vijayapuri T2.7 110 KV TL LILO 10.5 Swaminatham 8° 53’ 39.695” N 78° 2’ 53.010” E South 8° 49’ 13.780” N 78° 4’ 21.690” E Ottapidaram-TTN Auto & T Veerapandiyapura Sipcot feeder m

2.2 Objective/s of the CRVA or Rationale

19. The initial climate risk screening of the Project, has rated the overall climate related risk as “MEDIUM”. This “medium risk” rating of the Project is mainly because of risks associated with:

i. Hazard and Exposure Profile of Tamil Nadu: • high to very high susceptibility to earthquake9. • high susceptibility to floods and salinity.

ii. Climate projections (2030s): • temperature and precipitation are expected to increase. • extreme events (floods/flash floods, storms with strong winds) are more likely.

iii.Potential impacts of changing climate to project components: • change in temperature – high. • increase in rainfall intensity (and flood risks) – medium. • increased intensity of extreme winds from tropical cyclones – medium. • lightning – high.

20. TANTRANSCO deemed it necessary to quantify the climate risks and vulnerabilities of cyclonic incidents on lines and substations by identifying possible adaptation options to reduce the risks and vulnerabilities listed above. TANTRANSCO has made specific Technical Specifications of Bid documents for equipment, plant and erection that adhere to Indian Standard Code (IS code) of Practise.

2.3 Methodology, scope and limitations

21. In general, the detailed technical specification and the detailed project report by TANTRANSCO have a design life of 25-30 years for each of the sub-projects. A more comprehensive description of the design elements and infrastructure components proposed for capital works are detailed in the technical specifications and the other appraisal reports. which would include details of:

• Existing infrastructure and site conditions; • Proposed infrastructure, estimated cost and procurement plan; • Social & Environment assessment; and • Economic and Financial assessment.

22. Tamil Nadu has high dependence on natural resources and faces the threat of climate change and its impacts. Available evidence shows that there is high probability of increase in the frequency and intensity of climate related natural hazards and hence increase in potential threat due to climate change related natural disasters. Tamil Nadu is potentially sensitive and vulnerable to climate change and its impacts due to its coastal location at the southernmost tip of Indian Peninsula.

9 SARD climate risk screening framework and methodology was used

3. GOVERNMENT STRATEGY FOR COPING WITH CLIMATE CHANGE

23. The greenhouse effect is a natural process that keeps the Earth's surface around 30oC warmer than it would be otherwise. Without this effect, the Earth would be too cold to support life. The earth has warmed by approximately 1oC since pre-industrial times. Eleven of the warmest years in the past 125 years occurred since 1990, with 2016 being the warmest on record10. There is overwhelming consensus that this is due to emissions of greenhouse gases, such as carbon dioxide (CO2), from burning fossil fuels. Climate change threatens the basic elements of life for people around the world - access to water, food, health, and use of land and the environment.

24. After the 26 December 2004 tsunami, the soils in the coastal villages comprising Serudhur (near Velankanni), Pradhabaramapuram, Vellapallam (south of Nagapattinam), Erukkatancheri, Sathankudi, Kalamanallur, Manickapanngu, Pillaiperumanallur, Neithalvasal, Vellapallam (north of Nagapattinam) and Koozhaiyur, Nagapattinam district and Killai, Parangipettai, Devanampattiman, Thazhanduda and Uppalvadi, Cuddalore Districts were affected. The massive quantity of seawater that inundated the coastal agricultural lands for 0.5 to 2.0 km area inland, due to reasons of poor drainage, stood for a few days affecting the quality of soil and groundwater. The electrical conductivity (EC) of soil and shallow groundwater increased by about 10 times and 15 times respectively, and the degree of variations differed from place to place.

25. Tamil Nadu’s eco-systems are predominantly sensitive to climate changes. The projected potential impacts of climate change on Tamil Nadu could be disruptive and potentially very costly. Examples of the projected impacts based on scenarios in the IPCC Assessment Reports and other research findings for the state of Tamil Nadu generally include changes in:

• precipitation (rain and snowfall) with the average water levels in rivers, lakes less than normal with serious drought like conditions, and in rainy seasons flooding being more frequent, • areas currently subject to flooding would suffer flooding of greater severity and for more duration; areas currently flood-free would suffer from occasional floods and flash floods.

