Spatial and Temporal Variation of Impacts of Climate Change on the Hydrometeorology of Indus River Basin Using RCPs Scenarios, South East Asia

Abstract

In this study we assessed the spatio temporal impacts of climate change on the hydrometeorology of Indus River basin. A 0.5 by 0.5 degree resolution data of Coupled Model Intercomparison Phase5 (CMIP5) global climate models (GCMs) output of precipitation and temperature (maximum and minimum) and VIC (Vertical Infiltration CapacityMacroscale hydrological model) simulation results of evaporation and total runoff at the out let of the Arabian peninsula for 2030`s (2035-2064) and 2070`s (2071-2100) under (Representative Concentration Pathway) RCP 4.5 and RCP 8.5 emissions scenarios used. Arc GIS 10.2 extension of ordinary kriging Geostatistical interpolation techniques applied for spatial analysis of precipitation, temperature (maximum and minimum) and evaporation for the River basin. Future projection results as compared to the base period (1971-2005) showed that the, average multimodal monthly precipitation decreases during winter and, spring months and increases during summer months, ranging in between -25% and +43%. Average seasonal spatial precipitation changes resulted various ranges of precipitation distribution for 2070`s of RCP 4.5, average seasonal precipitation decreases in the mid part of the basin up to -20%. Average temperature increase for both future periods (2030`s and 2070`s) and RCPs (RCP 4.5 and RCP 8.5) emission scenarios, maximum temperature change observed in the Himalayas Mountains. All GCMs except MPI projected increase of future average annual evaporation. Average Multimodal GCMs projection results showed that the, average monthly runoff increases more during summer than winter. The increase of runoff at the downstream flow is as a result of snow and glacial melt at the high elevation regions of the Indus River basin. The increase of runoff flow probably has positive impacts in meeting the water requirement of small scale irrigation schemes. Moreover, water can be stored in a reservoir during summer season and distributed to arid areas of the basin. Due to the increased amount of flow during summer, there may be high chance of flooding in plain areas of the basin, therefore a precaution measure have to be taken in order to minimize the possible risks of flooding on agricultural and human welfare of the society