Groundwater

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 explains the occurrence of groundwater and deals with the vertical distribution of groundwater. To begin with, the openings in rocks in the zone of rock fracture such as intergranular openings, vesicles in volcanic rock, joints & fractures and solution cavities are described.

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 link on the CAG website provides the details of an international conference that was held on 15-16 March 2010, in the backdrop of the environmental audit proposed by the the Comptroller and Auditor General (CAG) of India, for management and conservation of the environment .

The purpose of this conference was to deliberate on the causes of pollution, action taken by governments and civil society to address this and environmental, management and legal interventions needed to put lakes, rivers and ground water on the path of sustainability.

More than 20 experts on water and water pollution issues were invited to share their views as panelists during the conference. Apart from these distinguished panelists, the heads of supreme audit institutions from countries like Austria, Maldives, Bangladesh and Bhutan were also present to share their experiences regarding audit of water pollution in their countries.

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.

This presentation by ACWADAM on community organization in groundwater management deals with the processes involved in people’s mobilization and participation. The requisites of groundwater management include: resource enhancement, demand management, equitable distribution, institutional mechanism and controlling of free riding. It deals with groundwater management at a local scale when compared to aquifer management.

Aquifer management involves:

• Identification of aquifer on the basis of geology;
• Identification of recharge and discharge areas;
• Assessment of aquifer capacity and yield through aquifer mapping;
• Protection of recharge area and increasing the groundwater level through artificial recharge in recharge area (based on the geology);
• Treating groundwater as a common property resource;
• Encouraging community use of groundwater and restricting individual use;
• Putting in place an institutional mechanism and legal back up for community groundwater management;
• Awareness generation regarding groundwater and science of hydrogeology.

This presentation by ACWADAM on hydraulic conductivity deals with the hydrologic properties of rocks that signify the status of a rock as a good or poor aquifer. The status of a rock with regard to groundwater occurrence and movement is decided by its porosity (specific yield, more practically) and its hydraulic conductivity. These properties decide whether a rock can store and transmit groundwater.

Hydraulic conductivity is also commonly called as permeability of the rock or rock material and is its ability to allow the flow of groundwater through it. A rock with good hydraulic conductivity allows groundwater to easily flow through it.  

The presentation describes Darcy’s Apparatus, which comprises of a glass cylinder filled with porous sand. The glass cylinder with the sand bed had an inlet for inflow of water and an outlet for outflow of water. Two vertical glass tubes (manometers) are fitted in the sand tube placed at a fixed distance from each other to measure the respective levels (hydraulic heads).

This presentation by ACWADAM deals with Karst hydrogeology, a term used to denote the topography over limestones, dolomites or gypsum rich rocks where there are sinkholes, caverns and lack of surface streams. Karst mainly refers to carbonate rocks: Limestones (CaCO3) or Dolomites (MgCa[CO]).

The formation of carbonate rocks can be traced to physical and chemical deposition. Physical deposition is clastic in nature formed by deposition of particles carried in suspension. It is marked by higher primary porosity and low secondary porosity. Chemical deposition is in the form of precipitate formed by deposition of particles from solution. Contrary to physical deposition it is marked by low primary porosity and high secondary porosity.