Scenario generation using geographical information system (GIS) based hydrological modelling for a multijurisdictional Indian River basin

Abstract

Lack of information about the futuristic scenarios of possible water allocations acts as a deterrent in resolving the conflicts pertaining to transboundary watercourses. It is increasingly being felt that technology, in the form of simulation modelling, has a very significant role to play in this context. For water resources engineering problem solving, geographical information system (GIS) offers a cognitive spatial representation of complex hydrologic and hydraulic systems. Of specific interest to decision makers is the capability of GIS to visually display information for interpretation of water resource model inputs and outputs, which enables users to take a more dynamic approach with data input, modification, scenario development, and evaluation (Martin et al., 2005). In the present study, GIS based hydrological modelling has been utilized for the purpose of assessment of the total amount of water available in the study area, as well as prediction of the impact of changes in the land management practices on the water availability in the study area, and consequently the amount of water allocated to each of the riparian states. The hydrological model used for the study is SWAT (soil and water assessment tool). The results of the study show that water yield of the basin is inversely proportional to the amount of forest cover. The study demonstrates that simulation modelling can play a very significant role in water resources management by generating a series of scenarios or options for the stakeholders, so as to enable them to take sound rational decisions. Key words: Geographical information system (GIS), hydrological modelling, soil and water assessment tool (SWAT), scenario generation.