The potable water usages in Aizawl are maintained by the water supplies through Public Health and Engineering Department, Govt. of Mizoram. The supply is supplemented mostly by springs (tuikhur), specially during Winter and Spring seasons, when numerous families fetch water from these springs to meet their domestic demands of water.

Water samples for their quality assessment were collected from various streams (tuikhur) situated in the localities namely, Ramthar veng, Ramthar North, Electric veng, Ramhlun veng and Aizawl venglai. All these localities are densely populated and situated on the eastern side of Aizawl, the capital city of Mizoram. Almost all the streams are located near a drain, and it seems that their sources have a close connection with the drain flowing nearby. There are no vegetations growing nearby these streams, except only at Pi Ruali tuikhur at Ramthar locality.

Water samples were analyzed for their physico-chemical characteristics in order to obtain the status of spring water quality in the city. The physical characters observed include colour, odour, taste, pH, turbidity and conductivity while chemical tests performed are P-alkalinity, M- alkalinity, total alkalinity, chloride, fluoride, iron and total hardness.

The results are suggestive of the fact that tuikhurs, quality of water from all the sources used for domestic purposes are found to be more or less within the tolerance limit.

The rainstorm of 29 to 31 Jul., 2006 which gave exceptionally heavy rains and caused intense floods all over the Gujarat region has been examined. It has been found that this rainstorm had its areal extension over more than 200000 sq.km of area. The raindepths obtained by this rainstorm for 1 to 3-days durations were compared with other severe most rainstorms of the Gujarat region. This study has shown that although the raindepths yielded by this rainstorm were comparatively higher for durations of 1 to 3 days, the rainstorm was not that intense when compared to severe most rainstorm of 1-3 Jul., 1941 which occurred over south Gujaratnorth Konkan region.

Seasonal variations of stream flow can lead to change of groundwater flow fields in an aquiferstream water system. For assessing spatial and temporal variations of flow fields due to the seasonal variations of stream flow, a hypothetical aquifer-stream water interaction system has been modeled using GMS software (Groundwater Modeling System). GMS software is one of the most sophisticated groundwater modeling environment software available today. The GMS software is a comprehensive package which provides tools for every phase of a groundwater simulation including site characterization, model development, post processing, calibration, and visualization. GMS is the only system which supports TINs, solids, borehole data, 2D and 3D geostatistics, and both finite element and finite difference models in 2D and 3D environment. It supports many other models within a single environment. Due to the modular nature of GMS, a custom version of GMS with desired modules and interfaces can be configured. Unlike other models, this software combines the functionalities of different groundwater models and the powerful GIS (Geographic Information Systems) interface. The aquifer-stream water interaction system depends on several factors, namely, location, geometry, elevation and physical setting and other inherent properties. This involves use of large database, which can be easily handled using the GIS functionalities available within GMS.

Influence of weekly, monthly and seasonal meteorological parameters such as minimum and maximum ambient temperature, minimum and maximum relative humidity, sunshine hours and wind velocity on the rate of evaporation has been examined using thirty six (1964 - 99) years meteorological data of Bhubaneswar. Correlation and simple regression analysis were used to observe the influence of individual meteorological parameters on pan evaporation rate. The results of correlation and regression analysis revealed that maximum ambient temperature was the most influencing parameter on pan evaporation rate which affected positively and maximum relative humidity also played significant role during kharif season indicating the negative relation with the evaporation rate. Weekly minimum air temperature and sunshine hour have shown the least co-relation with the weekly pan evaporation. The wind velocity plays significant role on pan evaporation during summer season, while the minimum air temperature affect the evaporation only during summer season. Similarly the minimum relative humidity indicates its influence on evaporation during summer season. However, the sunshine hours showed its least influence during kharif and rabi season.

Hydrochemistry of Loktak Lake water gives the baseline information of water resources in power generation, Irrigation and ecofriendly management of the Manipur state. Investigations on the origin of various ions in waters and the minerals present can be made by statistical relationship between the ions. To know whether the ions present in the lake have the same source or the increase of one ion causes the decrease of another ion because of the inflow of various tributaries and streams traversing through different rock types can be explained with the help of inter-relationship of various ions. In Loktak Lake water the dominent hydrochemical facies are Ca-Mg-HCO3 and Na-Cl-HCO3 with less predominant Na-K-Cl facies. There is a subdued trend of sympathetic rise in SO4 and K content with that of TDS and the negative trend in hardness vs TDS and Cl vs TDS. There is the paucity of iodide and fluoride both of epidemiological significance, in Loktak lake water regime. According to Gibb’s diagram most of the samples falls under rock dominance and evaporation crystallization to some extent. To construct the suitability of Loktak Lake water for Irrigation, drinking and public health purposes, hydrochemical parameters like EC, Electrical Conductivity, Salinity Hazard, Sodium Percent, Sodium Absorption Ratio, Residual Sodium Carbonate of the study area have been calculated for irrigation water quality. The interpretation on the basis of available data justified that the Loktak Lake water is suitable for irrigation and drinking purpose.

