Chapter 5 –Baseline Env

Kaladan Multimodal Transport Project in Mizoram EIA-EMP Report Construction of road from NH-54 to Indo-Myanmar border Chapter 5 –Baseline env. scenario CHAPTER 5- BASELINE ENVIRONMENTAL SCENARIO 5.1 Natural Environmental Setting of the project corridor 5.1.1 Temperature and Climate The project area has a pleasant climate. However, due to variation in altitude and features some areas of the project affected are subjected to tropical and sub-tropical climate. It is generally cool in summer and not very cold in winter. The temperature varies between 18 and 30 degree during summer and between 11 and 21 degree in winter. Pre-monsoon rains are experienced from March to May while regular south-west monsoon commences from June till October. The average relative humidity is 85%. 5.1.2 Rainfall Pre-monsoon rains are experienced from March to May while regular south-west monsoon commences from June till October. The average monthly rainfall is 254cms. However, the southern region receives relatively higher rainfall than the northern region. Despite such high rainfall, prolonged dry spells and occasional drought conditions are noticed. Crops are grown mostly rainfed depending upon the monsoon rainfall. Annual rainfall of the State is about 2500mm with 124 numbers of rainy days, but is concentrated between June to September. Except in the month of October and November when rainfall of <200mm and >70mm, respectively is received, there is practically no rainfall (>30mm) in the subsequent months (December - January). Although the pre-monsoon rainfall is more than 700mm, the distribution of rainfall in February and March is scarce (<110mm). 5.2 Physical setting 5.2.1 Land Use Buffer zone land use The land use pattern of the project area was studied during field studies and survey of India topo-sheets and land sat satellite imagery. For the entire alignment of 108.761 km, 5 km buffer zone along the Kaladan Mayanmer Multi Modal road network, land use and land cover map of that area was prepared using LANDSAT ETM satellite data. Government of Mizoram Page 5- 1- Public Works Department, Mizoram Kaladan Multimodal Transport Project in Mizoram EIA-EMP Report Construction of road from NH-54 to Indo-Myanmar border Chapter 5 –Baseline env. scenario Steps followed here: Digital copies 1:50000 scale toposheets were supplied by the client. Proposed road network was also marked on the map. Digital/raster copy of toposheets were first geo-referenced with the help of available and most accurate coordinate intersection points using PCI OrthoEngine. Geo corrected toposheets were mosaicked. Proposed road network digitized in PCI Focus environment and data was saved in...pix or .dxf file format. A 5 Km buffer zone created along the both sides of proposed road. LandSat ETM data of corresponding area were also geo-referenced against the toposheet and mosaicked to generate the image of entire project area. Image was clipped and subsetted for the buffer area only. Subsetted image was classified using Nearest Neighbor classification method in Definiense Developer software. We have taken the help all visible and NIR bands in LandSat ETM during classification. As the image was mostly vegetation covered, we use NDVI index in classification. Inferences The area is mostly covered (93.26%) with dense to moderately dense forest/vegetation. Water bodies like river and small-submerged land area are the smallest landuse unit (1.30%) in the area. Open land (some times water logged) near by habitation are interpretated as degraded Jhum cultivation. This open land and habitation class occupied nearly 5.45% of total buffer area. Following table and pie distribution chart shows overall landuse and landcover distribution. Class name Area (sq. km) Class percent Water Bodies 8.252 1.30 Dense Forest 293.450 46.07 Moderately Dense Forest 252.370 39.62 Sparse vegetation 48.244 7.57 Open land/Habitation 34.715 5.45 Total Area 637.032 100.00 Government of Mizoram Page 5- 2- Public Works Department, Mizoram Kaladan Multimodal Transport Project in Mizoram EIA-EMP Report Construction of road from NH-54 to Indo-Myanmar border Chapter 5 –Baseline env. scenario From the classified map it is interpreted that though the area of interest is mostly covered by dense forest, but the proposed road network in most cases passes through the moderately dense or sparsely vegetative area. It does not affect too much the dense/thick vegetation land. 40% Water Bodies Dense Forest Moderately Dense Forest 8% Sparse vegetation Open land/Habitation 5% 1% 46% Fig 5.1: Distribution of Land Use It is not possible to determine appropriate demarcation among different vegetation types using in this imagery (LansSat ETM). Higher resolution imageries like IKONOS, QUICKBIRD, WORLDVIEW, and ORBVIEW may be used for further detailed study of the proposed area. Vegetation type, individual tree crown etc can be detected correctly using this imageries. Ground checking