With the growing population and rapid industrialization, more thrust is inevitable on natural resources like water and land. This has necessitated for the planning and management of land and water resources. Therefore the quantitative analysis of watershed is being felt essential to evaluate the available water resources and its time variance. Each watershed has a number of distinct characteristics. In the present paper authors have carried out morphological study on Bennihalla watershed, a tributary of Malaprabha River. The watershed has been divided into five sub-watersheds and morphological parameters such as stream order, number of streams of each order, stream length, form factor, bifurcation ratio, circulatory ratio, elongation ratio, drainage frequency, relief ratio, constant of channel maintenance, rugged number, time of concentration etc. have been estimated in GIS environment along with establishing the relative importance of few of the parameters. An attempt has been made also to develop isochrones for the watershed.

The Shivalik and Sirowal (Terai) areas of Jammu Region are very distinct in the topographical and hydro-geologic features, which cause wide variation in occurrence/availability of water in these areas. In the present paper, a brief summary of water quality investigations of various surface and ground water resources of Shivalik and Sirowal areas has been presented. The study has shown alkaline nature of water. The major hydrochemical facies was found Ca2+, Mg2+, HCO3- in the study area. The groundwater in Sirowal shows higher salinity than Shivalik. In lake studies, a common problem of eutrophication has been observed under this study on the basis of phosphate data.

In many areas, the necessary meteorological data to calculate reference evapotranspiration is missing. It is very easy if we can get some reliable simpler techniques to calculate reference evapotranspiration with very limited input data. One of the most common and reliable techniques for estimating ETo is using pan evaporation data. Reliable estimation of reference evapotranspiration (ETo) using pan evaporation (Epan) data depends on the accurate determination of pan coefficients (Kpan). To evaluate pan coefficient with different methods, daily values of relative humidity, wind speed and fetch were used. Pan coefficient (Kpan) has been estimated using Synder, Cuenca, Allen & Pruitt, Modified Synder and Orang methods for different irrigation sites i.e Kadam, Gajula Dinne, Yeleswaram, Dowlaiswaram, Nizam sagar, LMDC, SRSP and Jurala in Andhra Pradesh. SEE value was calculated between ETo estimated with pan evaporation method and FAO-56 method and observed low in case of Gajula Dinne station and high in SRSP station. Modified Synder equation is an appropriate equation for irrigation stations located at Gajula Dinne, Nizam Sagar, LMDC and Jurala. Synder (1992) equation is an appropriate equation for irrigation stations located at Dowlaiswaram and SRSP. Cuenca (1989), Allen & Pruitt (1991) equation was found suitable at Kadam and Yeleswaram irrigation stations respectively. The results of all stations were not similar and no general conclusion would be possible due to differences in climatic conditions, selection of pan coefficient equation is site specific.

Hydrologic processes vary in space and time, random in nature or probabilistic in character. Precipitation is the driving element of the land phase of the hydrologic cycle, and the random nature of precipitation means the prediction of the resulting hydrologic processes like surface flow, evaporation and stream flow are always subject to degree of uncertainty. Furthermore, hydrologic systems are impacted by extreme events such as severe storms, floods and droughts. The magnitude of an extreme event is generally inversely proportional to its frequency of occurrence. In practice the frequency analysis of hydrologic data is conducted to relate the magnitude of extreme events to their frequency of occurrence by using probability distributions. The present study deals with the searching of rainfall excess and deficit situation of the water stressed region by determining index of wetness followed by trend analysis as well as per capita water availability. Further, it is attempted here to analyze the annual rainfall considering it as a purely random process and then to see its behavior in terms of commonly used statistical tools.

