Surface Water

The study undertakes hydrological soil classification of Suddagedda basin of Andhra Pradesh based on field and laboratory experiments on the soil samples. The hydrologic soil properties of an area are essential to accurately estimate the runoff generated due to storm in the area. The main soil parameters generally considered for analysis are soil texture, soil structure, infiltration rate and hydraulic conductivity.

The study develops a regional conceptual catchment water balance model for five catchments in the Western Ghat region of Karnataka. The model can be used to estimate the water yield from ungauged catchments located in the region.

The water yield is an integration of discharge as a function of time for a specified duration and reflects the volumetric relationship between rainfall and runoff. The estimation of water yield is required for solution of water resources problems normally encountered in design of storage facilities. It is of use in understanding the water availability for agriculture, industrial and drinking purpose as also for estimating the dependable water supply for power generation and irrigation projects.

The study uses HEC-RAS to analyse the water surface profiles of Malaprabha river system upto Khanapur for different combinations of discharges through various reaches of the river system. The river system is divided into eleven reaches, and forty one cross sections have been measured and interpolated within these reaches.

Discharge values have been assigned for different reaches according to the ratio of contributing area for each reach. The bridge across the river at Khanapur is reproduced in the modeling system to test its capabilities. Various return period floods have been allowed to pass through the river system to compute the individual water surface profiles.

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.