Multi-Basin Modelling of Future Hydrological Fluxes in the Indian Subcontinent

Ilias Pechlivanidis,Thomas Bosshard,Jonas Olsson,K.C Sharma,Devesh Sharma

doi:10.3390/w8050177

Ilias Pechlivanidis, Thomas Bosshard + Show 3 more

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https://doi.org/10.3390/w8050177

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Abstract

The impact of climate change on the hydro-climatology of the Indian subcontinent is investigated by comparing statistics of current and projected future fluxes resulting from three RCP scenarios (RCP2.6, RCP4.5, and RCP8.5). Climate projections from the CORDEX-South Asia framework have been bias-corrected using the Distribution-Based Scaling (DBS) method and used to force the HYPE hydrological model to generate projections of evapotranspiration, runoff, soil moisture deficit, snow depth, and applied irrigation water to soil. We also assess the changes in the annual cycles in three major rivers located in different hydro-climatic regions. Results show that conclusions can be influenced by uncertainty in the RCP scenarios. Future scenarios project a gradual increase in temperature (up to 7 °C on average), whilst changes (both increase and decrease) in the long-term average precipitation and evapotranspiration are more severe at the end of the century. The potential change (increase and decrease) in runoff could reach 100% depending on the region and time horizon. Analysis of annual cycles for three selected regions showed that changes in discharge and evapotranspiration due to climate change vary between seasons, whereas the magnitude of change is dependent on the region’s hydro-climatic gradient. Irrigation needs and the snow depth in the Himalayas are also affected.

Highlights

Climate change impacts can be complex in regions which are subject to other environmental and socio-economic changes, i.e., population growth, urbanization, land use change, and change in industrial and hydropower sectors [1]
The region is characterised by a strong hydro-climatic gradient due to the monsoon and the geographic features; posing extraordinary scientific challenges to understand, quantify, and predict future availability of water resources
The NSE and RE for all calibration and evaluation stations and periods are presented in Overall, the India-HYPE model achieved an acceptable performance for our purpose and is, considered adequate to describe the dominant hydrological processes in the region

Summary

Introduction

Climate change impacts can be complex in regions which are subject to other environmental and socio-economic changes, i.e., population growth, urbanization, land use change, and change in industrial and hydropower sectors [1]. India is a developing country with nearly two-thirds of the population depending directly on the climate- and water-sensitive sectors. The country already faces high risks of water shortages due to population growth, urbanization, and increasing demands in the agricultural, industrial, and hydropower sectors; India offers a unique opportunity to examine the impacts of climate change, which in some areas have already been observed [2,3,4]. Of particular interest are the Northern Indian Himalayan plains given the sensitivity of snow and glacier melt processes to climate variability and change [5,6,7]. Arid and semi-arid regions might experience changes in their hydrological cycle [8,9]

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