Groundwater Recharge

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.

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 measurement of weather parameters and outlines the methods used in weather related data collection and analysis. Weather information is necessary for the planning and implementation of watershed programmes, especially in understanding factors like groundwater recharge, the relationship between recharge & discharge and in aspects like irrigation planning.

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.

The paper by the Institute for Social and Economic Change documents the case of Ward No. 39 situated at the outskirts of the Bangalore city to understand the emerging groundwater crisis due to overdraft in urban areas. Bangalore has no perennial river, which resulted in the growth of many lakes, acting as a source of groundwater recharge earlier.

This paper by the Institute of Social and Economic Change (ISEC) examines the extent of groundwater dependency and quality status in four South Indian cities viz., Hubli, Dharwad, Belgaum and Kolar cities. Widespread water shortage problems have resulted in increased dependency on groundwater with tapping the resources to unsustainable levels. In Karnataka, out of 208 urban local bodies that come under Karnataka Urban Water Supply and Drainage Board, 41 depend on groundwater.

The study by National Institute of Hydrology attempts to model seawater intrusion using FEFLOW, an interactive finite element simulation system in the coastal area of Bardez taluka in North Goa and evaluate the impact of increasing groundwater development on the phenomenon. Coastal tracts of Goa are rapidly being transformed into settlement areas and the poor water supply facilities have encouraged people to develop their own sources of water by digging or boring wells.

Floods: lessons to be learnt from the massive flooding in Surat city

A report by IIM criticises the way in which dams are managed in the country and calls for the need to apply Management Science / Operations Research techniques and information technology to improve dam management and prevention of floods

Flood fury: are we ready to face such an event?