News and Articles

The study gives a systematic methodology to determine field hydraulic conductivity using Guelph Permeameter (GP), its limitation based on the experiences gained in the field and a comparison of its results with that estimated from the predictive method for the soils in Central Bihar. Predictive methods applying empirical formulae are used to ascertain hydraulic conductivity from easily determined factors like bulk density, porosity and water content.

Physically based hydrological models, soil water balance, groundwater flow and transport models require values of saturated and unsaturated hydraulic conductivity to solve the sub-surface flow and transport equations. Several field, laboratory and predictive methods are available for determination of this parameter. However, these methods have some advantages and some limitations. GP is used as a tool to determine the field hydraulic conductivity even when the water table is low. It is portable, durable and allows rapid field calculation of saturated and unsaturated hydraulic conductivity.

The study estimates the average soil loss using the Geographic Information Systems (GIS) tool of Integrated Land and Water Information Systems (ILWIS) and the Universal Soil Loss Equation (USLE) methodology for the Hire nadi catchment, in Yelbarga taluk, Koppal district of Karnataka, under different conditions.  

Scientific planning for soil conservation and water management requires knowledge of the relations among factors that cause and prevent soil and water loss.  Controlled studies on field plots and small watersheds have supplied vital information regarding these complex factors and their interrelations.

The report presents the status of urban hydrology and highlights some of the hydrological problems related to urbanization in the world and in India. It covers a discussion on urban hydrologic cycle, hydrological and related problems of India, impact of urbanization on streamflow and urban water management. Some information on available urban hydrological models and the recommendations for the management of urban areas is also included.

The problems of urban hydrology have been of world concern for several years, but there have been few compilations of background information and even fewer comprehensive investigations of specific urban situations. The new information and data are of vital importance to the development of urban hydrology research in future.

This report is a compilation of the hydrological news in the print media in the country for the year 2000. The report is an attempt to put forth diverse hydrologic information and events reflecting the problems and indicate solutions for hydrologists, planners and water resource managers in particular. National newspapers like Hindustan Times, Indian Express and Hindu have been referred to, for tracking the Indian hydrological events due to flood, drought, quality, demand supply and availability.

The report details out the status of landfill and waste disposal technologies in India & abroad and reviews the scientific studies undertaken to support its design for long-lasting performance. Hydrological considerations play a major role in the selection of landfill sites and in the design and performance of landfills for hazardous waste management. A landfill is a form of a biochemical reactor where the municipal solid waste (MSW) comes into contact with moisture, a catalyst, and gets decomposed into solid waste, gases and liquid contaminants (leachate) resulting in the release of heat. The design of the control and recovery systems requires the estimation of amount and composition of gas and leachate accurately, as also the changes in these with time. Lysimeters are used to simulate the landfill performance.

The report presents a review of several aspects of non-point source of pollution, like extent and effects of pollution in surface and groundwater bodies, pollution control, monitoring, modeling and management options. Non-point source pollution originates from diffuse land areas that contribute pollutants to surface and groundwater bodies. Sediments, nutrients and pesticides are transported from croplands either in a dissolved form in runoff or through adsorption onto eroded soil particles. Apart from this it can also enter groundwater through leaching.  

The report presents a literature review on the status of research related to saltwater intrusion and groundwater management in coastal and deltaic environments in the east coast of South India. The area is typically characterized by highly productive and alluvial aquifers and high use of both surface as well as groundwater. Seawater intrusion into the freshwater aquifers is extensive due to increased pumpages.

A quantitative understanding of the patterns of movement and mixing between freshwater and saline water and the factors that influence these processes is stressed in the report. It presents the mechanics of saltwater intrusion through studies by Ghyben and Herzberg and later on by Hubbert. A comprehensive review of studies by Reilly and Goodman relating to saltwater intrusion is discussed. Later advances in understanding saltwater-freshwater relationship through numerical models like sharp interface model and miscible flow model are described.

The study assesses waterlogging in a canal command area in Rohtak and Jhajjhar districts through waterlogging area zonation using multi-spectral and multi-temporal imagery like IRS LISS III data of pre and post monsoon period. Seasonal and permanent waterlogged area and standing water were delineated on the basis of remote sensing data, digital elevation model and groundwater data.

The study develops regional flood frequency relationship and flood formulae based on recently developed efficient techniques of flood frequency analysis to estimate floods of desired return periods for small to moderate size gauged and ungauged catchments of the middle Ganga plains (sub-zone 1F) encompassing parts of Uttar Pradesh, Bihar and West Bengal. A regional flood formula has been developed by coupling the L-moment based regional flood frequency relationship with the regional relationship between mean annual peak flood and the catchment area.

The study assesses the suitability of groundwater for drinking and irrigation use and examines the likely impact of Yamuna river water quality on groundwater. Delhi is faced with severe problems associated with groundwater quality and quantity. The quality varies spatially and seasonally, with depth and is primarily governed by the extent and composition of dissolved solids present in it. Surface water bodies play a role and the hydraulic gradient determines the lateral and vertical migration in the groundwater flow system.

Groundwater samples were collected through extensive field surveys covering entire Delhi area representing various geo-hydrological and land-use conditions. The data has been analysed with respect to BIS and WHO standards to examine its suitability for various uses. The area has a peculiar feature of infiltration of surface water to groundwater from river Yamuna and from various drains.