FOCUS: WATER AND ENVIRONMENTAL MANAGEMENT 

Project: Assessment of the Impact of Man-made modifications on the Varahi River Basin, Karnataka

Funded by: Department of Science and Technology, New Delhi

Duration:

Rivers are drying up at an alarming rate with devastating consequences for humanity, animals and the future of our planet. Water abstraction due to changing land usage patterns, sand mining and tourism in catchment areas, resulted in degraded water sources, vanishing tails, silted river beds, shrinking river channels and river courses running dry. Unfortunately, this is the case with many Indian rivers too.

The construction of dams or other water holding structures in a riverine ecosystem abruptly alters many physical and biological processes. To assess the influences of land usage and the effects of impoundments on the river system, measurements of possible variations in resources along the river course as well as upstream changes in natural conditions need to be considered. Despite several studies on human interventions on hydrological systems, in form of dams, roads, etc., much data is not available on Indian River Basins. It is of essence to quantify and illustrate the current status of hydrological alterations in River Basins in order to identify inconsistencies in data and find ways to improve the quantification of water resources.

The proposed study measures and evaluates the changes in water resources as a function of cumulative impacts of human interference. Further, the type, magnitude and direction of hydrological shifts, due to impoundments and other man-made alterations, in the river's catchment will be documented. A model study at the Varahi River Basin Dakshina Kannada will be carried out using data on hydrological, meteorological and other parameters, which are available from secondary sources as well as the public domain.

The impact of hydrological shifts is studied using remote sensing (RS) and geographic information system (GIS) techniques together with hydro-meteorological data, to derive the status and trend in the stream flow / sediment response. Essentially, this study will create an understanding of various parameters and how they act together to define the hydrology of the River Basin. The role of human interventions over the past few decades, upon land and water resources, primarily upon features such as trends, constraints and perspectives in the river, will be documented. There is a notable absence of suitable information on the nature and magnitude of various human impacts on the river regime.

Thus, the proposed project work will address this knowledge gap, serving as a tool for large scale planning and forecasting. The conduct of this initiative and additional studies the like at different parts of the globe are required to generalize the impacts of changes in the river. Planners, land managers and researchers can use the knowledge generated to address a range of issues relating to our land and water resources and the impacts of human activity on the environment.