Statistical analysis of flow for selected rivers in Pakistan

Since 1980 global climate change resulting from anthropogenic factors has gained widespread attention. An increase in greenhouse gases since the advent of machines using fossil fuels has caused global temperature rise. Consequently, the usual freshwater storage in the form of glaciers is not only depleting rapidly and causing flooding in the urban areas as well. The international response to the challenges posed by global warming and hence the climatic changes has involved extensive deliberations, technical studies, and political commitments
from governments on the future courses of action to arrest further changes and to cope with the potential adverse effects. The water crisis in Pakistan resulting from the recent dry years, most importantly in the southern part of the country has highlighted the importance of the changing climatic conditions. On the other hand, severe flooding has occurred in some years due to melting glaciers as a result of high temperatures. It is imperative to carry out a detailed analysis
of the surface and subsurface water resources in the country and proper management decisions made to prevent future shortages of water.
The main study area is a part of the Indus Basin in Pakistan. The Indus River is the main contributor (more than 60%) in sustaining agriculture in the country. The Indus Basin has approximately 863,508 km2 area and is major drainage of the northwest Himalayas and the Karakoram mountains. Because of global warming, the extent of snow cover is rapidly depleting which may affect the base flow of the river. The river water of the Indus is becoming insufficient to meet the country's growing needs as the uses of the water resources are interdependent. Thus, there is a need to use the resource efficiently and to build more storage to avoid floods and the wastage of water in the form of runoffs into the sea (Hussain et al. 2011). In an arid and semiarid region like Pakistan, sustainable water use in the domestic and agricultural sectors faces severe challenges under the changing climate, population growth, and higher living standards. According to an estimate, 10 years into the future, nearly 2.9 billion
people in 48 countries will face shortages of safe drinking water and Pakistan will be one of those countries with water scarcity (Watkins, 2006).
In the present study, a statistical analysis of historical flow data (from 1937 to 1996) of six rivers (Indus, Kabul, Jhelum, Chenab, Ravi, and Sutlej) in the Indus basin is carried out. Such data analysis will help to design storage facilities for mitigating future water scarcity. Moreover, the prediction of flows for various return periods is required for the design of flood protection structures, bridges, and channel improvements.