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The study area, upper Gadilam River basin, is located in Vizhupuram district of Tamil Nadu. The number of energized wells in this area has increased manifold due to free supply of electric power until recently by the government of Tamil Nadu, which has resulted in a regional decline in groundwater piezometric heads in this water table aquifer. A hydrogeological study was carried out in the study area. This paper deals with aquifer parameters estimation based on the pumping test data generated in the field. Water level observations in the area indicated that aquifer has undergone less stress condition within the course of time from the yesteryears or early 1995 to June 2004. Transmissivity computed by Theis (1935) method ranges from 301.82 gpd/sq. ft at Ponniyandal to 19,910.14 gpd/sq. ft in Pallavadi towards south central part of the study area. The specific capacity has a range of 0.906 gpm/ft. of dd in Ponniyandal to 121.91 gpm/ft of dd at Kottaiyampalayam in the eastern central part of the study area. Groundwater level in the basin by rainfall recharge and hydrodynamic method is estimated as 69 million cu.m of recharge and 33 million cu. m of groundwater storage. [ABSTRACT FROM AUTHOR]

Land use/land cover mapping serves as a basic inventory of land resources throughout the world. Detecting and analyzing the quantitative changes along the earth's surface has become necessary and advantageous because it can result in proper planning, which would ultimately result in improvement in infrastructure development, and economic and industrial growth. This paper examines the changes in land use/land cover types in Tiruchirappalli city, Tamil Nadu from 1998-2006, using remote sensing technology and Geographic Information Systems (GIS). The spatial and temporal changes of land use/land cover were analyzed through visual interpretation and image classification of IRS remote sensing data collected for years 1998, 2002 and 2006. The results of the study indicated an overall growth in built-up land by 80% over a span of eight years, with an incredible boost (58%) in development from 1998-2002. The area under agricultural wet land was found to have decreased from 3,776 ha to 2,689 ha, with an increase in agricultural dry land from 814 ha to 1,058 ha during this period, suggesting the wastage of land due to excessive use of fertilizers. [ABSTRACT FROM AUTHOR]

Groundwater is an important source of water supply throughout the world. It is very essential for irrigation industries and domestic purposes. It is a good source of freshwater available on the earth. It is an important renewable resource having several inherent advantages over surface water. Its wide distribution, negligible evaporation loss and low risk of contamination are considered as important qualities. Fifty-seven groundwater samples were collected from the Singipuram river basin of Salem district from shallow bore wells and open wells to maintain uniformity, to asses the quality and its suitability for domestic and irrigation purposes. Geologically, charnockites and gneisses constitute the country rocks of the study area. The weathering of host rocks and agricultural activities play an important role in modifying the chemistry of groundwater. The quality of the groundwater in the southern part of the area is far from satisfactory and needs careful management. Five broad types have been identified, which are Ca-Cl, Ca-Na-Cl, Ca-Na-HCO3, Ca-Na-HCO3-Cl and Na-HCO3-Cl. The salinity of Sodium Absorption Ratio (SAR), Residual Sodium Carbonate (RSC) and permeability index indicate that most of the groundwater samples are suitable for irrigation. [ABSTRACT FROM AUTHOR]