Assessment of Temporal Changes in Streamflow Characteristics Across Cauvery River Basin

Abstract

Changes in freshwater water availability have been noticed across several river basins over the years due to climatic and anthropogenic influences. The current study investigates the changes in streamflow characteristics over a semi-arid river basin in South India, viz., Cauvery River basin (area ≈ 81,155 km2), using daily streamflow data. The data has been thoroughly checked for consistency and completeness. Several streamflow indices representing the magnitude, frequency, and duration of peak and low flow conditions are derived from the daily data at fourteen stream gauging stations in the Cauvery basin. The change point and trend in the streamflow indices are analyzed by non-parametric Pettitt's and Modified Mann–Kendall and Spearman's rho tests, respectively. A significant change point in total annual runoff was reported for three stations, while the extreme flows did not exhibit any change point. The results indicated a decrease in the water availability, peak as well as low flows in the basin across most stations. Such a decrease in water availability and low flows would aggravate the water stress conditions in the basin and have adverse impacts on the stream ecology. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.