Computers & Geosciences, Published Online 17 May 2014

By Pradeep K. Rawat

“Highlights

• Average temperature has been increasing with the rate of 0.07 °C/year
• Average evaporation loss has been increasing with the rate of 4.03 mm/year.
• Average rainfall has been decreasing with the rate of 0.60 mm/year.
• Climate change accelerates drought hydrological problems during non-monsoon period.
• In order to that the non-monsoon crops yield has been decreasing 0.60% by each year.

“The main objective of the study was to assess climate change and its geohydrological impacts on non-monsoon crop pattern at watershed level through GIS development on climate informatics, land use informatics, hydro-informatics and agro-informatics. The Dabka watershed constitutes a part of the Kosi Basin in densely populated Lesser Himalaya, India in district Nainital has been selected for the case illustration. This reconnaissance study analyzed the climatic database for last three decades (1982–2012) and estimates that the average temperature and evaporation loss have been rising with the rate of 0.07 °C/year and 4.03 mm/year respectively whereas the average rainfall has been decreasing with the rate of 0.60 mm/year. These rates of climate change increasing with mounting elevations. Consequently the existing micro climatic zones (sub-tropical, temperate and moist temperate) shifting towards higher altitudes and affecting the favorable conditions of the land use pattern and decreased the eco-friendly forest and vegetation cover.

(a) Sketch diagram of high underground water level, perennial springs and streams with thick vegetation cover and dense forests in their recharge zones during 1982-1990, (b) Poor underground water level due to deforestation in the recharge zones of the springs consequently number of perennial springs and streams dried up till 2011, (c and d) Spatial distribution of perennial springs and streams in Dabka watershed respectively during 1982-190 and 2005-2011.

“The land use degradation and high rate of deforestation (0.22 km2 or 1.5%/year) leads to accelerate several hydrological problems during non-monsoon period (i.e. decreasing infiltration capacity of land surface, declining underground water level, drying up natural perennial springs and streams, decreasing irrigation water availability etc.). In order to that the non-monsoon crops yield has been decreasing with the rate of 0.60% each year as the results suggest that the average crop yield is just about 58 q/ha whereas twenty five to thirty year back it was recorded about 66 q/ha which is about 12% higher (8 q/ha) than existing yield. On the other hand the population increasing with the growth rate of 2% each year. Therefore, decreasing crop yield and increasing population raised food deficiency problem and the people adopting other occupations which ultimately affecting rural livelihood of the Himalaya.”

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