Surface Water

The study attempts to quantify geomorphological characteristics, generate various thematic databases in Geographic Information Systems (GIS) format and derive landuse information using remote sensing digital data for the Danda watershed in the Tehri-Garhwal district of Uttarakhand. Based on these it develops a land capability classification and generates alternate land use plan.

An integrated approach is followed wherein remote sensing and Geographical Information systems (GIS) techniques have been utilized for evaluation of the catchment characteristics such as geomorphology, landuse, soil and slope. The linking of the geomorphological parameters with the hydrological characteristics of the basin provides a simple way to understand the hydrologic behavior of the basin.

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 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.

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.