26. Lesser spring, summer rainfall causing regular water shortages, especially in the plain area would be affecting both people and the ecosystems. There would be less recharge of reservoirs during the summer; water shortages would occur regularly and would be longer than at present. The change in rainfall patterns may further cause regular water deficits, leading to accelerated soil erosion and loss of fertility and biodiversity.

27. The climate projections suggest that impacts are likely to be diverse and mixed, with some regions experiencing more intense rainfall and flood risks, while others will encounter sparser rainfall and prolonged droughts. Among the more substantial effects is a projected spatial shift in the pattern of rainfall towards the areas already having heavy rains, while in some regions water scarcity may increase thereby affecting land fertility and un-productiveness. The climate variability and climate change pose huge risks to life and threat to endanger the sustainability of the country's fast-growing economy.

3.1 Impact of Climate Change in Tamil Nadu

General Impacts on Project Components 28. The major climate change drivers that could adversely impact power sector in Tamil Nadu are:

3.1.1 Continuous increase in ambient temperature 29. Due to increase in temperature the conductor tends to sag thereby leading to less than optimal distance from ground receptors. The rise in temperature makes the metallic body of

10 Six years are hotter, with the el nino year 2016 currently the hottest, and the hottest 5 all occurring in the last five years (2014 – 2018). Source: NOAA.

conductor expands and as a result, the weight of conductor increases that is directly proportional to sag. In this case, the optimal type of conductor can be used to ensure proper ground clearances but there by increases the cost of material. Sometimes, tower type has to be changed to adapt to different heights.

3.1.2 Climatic Loads

30. Climate change is likely to induce changes in hydro meteorological parameters like evaporation, evapotranspiration, wind direction and wind speed etc. There are random loads imposed upon tower, insulator string, conductor and ground wire due to action of wind on transmission line and do not act continuously.

Increase in intensity of cyclones (wind speeds) 31. Withstand cyclonic force winds (at a minimum for winds and impacts consistent with a Category 4 cyclone). Increase in Wind velocity will increase apparent weight of the conductor, as a result increase in tension and due to increase in temperature there will be increase in sag. The span of the transmission line may be decreased in case of coastal lines.

32. Along with heavy rains during the north east monsoon in Tamil Nadu, the atmospheric depression and cyclones also hit the state. Due to climate change, if the cyclone intensities increase, they would have implications on power lines in the coastal zones.

Increase in heavy precipitation events/flooding

33. Towers, substation equipment, transformers, control panels, capacitor banks and diesel generator sets and other infrastructure located at a suitable elevation above the projected upper limit of sea level rise on the eastern coast of India or at an elevation based on the highest flood level (localized inundation) linked to extreme rainfall events11, whichever is higher.

Seawater intrusion and drought

34. A larger area and deeper inland areas are likely to be inundated with salt water from the sea due to formation of higher storm surges. Districts along the Tamil Nadu coast are at risk.

35. Also, any increase in spatial variability in precipitation, prolonged drought periods (i.e., drought conditions every five years) and risk of flooding of low-lying areas from extreme rainfall events. In both situations, the substations will be located away from any low lying areas whereas the towers need to be placed on pedestals to avoid flooding of the base.

3.2 Tamil Nadu Government Strategy for Climate Change Energy Sector

36. Climate change impacts on coastal zones in general and specifically, along the east coast of India (including Tamil Nadu) have been briefly discussed in Chapter 2. The long Tamil Nadu coastline with thirteen coastal districts forms a fairly large contiguous and narrow coastal strip dotted with fragile ecological features and significant development activities. There are major existing and proposed, economic and infrastructure development, including ports, power plants, highways and even airports, which are being planned very close to the shoreline along India’s coast.

37. Tamil Nadu being a coastal state is highly vulnerable to seasonal fluctuations in terms of rainfall, temperature, relative humidity, wind speed etc., causing uncertainty in agricultural production. Due to the effects of cyclones and monsoon in the Bay of Bengal, crops in coastal areas almost every year are heavily damaged. The saline and alkaline soil in coastal areas is a

11 Extreme rainfall—defined as the top five percent of rainy days.

major setback to agricultural activities in coastal areas.

38. It is likely that sea level rise will affect the coastline of India in a variety of ways, including inundation, flood and storm damage associated with severe cyclones and surges, erosion, saltwater intrusion, and wetland loss.

