Abstract:
Predicting accurately inflows into the reservoirs in order to
operate the dam Gates to safely release the floods in Indian rivers
has been a difficult task for the project engineers. Generally, the
flood water is released after the reservoir level reaches the danger
zone, causing man-made flood problem in the downstream of the
reservoir. One of the major constraints in developing forecast
model is the scarcity of climatic data and raingauge network. With
these limitations, the SCS-CN method developed by USDA is
suitable for predicting inflow into the reservoirs by using the
single model parameter “the Curve Number” and rainfall as input
to the model. In this study, the hydro-meteorological data
observed in Wainganga sub-basin of the Godavari river basin in
Madhya Pradesh has been used to develop of the SCS-CN based
rainfall-runoff model. In the SCS runoff model, the total rainfall is
separated into three components, viz. the initial abstraction, actual
retention after runoff begins and actual runoff. The SCS model
computes the runoff per storm basis. In India, generally the
rainfall is recorded on daily basis, i.e. during last 24 hours.
However, in reality there may be multiple storms of shorter
durations in a day or any storm may continue for more than one
day during the monsoon months. The observed rainfall and runoff
data have been used for development and validation of the flow
model under different watershed conditions, AMC-I, AMC-II and
AMC-III. The Direct Runoff computed from the model has been
used for comparison with the observed flow to check the
efficiency of the Rainfall-Runoff model. The results show good
correlation between the observed runoff and model runoff.
