The use of Landsat multispectral scanner data for the analysis and management of flooding on the river Severn,England

Remote sensing has emerged as one of the major techniques for the analysis and delineation of large floods. This analysis can provide data invaluable for the hydrological management of large river systems. A need for information on the extent of floodplain inundation for the lower reaches of the largest river in the UK was met by a search through Landsat images of floods and the analysis of the best example recorded. Automated classification of the Landsat imagery of this flood on the river Severn in 1977 was used to provide estimates of the extent and spatial distribution of inundation. Flood images were generated using the Plessey IDP 3000 image processor, and the maps derived accorded well with aerial photography and qualitative flood information. Three distinct floodplain environments were delineated and flood images produced by different spectral bands compared. Specific questions prompted by flood hazard management and concerning the processes and extent of flooding were answered by the Landsat data analysis. Management of the flood risk of large rivers is expensive and remote sensing data is a relatively cheap and effective way of monitoring control works and providing data for the prediction of the effects of future hydrological works. Remote sensing is a practical way in which spatial information concerning the behavior of large dynamic systems can be obtained both quickly and relatively cheaply.     

ELECTROPHORETIC WATER CLARIFICATION TECHNIQUES1

Only very recently has a limited amount of attention been focused directly on electrophoresis as a method for improving water quality. This approach has been proposed primarily as a method for removal of suspended colloidal material, although solutes can also be removed by this method. Very simply electrophoresis is defined as the movement of charged suspended particles in a dc electric field. Several electrophoretic clarification systems and techniques have been developed and evaluated primarily for removing colloidal clay from suspension. The methods should apply equally well to any negatively charged particulate matter. Design for optimal clay removal efficiency and operating cost efficiency has been based upon previous theoretical results and upon modification of the combination filter-el ectrophores is model of Bier. These systems and techniques along with the theoretical developments leading to their design are discussed. Results and conclusions are given for tests that have been concluded concerning the feasibility or practicality of these electrophoretic clarification systems for commercial use. These are viewed in light of various limiting factors such as electrical conductivity of the medium, quality of water desired, colloid concentrations and electrophoretic mobility of the suspended materials.     

Depolarising the 'Broadened' and 'Back-to-basics' Relief Models

Prompted by the calls in recent years to link relief practice to peace-building, development, or both, several conferences and papers have recently mounted a strong critique, seeing these 'broadenings' of relief as 'eroding' or 'corrupting' core humanitarian principles and playing into neo-isolationist agendas to slash humanitarianism. This paper argues that whereas these critiques have important goals in mind when they encourage a concentration on the basics of relief, there has been a loss of subtlety in the ensuing debate. Considering each element of the debate in turn, the paper argues that there is more common ground between 'new' and 'old', 'broadened' and 'basics' relief than at first appears. In concluding, it is argued that further research on key questions, and an openness to hear all perspectives will get us further than entrenched positions and rallying cries.     

Accounting for the quality of work life

This study describes the development and issuance of an independent report on the quality of work life in a Corporation. The theory underlying the report, criteria, definitions, measurement procedures, the properties of the measures, and report itself are presented. A survey indicating a favourable reception to the data by stockholders, financial analysts, and employees is analysed. Recommendations for increased collaboration between accountants and behavioural scientists in the measurement and assessment of the quality of work life are presented in an effort to stimulate further research in the development of standardized measures and in the preparation of independent reports on the quality of work life in organizations.     

Future areas of investigation regarding the problem of urban road dust

In a number of metropolitan areas of the country, failure to attain national primary air quality standards for total suspended particulates (TSP) has fostered a detailed reexamination of the nature of the urban TSP problem. Reentrained dust from paved streets and other traffic-related emissions are now recognized as major sources of TSP in urban areas. While numerous reports and studies have examined this subject, some significant aspects of urban road dust have not been studied in enough detail, if at all. Examples of this are the effects of gutters and pavement composition and shape. This paper discusses those areas of the urban road dust problem that are felt to require further attention and outlines the priorities with which the data should be obtained.     

Contrasting effects of manure and compost on soil pH, heavy metal availability and growth of Chenopodium album L. in a soil contaminated by pyritic mine waste

Chenopodium album L. was found to be one of the initial plant species colonising a heavy metal-contaminated site, polluted by pyritic (sulphide-rich) waste from the Aznalcóllar mine spill (South-western Spain). This indicates its importance in the re-vegetation of this soil. In a pot experiment, C. album was sown in soil collected from the contaminated site, either non-amended or amended with cow manure or compost produced from olive leaves and olive mill wastewater, in order to study the effect on heavy metal bioavailability and soil pH. In non-amended and compost-amended soils, soil acidification, probably resulting from oxidation and hydrolysis of sulphide, led to increases in the concentrations of soluble sulphate and plant-available Cu, Zn and Mn in the soil (extractable with 0.1 M CaCl(2)). Under these conditions, shoot growth of C. album was negligible and shoot concentrations of Zn (2,420-5,585 microg g(-1)) and Mn (5,513-8,994 microg g(-1)) were phytotoxic. Manure application greatly increased shoot growth and reduced the shoot concentrations of Cu, Zn, and Mn, and their plant-available concentrations in the soil. These effects appeared to be related to an increase of soil pH, due to an inhibition of sulphide oxidation/hydrolysis, relative to the non-amended soil. For metal sulphides-contaminated soil, liable to acidification, manure application appears to be able to enhance the initial stages of re-vegetation, by species such as C. album.     

Explaining Agricultural Expansion, Resource Booms and Growth in Latin America

The following paper examines the main factors determining long-run agricultural land expansion in Latin America compared to other tropical regions. Given the importance of natural resource-based sectors for most economies in Latin America, the impact of price-induced "resource booms" on economic growth in the region is explored. In addition, the paper examines whether there is an inherent "boom and bust" pattern of economic development associated with agricultural land expansion in Latin America, and the extent to which economic policies in the region exacerbate this problem. The paper concludes by examining the role of targeted policies in alleviating the structural obstacles to Latin American agricultural and economic development.     

OPTIMAL WATER USE AND SALINITY CONTROL FOR ENERGY - UPPER COLORADO RIVER BASIN1

ABSTRACT: The Upper Colorado River Basin contains appreciable amounts of undeveloped fuel resources. Large quantities of oil shale, coal, and uranium have attracted recent economic and commercial interests. Development of these resources and subsequent conversion to alternative energy forms require an adequate supply of water. Water use for large scale energy development will place increasing demands on an already overstressed allocation of Colorado River water. Present water quality is at a concentration where increased salinity will result in economic detriments to holders of downstream water rights. The salt and water exchange in mining, processing, and spent fuel disposal processes has been incorporated as part of a two-level minimum cost linear programming algorithm. Mathematical simulation results provide an optimal use of Upper Colorado River water for levels of energy output such that salinity concentrations are maintained below predetermined levels.