39. Energy consumption of a city is closely related to its ambient temperature. However, urban temperature is changing because of heat island effect and global warming. IPCC forecasts that the global temperature will be rising in the next 100 years; the temperature rise in 2100 relative to 2000 would range from 1.4 to 5.8oC under different adaptation scenarios. Further, there have been a number of scientific studies which estimate that, with a 1oC ambient temperature rise, the consumption of electricity would increase by 9.2% of domestic consumption, 3% of commercial consumption and 2.4% of industrial consumption, Funga et al, 2006. In the case of Tamil Nadu, the mean of the locations studied under the HadCM3 A1B scenario indicates likely rise changes in maximum temperature.

40. Based on the above, it is estimated that there would be approximately a 14-15% increase in electricity consumption in the state, due to temperature rise. Other factors such as increasing growth of domestic consumers, increase in consumption due to growth in GDP etc., increase in electricity coverage area, etc. would continue to have a bearing on electricity consumption Tamil Nadu has been plagued with acute power shortages since the last few years. The energy and peak shortages stood at 6.5% and 11.0% respectively in 2010-11. With increase in temperature and resultant increase in the use of fans, air-conditioners, the peak usage is bound to increase in a climate- constrained scenario.

41. The state has recognized some of these weak links and a state mission specifically with the mandate to ensure coordination of all departments for energy efficiency and conservation has been created. Some of the key concerns and strategies are given below:

Table 3.1: Key Strategies to Address Climate Concerns for the Energy Sector Issues of Concern from a Strategies to Address it Climate Perspective Energy scarcity in an Promoting energy efficiency and sustainable use of electricity at all increased demand, low levels and categories of usage such as: supply scenario due to • Identifying and converting the lighting devices in all key climate induced government buildings to energy efficient lighting by 2015 circumstances amongst • In a phased wise manner, converting all street and public other contributors lighting to LED Lighting • Energy auditing of all government buildings • Promotion of building star rating systems and incorporate building by-laws for energy conservation • Program for awareness building on BEE star labelled appliances • Initiating and Implementing demo projects on energy efficiency in commercial sector • Reducing T & D Losses • Stringent implementation of Demand Side Management across all key energy sectors • Investment to strengthen grid and smarten the grid. This would also include imposing norms on Independent Power Producers particularly for large wind farms of 10 MW and above to an accuracy of 70 percent • Take a lead to setup as upload dispatch centre for renewable energy generation Increasing carbon emissions • Reducing the dependence on central grid of energy supply by

Issues of Concern from a Strategies to Address it Climate Perspective due to temperature rise – augmenting own clean electricity generation capacities higher consumption of • In addition to promoting wind, proactive policies to promote conventional fuel for solar generation as well producing energy to meet • Exploring possibilities of decentralized renewable enhanced demands Impacts on forests cover • Increasing de-centralised energy applications to avoid forest due to cutting and lopping of area lines trees for various projects • Ensuring energy access for all Source: Tamil Nadu State Action Plan for Climate Change

3.3 Summary 42. As the climate changes, the Tamil Nadu state, whose economy relies on its coastal assets, it must prepare to respond by designing suitable adaptation measures. To effectively address the challenges that a changing climate will bring, climate adaptation actions must complement each other, efforts within and across sectors must be coordinated. These approaches have been viewed as alternatives, rather than as complementary and equally necessary approaches.

43. The strategy considers the prevailing developmental process-its achievements and losses; as well as identification of solutions and actions, as may be required at various levels such as regulatory, institutional, program, policy and plan.

4. CLIMATE CHANGE IMPACTS THAT CAN AFFECT PROJECT COMPONENTS 44. The state of Tamil Nadu, the 11th largest state in India, is located in the country’s southern part. It has a total area of 130,058 km2 and 1,076 km of coastline. To its east is the Bay of Bengal and at its southernmost tip is the town of Kanyakumari (the meeting point of the Arabian Sea, the Bay of Bengal and the Indian Ocean). Tamil Nadu’s population is 76.67 million per the 2018 statistics. Tamil Nadu is the most urbanized state in India with a population density of 586 persons/sq.km, which is significantly higher than the Indian average of 400 persons/sq.km.

45. Tamil Nadu is bound on the western boundary by the Western Ghats (mountain range) and falls on the leeward side of the mountain range thus receiving a relatively lower quantum of the rainfall from the southwest monsoon. The eastern parts comprise coastal plains. The central and the south-central regions are arid plains and receive lesser rainfall than the other regions. The general drainage trend for the river system in Tamil Nadu is from west to east into the Bay of Bengal.

