Rationality and Power: Democracy in Practice

Solid waste management in European countries: a review of systems analysis techniques.

Groundwater is one of the most valuable natural resources, which supports human health, economic development and ecological diversity. Overexploitation and unabated pollution of this vital resource is threatening our ecosystems and even the life of future generations. With the advent of powerful personal computers and the advances in space technology, efficient techniques for land and water management have evolved of which RS (remote sensing) and GIS (geographic information system) are of great significance. These techniques have fundamentally changed our thoughts and ways to manage natural resources in general and water resources in particular. The main intent of the present paper is to highlight RS and GIS technologies and to present a comprehensive review on their applications to groundwater hydrology. A detailed survey of literature revealed six major areas of RS and GIS applications in groundwater hydrology: (i) exploration and assessment of groundwater resources, (ii) selection of artificial recharge sites, (iii) GIS-based subsurface flow and pollution modeling, (iv) groundwater-pollution hazard assessment and protection planning, (v) estimation of natural recharge distribution, and (vi) hydrogeologic data analysis and process monitoring. Although the use of these techniques in groundwater studies has rapidly increased since early nineties, the success rate is very limited and most applications are still in their infancy. Based on this review, salient areas in need of further research and development are discussed, together with the constraints for RS and GIS applications in developing nations. More and more RS- and GIS-based groundwater studies are recommended to be carried out in conjunction with field investigations to effectively exploit the expanding potential of RS and GIS technologies, which will perfect and standardize current applications as well as evolve new approaches and applications. It is concluded that both the RS and GIS technologies have great potential to revolutionize the monitoring and management of vital groundwater resources in the future, though some challenges are daunting before hydrogeologists/hydrologists.

Groundwater management and development by integrated remote sensing and geographic information systems: prospects and constraints

and-use change may be the single greatest factor affecting ecological resources. Allan and Flecker (1993), who have identified six major factors threatening the destruction of river ecosystems, state that various transformations of the landscape-hydrologic changes to streams and rivers resulting from changes in land use, habitat alteration, and nonpoint source pollution-are probably the most widespread and potent threats to the well-being of lotic ecosystems. Measures of landscape structure are necessary to monitor change and assess the risks it poses to ecological resources (Graham et al. 1991, Hunsaker et al. 1990). Landscape ecologists seek to better understand the relationships between landscape structure and ecosystem processes at various spatial scales (Forman and Godron 1986, Risser 1987, Turner 1987, 1989). We use the word structure to refer to the spatial relationships of ecosystem characteristics such as vegetation, animal distributions, and soil types. Processes or function refers to the interactions-that is, the flow of energy, materials, and organismsbetween the spatial elements. Because landscapes are spatially het-

Hierarchical Approaches to the Study of Water Quality in RiversSpatial scale and terrestrial processes are important in developing models to translate research results to management practices

Using the USLE: Chances, challenges and limitations of soil erosion modelling

In the southeast in Norrk÷ping, Sweden, is a small fjord-like bay called SlΣtbaken. The water quality in SlΣtbaken - with its narrow outlet to the Baltic Sea - depends highly on the water quality o ...

Non-point source critical area analysis in the Gisselö watershed using GIS

This study describes approaches to create surface maps of radon in groundwater based on measurements of radon (222Rn) in drilled bedrock wells at unevenly distributed sites and uranium bedrock maps from the South East of Sweden, the Ostergotland county (N 58°14’ – N 58°56’ and E 14°53’ – E 16°06’), see figure 1. Geostatistical techniques of inverse distance weighted (IDW), kriging and cokriging were compared in terms of their interpolation power and correlation between the produced radon in the water layer and the bedrock uranium layer. The goal of these analyses and calculations is to improve our understanding concerning the factors influencing the transport of radon. Therefore, these interpolation techniques were investigated by optimizing parameters that are used in the specific interpolation. Using the IDW interpolator method at fixed radius enabled us to determine the linkage or search distances for auto correlation, and linkage between radon in water and bedrock. This method showed good agreement with the cokriging method when using uranium concentration as a secondary variable. Good interpolation layers (with least root mean square errors RMSE=232) were obtained by kriging. However, the kriged radon surface showed poor correlation with bedrock uranium layers. The best radon in water layer that match with uranium in bedrock layer was produced using IDW interpolator (RMSE=377, using all points). The correlation coefficient (R2) is 0.5 while for the kriging method the best correlation is R2 = 0.1. A compromise between the two approaches is demonstrated.

Spatial correlation between radon (222Rn) in groundwater and bedrock uranium (238U): GIS and geostatistical analyses

The use of remote sensing techniques, image processing, computer mapping and overlays to make inventories of land use and to improve land and water management has increasing potential. Advantages of these techniques include greater geometric resolution and potential time and money savings. The increasing capabilities of personal computers and workstations (hardware and software) and the greater availability of databases have simplified the application of these techniques. In this application, a geographical information system (GIS) was used to facilitate the identification of critical non-point source areas of pollution by sediment-related nutrients. This critical source area information might then be used to aid in the development of non-point source control strategies or for monitoring programme design. This study shows the potential of using GIS in selecting critical source areas for sediment-related water quality problems and land resource protection.

A GIS method to aid in non-point source critical area analysis

Comparative study of the silica and cation geothermometry of the Malawi hot springs: Potential alternative energy source

2 Abstract- Flood is a type of hydro-meteorological phenomenon and it is very hazardous as it can cause devastating losses in property and human lives. Fast and unplanned development aggravates the consequences of flooding by increasing the monetary costs of losses. These kinds of losses are especially high in urban areas which would be possible to ease with proper planning and management of the urban structures. Geographical Information Systems (GIS) based modeling and Remote Sensing (RS) techniques can help by supplying maps and techniques as assistance to make early warning for risk areas. In this case study, different criteria have been analyzed that have potential impact on the amount of devastation, such as the elevation of the areas, flooding depth, building density, terrain slope, soil type, land use types etc. Based on different factors analysis, results are visualized with the help of GIS and RS presentation and dissemination techniques. In addition, the impacts of different factors on flooding itself are also discussed. Finally, a flood prediction map for Dhaka City Corporation (DCC) in Bangladesh was prepared using the Multi-Criteria Evaluation (MCE) method with particular focus on the different criteria that influence the flooding in Dhaka city.

Åke Sivertun

Papers

Non-point source critical area analysis in the Gisselö watershed using GIS

Spatial correlation between radon (222Rn) in groundwater and bedrock uranium (238U): GIS and geostatistical analyses

A GIS method to aid in non-point source critical area analysis

Comparative study of the silica and cation geothermometry of the Malawi hot springs: Potential alternative energy source

GIS and RS Combined Analysis for Flood Prediction Mapping - A Case Study of Dhaka City Corporation, Bangladesh