Modelling surface run-off and trends analysis over India
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- 作者：P K Gupta ; S Chauhan ; M P Oza
- 关键词：Run ; off ; curve number ; Mann–Kendall test ; medium river basin.
- 刊名：Journal of Earth System Science
- 出版年：2016
- 出版时间：August 2016
- 年：2016
- 卷：125
- 期：6
- 页码：1089-1102
- 全文大小：3,360 KB
- 刊物类别：Earth and Environmental Science
- 刊物主题：Earth sciences
- 出版者：Springer India
- ISSN：0973-774X
- 卷排序：125
文摘
The present study is mainly concerned with detecting the trend of run-off over the mainland of India, during a time period of 35 years, from 1971–2005 (May–October). Rainfall, soil texture, land cover types, slope, etc., were processed and run-off modelling was done using the Natural Resources Conservation Service (NRCS) model with modifications and cell size of 5×5 km. The slope and antecedent moisture corrections were incorporated in the existing model. Trend analysis of estimated run-off was done by taking into account different analysis windows such as cell, medium and major river basins, meteorological sub-divisions and elevation zones across India. It was estimated that out of the average 1012.5 mm of rainfall over India (considering the study period of 35 years), 33.8% got converted to surface run-off. An exponential model was developed between the rainfall and the run-off that predicted the run-off with an R2 of 0.97 and RMSE of 8.31 mm. The run-off trend analysed using the Mann–Kendall test revealed that a significant pattern exists in 22 medium, two major river basins and three meteorological sub-divisions, while there was no evidence of a statistically significant trend in the elevation zones. Among the medium river basins, the highest positive rate of change in the run-off was observed in the Kameng basin (13.6 mm/yr), while the highest negative trend was observed in the Tista upstream basin (−21.4 mm/yr). Changes in run-off provide valuable information for understanding the region’s sensitivity to climatic variability.