Author(s): Waqas Ul Hassan; Frank Seidel; Irina Klassen; Franz Nestmann; B. Muhammad Khurram Shahzad
Linked Author(s):
Keywords: Climate change; Suspended sediment concentration; Upper Indus Basin; Trend analysis; Tarbela dam
Abstract: In the Upper Indus Basin (UIB), to assess the long-term climate change impact on flows and suspended sediment concentration (SSC), Mann Kendall trend test, Spearman’s rank test and Pearson Correlation tests were used with climatic parameters. The Upper Indus Basin has been gauged since 1960 to measure flows and suspended sediment concentrations. The present study focuses on the assessment of impact of climate change on SSC in Upper Indus Basin. The Tarbela dam is the world largest earth-fill reservoir and was constructed on the Indus River in 1976. Today the dam is facing the challenge of loss of storage capacity due to siltation within the reservoir. This study assesses the past 31 years trends from 1980 to 2010 in terms of flows and SSC on 13 gauging stations in UIB. The available dataset consists of the instantaneous (discontinuous) values of flows and SSC measured on same dates with frequency of once after every week during high flow seasons and once after 2 to 3 weeks during low flow seasons. For climate change assessment total monthly rainfall and averaged air temperatures from 1980-2010 were calculated from daily rainfalls and daily maximum and minimum temperatures datasets respectively. The changes in SSC due to climate change in the four sub-basins: upper basins (Gilgit, Astore) and lower basins (Brandu, Gorband) have been evaluated and assessed over monthly, seasonal and annual basis. Statistical Mann Kendall test and Sens slope estimation method were used for the investigation of variability in flows, SSC and climatic parameters. The correlation coefficients between the parameters of SSC/flows vs. rainfall/mean air temperatures were assessed with the use of Pearson Correlation test and Spearman’s rank test.
DOI: https://doi.org/10.3850/978-981-11-2731-1_372-cd
Year: 2018