46. The study, “Future Sea Level Rise: Assessment of Loss and Damage in Chennai in 201512”, projects that between 143 sq.km. to 356 sq.km. of land in Tamil Nadu will be submerged if sea levels rise by one metre to three metres by the middle of the century. India has a 7,500-km- long shoreline and the 1,076 km Tamil Nadu coastline makes up 15% of this. Nearly 35% of the country’s population lives within 100 km of the shore. Economic growth in past decades has coincided with increased investment in infrastructure and development activity along the shoreline.

4.1 Temperature 4.1.1 Temperature – Past Trends

47. Tamil Nadu can be divided broadly into two natural divisions: (a) the coastal plains, and (b) the hilly western areas. The proximity of sea influences the climate of the eastern and southern parts of the state, which have mild winters and humid summers; while the remaining part of the state have a sub-tropical climate that is hot and seasonally dry. Average temperature in the plains

12 Study was conducted by the Indo-German Centre for Sustainability at the Indian Institute of Technology, Madras, and presented at the Madras Institute of Development Studies on January 20.

varies between 21.6ºC and 31.8ºC and in the hilly areas varies between 9.4ºC and 22.8ºC. The mean annual temperature is 28.2ºC in the plains and 15.2ºC in the hills.

4.1.2 Change in Temperature (Increase)

48. Mean annual temperature is projected to increase by up to 2ºC by the 2030s and by up to 4.3ºC by the end of the century (2100). The maximum temperature across the state of Tamil Nadu is projected to increase by 1ºC, 2ºC and 3.1ºC for the periods 2010-2040, 2040-2070, 2070- 2100 respectively with reference to the baseline 1970-2000 (SRES A1B scenario)13.

49. It can be observed that the overall trend points to a marked increase in both the minimum and maximum temperature bands across the state in all the sub-project areas. It should also be mentioned that, while the SRES A1B scenario projects introduction of efficient technologies in the latter half of the century, the impact of governmental actions on lowering greenhouse emissions is expected to mitigate the risks of temperature increase thereby lowering the overall impact on resources. However, it is important to consider that the projected increase in surface temperatures can affect surface water evaporation and flows, as well as groundwater systems.

50. All climate models project an increase in the number of warm nights by the end of the 21st century. The increase in the number of warm nights ranges from 40% of nights to 85% of nights. Higher temperatures and fewer cool nights will increase evaporation of surface waters elevating household demand for water supplies and irrigation. Research has indicated that a one (1) degree increase in temperature can increase the moisture absorption capacity of the atmosphere by about 7%14.

4.1.3 Temperature Projections Maximum Temperature:

51. District wise changes (Figure 4.1) indicate a general maximum increase of about 3.4ºC over the North western districts of Nilgiris, Coimbatore, Tiruppur and western parts of Dindigul District at the end of the century. The maximum increase of about 2.1ºC is seen over Dindigul, Karur, Perambulur, Theni, Villupuram while 2.20C at Tiruppur by 2040-2070.

Table 4.1: District-wise Projected Change in Maximum Temperature in 0C with Reference to 1970-2000* District Name Change in maximum temperature in ºC with reference to 1970-2000 2010-2040 2040-2070 2070-2100 Ariyalur 1.1 1.9 3.1 Chennai 1.0 2.0 3.1 Coimbatore 1.3 1.9 3.1 Cuddalore 1.1 2.0 3.2 Dharmapuri 1.1 2.0 3.2 Dindigul 1.2 2.1 3.3 Erode 1.2 2.0 3.2 Kancheepuram 1.1 1.8 3.0 Kanyakumari 1.0 1.7 2.7 Karur 1.2 2.1 2.3 Krishnagiri 1.2 2.0 3.2

13 The Special Report on Emissions Scenarios (SRES) is a report by IPCC that was published in 2000. The greenhouse gas emissions scenarios described in the Report have been used to make projections of possible future climate change. A1B scenario deals with balance emphasis on all energy resources. 14 Kevin E Trenberth, 2007 “The Impact of Climate Change and Variability on Heavy Precipitation, Floods and Droughts”, United States National Centre for Atmospheric Research, National Science Foundation, Boulder, Colorado, USA: Encyclopedia of Hydrological Sciences.

