National Institute of Hydrology (NIH)

The study on groundwater quality of Greater Guwahati analyses various trace elements in samples and ascertains that their concentration is much higher than the tolerance limit prescribed for drinking water. The trace element analysis focuses on metals such as Cu, Co, Cd, Fe, Zn and Pb.

Owing to the inadequacies of piped water supply, the Greater Guwahati area depends on groundwater from ringwells and tubewells for drinking purposes. Groundwater is mostly polluted from the effluents discharged by industries on land, seepage from sewage lines & tanks and application of pesticides on agricultural land. Due to the low flow velocity, groundwater once contaminated will remain so for longer periods. Metals assume significance because of their greater toxicity, accumulative and non-biodegradable behavior. 

The study attempts to find out the pollution potential in the Hindon river, a polluted river in western Uttar Pradesh. Qualitative and quantitative estimation of pesticides was done using gas chromatography. Among various organic, inorganic and biological water pollutants, pesticides are very dangerous and harmful because of their carcinogenic properties. Pesticides are bio-accumulative and relatively stable and therefore require close monitoring.

The hydrological study develops a water balance of the Lake Nainital to facilitate the utilization of its water in a planned and systematic manner. The lack of knowledge of input and output parameters such as subsurface inflow, use of lake water for domestic and industrial purposes, evaporation loss and leakage from lake including the outflow through sluice gates had created uncertainty in determining the availability of water in the lake. The study attempts to understand the behavior of the input and output parameters in detail by using both conventional and isotopic techniques.

The lake meets the local drinking and domestic water needs and is for the most part fed by rainfall during monsoon and by inflow from perennial springs and subsurface inflow during the non-monsoon season.

The study seeks to understand the problem of rainfall, particularly for identification of any trend or persistence in the rainfall series in the five districts of Sagar division of Madhya Pradesh. A statistical analysis of the rainfall pattern is conducted using World Meteorological Organization (WMO) recommended statistical techniques for climatological analysis. Besides studying the statistical parameters and cross correlation, other techniques like linear regression and polynomial regression have been applied to identify the presence of any trend. 

The study attempts to do a field and laboratory determination of soil moisture characteristics such as particle size distribution, hydraulic conductivity and soil moisture retention curve in a part of the Hindon river catchment and studies the variation of these along the river in its upstream reach.

The study attempts to develop a computerized model for Geomorphological Instantaneous Unit Hydrograph (GIUH) for estimation of flood hydrographs resulting from intermittent storms of varying intensity. The model applied to the rainfall-runoff data of the Myntdu-Leska basin of Meghalaya infers that the channel network and geomorphological features are closely related to the retention and discharge characteristics of the basin.

The theory of GIUH assumes that rainfall that occurs over a basin is assumed to be composed of infinite number of non-interacting drops of uniform size. After spending some time in one state in the channel or overland region, the drop makes transitions to another state to reach the basin outlet. Assuming one parameter, exponential time distribution of one drop chosen at random from the basin defines the IUH of the basin.

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.