ESTIMATION OF ACTUAL EVAPOTRANSPIRATION USING MAPPING EVAPOTRANSPIRATION AT HIGH RESOLUTION USING INTERNALIZED CALIBRATION (METRIC) MODEL UNDER VARIABLE CLIMATIC CONDITIONS IN PESHAWAR BASIN, PAKISTAN

Abstract

Evapotranspiration (ET) plays a major role in maintaining water balance and studying its spatial and temporal variations. It helps in irrigation planning and water resource management. It is very difficult to measure ET in field, and is estimated by indirect methods. Satellite remote sensing data in this respect is helpful for estimation of ET at large scales. In this study, the actual evapotranspiration was estimated using METRIC model employing Landsat 5 TM, Landsat 8 and meteorological data in Peshawar basin for time period 1998-2000 and 2009-2013. The land use land cover classification was carried out for the basin using ISODATA clustering. The model was validated against the reference ET calculated using FAO-56 Penman-Monteith equation and the estimates agreed well with R2 = 0.70. The ET of tehsils were calculated by overlaying tehsils boundary and the ET of agricultural land use was also calculated.