District Name Change in maximum temperature in ºC with reference to 1970-2000 2010-2040 2040-2070 2070-2100 Madurai 1.2 1.8 3.0 Nagapattinam 1.0 1.6 2.7 Namakkal 1.2 2.0 3.2 Nilgiris 1.3 2.1 3.2 Perambalur 1.2 2.0 3.3 Pudukkottai 1.0 1.7 2.9 Ramanathpuram 0.9 1.6 2.7 Salem 1.2 1.9 3.2 Sivaganga 1.1 1.9 2.7 Thanjavur 1.0 1.8 2.9 Theni 1.2 2.1 3.3 Thiruvallur 1.1 1.6 2.8 Thiruvannamalai 1.2 2.0 3.2 Thiruvarur 1.0 1.1 2.3 Thoothukudi 1.0 1.8 2.8 Trichy 1.2 2.0 3.3 Tirunelveli 1.0 1.8 3.0 Tiruppur 1.2 2.2 3.4 Vellore 1.1 1.9 3.2 Villupuram 1.1 2.1 3.4 Virudhunagar 1.1 1.9 3.1 Rows in grey color represent project areas. * As per SRES A1B Standard

Figure 4.1: Change in Maximum Temperature (ºC) Projections for 2010-2040, 2040-2070, 2070-2100 with Reference to Baseline (1970-2000)

(Source: Centre for Climate Change and Adaptation Research (CCCAR), Anna University, Chennai) (Using IPCC A1B SRES)

4.1.4 Minimum temperature projections:

52. Projections of minimum temperature over Tamil Nadu as a whole for 2010-2040, 2040- 2070, 2070-2100 with reference to baseline 1970-2000 indicates that it is likely to increase by 1.1ºC , 2.4ºC and 3.5ºC respectively (Table 4.2).

53. District wise changes (Figure 4.2) indicate generally lesser changes over the western parts

and close to the coast. A general rise in temperature is seen ranging from 1ºC to 1.5ºC for the period 2010 to 2040 and between 2ºC to 2.6ºC for the period 2040-2070 and between 2.7ºC to 3.8ºC for the period between 2070 to 2100. The southern districts Kanyakumari and Tirunelvelli show minimum increase, while the central interior districts Karur, Tiruppur, and Namakkal show maximum increase in the minimum temperature.

Figure 4.2: Change in Minimum Temperature (ºC) Projections for 2010-2040, 2040-2070, 2070-2100 Reference to Baseline (1970-2000) *

*(Source: CCCAR, Anna University, Chennai) (Using IPCC A1B SRES)

Table 4.2: District-wise Change in Minimum Temperature in ºC with Reference to 1970-2000* District Name Change in minimum temperature in ºC with reference to 1970-2000 2010-2040 2040-2070 2070-2100 Ariyalur 1.4 2.6 3.7 Chennai 1.1 2.2 3.2 Coimbatore 1.2 2.3 3.3 Cuddalore 1 2.2 3.3 Dharmapuri 1.2 2.4 3.6 Dindigul 1.1 2.3 3.4 Erode 1.3 2.6 3.7 Kancheepuram 1 2.2 3.3 Kanyakumari 0.8 1.8 2.7 Karur 1.5 2.6 3.8 Krishnagiri 1.3 2.5 3.6 Madurai 1 2.2 3.3 Nagapattinam 1.1 2.2 3.2 Namakkal 1.3 2.5 3.7 Nilgiri 1.2 2.3 3.3 Perambalur 1.1 2.3 3.5 Pudukkottai 1.1 2.3 3.3 Ramanathpuram 1.1 2.2 3.2 Salem 1.2 2.4 3.6 Sivaganga 1.1 2.4 3.5 Thanjavur 1 2.1 3.3 Theni 1 2.2 3.2

District Name Change in minimum temperature in ºC with reference to 1970-2000 2010-2040 2040-2070 2070-2100 Thiruvallur 1.1 2.2 3.3 Thiruvannamalai 1.3 2.5 3.6 Thiruvarur 1.1 2.2 3.3 Thoothukudi 1.1 2.2 3.1 Trichy 1.2 2.4 3.6 Tirunelveli 0.55 1.65 2.65 Tiruppur 1.42 2.62 3.62 Vellore 1.3 2.6 3.7 Villupuram 0.9 2.1 3.1 Virudhunagar 0.85 1.95 2.95 (Source: Centre for Climate Change and Adaptation Research, Anna University, Chennai) Rows in grey color represent project areas. * As per SRES A1B Standard

4.1.5 Risk Management within sub-project

54. The proposed transmission lines are designed to withstand the project increase in temperature. The increase in line sag has been taken into account in designing the tower spans. The thermal limit on current carrying capacity has been set after taking into account the expected maximum ambient temperature. The increase in ambient temperature will result in reduction in line resistance and reduced transmission losses. However, the efficiency (due to higher iron losses) and overload capacity of power transformers will be reduced and this has been taken into account.

