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Displaying 13513 - 13524 of 17903

Formalizing expert judgements in land degradation assessment: a case study for Ethiopia

Journal Articles & Books
december, 2003
Ethiopia

Expert judgements are potentially a valuable source of information in land degradation assessment, especially in areas where data paucity impedes the use of quantitative models. However, expert opinions are also much disputed because they are not tested for consistency, abstain from formal documentation, while their quantitative interpretation is inherently unidentifiable. This paper evaluates and formalizes the use of expert judgements to conduct a nationwide water erosion hazard assessment in Ethiopia.

Towards a standardised procedure for determining the potentially mineralisable nitrogen of soil

Journal Articles & Books
december, 2003

Reliable techniques for predicting N mineralisation dynamics in soil are required for sustainable management of land resources. The concept of potentially mineralisable N (N ₀) and its determination procedures were re-appraised in this study. Leaching soil before incubation removed considerable amounts of soluble organic N. But the leached soils had higher rates of net N mineralisation than the unleached controls during a subsequent 2-week incubation, suggesting that using the total amount of leached- (organic + inorganic) N for calculating N ₀ may not be warranted.

Processing tomato water and nutrient integrated crop management: state of the art and future horizons

Journal Articles & Books
december, 2003
United States of America

Growing processing tomatoes represents one of the most intensive forms of land use in terms of water consumption and nutrient inputs. During the last decade in many European countries and in the United States, Integrated Crop Management guidelines have also been applied for fertilisation and reducing nitrogen inputs to crops has become compulsory. A large number of Best Management Practices, rules and tools have been developed to steer farmers toward sustainable farming practices.

Lessons from success and/or failure of irrigation development

Journal Articles & Books
december, 2003
Honduras
Greece
Haiti
Japan

World population is increasing, particularly in the developing countries. Groundwater reserves are being depleted; lands are being degraded. The required increase in food production must come principally from new supplies of water for irrigated lands. If irrigated lands fail to produce the required food, increased destruction of resources and degradation of the environment from increasing slash and burn agriculture is anticipated. Various countries and international agencies have recognized the possibility of future food shortage.

Assigning life-history traits to plant species to better qualify arid land degradation in Presaharian Tunisia

Journal Articles & Books
december, 2003
Tunisia

Apart from a decrease in total perennial plant cover, degradation of North-African arid lands is not easy to qualify. Yet, simple and comprehensive yardsticks are necessary to assess degradation. We assigned components of competitive ability (C), stress tolerance (S) and ruderality (R) to 15 common perennials of Presaharian Tunisia. We used for that purpose phyto-ecological studies, data about life-form, grazing value and demography and circumstantial data.

Doubly segmented proxy images for multi-scale landscape ecology and ecosystem health

Journal Articles & Books
december, 2003

Multi-band remotely sensed image data contain information on landscape pattern and temporal changes that are greatly underutilized in this technological era when monitoring of disturbance and ecological dynamics is increasingly important to address questions regarding sustainability of ecosystem health and climate change.

Potentials and constraints of the farmer-to-farmer programme for environmental protection in Nicaragua

Journal Articles & Books
december, 2003
Nicaragua

The natural environment in Nicaragua has been damaged by rural development policies geared for the export of cash crops, by uneven land distribution and the near absence of concerns about the environmental effects of the prevailing model of development. The demands made by market forces for the export of primary materials have been reasons for land degradation in the big farms, and the need to survive a poverty stricken existence has forced the peasantry to damage the marginal and fragile land they worked.

Rangeland development of the Mu Us Sandy Land in semiarid China: an analysis using Landsat and NOAA remote sensing data

Journal Articles & Books
december, 2003
China

Degradation of the dry semiarid ecosystems in the Mu Us Sandy Land of north central China was explored using high-resolution satellite images from 1978, 1987 and 1996. This study monitored both changes in grassland biomass production and reclamation activities to detect the nature and scale of land degradation since major economic reforms were introduced in 1978. The position of the high-resolution images within the vegetation cycles was inspected from National Oceanographic and Atmospheric Administration (NOAA) NDVI images at 10-day repetition and seasonal precipitation patterns.

causes and spatial pattern of land degradation risk in southern Mauritania using multitemporal AVHRR-NDVI imagery and field data

Journal Articles & Books
december, 2003
Mauritania
Chad

Multitemporal 1 km NOAA/AVHRR Normalized Difference Vegetation Index (NDVI) maximum composite imagery was utilized in combination with rainfall, soil types, and field survey data on dominant rural activities to assess the risk of land degradation in southern Mauritania. Mauritania is one of eight continental West African Sahel countries that stretch from Chad to the northwestern Atlantic coast, and from the southern fringe of the Sahara Desert to the northern limit of the Sudanian climatic zone.

Accessibility as a determinant of landscape transformation in western Honduras: linking pattern and process

Journal Articles & Books
december, 2003
Honduras

This study evaluates the relationship between landscape accessibility and land cover change in Western Honduras, and demonstrates how these relationships are influenced by social and economic processes of land use change in the region. The study area presents a complex mosaic of land cover change processes that involve approximately equal amounts of reforestation and deforestation.

From social-enquiry to decision support tools: towards an integrative method in the mediterranean rural environment

Journal Articles & Books
december, 2003

Policy-relevant approaches to assessing land-use change must be based upon a number of transdisciplinary mechanisms. This approach demands a number of skills—social enquiry, modelling and soft complex systems thinking, which are necessary to facilitate an effective cross-disciplinary dialogue. Underpinning the development of these transdisciplinary skills, and the acceptance of systems as complex and subject to multiple interpretations, is the need to move away from the desire to predict and towards enhancing the capacity to adapt.