Climate change and hydrological regime of the high-altitude Indus basin under extreme climate scenarios

Zakir Hussain Dahri; Fulco Ludwig; Eddy Moors; Shakil Ahmad; Bashir Ahmad; Sarfraz Ahmad; Muhammad Riaz; Pavel Kabat

doi:10.1016/j.scitotenv.2020.144467

Climate change and hydrological regime of the high-altitude Indus basin under extreme climate scenarios

Sci Total Environ. 2021 May 10:768:144467. doi: 10.1016/j.scitotenv.2020.144467. Epub 2021 Jan 2.

Authors

Zakir Hussain Dahri¹, Fulco Ludwig², Eddy Moors³, Shakil Ahmad⁴, Bashir Ahmad⁵, Sarfraz Ahmad⁵, Muhammad Riaz⁶, Pavel Kabat⁷

Affiliations

¹ Water Systems and Global Change, Wageningen University and Research, the Netherlands; Pakistan Agricultural Research Council, Islamabad, Pakistan. Electronic address: zakir.dahri@wur.nl.
² Water Systems and Global Change, Wageningen University and Research, the Netherlands.
³ IHE Delft Institute for Water Education, Delft, the Netherlands; Earth and Climate Cluster, VU University Amsterdam, the Netherlands.
⁴ NUST Institute of Civil Engineering, National University of Science and Technology, Islamabad, Pakistan.
⁵ Pakistan Agricultural Research Council, Islamabad, Pakistan.
⁶ Agricultural Department, Government of Punjab, Pakistan.
⁷ Water Systems and Global Change, Wageningen University and Research, the Netherlands; World Meteorological Organization, Switzerland.

PMID: 33454464
DOI: 10.1016/j.scitotenv.2020.144467

Abstract

Climate change is recognized as one of the greatest challenges of 21st century. This study investigated climate and hydrological regimes of the high-altitude Indus basin for the historical period and extreme scenarios of future climate during 21st century. Improved datasets of precipitation and temperature were developed and forced to a fully-distributed physically-based energy-balance Variable Infiltration Capacity (VIC) hydrological model to simulate the water balance at regional and sub-basin scale. Relative to historical baseline, the results revealed highly contrasting signals of climate and hydrological regime changes. Against an increase of 0.6 °C during the last 40 years, the median annual air temperature is projected to increase further between 0.8 and 5.7 °C by the end of 21st century. Similarly, a decline of 11.9% in annual precipitation is recorded, but future projections are highly conflicting and spatially variable. The Karakoram region is anticipated to receive more precipitation, while SW-Hindukush and parts of W-Himalayan region may experience decline in precipitation. The Model for Interdisciplinary Research On Climate version-5 (MIROC5) generally shows increases, while Max Planck Institute Earth System Model at base resolution (MPI-ESM-LR) indicates decreases in precipitation and river inflows under three Representative Concentration Pathways (RCPs) of 2.6, 4.5 and 8.5. Indus-Tarbela inflows are more likely to increase compared to Kabul, Jhelum and Chenab river inflows. Substantial increase in the magnitudes of peak flows and one-month earlier attainment is projected for all river gauges. High flows are anticipated to increase under most scenarios, while low flows may decrease for MPI-ESM-LR in Jhelum, Chenab and Kabul river basins. Hence, hydrological extremes are likely to be intensified. Critical modifications in the strategies and action plans for hydropower generation, construction and operation of storage reservoirs, irrigation withdrawals, flood control and drought management will be required to optimally manage water resources in the basin.

Keywords: Climate change; GCM projections; High-altitude Indus basin; Hydrological extremes; Hydrological regime.