WATER MANAGEMENT OF MINOR IRRIGATION PROJECT IN CHANGING CLIMATE

Abstract

The consequence of climate change on watershed area connected with hydrological systems varies regionally and between climate scenarios. To assess the hydrological impacts of ecological change, numerous methods have been produced. Which primarily succumb to two aggregations; time series study (statistical method) and hydrological modeling. The factual routines were utilized to study temporal patterns and their spatial conveyance of recorded yearly and seasonal precipitation and temperature arrangement in the past and evaluating huge pattern in hydro-climatic time arrangement, without detailing if the pattern is straight or nonlinear. The true slope (change per unit time) was projected by using a simple non- parametric procedure developed by Sen's Slope Method. The study uncovered a long-term unimportant decrease pattern of yearly rainfall, whereas increasing trend in post-monsoon season over the Study territory. Precipitation throughout winter and summer periods indicated an expanding pattern. Factually, storm precipitation might be acknowledged as extremely steady as the coefficient of variety is 15.3%. This pattern is heading in most recent 10 years. In light of takeoff from mean, precipitation investigation likewise demonstrated an expanded number of dry years contrasted with wet years this adapting precipitation incline throughout premoonsoon months is a major concern for the study zone, which is essentially of rain-fed agriculture. Hydrological modeling especially distributed hydrological modeling is used to simulate hydrological processes in watersheds. Soil and Water Assessment Tool (SWAT 2009) is applied to estimate and recognize the hydrological behavior of watershed area. The SWAT model has been calibrated and validated using the observed discharge data. Daily discharge for the period from 197-2005 was used for model calibration and validation. The sensitivity analyses of model parameters were performed before calibration and validation to determine the most sensitive parameter. Coefficient of Determination (R2), Nash-Sutcliffe Efficiency(NSE), Percentage Bias (PBIAS), and ratio of the Root Mean Square Error (RMSE), (MAE) were used to evaluate the model in order to obtain the goodness of fit. The calibration result shows the linear coefficient (R2), NSF, PBIAS, RMSE and MAE to be 0.886,0.884,-17.917,0.008 and 0.193 respectively. Similarly for the validation period (1991-2005), the analysis parameter's values are 0.859,0.885,-18.590, 0.009 and 0.212 respectively.For the total simulation period, out of average Iv annual precipitation of 1354 mm, the water yield and ET accounts 46% and 52% respectively. For the forecast period of thirty years (2006-2035), it can be seen that the trend of rainfall and runoff is insignificant. The dry year (with least rainfall) will occur in 2014 and wet year (with maximum rainfall) will occur in 2030.The runoff pattern follows rainfall but for the evapotransp i ration, there is no trend.The Trend analysis for the forecast period shows thatdischarge is slightly positive therefore in future; the water availability will decrease. Necessary steps should be taken for management of water resources in Minor Irrigation Project for its sustainability.The BMP scenarios havebeen studied in the cultivable area of the watershed by simulating two crops viz, wheat and rice with irrigation. The effects of vegetative filter strips (VFS) were also assessed. The results showed that sediment yield will increase with the application of irrigation and the 61 simulation of VFS tends to decrease sediment yield drastically. The comparison of SWAT simulated discharge and DPR of the project (Andherinala MIP) revealed that significant amount of flow is available during non-monsoon period as per SWAT simulation, while DPR shows no flow and cropping intensity has been put to the minimum (8%) during Rabi season. The cropping intensity thus can be improved. Furthermore, due to availability of significant amount of groundwater, conjunctive use can be given due consideration in the project area. Thinking seriously about from IPCC for the twentieth century (2020s) and additionally from the pattern investigation come about, changes in temperature has been set at T (-1°c) up to T (+1°c) and for precipitation were set to P (-5%) up to p (+5%) for the distinctive climatic affectability situation. These values have been received since in some cases compelling occasions have expanded in recurrence lately and are prone to press on to expand sometime to come. The estimate future atmosphere conditions were investigated utilizing the Special Report of Emission Scenario (SRES) by IPCC. Response of hydrological processes to the sensitivity scenario had variation in the water volume in the study Area. From this study, it is seen that the ground water and evapotranspiration is most sensitive to change in temperature, while ground water and total water yield is most sensitive to change in precipitation. Therefore this result of this study together with an integrated basin management is required to make a good decision making process in order to get the best environment condition to adjust meteorological phenomena in this water shed area.