Mangrove Mapping of Uttara Kannada District
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Lake 2016: Conference on Conservation and Sustainable Management of Ecologically Sensitive Regions in Western Ghats [THE 10TH BIENNIAL LAKE CONFERENCE] th Date: 28-30 December 2016, http://ces.iisc.ernet.in/energy Venue: V.S. Acharya Auditorium, Alva's Education Foundation, Sundari Ananda Alva Campus, Vidyagiri, Moodbidri, D.K. Dist., Karnataka, India – 574227 Mangrove Mapping of Uttara Kannada District Prakash N. Mesta, Subash Chandran, M.D. and Ramachandra, T.V. Energy & Wetlands Research Group, Centre for Ecological Sciences, Indian Institute of Science, Bangalore – 560 012, INDIA E-mail: [email protected]; [email protected]; [email protected] Abstract__ This study has mapped mangrove habitat and series of measures to enrich estuaries and other assessed the mangrove potential area with the use of suitable coastal backwaters with mangrove Remote sensing imageries of MODIS, IRS & Google vegetation. The CRZ-2011 has also considered maps of different years and integrated with geographic mangrove areas as inviolable. The Government, both information system (GIS) in the entire Uttara Kannada Centre and State are working together for mapping District Karnataka State, India. The results are important to planning and sustainable managem,ent of mangrove areas, countrywide, to declare them as natural resources. Mapping reveals mangrove area of ‘ecologically sensitive areas’ under the CRZ-I 1119.73 hectares and potential area of 1786.75 hectares. category. Keywords__ Coastal ecosystems, Mangroves, Uttara Importance of Mangrove Mapping: Mapping of Kannada District,, Estuaries, Creeks, RS-GIS, natural resources is a key component of many planning applications. When the public views an INTRODUCTION application, they may not fully understand what the Mangrove vegetation (Kandla in Kannada) is a application entails. Therefore, plans and drawings are characteristic plant community growing in the coastal a valuable communicative tool within the realm of the zones of tropics and sub-tropics. Mangroves consist planning process. The west coast estuaries, despite of a group of mostly woody plants which grow in the their high productivity and biodiversity, faced neglect zone between high tide and low tide in estuaries and regarding mangrove conservation and development other backwaters, and cannot grow anywhere else. programmes, probably on account of lack of data. Mangroves form the foundation of a highly These estuarine regions, densely populated due to productive and biologically rich ecosystem which high productivity, are prone to rising human pressures provides a home and feeding ground for a wide range causing greater mangrove fragmentation and losses. of species, many of which are endangered. They are The lack of spatial quantitative maps on mangroves highly valuable ecosystems, providing an array of for the west coast has often crippled restoration essential goods and services which contribute programmes. In the Uttara Kannada district of significantly to the livelihoods, well-being and Karnataka State, mangrove planting works in the security of coastal communities. Mangroves deliver a small estuaries attempted during the recent years have range of economic, social and environmental benefits raised high hopes of better ecology and higher to people, collectively referred to as their ecosystem biological production. Yet the local forest goods and services. Many of the services provided by departments, which manage most mangrove areas, are healthy intact mangroves are not marketable goods to be equipped with spatial, quantified data on and this means that they are often undervalued in mangroves and potential area for mangrove planting. market based cost benefit©Lake2016-EWRG, analyses. The accelerating The district has three agro IISc-climatic regions - coastal, destruction of natural habitats and consumption of Ghats and Plains region. Kali, Gangavali, natural resources by rapidly expanding human Aghanashini, Sharavathi and Venkatapur Rivers are populations has caused huge impacts to ecosystems the important rivers of the district having their across the globe (Defeo et al. 2009). Many of these estuaries with most of the mangrove areas. In impacts are focused on world’s coastlines that include addition are some minor rivers/rivulets/creeks such as a mosaic of mangrove ecosystems. Thus, there is a Belikeri river, Kumta creek, Sankandhole (Ankola demand to assess the mangrove ecosystems at creak) and Belamber creek are other coastal water national levels to satisfy a great number of needs, bodies where mangroves are situated. The notable including scientific ones as well as planning and earlier works on mangroves in the district were by environmental managements in