4.2 Change in Precipitation 4.2.1 Rainfall - Observed Pattern

55. The state mainly receives its majority of its rainfall in three seasons: the southwest monsoon, the northeast monsoon and the pre-monsoon season. The normal average annual rainfall is 958.4 mm. About 50% of the total annual average rainfall is received during northeast monsoon and about 31% during the southwest monsoon. The coastal districts receive about 65– 75% of the annual rainfall land and interior districts get about 40-50% in this season. The percentage share of rainfall of different locations coastal/inland/hilly stations for four seasons are given in the Table 4.3. The hilly regions in the west and hilly/plain lands in north western half of the region receive major share from south west monsoon. Figure 4.3 shows the spatial pattern of rainfall during north east monsoon season.

Table 4.3: Seasonal Rainfall of Selected Stations in Tamil Nadu * Stations Lat. Long. Percentage share of rainfall in various seasons Winter Pre-monsoon South-west North-east monsoon monsoon Meenambakkam 13.07 80.19 2.2 5.3 33.5 59.0 Nungambakkam 13.07 80.25 3.6 5.0 30.8 60.6 Vellore 12.92 79.15 3.0 10.1 46.1 40.8 Kanchipuram 12.83 79.72 2.9 7.0 43.7 46.4 Chengulpattu 12.70 79.95 3.1 5.6 38.4 53.0 Tiruvannamalai 12.23 79.08 3.9 10.8 43.7 41.6 Dharmapuri 12.13 78.18 2.3 18.9 42.4 36.4 Villupuram 11.93 79.50 4.0 7.3 38.3 50.3 Cuddalore 11.77 79.77 5.2 6.3 26.3 62.1 Salem 11.65 78.18 1.8 17.3 49.7 31.3 Ooty 11.40 76.73 2.7 20.6 45.9 30.9 Erode 11.35 77.67 3.3 20.2 35.2 41.3

Stations Lat. Long. Percentage share of rainfall in various seasons Winter Pre-monsoon South-west North-east monsoon monsoon Mettupalayam 11.30 76.25 7.8 21.4 19.4 51.4 Coimbatore 11.03 77.05 3.5 20.7 24.8 51.0 Karur 10.95 78.09 2.1 16.9 26.3 54.7 Tanjavur 10.78 79.13 5.7 11.1 34.1 49.2 Tiruchirapalli 10.77 78.72 3.8 15.0 35.2 45.9 Vedaranyam 10.37 79.85 21.5 8.4 13.6 56.5 Dindigul 10.35 77.97 4.8 16.2 29.7 49.3 Adiramapattinum 10.33 79.88 6.2 11.7 27.4 54.7 Kodaikanal 10.23 77.47 6.0 21.2 34.3 38.4 Madurai 9.92 78.12 1.9 12.6 37.0 48.5 Tondi 9.77 79.03 5.2 16.2 16.3 62.3 Virudhunagar 9.68 77.97 4.5 20.0 29.0 46.5 Tuticorin 8.80 78.15 8.0 17.7 5.4 68.9 Palayamkottai 8.73 77.75 9.8 18.4 9.7 62.1 Tiruchendur 8.50 78.12 12.1 12.7 3.3 71.8 Kanyakumari 8.08 77.05 3.6 17.5 29.1 49.8 Tamil Nadu 4.3 13.1 31.9 50.7 Source: http://www.tn.gov.in/dept.st/climate and rainfall.pdf Rows in grey color represent project areas. * As per SRES A1B Standard

56. A review study carried out by Jain and Kumar (2012)15, indicates that the annual rainfall has increased by +8.5 percent and +4.4 percent in the Cauvery river basins and the river basins north to Cauvery river basin in Tamil Nadu respectively in the last 100 years with respect to the average rainfall during this period. The river basins that are in the south of the Cauvery river basin have experienced decrease in annual rainfall by -9.8 percent. An analysis of annual rainy days indicates that there is no change in the Cauvery basin in the last 100 year period. However, the river basins north and south of the Cauvery basins have experienced decreasing trend by -3.6 percent and -32.3 per cent. The quantified changes in annual rainfall and number of rainy days is indicated in Table 4.4 at annual and seasonal levels.

