Rainfall Runoff Analysis for a Compacted Area

Abstract

Rainwater harvesting is going to be the most applicable method for eliminating water scarcity and to meet the escalating demand. Hydrological analysis is unavoidable in any water harvesting structural designing. A study was done at KCAET, Tavanur to analyze the rainfall-runoff characteristics by selecting the college playground as the study area. Runoff for seven storms was measured and the runoff volume obtained was 9.13m 3 , 10.55 m 3 , 102.01 m 3 , 9.71 m 3 , 37.32 m 3, 11.45 m 3 and 9.22 m 3 respectively. A relation between discharge and corresponding head for the notch was calculated as Q = 0.7661H 1.4503 .The R 2 value obtained was 0.98. The runoff coefficient for the compacted study area was 0.12. Unit hydrograph from various storm hydrograph were derived and the unit hydrograph for the storm on P 1 and P 7 was considered for the derivation of representative unit hydrograph. A relation between rainfall and runoff was found out as Y = 0.201X – 0.8467 and the R 2 value was 0.98. From rainfall chart analysis, a relation between maximum intensity and duration was obtained as Y = 9.0029X–0.6986. The R 2 value was 0.9506.