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Displaying 1765 - 1776 of 2001

Use of geoprocessing in the study of land degradation in urban environments: the case of the city of São Carlos, state of São Paulo, Brazil

Journal Articles & Books
Dezembro, 2007
Brasil

This paper presents a methodology for the geological engineering survey of land degradation in urban environments using both remote sensing and geoprocessing tools. The area under study was the city of São Carlos, state of São Paulo, Brazil (urban and expansion area). The data presented here were obtained from earlier studies, photointerpretation and geological engineering mapping. The Envi 4.1 software package was used to prepare the digital orthophotos that served as a reference base for the information.

Adaptive Ecosocial System Sustainability Enhancement in Sub-Saharan Africa

Journal Articles & Books
Dezembro, 2007
Etiópia
África

A conceptual framework is developed and used for improving the livelihood of Sub-Saharan communities faced with multiple stresses resulting from adverse environments, vector-transmitted diseases, and limited food. Ecosocial systems are the units for management. The accumulation of ecological, economic, and social capital is the objective of management, the reduction of maintenance costs is the key strategy, and technologies must satisfy ecological, economic, and social criteria.

Farmer management of production risk on degraded lands: the role of wheat variety diversity in the Tigray region, Ethiopia

Journal Articles & Books
Dezembro, 2007
Etiópia

This article investigates the effects of wheat genetic diversity and land degradation on risk and agricultural productivity in less favored production environments of a developing agricultural economy. Drawing production data from a household survey conducted in the highlands of Ethiopia, we estimate a stochastic production function to evaluate the effects of variety richness, land degradation, and their interaction on the mean and the variance of wheat yield. Ethiopia is a center of diversity for durum wheat and farmers manage complex variety mixtures on multiple plots.

Effect of Soil Erosion on Europe's Crop Yields

Journal Articles & Books
Dezembro, 2007
Europa

Soil erosion negatively affects crop yields and may have contributed to the collapse of ancient civilizations. Whether erosion may have such an impact on modern societies as well, is subject to debate. In this paper we quantify the relationship between crop yields and soil water available to plants, the most important yield-determining factor affected by erosion, at the European scale. Using information on the spatial distribution of erosion rates we calculate the potential threat of erosion-induced productivity losses.

Land Use Change and Land Degradation in Southeastern Mediterranean Spain

Journal Articles & Books
Dezembro, 2007
Espanha

The magnitude of the environmental and social consequences of soil erosion and land degradation in semiarid areas of the Mediterranean region has long been recognized and studied. This paper investigates the interrelationship between land use/cover (LULC) changes and land degradation using remotely sensed and ancillary data for southeastern Spain.

Oasis land-use change and its environmental impact in Jinta Oasis, arid northwestern China

Journal Articles & Books
Dezembro, 2007
China

Land use change resulted in land degradation is a focus of research on global environmental changes and plays a significant role in the stability and economic development of oases in arid regions of China. Jinta Oasis, a typical oasis of temperate arid zone in northwestern China, was investigated to assess land-use change dynamics during 1988-2003 with the aid of satellite remote sensing and GIS, and to explore the interaction between these changes and oasis environment.

Effects of salinity and sodicity on some soil physical properties

Policy Papers & Briefs
Dezembro, 2007
Turquia

Effects of salinity and sodicity on some soil physical properties were discussed in this article. Effects of salinity and sodicity on floculation, dispersion, infiltration, hydraulic conductivity, runoff and seal formation were taken into consideration in assessment. In many studies it is indicated that high natrium concentration of soil decreases infiltration and hydraulic conductivity values and stimulates crust formation and dispersion occurrence associated with many factors such as texture, structure, Ca and Mg concentration in solution.