The major part of the total seasonal rainfall is concentrated in July and August months only in Janagadh region. Due to this concentrated rainfall, the most of it runs away to the sea as runoff. The frequent dry spells and early withdraw of the monsoon is not uncommon. Due to non existence of big rivers in this region, the small water harvesting structure for the life saving irrigations during frequent droughts and supplemental irrigation in case of early withdraw of monsoon as well as ground water recharge for the winter crops are highly required. There is little scope for the natural recharge due to sloppy land. The rainfall intensity-duration-return period/frequency (I-D-F) equation and nomograph are required for the sound design of such structures. The rainfall intensity-durationreturn period equation and nomographs are location specific and available only for the Bhuj and Veraval stations in Gujarat State. So an attempt is made to develop the rainfall intensity-durationreturn period relationship and nomograph for the Junagadh station. All of the duration data series followed the Gumbel distribution. The mathematical form of I-DF relationships was found as; I = 12.63 T0.22 / (t+1.36 )1.207 . The percentage deviation of rainfall intensity estimated by Gumbel distribution and I-D-F model as well as well as estimated by I-DF model and nomograph were within the acceptable limit (<20 %) and seems quite reasonable.

A detention tank with gate (control structure) opening used in urban drainage is one of the methods of minimizing local flooding. This is achieved by improved optimization of existing drainage system by actively controlling the flow in the system during heavy rainfall event by judicious opening of gate. The efficient working of such a system would entirely depend on the suitability of the numerical model, which is used to automatically control the gate of the detention tank based on the set of desired feed backs. With this in view, an effort has been made in this study to develop a dynamic numerical model, to propose a suitable control strategy for the operation of gates. Further, the desired response characteristics of the detention tank, which a field engineer should look for, based on the frequency domain approach has also been discussed.

Reverse Osmosis (RO) process is widely used for defluoridation of water in many Indian villages. This process not only reduces the fluoride content in the water but also reduces the overall salt concentration in the water. If the plant is not maintained properly there will not be any difference in the quality of the influent & the effluent. If the treated water quality is not checked periodically the water with high fluoride content is supplied to the public. Sixteen RO plants installed in different villages of Muddebihal taluka were selected for this study and the performance of most of the plants was found to be unsatisfactory.

Based on the weekly water balance computations for 15 years (1981-1995) variability in the mean length of growing season was analysed. The date of commencement of kharif season rains was found to influence considerably, the period of water availability for crop growth. Appropriate cropping plan is discussed. Based on the analysis cultural operation schedule is suggested. Water harvesting potential in the region is projected with different amounts.

The knowledge of the physics of soil water movements in the unsaturated zone is very important for the studies related to watershed hydrology, irrigation and recharge to groundwater. The design and functioning of subsurface drainage systems also depends to a great extent on water retention characteristic of the soil. Therefore, a sustained research effort towards the relationship between moisture content and suction head (Θ-Ψ) and unsaturated hydraulic conductivity and suction head (K-Ψ) have resulted in the development of several laboratory, field and theoretical methods. In this paper, an attempt has been made to derive the water retention characteristics for different types of soil of Lokapavani catchment, under KR Sagar command, in Mandya District, Karnataka, India. Disturbed and undisturbed soil samples were collected from 18 different locations and along different depths. Extensive field and laboratory investigation have been carried out for each of the soil samples. Disturbed soil samples were used to determine the water retention characteristic using pressure plate apparatus whereas undisturbed samples were used to determine saturated hydraulic conductivity using ICW Permeameter in Laboratory. The soil water retention characteristics parameters of Haverkamp model were obtained using non-linear regression analysis. The coefficients of correlation for regression were high, which shows good correlation.

The seasonal autoregressive integrated moving average (ARIMA) models of different orders were tried for modelling of monthly stream flow of Betwa River. The parameters of seasonal ARIMA models were estimated by fitting ARMA models to differenced series. The goodness of fit of models was tested by Box-Pierce Portmanteau test and by comparison of historical and forecasted data correlograms. Forecasting performance of the models was evaluated by using the goodness of fit tests. The lower values of mean relative error, integral square error and higher values of correlation coefficient indicated closer agreement between forecasted and historical monthly stream flow series data.