Footprints of climate change on hydrological behaviour of Jhelum, Upper Indus and Hunza river basins, Pakistan

Abstract

Background: Agriculture based economy of Pakistan is under the direct influence of climate change which can bring substantial changes in characteristics and magnitude of her water resources. Methods: This paper accords the spatio-temporal analysis of impact of climate change on four catchments of Indus, Hunza and Jhelum rivers basins. For this purpose, mix of approaches such as mean monthly analysis of hydro-meteorological variables, Pearson’s and Mann Kendall’s tests, investigation of flow duration curves (FDCs) and Inverse Distance Weighted (IDW) interpolation were used. Results: Results of the study illustrate that there is an increasing trend of winter warming and summer cooling in the studied basins. Discharge is positively controlled by temperature. This effect is more pronounced in case of minimum temperature. With increasing temperature glacier melt is accelerated so runoff is increased both in summer and monsoon seasons. Precipitation controls the magnitude of runoff in basins to a very small extent. In addition, shift in monsoon season owing to transition in temperature and precipitation have been also observed. Examination of flow deviation recommends the availability of maximum discharge during June-September i, e., 79% at Kachura, 75% at Besham Qila, 80% at Dainyor and 53% at Domel. Flow duration curves of the twenty years (1993-2013), report the persistence of flow 22%, 20%, 17% and 7% of time above their respective means at Kachura, Besham Qila, Hunza and Domel. Conclusion: Modification in water resource management in agriculture, irrigation, power and disaster control sectors is strongly felt to cope the challenges of climate change.