IMPACT OF CLIMATE ON IRRIGATION WATER REQUIREMENT

Abstract

Climate change term is numerously used in many research studies, climate change occurs when the expected weather changes its course mainly due to increasing CO2 emissions. As we know that there is relationship between hydrological cycle and climate system, any change in climate system leads to affect meteorological parameters and this made changes in irrigation water requirement. In this study assessing impact of climate on irrigation water requirement for sugarcane crop in Haridwar District of Uttarakhand State was carried out by using meteorological observed data required like maximum and minimum temperature, relative humidity, solar radiation, precipitation. Using this data reference evapotranspiration, crop evapotranspiration and irrigation water requirement was calculated using CROPWAT 8.0. Trend analysis had been carried out on temperature & precipitation, using Mann-Kendall test and theil-sens‘s slope estimator for the period of 1901-2001. After that future climate data was projected for the periods of 2011-2030, 2046-2065 and 2080-2099 by downscaling GCM data and outputs of GCM were forced by taking A2 emission scenario of the IPCC SRES. SDSM 5.2 tool helps in downscaling GCM data to station level; in this study HadCM3 (Hadley Centre Unified Model 3) GCM model was used. Statistical downscaling model (SDSM) is a mixture of a weather generator and regression based model. Reference crop evapotranspiration (ETo) was calculated using mean monthly weather data with the help of CROPWAT 8.0 and then Irrigation water demand (ETc) and Crop Water requirement for Sugarcane crop in Haridwar was estimated.