In India, percolation ponds have been known to have the potential to serve as one of the important types of artificial recharging structures. In early 1980 to 1990’s Central as well as State Governments have implemented in a large scale constructing of percolation ponds, but later on the programs were gradually dropped. A systematic study in order to asses the extent and intensity of the influence of the percolation pond both spatially and temporally on the wells in the neighbourhood has been reported herein. Two percolation ponds in Tamil Nadu, India has been observed for three years to assess their potential zone of influence. Five different approaches were adopted to demarcate the extent of the zone of influence based on water level and electrical conductivity fluctuation in the wells. The intensity of zone of influence was categorized as ‘strong’, ‘moderate’, ‘weak’ and ‘negligible’. In one of the cases, the zone of influence was noted to be polygonal with about 200 m width near the pond to about 400 m width at a distance of about 840 m. In another case it is only half of the above values inspite its capacity being twice. The wells outside this zone were geo-hydrologically unconnected with the percolation pond. In one of the pond, it was found that the percolation pond recharges upstream side also. From the study it is found that the effectiveness of a percolation pond depends upon the sitting and active usage of recharged water. This study reveals that the Governments can rethink of introducing the scheme of percolation pond with proper emphasis on sitting and usage.

An attempt was made in Salem district of Tamilnadu, India to demarcate weathered zone its thickness and to identify groundwater potential zones using electrical resistivity method. Schlumberger arrangement was carried out due to short time duration in arranging the electrodes, fewer movements of potential electrodes, depth soundings > 40 m is possible and long current carrying cables are avoided when compared with Wenner. A total of 54 VES soundings were carried out to signify complete lithology of the study area and interpretation was carried out by using curve matching techniques. 83% of study area is dominated by A type curve and the rest by K type. The thickness of weathered zone was found to be greater in the contact of Peninsular gneiss and Charnockite regions. The maximum, minimu, mean and arithmetic mean were plotted and found in weathered layer; background resistivity values are higher in Charnockite. The overlay of maximum, minimum curves for different layers signifies variation of weathering intensity with depth or presence of weaker zones. In general lithology plays a significant control over weathering of rocks and groundwater potential

The 944 mm rainfall event in 24 hours on 26th July 2005 caused extreme flooding and sever disruption in Mumbai. Subsequently, 26 weather stations with automatic tipping-bucket rain gauges have been installed in Mumbai in May 2006 with an average density of 1 per 16 km2 by the Municipal Corporation of Greater Mumbai to determine the spatial distribution of rainfall in Mumbai (area of 437.71 km2) in real-time. This paper presents a detailed analysis of the spatial and temporal distribution of rainfall for the 3-5 July, 2006 event, which resulted in a 3-day rainfall of 409.8 mm and caused flooding in several parts of Mumbai. The analysis carried out in this study suggests that rainfall data from one or two sites cannot be taken as representative of rainfall over a metropolitan region.

Ground water prospects of any area depend on its geological structures, geomorphic features and their hydrological characters. Identification and mapping of these elements is thus imperative for ground water exploration and optimal management of this precious resource. In the present paper ground water potentiality in Bobbili Mandal, Andhra Pradesh has been evaluated by analyzing the hydro geomorphic parameters using GIS and Remote Sensing techniques. Satellite image and Topographical map have been used to prepare the required thematic maps like geology, lineaments, geomorphology, surface water bodies and drainage. These maps have been integrated in GIS environment to demarcate the hydro geomorphic units. Nine hydrogeomorphic units viz. Flood plain (FP), Moderately Weathered Pedi plain (PPM), Shallow Weathered Pedi plain (PPS), Residual Hill (rh), Denudational Hill (dh), Structural Hill (sh), Inselberg (i), Pediment (pd) and Bajada (bj) have been derived from the integrated map. Ground water potentiality has been qualitatively assessed by analyzing the derived hydro geomorphic units after considering the field information.

The study area Chittar-Uppodai Water shed is a sub-basin of Tambaraparani river which is geologically confined with the hard rocks of charnockite and biotite gneisses. In the present study, about 102 ground water samples were collected from both open and bore wells of the water shed during the month of January 2005. The ground water samples were collected from both domestic and agricultural wells. The pH varies from 6.6 to 7.9 and EC values with a range of 300 micro-siemens / cm to 4550 micro-siemens / cm. The TDS and Total Hardness values are varied from 196 mg/l to 3185 mg/l and 97 mg/l to 1151 mg/l respectively. The Fluoride (F) concentration varies from zero to 1.4 mg/l which shows about 70% of the groundwater samples were having the range of 0.5 mg/l to 1.4 mg/l. The water level fluctuation, weathering process, time and area of contact are the main contributors to the present level of F in open wells rather than bore wells. The source for the present level of F contamination in groundwater is mainly from the silicate minerals of the weathered rocks. Low soluble nature of fluoride bearing minerals and the season of sampling could be the reason for low F concentration in the study area.