National Institute of Hydrology (NIH)

The study evaluates groundwater on the basis of widely used graphical methods like Piper, Stiff and US Salinity Laboratory classification. The study concludes that, in general, the groundwater in the area varies from medium salinity to very high salinity, the latter being more common in the irrigated stretches. The irrigators are advised to ensure good land and water management practices in the fields, with particular emphasis on creating favorable leaching and drainage conditions to avoid further development of saline conditions in the area. 

The study develops a relationship between suspended sediment load and discharge for three basins - Kasol, Suni and Lower Satluj. The sediment load (tonnes/ year) and sediment yield (tonnes/ sqkm/ year) in suspension and as bed load of sand & gravel through the river channel, reflects upland erosion in the drainage basin and deposition of sediments in the alluvial bottomlands. A good deal of the sediment eroded from upland areas is deposited on lower hills slopes, in bottomlands, lakes and reservoirs.

The study aims to establish relationship between spectral reflectance of rice canopy, crop growth, chlorophyll concentrations and water use. Two fields were chosen for radiometric and agronomic measurements over the period from flowering to maturity (August to November).

The study applies geostatistical techniques to the groundwater quality data of December 1994 in parts of Jammu district. Groundwater quality deterioration has led to considerable interest in the design of investigative studies and monitoring programs on the issue.

Various management measures need to take into account the spatial and temporal behavior of groundwater. The spatial dependence between observations can be expressed by semi variance, which is a measure of the average similarity between observations at a given distance apart. One of the prime reasons for obtaining a semivariogram is to use it for estimation of the variable at unsampled locations.

The study assesses sedimentation rate, water spread area and volume of the Bhakra reservoir in Satluj basin using remote sensing data of IRS-1B satellite and LISS-II sensor data of the years 1988-89 and 1996-97. The original elevation-area capacity curves and the reservoir levels on the eight dates of pass of the satellite were obtained from the Bhakra Beas Management Board, Nangal.

Using the trapezoidal formula, the capacity in between the maximum (513.904 m) and minimum (450.436 m) observed levels was assessed for the year 1996-97. The loss of capacity till 1988-89 was 491.315 mcum and till 1996-97 was 807.354 mcum. These could be attributed to the sediment deposition in the zone of study of reservoir.

The study develops a water balance of a sub-basin, Pachaiar, of the Tambarapani river basin in Tamil Nadu. The various components of water balance have been estimated by using the process generating module of Simulator for Water Resources in Rural Basins (SWRRB), a model developed by the United States Department of Agriculture (USDA).

The performance of the USDA model has been validated internationally by various researchers. Since the model required continuous weather data, a time series of it has been generated using another model. The efficiency of this model has been checked with a meteorological station outside the basin.  

The study develops a precipitation network design for the Myntdu-Leska basin, which lies near Cherrapunji, the zone of highest rainfall in the world. Network design offers an estimation of the number and location of the rain gauge stations to provide adequate information regarding rainfall falling over the catchment. 

A detailed survey of the river Hindon was carried out to understand the nature of waste effluents and their impact on water quality.  As per the study, the river water is subject to varying degrees of pollution, caused by numerous untreated waste outfalls of municipal and industrial effluents.

The main sources, which create pollution in the river, include municipal wastes of Saharanpur, Muzaffarnagar and Ghaziabad districts received through tributaries as well as direct outfalls. In the non-monsoon months, the river is completely dry, right from its origin upto Saharanpur town. The effluents of Nagdev nala and Star Paper Mill at Saharanpur generate the flow of water in the river.

The study assesses the quantum of seepage to the aquifers through percolation ponds and establishes their zone of influence, and based on these, correlates the quantum of seepage to the total storage loss in the pond. The assessment of the benefits of the ponds, in terms of artificial recharge to the aquifers is done through an intensive study of two percolation ponds in Tamil Nadu.

A percolation pond is a small water harvesting structure, constructed across a natural stream or water course to harvest and impound the runoff from the catchments for a longer time, to facilitate vertical and lateral percolation of impounded water into the soil substrata, thereby recharging groundwater storage in the zone of influence of the pond.

The study presents a preliminary hydrological investigation of the Deepar Beel, a natural freshwater lake near Guwahati, and notes the theoretical aspects of the techniques to be used, methodologies and instruments for conducting a detailed study of the natural processes at hand.

Deepar Beel acts as a natural stormwater reservoir during monsoon period and is greatly influenced by the rapid urbanization and improper land use pattern of Guwahati. It receives a large portion of sewage of the city, but the preliminary investigations reveal that the Beel is largely free from significant levels of pollution. This is due to the dilution effects of large storm water runoff during monsoons as also the release of the Beel water to river Brahmaputra through the Khanajun outlet. Yet, the soil quality is found to have deteriorated to a large extent.

Various parameters of soil and water quality indicate that the process of eutrophication is in progress in this wetland. Although many trace elements are present in the Beel sediments, no known toxic effects are observed on aquatic life. Increasing sedimentation and reduction in lake water capacity and inflow are also observed.