with these data will be more informative. Land use pattern of the land on which proposed road alignment has been proposed i.e. the land which is to be acquired for the project has following land use pattern: Total Land Requirement = 239.59 Hectares Total Forest Land = 6.36 % (15.24 Hectares) Total Private Land = 17.88% (42.84 Hectares) Degraded Jhum Land = 75.78% (181.51 Hectares) (Deem Forest Land) Government of Mizoram Page 5- 3- Public Works Department, Mizoram Kaladan Multimodal Transport Project in Mizoram EIA-EMP Report Construction of road from NH-54 to Indo-Myanmar border Chapter 5 –Baseline env. scenario Forest Land Forest Land Habitation Private Land Water body Degraded Jhum land Degraded Jhum land Figure 5.2 Land use pattern of project Figure 5.3 Land use pattern of Proposed Influence area project road alignment 5.2.2 Topography The hills are covered with dense forest and thick undergrowth of evergreen bush, bamboo and kail. The project road is traversing between 907m and 55m altitude above mean sea level, at the start and end at India-Myanmar border. The maximum altitude of about 1037m has been found at Village Paither. The hills are made of sandstone, shale, mudstone and slate. 5.2.3 Seismicity The project area is part of Northeast India, which is seismically one of the six most active regions of the world, the other five being Mexico, Taiwan, California, Japan and Turkey. The complete project alignment falls in Zone V of the seismic zoning classification of India (Refer fig 5.3). Though the project area is not reported to have originated any earthquakes, but has experienced many shocks/tremors due to earthquakes occurring in the neighbouring region till recent past. According to GSHAP data, the states of Mizoram & Tripura fall in a region of high to very high hazard. As per the 2002 Bureau of Indian Standards (BIS) map, both states fall in Zone V. Historically, parts of these states have experienced seismic activity greater than M6.0. Approximate locations of selected towns and basic political state boundaries are displayed in fig 5.4 Government of Mizoram Page 5- 4- Public Works Department, Mizoram Kaladan Multimodal Transport Project in Mizoram EIA-EMP Report Construction of road from NH-54 to Indo-Myanmar border Chapter 5 –Baseline env. scenario Zone 5 covers the areas with the highest risk zone that suffers earthquakes of intensity MSK IX or greater. The IS code assigns zone factor of 0.36 for Zone 5. Structural designers use this factor for earthquake resistant design of structures in Zone 5. The zone factor of 0.36 is indicative of effective (zero period) peak horizontal ground accelerations of 0.36 g (36 % of gravity) that may be generated during MCE level earthquake in this zone. It is referred to as the Very High Damage Risk Zone. The state of Kashmir, Punjab,the western and central Himalayas, the North-East Indian region and the Rann of Kutch fall in this zone. Generally, the areas having trap or basaltic rock are prone to earthquakes. The high seismicity in the region is attributed to the collision tectonics between the Indian plate and the Eurasian plate in the north and subduction tectonics along the Indo- Myanmar range (IMR) in the east. Kaladan fault covers a distance of almost 270-km, marks the eastern boundary of the Mizoram-Tripura-Chittagong folded belt. The fault trends northeast- southwest along the Kaladan River of Arakan coast. On the basis of faulting nature and pattern it is termed as a dextral transformed fault. The complete proeject alignment falls in Zone V of the seismic zoning classification of India. Though the project area is not reported to have originated any earthquake, but as experienced many shocks / tremors due to earthquakes occurring in the neighboring region. Government of Mizoram Page 5- 5- Public Works Department, Mizoram Kaladan Multimodal Transport Project in Mizoram EIA-EMP Report Construction of road from NH-54 to Indo-Myanmar border Chapter 5 –Baseline env. scenario PROJECT AREA Fig 5.4 : Map showing seismic zones of India Government of Mizoram Page 5- 6- Public Works Department, Mizoram Kaladan Multimodal Transport Project in Mizoram EIA-EMP Report Construction of road from NH-54 to Indo-Myanmar border Chapter 5 –Baseline env. scenario PROJECT AREA Fig 5.5 Hazard map of Mizoram 5.2.4 Physiography The project road alignment passes through the Southwestern part of Mizoram, which is characterized, by alternating ridges and valleys. The terrain of the project corridor is mostly mountainous to hilly with a series of parallel North-South ridges. Due to its topography the area is well drained even though it receives high rainfalls with annual average of 2700 mm. The project road follows the pattern of the ridges and traverse through the hill or mountainous sides mostly running at an altitude of 907m – 55m above mean sea level at the start and end point at in the Myanmar Border.

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