THE IMPACT OF CLIMATE CHANGE ON STREAM FLOW

Abstract

Climate change as triggered by global warming is likely to significantly impact water resources and also the human life. As a result of global warming, snow is likely to melt at accelerated rates in many parts of the world, resulting in increased flow of rivers and rising sea levels. Extreme climate may cause increased flooding and drought in various regions. Increased flood and drought are causing many problems in human life and the decline in water quality. A large number of hydrologic models have been developed to simulate the response of a catchment. Among the various model types, physically based distributed model are the best to study the impacts of climate and land use changes. Geographic information systems (GIS) and model—GIS interfaces aid in efficient creation of input data files required by such models as well as display/presentation of results. One such model widely used by water resources professionals is the Soil and Water Assessment Tool (SWAT). SWAT is a river basin or watershed scale model developed to predict the impact of climate and land management practices on water, sediment, and agricultural chemical yields in large, complex watersheds with varying soils, land use, and management conditions over long periods of time. The study was aimed to evaluate the impact of climate change on stream flow in the Wonogiri catchment and on hydropower generation. The study was conducted using 20 years of records (1984-2003) of climate variables and 10 years (1994-2003) of discharge. SWAT calibration was performed for the period of 1994 through 1999, while the data for the period 2000-2003 was used for validation. Mann-Kendal statistical method was used in this study to do trend analysis and this together with IPCC (2007) recommendations for South-East Asia were used to create future climate scenarios. Two type of scenarios were conducted: corresponding to the maximum change and the minimum change in precipitation and temperature...