Authors: Ashoke Basistha D S Arya N K Goel
Publish Date: 2007/12/18
Volume: 22, Issue: 10, Pages: 1325-1346
Abstract
Continuous rainfall data in grid format are required to run models for hydrological and agricultural research as well as water resources planning and management The present work attempts to prepare a normal annual rainfall map in Himalayan region of India lying in Uttarakhand state at 1 km spatial resolution which currently is not available In the region India Meteorological Department maintains observatories/raingauge stations and data from 44 stations were used in this study A comparative analysis of interpolation techniques like Inverse Distance Weighted Polynomial Splines Ordinary Kriging and Universal Kriging shows that Universal Kriging with holeeffect model and natural logarithmic transformation with constant trend having Root Mean Square Error RMSE of 3287 is the best choice This is followed by Ordinary Kriging RMSE 3291 Splines RMSE 3924 Inverse Distance Weighted RMSE 4098 and Polynomial Interpolation RMSE 4185 Cross validation of the results shows the largest over prediction at Tehri rainfall station 625 and largest under prediction at Nainital station −365 Physiographic zone wise the least errors occur in the plains and the largest in the Great Himalayas The spatial average rainfalls are 1472 mm for Terai/Bhabar 1782 mm for the Shivalik ranges 1591 mm for the Lesser Himalayas and 1635 mm for the Great Himalayan region The mean areal rainfall in the region is 1608 mm
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