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Watershed Level (watershed + level)

Distribution by Scientific Domains

Business, Economics, Finance and Accounting	40%

Selected Abstracts

Economic Impacts of Technology, Population Growth And Soil Erosion At Watershed Level: The Case Of the Ginchi in Ethiopia

JOURNAL OF AGRICULTURAL ECONOMICS, Issue 3 2004
B.N. Okumu
A dynamic bio-economic model is used to show that, without technological and policy intervention, soil loss levels, income and nutrition could not be substantially or sustainably improved in a highland area of Ethiopia. Although cash incomes could rise by more than 40% over a twelve-year planning period, average per ha soil losses could be as high as 31 tonnes per ha. With the adoption of an integrated package of new technologies, however, results show the possibility of an average two-and-a-half-fold increase in cash incomes and a 28% decline in aggregate erosion levels even with a population growth rate of 2.3%. Moreover, a minimum daily calorie intake of 2000 per adult equivalent could be met from on-farm production with no significant increases in erosion. However, higher rates of growth in nutritional requirements and population introduce significant strains on the watershed system. From a policy perspective, there is a need for a more secure land tenure policy than currently prevailing to facilitate uptake of the new technology package, and a shift from the current livestock management strategy to one that encourages livestock keeping as a commercial enterprise. It would also imply a shift to a more site-specific approach to land management. [source]

DEVELOPMENT AND EVALUATION OF MULTIPLE-OBJECTIVE DECISION-MAKING METHODS FOR WATERSHED MANAGEMENT PLANNING,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 2 2002
France Lamy
ABSTRACT: Making decisions for environmental management is a complex task due to the multiplicity and diversity of technological choices. Furthermore, the exploitation of natural resources and the preservation of the natural environment imply objectives that are often in conflict within a sustainable development paradigm. Managers and other decision makers require techniques to assist them in understanding strategic decision making. This paper illustrates the use of a multiple-objective decision-making methodology and an integrative geographical information system-based decision-making tool developed to help watershed councils prioritize and evaluate restoration activities at the watershed level. Both were developed through a multidisciplinary approach. The decision-making tool is being applied in two watersheds of Oregon's Willamette River Basin. The results suggest that multiple-objective methods can provide a valuable tool in analyzing complex watershed management issues. [source]

Assessment of soil erosion hazard and prioritization for treatment at the watershed level: Case study in the Chemoga watershed, Blue Nile basin, Ethiopia

LAND DEGRADATION AND DEVELOPMENT, Issue 6 2009
W. Bewket
Abstract Soil erosion by water is the most pressing environmental problem in Ethiopia, particularly in the Highlands where the topography is highly rugged, population pressure is high, steeplands are cultivated and rainfall is erosive. Soil conservation is critically required in these areas. The objective of this study was to assess soil erosion hazard in a typical highland watershed (the Chemoga watershed) and demonstrate that a simple erosion assessment model, the universal soil loss equation (USLE), integrated with satellite remote sensing and geographical information systems can provide useful tools for conservation decision-making. Monthly precipitation, soil map, a 30-m digital elevation model derived from topographic map, land-cover map produced from supervised classification of a Land Sat image, and land use types and slope steepness were used to determine the USLE factor values. The results show that a larger part of the watershed (>58 per cent of total) suffers from a severe or very severe erosion risk (>80,t,ha,1,y,1), mainly in the midstream and upstream parts where steeplands are cultivated or overgrazed. In about 25 per cent of the watershed, soil erosion was estimated to exceed 125,t,ha,1,y,1. Based on the predicted soil erosion rates, the watershed was divided into six priority categories for conservation intervention and 18 micro-watersheds were identified that may be used as planning units. Finally, the method used has yielded a fairly reliable estimation of soil loss rates and delineation of erosion-prone areas. Hence, a similar method can be used in other watersheds to prepare conservation master plans and enable efficient use of limited resources. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Landscape features and crustacean prey as predictors of the Southern river otter distribution in Chile.

ANIMAL CONSERVATION, Issue 6 2009
M. A. Sepúlveda
Abstract Understanding the processes that affect freshwater ecosystems at the watershed level is fundamental for the conservation and management of river otters. During 2 consecutive years, we surveyed the occurrence of the Southern river otter Lontra provocax and its main prey (crustaceans) in a watershed of 9900 km2 in the Chilean temperate forest. We modeled predator and prey distributions with a variety of statistical techniques by relating a set of environmental predictors to species occurrence records. Otter and crustaceans were associated with areas of intermediate to low human disturbance with a mosaic of riparian vegetation densities, mainly at low altitudes. The singularity of the Andean Range, with a very marked elevation gradient and oligotrophic watercourses in the higher areas, created more vulnerable conditions for otter presence because prey abundances were limited in those areas. Human impacts affected otter populations at a landscape scale through the presence of main roads, as these were mostly located in lower parts of the watershed where otters have their primary habitat. These results point to the importance of land management and protection of low-elevation areas where otters still occur to ensure the long-term viability of its freshwater populations. [source]

The Economics of Erosion and Sustainable Practices: The Case of the Saint-Esprit Watershed

CANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 2 2000
Jean-Christophe Dissart
This paper examines the economics of the adoption of sustainable production practices for soil erosion control. The research was conducted on three case farms within the Saint-Esprit watershed in Quebec using a two-stage process. The first stage involved the use of GIS (Geographical Information Systems) to record erosion characteristics (slope, etc.) for these farmers'fields. This erosion information was then included as input information in the second stage of the process. Mixed integer linear programming (MILP) was used to model both individual farms and the watershed. Increasing erosion constraints were applied to these models to investigate changes in crop production mixes for farms and the watershed. A comparison of the results (farms versus watershed) was used to investigate policy questions concerning an optimal erosion constraint for society. Results generated indicate that farms with higher net incomes would be advantaged by erosion constraints set at the watershed level, whereas farms with lower net revenues would be disadvantaged. Thus, trading of pollution permits could be encouraged. Cet article examine les aspects économiques de l'adoption de pratiques de production durables visant a réduire l'érosion du sol. La recherche fut effectuée sur trois fermes situées dans le has sin du Saint-Esprit au Québec, et impliqua un processus à deux étapes. Le premier étape consiste en l'utilisation du systéme d'informations géographiques " SIG " afin de noter les caractéristiques de l'érosion (pente, etc.) dans ces champs agricoles. Ces renseignements servirent de données au sein du deuxième étape. La méthode de programmation linéaire à nombres entiers mixtes fut employée afin de modéliser les fermes individuelles, ainsi que le bassin. Ensuite, les contraintes d,érosion furent appliquées sur ces modèles de manière croissante, et ce afin d'étudier les changements dans le melange des productions de cultures pour les fermes et le bassin. Une comparaison des résultats (fermes vs. bassin) fut accomplie pour examiner les questions de politiques pouvant mener à une contrainte d,érosion optimale pour la société. Les résultats obtenus démontrent que les fermes ayant des revenus nets élevés seraient avantagées par des contraintes d'érosion établies au niveau du bassin, tandis que les fermes aux revenus nets plus bas en seraient désavantagées. En conséquence, l'échange de permis de pollution est recommandé. [source]