Deep Aquifers

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 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.

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 springs, their characteristics and types. Springs are indicated by locations or points on the ground surface, where water from beneath the ground emerges on to the surface. A common example is of an overflowing unconfined aquifer.

Some of the characteristics of springs are:

• Discharge from spring may be constant or variable.
• Springs can be perennial or seasonal.
• Discharge from a spring may vary between from a trickle to about 100 cum per second.
• Difficulty in access.
• Variation in discharge.
• Temperature of spring water may vary from mean atmospheric temperature to lower or higher, even boiling temperatures. Hot quality water springs are common to many parts of the world.

The presentation by ACWADAM deals with Pani Panchayats as a model of groundwater management.

Pani Panchayat is the name first given to a movement by Mr. Vilasrao Salunke for motivating farmers of Naigaon village of the drought-prone Purandhar taluka of Maharashtra in 1974. The government's inability to deal with the drought situation prompted him to take a 40 acre land on lease from the village temple trust and develop a recharge pond in the recharge area of the village, a dug well in the discharge zone and a lift irrigation system.

Farmers got impressed with the results demanding a scale up of the experiment leading to the setting up of Gram Gaurav Pratisthan (GGP) through which the work was expanded to encompass both groundwater and surface water management. 

The presentation by ACWADAM deals with a case study of augmenting groundwater resources by artificial recharge in Kolwan valley, Mulshi taluka, Pune. The DfID funded project was undertaken by the British Geological Survey in collaboration with its partners in India from 2002–2005. The objectives of the study were:

• Improved knowledge of the impacts of managed aquifer recharge in different physical and socio-economic settings.
• Guidance on scope and effectiveness of managed aquifer recharge for implementers, funders and policy makers.
• Dissemination of knowledge.