The study undertakes hydrological land use mapping in Narmada basin from Jabalpur to Hoshangabad by using various methods right from empirical formulae to Soil Conservation Services Curve Number (SCS-CN) method for design discharge computations and continuous runoff modeling. The SCS Curve Number method is used to derive an empirical relationship of the catchment hydrological variables and based on this the dimensional unit hydrograph is prepared and continuous runoff modeling done.
The computations are done for a watershed in Narmada basin for 25, 50 and 100 years return period and a one-day design storm. The one-day duration rainfall depths for the above return period are 143mm, 161mm and 181mm respectively.
Land use mapping is done for a part of the Narmada basin from Jabalpur to Hoshangabad using satellite data of sensors WIFS and LISS III onboard IRS. GIS softwares, ILWIS and digital image processing software ERDAS are used in the study. Sequential clustering technique is applied. ILWIS software is used for computing of watershed physical properties such as length, area and slope. Curve Numbers are assigned to land use cover classes using land use cover map and collateral data on soils. A composite Curve Number is computed for a watershed in the Narmada basin for design runoff hydrograph computations.
The study observes that WIFS data was easier to handle due to less storage space and processing time as compared to higher resolution data from LISS II and LISS III sensors.
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