Hydro-climatic aspects of Indus River flow propagation

Abstract

One of the world's largest irrigation networks of Pakistan is based onIndus River System.These networksface serious scarcity of water in 1 year, and agricultural land de- structive disastrous floods in the other. To understand the physical basis of statistical variations in space and time in the river flow, this study assesses the reasons governing the system. Therefore, time series analysis of the mean monthly river flow data is performed. The results show strong linear and seasonal behaviour among the river flow of each station. However, the river is regularly energised by the melting of snow/glaciers, and in the monsoon seasons, it experiences strong control by orographic rainfall. On several occasions, the Indus River shows unpredictable disturbances in its usual natural seasonal characteristic flow and their propagation along the network. Therefore, owing to linear, seasonal and monsoonal behaviours, it is expected some contribution of two major local climatic parameters on the river flow. To examine these relations, this paper analyse sum of monthly precipitation and mean monthly temperature with the mean monthly river flow of each station along the Indus River. The real time impact shows that the temperature is more in- fluential at early stations of the Indus River, whereas the rain- fall is more affective in case of middle stations. However, the temperature and rainfall display opposite impacts to the river flow at 1-month delay time lag along the Indus River and it explores that the lower three stations river flows are more influential with precipitation than the temperature.