DEVELOPMENT OF SIMULATION PROTOCOL TO ASSESS SPATIAL VARIABILITY OF RAINFALL DISTRIBUTION AT WATERSHED Scale

Abstract

newline The spatial variability of rainfall across Huti-2 (43,035 ha) and Machkula (45,440 ha) newlinewatersheds situated in two neighboring sub catchments of river Krishna basin are newlinedistinguishable from the perspective of shape both (elongated), relief ratio (0.36 and 0.28), newlineand interms of rainfall pattern (event depth and numbers) and their distribution as a result of newlinechanging stream network properties and spatial morphological limitation. The kriging newline(ordinary) with circular model as a geospatial interpolative technique used to delineate newlineoptimal radial zones of equitable distribution of events both interms of numbers and depth newline(mm) from the network of existing rainfall stations of these study watersheds of Huti-2: newline4D7B3 (14 No) and Machkula: 4D5B3 (22 No), situated at the difference of 1 degree 27 min newlinelatitude. The study distinguished the events into smaller (15 and 30 minutes), medium (45 newlineminutes to 1 hour 45 minutes) and that of longer duration (and#8805; 2 hours) during the period newline(2014-2020) while driving statistical inference of the variability and their weighted influence. newlineThe different duration of events as against recurring numbers have station the power newlinefunctional relation (y = 90.38x-1.81) and (y = 122.1x-1.80) with a good agreement (R2 newline0.95) in newlinecase of both Huti-2 and Machkula watershed respectively. The study (numbers and depth) newlinereveals that across all the existing gauging station of both the watersheds, independently newlinerepresentativeness of a particular rain gauge station would be at its best (R2 newlinegt0.8) for radial newlinezone with radius of 3 km in case of Huti-2 and 4 km in case of Machkula watershed. The newlineincremental increase of radial distance pertaining to each gauging station with a stretch newlinebeyond 3 km would be reducing the reliability (R2 newline=0.6-0.8) by a margin of 20 per cent. newlineSimilarly in case of Machkula the same result would be for beyond 4 km (R2 newline=0.6-0.8).The newlineplacement of optimal number of gauging stations and their relative location within the newlinewatershed area can be counted upon selecting radial influencin