Geospatial Technology Based Water Management Action Plan for South Forest Division of Nilgiris, Tamil Nadu

Aims: Recent climate change impacts rainfall patterns, increasing wildlife and livestock populations in higher densities, which are likely to aggravate water scarcity in forest areas. A sustainable water management strategy and action plan based on scientific inputs are crucial and need of the hour to resolve the water scarcity problem. Hence, the study aims to prepare an action plan and water management strategy for rangelands of Nilgiris using geospatial tools.

Study Design: Field survey was conducted to identify the existing water storage structures and water requirement and ASTER GDEM and GIS were used to prepare the water management strategies for Nilgiris south forest division.

Place and Duration of the Study: The study was carried out in Nilgiris south division located in between 760 28' 08’’and 760 44' 08" East longitude and 110 10' 81’’and 110 31' 80" North latitude during 2014-2016.

Methodology: The study area has been delineated as macro watersheds, and the altitude, slope, forest cover and drainage lines were extracted from ASTER GDEM for generation thematic maps. Rainfall data for twenty years (1995-2014) was collected and runoff was worked out using runoff coefficient of a different land. A field survey was conducted for identifying the existing water storage structures, spatial occupancy of herbivores, spread and water requirement of invasive species in the Nilgiris south forest division.

Results: GIS based thematic maps for slope, contour, area coverage under forest range and macro watershed have been prepared, and water availability and water balance components like runoff and evapotranspiration have been determined. After identifying water availability and water balance according to the site conditions and strategies one Earthen cum masonry embankment, 2 Earthen pond with Major check dam, 2 Masonry embankments, 2 Major check dam 7 Medium check dam 100 Minor check dam, 1 RCC Embankment and 99 gabion check dams in South forest division of Nilgiris.

Conclusion: Suitable locations were identified and location specific water harvesting structures have been suggested to store 68844 cum of water.