Table 4.4: Changes in Annual and Seasonal Rainfall and in Number of Rainy Days in the Last 100 Years * Basin Annual Pre-monsoon Monsoon Post Winter Monsoon R f RD R f RD R f RD R f RD R f RD EF1 0.044 -0.032 -0.345 -0.032 -0.214 -0.047 0.659 0.000 0.197 0.000 Cauvery 0.879 0.000 -0.563 0.000 0.075 0.028 1.748 0.050 0.024 0.000 EF2 -0.950 -0.333 -0.800 -0.143 -0.500 -0.125 0.491 0.000 -0.246 -0.032 Rf: Rainfall in (mm/yr); RD: Rainy days (Days/yr) EF1 – East flowing river basins that are North of Cauvery river Basin EF2- East flowing river basins that are South of the Cauvery river Basin * As per SRES A1B Standard

15 Trend analysis of rainfall and temperature data for India SK Jain, V Kumar- Current Science (Bangalore) 102 (1), 37-49

Figure 4.3: Rainfall (mm) over Tamil Nadu during (a) Oct; (b) Nov; (c) Dec; and (d) NE Monsoon Source: Tamil Nadu State Action Plan for Climate Change (Using IPCC A1B SRES)

57. Spatial distribution of the rainfall received over Tamil Nadu is highly variable. Rainfall over coastal areas is more and decreases in the inland areas since the rainfall causing systems are forming over Bay of Bengal and moving towards the coast of Tamil Nadu. Also, the rainfall over northern end is more than the southern locations.

4.2.2 Rainfall Projections Annual Rainfall: 58. The rainfall projection indicates a slight decrease of about 50 mm by end of the century (2070-2100) with reference to the baseline16 (Fig.4.4). However, district wise projection indicates variant distribution which has been given in Table 4.5.

Seasonal Rainfall: 59. South west and north east monsoons being principal rainy seasons, analyses have been carried out for these two seasons. North east monsoon may experience more intense rainfall when compared to south west monsoon by end of the century.

16 The projections of temperature and precipitation based on UK Met Office Hadley Centre regional climate model PRECIS with boundary data inputs from 6 out of 17- member perturbed-physics ensemble (HadCM3Q0-Q16, known as 'QUMP').The model was run at CCC&AR, Anna University at a spatial resolution of 25 km x 25 km and the GHG emission drivers are generated by the IPCC A1B SRES scenario. Source: Tamil Nadu SCCP Final Report.

Table 4.5: District-wise Percentage Change in Annual Rainfall with Reference to 1970-2000* Districts 2010-2040 2040-2070 2070-2100 Ariyalur -6 -7 -3 Chennai -9 -14 -4 Coimbatore -3 4 6 Cuddalore -6 -6 3 Dharmapuri -5 -4 -3 Dindigul -4 -3 1 Erode -6 -6 0 Kancheepuram -8 -12 -3 Kanyakumari 6 11 6 Karur -3 -3 -2 Krishnagiri -4 -5 -2 Madurai -2 0 1 Nagapattinam -7 -5 3 Namakkal -4 0 -3 Nilgiri -3 5 7 Perambalur -6 -6 -3 Pudukkottai -6 -1 9 Ramanathpuram -4 2 9 Salem -4 -1 -3 Sivaganga -4 -2 4 Thanjavur -6 -1 7 Theni -7 0 4 Thiruvallur -6 -13 -5 Thiruvannamalai -6 -11 -7 Thiruvarur -7 -2 8 Thoothukudi -1 8 19 Trichy -5 -2 -2 Tirunelveli 1 6 6 Tiruppur -7 -3 2 Vellore -6 -11 -6 Villupuram -7 -9 1 Virudhunagar -7 1 7 (Source: Centre for Climate Change and Adaptation Research, Anna University,Chennai) Rows in grey color represent project areas. * As per SRES A1B Standard

Figure 4.4: Change in Annual Rainfall (mm) Projections for 2010-2040, 2040-2070 and 2070-2100 with Reference to Baseline (1970-2000) *

*(Source: CCCAR, Anna university) (Using IPCC A1B SRES)

60. Increased precipitation variability can impact quantity and quality of surface source availability and flows. Flooding risks and flash flood flows from extreme rainfall events can damage infrastructure (foundations, underground installations, transformation equipment etc.) located in the path of flow. The increased frequency of extreme rainfall events, combined with loss of vegetative cover and drainage asset mismanagement (Janakarajan et al, 2006) is likely to increase the extent and frequency of river flooding. Severe, intense rainfall events are expected to increase significantly, which can inundate transmission equipment and cause interruption in service delivery.

