http://117.252.14.250:8080/jspui/handle/123456789/6898 2026-04-05T23:28:52Z 2026-04-05T23:28:52Z National Institute of Hydrology http://117.252.14.250:8080/jspui/handle/123456789/6904 2022-07-04T21:39:40Z 2010-01-01T00:00:00Z

Title: Contents Authors: National Institute of Hydrology

2010-01-01T00:00:00Z Gopal, Brij http://117.252.14.250:8080/jspui/handle/123456789/6903 2022-07-04T21:38:55Z 2010-01-01T00:00:00Z

Title: 1-Ecohydrology - The Concepts its Development and Application. Authors: Gopal, Brij Abstract: Ecohydrology is a new emerging interdisciplinary science that deals with the interface between hydrology and ecology and seeks to focus on the role of ecological processes in modeling the hydrological processes and vice versa for better water resources management. It draws heavily upon the concepts and theories of aquatic ecology developed during the past fifty years and hence, is also considered synonymous with hydro ecology or aquatic ecology. Though a clear definition and scope are still being debated, the rapidly growing interest in this new field, despite its growth into different directions, holds great promise for the sustainable management of water resources and finding solutions to problems such as those of concerned with environmental flows and water quality degradation. It requires the development of synergies between hydrologists and ecologists working on the scales of landscapes as well in aquatic environments.

2010-01-01T00:00:00Z Ranade, Ashwini A. Singh, Nityanand Singh, H. N. http://117.252.14.250:8080/jspui/handle/123456789/6902 2022-07-04T21:35:44Z 2010-01-01T00:00:00Z

Title: 2-Effect of La Nina-El Nino on Climatic Fluctuations over Major Hydro-ecozones Across India. Authors: Ranade, Ashwini A.; Singh, Nityanand; Singh, H. N. Abstract: During boreal summer, the troposphere over southern hemisphere is warming at a faster rate compared to that over northern hemisphere, and the intensity of the general atmospheric as well as the Asian-Indian monsoon circulation shows decreasing trend. Over the equatorial central and eastern Pacific (Nino region), the easterlies are weakening and the SSTs rising, and there is a tendency for occurrence of frequent and intense El Nino than La Nina. Rain-producing weather systems (convergences) are frequent and intense along the western Indian subcontinent, and weaker and infrequent over Indo- Gangetic plains, central India and Bay of Bengal. Consequently, monsoon rainfall is somewhat subdued over Indo-Gangetic plains and central India. The La Nina-El Nino phenomenon provides vital information for extreme rainfall activities across India. To understand effect of the phenomenon on the hydro-ecosystems of the country, difference between La Nina and El Nino years in the parameters of the hydrological wet season (HWS), summer monsoon and wet-dry spells over major/minor/sub-basins have been examined. During El Nino years, climatic condition is considerably adverse over almost the entire hydro-ecosystems across the country compared to that during La Nina years.

2010-01-01T00:00:00Z Arora, Manohar Kumar, Rakesh http://117.252.14.250:8080/jspui/handle/123456789/6901 2022-07-04T21:29:39Z 2010-01-01T00:00:00Z

Title: 3-Environmental Flow Requirement and its Assessment. Authors: Arora, Manohar; Kumar, Rakesh Abstract: Environmental flow refers to the water considered sufficient for protecting the structure and function of an ecosystem and its dependent species. This means enough water is left in our rivers, which is managed to ensure downstream environmental, social and economic benefits. So, environmental flow is compromise between the development and the ecology of the river. Environmental flow assessment is required to be done in order to understand the natural flow regime of the river which is required to exist for the sustainability of the ecosystem. The two broad categories of the environmental flow assessment are the detailed environmental flow assessment method and the desktop environmental flow assessment method. Both the methods are further divided into several categories out of which it is the Desktop Analysis that is used mostly. All the methodologies still needs some modifications as these methodologies are not global and are data intensive. In India previously it was the Tennant Method of environmental flow assessment that was used for the computation of environmental flow requirement but in recent years, the Desktop Reserve Model, Flow Duration Curve Analysis and Hydrological Analysis is also made use of. Sound environmental flow management hedges against potentially serious and irreversible damage to freshwater ecosystems from climate change impacts by maintaining and enhancing ecosystem resiliency. Progress has been made, but much more attention is needed. Several governments have instituted innovative water policies that explicitly recognize environmental flow needs. Environmental flow needs are increasingly being considered in water infrastructure development and are being maintained or restored through releases of water from dams, limitations on groundwater and surface water diversions, and management of land use practices. Even so, the progress made to date falls far short of the global effort needed to sustain healthy freshwater ecosystems and the economies, livelihoods, and human wellbeing that depend upon them,

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