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Assessing Agricultural Sustainability in Watersheds in India using GeomaticsResults & Discussion The issue of sustainability of rainfed agriculture was analysed using a wide range of indicators which included a few indicators that can be deduced from satellite data and analysed using GIS. While the viability of WDP was assessed using indicators pertaining to Farmer’s Satisfaction, Resource Conservation and activities initiated under Watershed Development program, as indicated through cob-web diagrams (figs. 4 & 5); use of satellite data and GIS for study of aspects of LUCC (fig. 6) and NDVI (fig. 7) have been discussed here. The issue of equity was also analysed for the TMWS & UTMWS in the study area. It was found that equity was better addressed in TMWS (0.36) which is slightly poorer than the national average for India (0.30 - 0.34) while in UTMWS (0.47) the inequality among farmers was severe (Fig. 8).      Land Use Cover Change (LUCC) analysis In order to study the impact of sustainability of WDP satellite imagery of the study area (IRS LISS-III- 1D Path -Row 100-60) of pre-WS period (16 Nov. 1998) and Post-WS period (IRS P6 of 4 Nov. 2005) were classified using ERDAS Imagine Ver. 9.0. Figure 6 indicates the trend in change of land use and land cover in the two MWS. While agricultural area is largely stabilized in the TMWS there is a large expansion of agricultural activity in marginal lands belonging to LCC IV and V with slope of 4 -5 % that would induce soil erosion (Fig.9). Land fallow which is essential for rejuvenation of land is being maintained in the TMWS, while there is no fallowing practiced in UTMWS. Tree groves have been depleted in UTMWS and vegetative cover from scrublands have also decreased which would adversely affect soil OC content. All these trends indicate unsustainable trend in UTMWS.  Normalized Difference Vegetation Index (NDVI) Light reflectance from vegetation was compared in the post-kharif season period in 1998 and 2005. NDVI was calculated using the formulae IR–IR/IR+IR where IR stands for infrared and R stands for red portion of the EM spectrum. The Vegetation Index (VI) was normalized for topographic effect and the difference of NDVI in the study area in pre- and post-watershed project period is indicated in Fig. 7. Evidently in pre-watershed period, NDVI in both TMWS and UTMWS was lower. In 2005, NDVI was higher in large parts of TMWS which indicates better rabi-crop stand. Higher NDVI was also recorded in UTMWS in Nov. 2005 which is indicative of good vegetation stand. Conclusion WDP is essential for development of rain fed agriculture in India as it would ensure agricultural production through natural resource conservation viz., water harvesting and halting of soil erosion. Although WDP was initiated by Govt. of India in 1985 with massive public investment, not all projects are yielding sustainable agricultural growth as indicated by our methodology. The merit of this method for evaluation lies in the fact that it derives data and information heavily from Geomatics and uses them successfully to identify the strengths and weakness of the WDP in an area. The methodology permits temporal analysis of indicators, comparison of various WDP across AER and at different periods of time. Most importantly, it helps identify weak linkages in a given WDP which can be corrected to achieve agricultural sustainability in rain fed areas. Acknowledgement: Authors thank the Indian Council of Agriculture Research (ICAR) for awarding and funding of research under National Fellowship Scheme to the first author. They appreciate the constant encouragement provided by Director, Central Research Institute for Dryland Agriculture (CRIDA), Hyderabad, during this study. References
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