61. Higher temperatures and lower precipitation are likely to increase the frequency, intensity and duration of droughts. Prolonged drought events are expected to occur on average of every 5 years. Tamil Nadu is significantly dependent on monsoon rains for water resources recharge. The highly variable spatial distribution of rainfall can lead to acute water scarcity and severe drought conditions across the state particularly in the north-western regions such as Vellore. Variation in annual average rainfall can be as high as 25%.

Extreme Rainfall 62. Long term studies carried out for the period 1901- 200517, indicate that Tamil Nadu is experiencing more dry days than wet days every year. However, there has been a significant increase in heavy precipitation events as indicated in the recordings of the IMD (India Meteorological Department) observing stations in the State (Figure 4.5). Increase in one day extreme rainfall events of the order of 5 to 10 cm has been observed along the northern coast of the State. In rest of the State, the extreme rainfall event has increased by less than 5 cm or less. The analysis of 25‒year return period of rainfall shows a large variation from 10cm in the western parts of Tamil Nadu to 25 cm and more in the northern and central coastal regions of the State.

17 Impact of climate change on extreme rainfall events and flood risk in India, Journal of Earth System Science, June 2011, Pulak Guhathakurta, O. P. Sreejith, P.A. Menon

Figure 4.5: Stations with Significant Increasing/Decreasing Trends in One Day Extreme Rainfall

Rainfall and water balance projections in Mid Century 63. In support to the National Water Mission’s National Action Plan on Climate Change (NAPCC), the Asian Development Bank18 had carried out a study during 2011 to assess the likely changes in water balance projections for the Cauvery river basin which occupies about one third portion of geographical area of Tamil Nadu and is the main river basin in the state, shared along with the State of Karnataka. (Figure 4.6, and Table 4.6). The study uses SWAT (Soil and Water Assessment Tool) model with inputs from PRECIS19 Regional Climate Model run on IPCC A1B SRES. One realisation of the HADCM3 QUMP (Quantifying Uncertainty in Model Predictions, Q14) has provided the boundary conditions for the PRECIS run.

18 TA 7417- IND: Support for the National Action Plan on Climate Change Support to the National Water Mission 19 The PRECIS climate model (stands for "Providing Regional Climates for Impacts Studies") is an atmospheric and land surface model of limited area and high resolution which is locatable over any part of the globe

Figure 4.6: Boundary of the Cauvery River Basin

64. The projections under the A1B scenario indicate the following: • Annual Rainfall – There is no significant change of annual rainfall until mid-century A1B scenario. Annual precipitation is highest in the Cauvery delta and in the northwest of the basin where over 1000 mm occurs. • Changes in annual average evapotranspiration – These values are projected to increase during mid-century. • Southwest monsoon rainfall - For the southwest monsoon, the indications of the PRECIS A1B results are that there will be a reduction in precipitation by up to 10 percent by mid-century. The implications of this projection are increased demand for irrigation water in the upper basin, coupled with a reduction in surface water availability for the delta part. The surface water resource available to the Cauvery delta is likely to decrease during the southwest monsoon under this scenario. • For the northeast monsoon - the PRECIS A1B scenario indicates a 10 percent to 20 percent increase in precipitation in the Cauvery delta. Drainage is already a problem in the lower parts of the delta, and increased north east monsoon precipitation coupled with higher sea levels will exacerbate the problems. • Rainfall Projections by End of the Century: IIT Madras in collaboration with Tamil Nadu Agricultural University carried out a study to assess the likely rainfall scenario in

the mid-century. This study was part of the ClimaRice20 project and was supported by the Norwegian Government. The climate change data used for this study was simulated by the GCM21 run by the International Pacific Research Centre (IPRC) Hawaii. Climate 22 change simulations were made using GFDL doubling of CO2 concentration in the end- century (A1B scenario) and the GCM results were downscaled to 25 km resolution using IPRC-Reg SIM model23. The results are shown in Figures 4.7 to 4.8.

Figure 4.7: Annual Rainfall - Baseline and Projections