ABSTRACT
Geospatial technologies provide huge potential for land degradation and climate change impact assessments. The endeavor was to analyze the long term trends in the moisture and aridity conditions prevailing in the Kancheepuram district, South India and project decadal changes in peanut yield using Decision Support System for Agro Technology Transfer (DSSAT) under medium emission scenarios RCP 4.5. Precipitations (P) and potential evaporation (PE) data were used to create Moisture Index and to assess the temporal and spatial variations in aridity status. Gridded data analysis of the mean annual moisture conditions during the period 1951–2008 showed no significant trend for any of the stations. The annual mean moisture index for Chittamur, Madhuranthakam, Thirukazhikundram, Kancheepuram, Wallajabad, St. Thomas Mount were −35.8, −35.5 −28.6, −42.4, −36.2, −28.4, respectively. Among the stations, Kancheepuram recorded the lowest moisture levels, indicating its critical semiarid conditions throughout 57-year period. Similarly GIS analysis showed that aridity may be increased in the coastal areas. PNUTGRO crop simulation model output revealed that the productivity of the peanut crops may fall toward the end of the 21st century. Yield of groundnut indicated a strong declining trend in the mid-century. The decadal mean yield under the 188control simulation over 127 years was 1732.4 kg/ha, whereas the decadal mean groundnut yield under elevated carbon dioxide condition was 1846.03 kg/ha. The yield is likely to be reduced by −12.7% for the decade 2091–2098 due to climate change. This spatiotemporal assessment threw light on observed hydroclimatic conditions and crop yield changes under climate change and the urgent need for water and land management to cope with climate change impacts.