conservation efforts. Ananda Rao (2001) and Andrade (2003). M.D.Subhash Chandran(2012). The Forest Survey of Importance in Indian context: Realizing the India estimated just 2 sq.km of mangroves in the importance of mangroves the Government of India, State of Karnataka, during 2001, vide CRZ Notification of 1991, has proclaimed mangroves as vegetation to be protected as CRZ-1. The Ministry of Environment and Forests initiated a Proceedings – Lake 2016: Ramachandra T V, Subash Chandran M D, Mohan Alva, et al., 2018. Conservation and Sustainable Management of Ecologically Sensitive Regions in 127 Western Ghats, , Sahyadri Conservation Series 65, , ENVIS Technical Report 120 Environmental Information System, CES, Indian Institute of Science, Bangalore 560012 Lake 2016: Conference on Conservation and Sustainable Management of Ecologically Sensitive Regions in Western Ghats [THE 10TH BIENNIAL LAKE CONFERENCE] th Date: 28-30 December 2016, http://ces.iisc.ernet.in/energy Venue: V.S. Acharya Auditorium, Alva's Education Foundation, Sundari Ananda Alva Campus, Vidyagiri, Moodbidri, D.K. Dist., Karnataka, India – 574227 OBJECTIVES The overall objective of the present study was to map To study estuaries and creeks of Uttara kannada mangrove habitat areas with the use of satellite district for mangroves and estimate and map images integrated with geographic information potential area available for planting with system (GIS). Using open source GIS software mangroves, estuary-wise. (QGIS) and remote sensing software (GRASS) and To document mangrove species diversity and IRS imageries and Google satellite images mangrove distribution of mangroves, species-wise, in areas and potential areas available for planting in estuaries in relation to salinity and sediment river estuaries and creeks in the Uttara Kannada conditions. district of Karnataka State were mapped. To recommend suitable species for planting in demarcated potential areas. The study of this nature, using GIS and remote sensing are handy tools for scientific planning and MATERIALS AND METHODS management of mangroves even at a micro-level. The Study area: Uttara Kannada District is the applicability of such modern techniques to micro- northernmost district located on the west coast of level mapping of mangroves, for depicting potential Karnataka. The district has 11 Taluka out of which mangrove areas, assessing threats to mangroves Karwar, Ankola, Kumta, Honavar and Bhatkal are through diversion of mangrove areas etc., for the costal taluks. District is situated within Northern relatively smaller west coast estuaries and creeks, is latitude 13° 55' 28" to 15° 31' 26" and Eastern expected to pave way for increase in area under longitude of 74° 5' 9.8" to 75° 6' 12.7". (Fig. 1) The mangroves and improve the efficiency of mangrove total notified forest area in the District is management even at the village level. 813,595Hectares Fig. 1; Map showing location of estuaries and creeks of Uttara kannada district ©Lake2016-EWRG, IISc Materials used: GPS, Water analyzing Kit, Sediment METHODS: grabber, Survey of India Topo-sheets (1:50,000 Area calculation using GIS: scale), Census Village maps, Remote sensing Step 1: Mangrove areas (areas under canopies of imageries of MODIS, IRS & Google maps of mangrove crowns) and Potential areas (exposed areas different years. during low tides, without mangrove crowns, excluding seasonal sand bars and bivalve beds) have Proceedings – Lake 2016: Ramachandra T V, Subash Chandran M D, Mohan Alva, et al., 2018. Conservation and Sustainable Management of Ecologically Sensitive Regions in 128 Western Ghats, , Sahyadri Conservation Series 65, , ENVIS Technical Report 120 Environmental Information System, CES, Indian Institute of Science, Bangalore 560012 Lake 2016: Conference on Conservation and Sustainable Management of Ecologically Sensitive Regions in Western Ghats [THE 10TH BIENNIAL LAKE CONFERENCE] th Date: 28-30 December 2016, http://ces.iisc.ernet.in/energy Venue: V.S. Acharya Auditorium, Alva's Education Foundation, Sundari Ananda Alva Campus, Vidyagiri, Moodbidri, D.K. Dist., Karnataka, India – 574227 been digitized as separate vector polygon layers using RESULTS & DISCUSSION Google Earth, Bing map & Geo-referenced IRS images. Estuary and creek wise mangrove situation in Uttara Kannada District: Among the estuaries Kali Step2: These polygons (regions) are overlaid on estuarine complex topped the list with 606.47 ha of Revenue Taluk ADM vector (based on Census 2001) mangroves and 605.48 ha of potential area for and split using polygon split into Taluka as a units planting followed by Aghanashini estuary (169.38 ha and 707.3 ha respectively) and Sharavathi-Badgani Step3: Each region’s spatial tables are updated with estuarine complex (136 ha and 136.24 ha coordinate extractor,