Search

Formulation of a proper watershed management plan requires reliable and up-to-date information about various factors such as morphologic (size and shape of the watershed, drainage parameters, topography), soil and their characteristics, land use, and land cover, etc. that affect the behavior of a watershed. Satellite based remote sensing technology and GIS meets both the requirements of reliability and speed and are ideal tools for generating spatial information needs. In this study, a locale-specific watershed development plan was generated for the case study area of a small agricultural watershed of Karso, Hazaribagh, India using remote sensing and GIS techniques. Indian Remote Sensing Satellite (IRS-1C), Linear Imaging Self Scanner (LISS-III) satellite data along with other datasets, e.g. existing maps and field observation data have been utilized for generating a land use/land cover map and to extract information on morphological parameters (bifurcation ratio, elongation ratio, drainage density, ruggedness number, relief ratio, and circulatory ratio) and other thematic maps which are an essential prerequisites for watershed development. Morphological parameters of subwatersheds were derived to understand its usefulness for surface water development. The conceptual framework for plan and site suitability mapping for soil and water conservation structures is developed and subsequently, these parameters were integrated with other thematic information viz., land use/cover, drainage, slope, and soil in the GIS environment to arrive at a decision regarding a suitable site for having soil and water conservation structures (, check dam, and percolation tank) in its place adopting a holistic approach. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A systematic planning of groundwater exploitation using modern techniques is essential for the proper utilization and management of this precious but shrinking natural resource. With the advent of powerful and high-speed personal computers, efficient techniques for water management have evolved, of which RS (remote sensing), GIS (geographic information system) and GPS (Global Positioning System) are of great significance. In the present study, an attempt has been made to delineate and classify possible groundwater potential zones in the West Medinipur district of West Bengal, India using integrated remote sensing and GIS techniques. The thematic layers considered in this study are lithology, landform, drainage density, recharge, soil, land slope and surface water body, which were prepared using the IRS-1D imagery and conventional data. All these themes and their individual features were then assigned weights according to their relative importance in groundwater occurrence and the corresponding normalized weights were obtained based on the Saaty's analytical hierarchy process. The thematic layers were finally integrated using ArcInfo GIS software to yield a groundwater potential zone map of the study area. Thus, three different groundwater potential zones were identified, namely 'good', 'moderate' and 'poor'. The area having good groundwater potential is about 1400 km2, which is about 15% of the total study area. The eastern portion and some small patches in the central and northern portions of the study area fall under moderate groundwater potential zone, which encompasses an area of 5400 km2 (55%). However, the groundwater potential in the western, south-western and parts of north-eastern portions of the study area is poor, encompassing an area of about 3000 km2. Moreover, the average annually exploitable groundwater reserve in the good zone was estimated to be 0.29 MCM/km2, whereas it is 0.25 MCM/km2 for the moderate zone and 0.13 MCM/km2 for the poor zone. Finally, it is concluded that the RS and GIS techniques are very efficient and useful for the identification of groundwater potential zones. [ABSTRACT FROM AUTHOR]

Inclined plate settlers are used in treating wastewater due to their low space requirement and high removal rates. The prediction of sedimentation efficiency of these settlers is essential for their performance evaluation. In the present study, the technique of dimensional analysis was applied to predict the sedimentation efficiency of these inclined plate settlers. The effect of various geometric parameters namely, distance between plates (w(p)), plate angle (alpha), length of plate (l(p)), plate roughness (epsilon(p)), number of plates (n(p)) and particle diameter (d(s)) on the dynamic conditions, influencing the sedimentation process was studied. From the study it was established that neither the Reynolds criterion nor the Froude criterion was singularly valid to simulate the sedimentation efficiency (E) for different values of w(p) and flow velocity (v(f)). Considering the prevalent scale effect, simulation equations were developed to predict E at different dynamic conditions. The optimum dynamic condition producing the maximum E is also discussed.