Experimental Verification of the Effect of Slope and Land Use on SCS Runoff Curve Number

• Published in: Water resources management Vol. 28; no. 11; pp. 3407 - 3416
• Main Authors: Mishra, S. K, Chaudhary, Anubhav, Shrestha, Raj Kaji, Pandey, Ashish, Lal, Mohan
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer-Verlag 01.09.2014; Springer Netherlands; Springer; Springer Nature B.V
• Subjects: Atmospheric Sciences; Civil Engineering; corn; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Environment; Exact sciences and technology; Falling; Geotechnical Engineering & Applied Earth Sciences; Handbooks; Hydrogeology; Hydrology; Hydrology. Hydrogeology; Hydrology/Water Resources; Investigations; Land use; Loam soils; Rain; Resource management; Runoff; Slopes; Soil (material); Soil conservation; Soil erosion; Studies; Sugarcane; sugarcane soils; Water resources; Water resources management; Watersheds; Zea mays; Asia; India; Curve number; Slope adjusted CN; Direct surface runoff; SCS-CN method; Experimental verification of CN; models; efficiency; rainfall; runoff; rain water; drainage basins; land use; water resource management; soils; methodology
• ISSN: 0920-4741; 1573-1650
• DOI: 10.1007/s11269-014-0582-6

The present study investigates experimentally the effect of watershed (i.e. field plot of 22 m × 5 m) slope on rainfall-generated runoff and, in turn, the runoff curve numbers (CN) resulting from field plots (with land use of maize and sugarcane on the soil falling in Hydrologic Soil Group C) located in Roorkee, (India). The results indicated that the plot of 5 % slope yielded the largest runoff and, in turn, CN compared to those due to the plots of 3 and 1 % grades, for the same rainfall, soil, and land use. The CN derived from the present study were quite close to the NEH-4 CN-values, indicating satisfactory match between the two. The use of slope adjusted CN-values in the standard CN method significantly (at 5 % level) improved the otherwise underestimated large runoff events, i.e. model efficiency E improved from 0.47 to 0.78, and R² from 0.71 to 0.83.