Estimation of Surface Runoff from Semi-arid Ungauged Agricultural Watershed Using SCS-CN Method and Earth Observation Data Sets

In the present study, Soil Conservation Service -Curve Number (SCS-CN) method, Earth Observation (EO) data sets and Geographic Information System (GIS) have been used in order to estimate the surface runoff from Jhagrabaria an agricultural watershed of Allahabad district, Uttar Pradesh (India). LANDSAT-7ETM+, NOAA data and hydrologic soil groups have been used to prepare land use/land cover, rainfall and soil map. The traditional SCS-CN method for calculating the composite CN is very tedious and time demanding process of the hydrologic modeling. Therefore, GIS is now being used in combination with the SCS-CN method. The outcome of work showed 79.35 (CNII) of normal condition, of dry condition 61.76 (CNI) and of wet condition 89.84 (CNIII), respectively. This investigation outline that ungauged watershed exhibits an annual average of 14 years runoff volume as 3.58 x 10(6) m(3) from an average annual rainfall of 14 years 110.77 cm and the average annual surface runoff of 14 years was 23.83 cm and annual average runoff coefficient of 14 years was 0.22. The correlation analysis suggests that the strong correlation as R-2 (0.91) was observed between satellite drive rainfall and runoff from SCS-CN method. The developed rainfall-runoff model for the region will be useful to understand the watershed and its runoff flow characteristics.