Karnataka

This document provides the background for a workshop on 'Water Challenges in Greater Bangalore', organised by NIAS and CASSUM at the National Institute of Advanced Studies (NIAS), Indian Institute of Science (IISC) campus on March 27, 2007.

The document highlights the current scenario of privatisation of water services that are being funded by international financial institutions under the water sector reforms in the city of Bangalore, which have had a very negative impact on the urban poor, who continue to face the problem of inadequate, unreliable and unsafe water supply as compared to other posh and water rich areas in the city.

The report deals with Geographical Information Systems (GIS) based rainfall-runoff modeling using Topography Model (TOPMODEL) for the Hemavathy catchment of Cauvery basin in Western Ghats of Karnataka. The TOPMODEL is a variable contribution area model in which the predominant factors determining the formation of runoff are represented by the topography of the basin and a negative exponential law linking the transmissivity of the soil with the vertical distance from the ground level.

The study deals with the analysis of surface and groundwater flow process in Dakshina Kannada district in Western Ghats of Karnataka. The area receives over 4000 mm rainfall annually but is still faced with acute shortage of freshwater during summer months. The study attempts to identify the surface and sub-surface flow process through geohydrological and geomorphological investigations in the Sithanadhi and Netravathi basins.

The study deals with estimation of surface soil properties in Malaprabha command area. It can be broadly concluded that generalization of soil properties for an area is difficult since the soil and land use type varies drastically from one point to another in a short distance. It is only possible to have an average value for a particular type of soil. Also, it can be seen from the results that the percentage of silt-clay plays an important role in shaping the hydraulic properties of a soil.

The report presents a study of the Rakaskop tank, which caters to the drinking and domestic water purposes of the Belgaum city of Karnataka. In recent past, it has been observed that the amount of water stored during the monsoon season is not sufficient for domestic purposes in the city throughout the year. The study estimates the dependable yield of the tank and also the evaporation from the tank.

In this report, groundwater quality scenarios of the worst affected region of Nargund-Navalgund area of Malaprabha command in Dharwar, Karnataka have been simulated through a three dimensional finite difference code SWIFT III. Mathematical modeling of the groundwater quality was done on a local rather than a larger regional scale.

My house is about 20 years old and is located in R T Nagar in Bangalore. In 1990, I had got a borewell dug. The Borewell is about 150 feet deep and has been giving me excellent quality water until about 2 years ago when I started noticing muddy water. The water that is pumped to an overhead tank contains fine particles of mud which tends to settle down in the overhead tank.

In the present study, an attempt has been made to estimate the soil erosion rate in Malaprabha representative basin by using WEPP model and Universal Soil Loss Equation. Soil erosion and sedimentation are the two important natural processes, which need immediate attention from the scientific community. Two major types of erosion are geological erosion and erosion from human or animal activities.

The report deals with water conservation measures in the arid and semi arid area of the hard rock region viz Somadevarahalli watershed (Bijapur taluka) and Herehalla watershed (Hangund taluka) of the Bijapur district of Karnataka. Soil and water, the most valuable natural resources for farming, are not preserved in-situ and conserved for future use owing to the inadequacies and ineffectiveness of the existing structures and measures. In view of this, to assess the overall situation of water resources for the development and management of watersheds, the annual and monthly rainfall and its distribution over the study area, and the status of groundwater occurrence has been analyzed.

In the study, the methodology developed at the National Institute of Hydrology to relate Clark model parameters to geomorphological characteristics has been used to develop unit hydrograph for two hard rock catchments, Barchi nala and Malaprabha up to Khanapur. This model has already been successfully implemented for simulation of flood events in small catchments of Upper Narmada and Kolar sub-basin of Narmada river as well as the Tapi sub-zone.