Hydro-meteorological Characteristics of Indus River Basin at Extreme North of Pakistan

Abstract

This paper presents the impact of climate change on three tributaries of Indus River, in four gauge stations, situated in the extreme North of Pakistan i.e. Himalaya, Karakoram and Hindukush ranges. The analysis revealed that change in temperature has a profound influence on the snow/glacial melt in comparison to the mean monthly rainfall. This is because majority of the northern area rivers are faded by the snow and glacial melt and receive a lot of snowfall from winter (Dec-Feb) to pre-monsoon (April-May). In studied rivers 21% of the times the discharge rate remain above the mean in the monsoon period (Jul-Sep), while 64% of the time the discharge is less than the mean in the pre-monsoon (April-May) period. It means that 15% of the time the discharge is in access of 200 to 500% of the mean flow, indicating that a rise in water yield and river discharge rate due to increase in mean monthly maximum temperature. Higher water contribution rate was found in Astor and Indus/Skardu rivers with significant differences compared to other studied rivers.In monsoon period approximately 20% discharge rate was recorded with mean monthly maximum temperature (32°C) and rainfall (17 mm). In pre-monsoon period the discharge rate was (9%) at mean monthly maximum temperature (26°C) and highest mean monthly rainfall (32 mm). This shows that the transfer of climate change signals into hydrological changes is more significant and consistent among the studied rivers. Our findings are useful for hydropower, agriculture, watershed management sectors in the future planning. In countries like Pakistan, water resources estimation under climate change scenario is important for planning especially in dry season for sustainable food security and for operation of hydrological installations regarding electric power crisis.