Climatic changes and its influence on the runoff data over a major river basin in india – a case study

Abstract

Climate change has profound effect on various environmental variables including rainfall-runoff processes in many regions around the world. The changes in rainfall-runoff characteristics directly impact hydrology, water resources management, agricultural practices and the ecosystems. Therefore, it is vital important to investigate the spatial and temporal runoff characteristics to facilitate better water management practices and strategy. In this study, nonparametric statistical methods, namely Mann-Kendall Rank Correlation (MK) method is employed to test the existence of trends in average annual and monthly maximum, and minimum runoff data in the Tel river basin of Mahanadi river basin in Orissa, India. There is an increase in the non-monsoon runoff in the observed discharge station, signifying the potential of longer drought spell and the importance of better water management practices in the future. Changes in the monthly and annual surface runoff of the Mahanadi river basin in India are analyzed and presented in this paper. The trends in the important climatic elements are evaluated by linear trend analysis. The results indicate that there is a significant uptrend in the non-monsoon means monthly and maximum discharge values in the basin based on data from rain gauges – discharge stations for the period 1971-2008. Results of the trend analysis of the stations are presented and discussed. Increase in greenhouse gases in the atmosphere over India, recent land-use pattern changes and agricultural practices in the region appear to have a bearing on the observed trend.