National Institute of Hydrology (NIH)

The study undertakes an exhaustive survey of the morphometric features of the Mansar lake, Udhampur district to prepare a bathymetric map of the lake. The map is useful in understanding the lake hydrological behavior through a study of volume, sedimentation rate and identification of the high siltation zone. The study is significant as the lake water can be utilized for drinking and irrigation purposes for the water scarce Kandi belt of Jammu.

The study prepares a landuse and landcover map of Devak catchment of Ujh river basin in Jammu for the years 1958, 1979, 1990 and 1998 using image processing and visual interpretation techniques. It involves analysis of IRS-1A L2B2 (FCC) data for the year 1990, IRS -1C LISS III (digital data) for the year 1998 and SoI topographic maps for the year 1958 and 1979.

The study applies a simple five-parameter model based on the concept of probability distributed method as proposed by Moore (1985) to simulate the daily runoff over a nine-year period of 1989-1997 at Tamavaram in Prakasham district of Andhra Pradesh on the Gundlakamma river.

The study suggests a procedure based on the methodology of Gustard et al (1992) for estimation of baseflow index (BFI) using the mean daily discharge data over a period of 4 to 6 years for three rivers between the Mahanadi and Godavari deltas. The rivers from the Zone 4 (A) are Rushikuliya at Purushottampur in Orissa, Nagavalli at Narayanpuram wier and Sarada at Anakapalli in Andhra Pradesh.

The study presents the spatial analysis of groundwater levels and its quality for the year 1998 for Kakinada town in coastal Andhra Pradesh. The Deltaic Regional Centre of NIH has been monitoring groundwater levels and its quality in and around Kakinada town since 1994. Groundwater samples have been analyzed for physical and chemical parameters. The variation in each parameter is discussed in the report.

A total of 164 samples were collected from 41 observation wells during the months of February, May, August and November 1998. The area covered by these observation wells is around 82 sqkms. The groundwater table contours were plotted for pre-monsoon (May 98) and post monsoon (November 98) periods and the approximate flow direction had been demarcated.

The study defines the climatic regions in terms of readily available climatic parameters like ratio of mean annual precipitation to global terrestrial mean annual precipitation and ratio of mean annual potential evapotranspiration to mean annual precipitation (Ep/ Pa).

The study focuses on the drought characteristics of the sub-humid climatic regions across different parts of the country. It establishes that the drought frequency and intensity have a significant relationship with the above regional climatic parameters. Average drought frequency (yr) is seen to increase gradually from dry to wet regions, from 4 years in the regions with Ep/ Pa ≥ 2 to above 8 years in the regions with Ep/Pa ≤ 1.

The study attempts to advance the understanding of regional drought phenomenon in the Kalahandi district of Orissa and present mitigation strategies. The dry spells during the monsoon crop growing season and wide variations in the quantum of rainfall from year to year result in frequent failure of crops in Kalahandi and as a result the district is categorised as drought prone. 

The study applies the methodology developed by United States Department of Agriculture’s (USDA), Soil Conservation Services (SCS) for the nine subwatersheds of the representative Dudhnai basin in Assam & Meghalaya and estimates the runoff volume on a daily basis for the period 1986-1991. The method is widely adopted for the estimation of runoff from rainfall depths and takes into account the important physical aspects of a basin on which runoff depends such as land-use, hydrological soil cover and antecedent moisture condition.

The study attempts to determine the water quality of all available sources of water be it surface, ground or waste water and find out the likely sources of pollution for the Hardwar district of Uttar Pradesh. The physico-chemical parameters of the water were determined. The effect of monsoon on the water quality was studied by collecting and analyzing the pre and post monsoon samples.

The study attempts to determine the adsorption characteristics of bed sediments of rivers for the control of metal pollution. In particular, it looks at adsorption of zinc ions on bed sediments for the river Ganga at Hardwar. In the natural conditions of river water, suspended loads and sediments have an important function of buffering higher metal concentrations of water, particularly by adsorption or precipitation.