Groundwater Recharge

This presentation by ACWADAM deals with the subject of groundwater balance. It begins by describing the skeleton for the water balance equation viz., ground surface, soil, aquifer and bed rock. It describes the processes subsequent to rainfall such as interception, initial detention, depression storage, infiltration, runoff, streamflow, soil moisture retention and recharge.

The watershed water balance equation is explained in terms of input (rainfall and water transfers) and output (runoff, evapotranspiration and infiltration). It notes that the input to a generalized water balance is rainfall whereas the input to a groundwater balance is infiltration. The difference between infiltration & recharge, natural & artificial recharge and interflow & discharge are explained thereafter. The water balance for an aquifer may vary, depending upon the nature of groundwater system –

• Watershed with a deep aquifer
• Watershed has both shallow and deep aquifers
• Watershed has only shallow aquifer

This presentation by ACWADAM deals with geological mapping. The occurrence of water within a watershed is governed by the rock types occurring both at the surface and within the subsurface, their sequence and their structure. The physical structure which plays host to the water within the watershed is geological. Every watershed programme must therefore include a fundamental understanding of this framework so that the development and management measures planned through such programmes are meaningful and properly justified technically.

This presentation by ACWADAM deals with the conceptual framework of groundwater management.

This presentation by ACWADAM deals with the issue of groundwater management under the climate change scenario in India. Climate change is a change in the statistical distribution of weather over periods of time that range from decades to millions of years. The causes are -variations in solar radiations, plate tectonics, volcanism and change in earths orbit & axis.

This presentation on aquifer properties by ACWADAM deals with the storage and transmission properties of aquifers. The two functions of an aquifer, accumulation of water (storage) and flow of water (transmission) are discussed. The permeability or hydraulic conductivity of the aquifer which allows water to flow towards the well is described. 

This presentation by ACWADAM deals with hydrologic properties of the rock framework in which groundwater occurs and through which it moves. In watershed programmes, it is necessary to develop a correct understanding of the storage and transmission of water within such channels because the shape of openings in a rock or sediment, their size, volume and interconnection play a vital part in the hydraulic characteristics of an aquifer.

This presentation by ACWADAM deals with introducing groundwater management protocols for wells in different phases of groundwater use. These protocols include geo-hydrology in watershed development, protection of recharge areas, efficient well use, pump capacity regulation, distance with respect to drinking water well regulation, depth regulation in drinking water well, regulation of agricultural water use and groundwater management through sharing.

This presentation by ACWADAM deals with weather, the most fundamental process that shapes the earth. Meteorology, the science of studying weather, is described where some predictions can be made using atmospheric conditions or some data can be generated using simple equipments. These can in turn be used for measurement of weather for better implementation of a watershed project.

This presentation by ACWADAM deals with the three basic types of rocks that are found in nature – igneous, sedimentary and metamorphic. Rocks are classified on the basis of minerals & chemical composition, by texture and by the processes that formed them.

This report by ACWADAM is a synopsis of the hydrogeological study carried out for BIRD-K in Pavagada, Sira and Bagepalli areas of Tumkur District, Karnataka. The study aimed at an impact analysis of recharge through borewells as well as suggesting new sites for the same.

The principle objectives of the study were:

•  Impact analysis of aquifer recharge through borewells done by BIRD-K in Pavagada and Sira Clusters
• Suggest new sites for aquifer recharge through borewells in Bagepalli cluster.

The methodology used a background study of the area through images from Google Earth. A detailed geological fieldwork in the area was carried out. Various structural and hydrogeological measurements were made to map out the aquifer systems within the area. Water levels in borewells and dug wells were measured. The study area included seven watersheds and falls in two clusters namely Pavagada and Sira. Both these clusters are located in the Tumkur district of Karnataka.