Assessment of human-induced impacts on hydrological regime of Gomti river basin, India

摘要

Purpose - The purpose of this paper is to evaluate the potential impact of human-induced intervention on hydrological regimes of Gomti river, one of the important tributaries of the Ganga Alluvial Plain in India aiming at an overall assessment of the status quo. Design/methodology/approach - The research methodology includes following four components: study of basin morphology, sub-surface geology and sediments profile of Gomti river; a comparison of LANDSAT satellite data of 1978 and IRS-1C/LISS-III satellite data of 2008 to study the changes occurring in the built-up area, forest and water bodies of the basin; study of flow patterns in different stretches of river Gomti from 1978 to 2012; and water quality assessment at different sites from origin of the river to its confluence in the Ganges. Findings - The paper shows that over the years, the water source in the tributaries feeding the river Gomti has shrunk, reducing the flow in the river. A steady increase in developed land area due to rapid urban sprawl has occurred in recent decades, due to which forest cover and wetlands are decreasing, the river and floodplains are getting fragmented, the hydromorphology changed considerably and several tributaries are getting dried as a result of indiscriminate exploitation of groundwater. There is no flow in the initial 57 km stretch of the river with wide encroachment in active floodplains. Groundwater over-extraction to meet the demands of increasing population and intensive agriculture has led to reduction in base-flows and in some reaches even negative. Extensive land-use changes in the Gomti river basin (GRB) severely impact the river and floodplain connectivity, the impacts are already evident as several tributaries are getting dried during the non-monsoon months. Research limitations/implications - The information provided by the paper for GRB is significant for the understanding of the basin and to formulate integrated management and development plan of the basin. Significant changes have taken place in the GRB over the recent past and are still continuing. Because of the chosen river basin and the site-specific research approach, the research results may lack generalization. However, it provides a general framework of analysis which could be applied to other regions. Practical implications - River channels with their floodplains and adjoining ecosystems have to be addressed as interconnected ecological entity in a holistic way. This requires comprehensive observations of the river systems and catchment characteristics using long-term data. The paper could be used as the starting point in the development of management and development strategies for the basin. Originality/value - River and its floodplain offer multiple ecosystem services and deserve an integrated approach for their conservation and restoration. Conservation and protection of ecologically intact river-floodplain systems is extremely important and urgently needs integrated planning and management. This paper has adopted a integrated approach to study the integrity of river ecosystems and the potential pressures on them.