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1.
The paper defines the concept of land degradation and costs and effects of soil erosion. Through the concept of optimal levels of soil erosion, a conceptual model of the social costs of soil degradation is elaborated. The discussion focuses on the measurement aspects of the economic scarcity of soil in the agriculture sector. Reliable estimates of the true impacts of soil degradation can only be made if data on marginal damage costs and marginal conservation costs are available. The different scarcity indicators are evaluated and competitive land rental prices are considered as appropriate in indicating soil scarcity in agriculture. 相似文献
2.
2 Copper Basin in southeastern Tennessee became the site of increasingly extensive and successful reforestation efforts. To determine the effectiveness of more than 50 years of reforestation efforts, we compared rainfall infiltration, sediment detachment, and soil organic matter of reforested sites to those properties of unvegetated sites and forested reference sites outside the basin. Results of 54 rainfall simulation experiments conducted in zones of the basin known to have been planted during different decades demonstrate that hydrologic recovery of soils in the Copper Basin lags significantly behind the establishment of tree cover and the protection offered by vegetation against soil erosion. Soils in new “forests” have significantly less organic matter and lower infiltration than forests more than 50 years old. The long-term persistence of low infiltration rates serves as a reminder that, at sites where the A and B soil horizons have been lost, restoration of the hydrologic function of a landscape requires decades, at least. 相似文献
3.
Land Degradation: A Challenge to Ethiopia 总被引:8,自引:3,他引:8
Taddese G 《Environmental management》2001,27(6):815-824
Land degradation is a great threat for the future and it requires great effort and resources to ameliorate. The major causes
of land degradation in Ethiopia are the rapid population increase, severe soil loss, deforestation, low vegetative cover and
unbalanced crop and livestock production. Inappropriate land-use systems and land-tenure policies enhance desertification
and loss of agrobiodiversity. Utilization of dung and crop residues for fuel and other uses disturbs the sustainability of
land resources. The supply of inputs such as fertilizer, farm machinery and credits are very low. The balance between crop,
livestock, and forest production is disturbed, and the farmer is forced to put more land into crop production. For environmentally
and socially sustainable development, there is an urgent need to promote awareness and understanding of the interdependence
of natural, socioeconomic, and political systems at local and national levels. Understanding the current status and causes
of land degradation is very important. This paper reveals the important elements of land degradation in Ethiopia and suggests
possible solutions that may help to ameliorate the situation. 相似文献
4.
An integrated assessment model of carbon sequestration benefits: a case study of Liping county, China 总被引:4,自引:0,他引:4
Caldwell IM Maclaren VW Chen JM Ju WM Zhou S Yin Y Boland A 《Journal of environmental management》2007,85(3):757-773
This research attempts to model the complexity of planting trees to increase China's CO(2) sequestration potential by using a GIS-based integrated assessment (IA) approach. We use the IA model to assess the impact of China's Grain for Green reforestation and afforestation program on farmer and state incomes as well as CO(2) sequestration in Liping County, Guizhou Province. The IA model consists of five sub-models for carbon sequestration, crop income, timber income, Grain for Green, and carbon credits. It also includes a complementary qualitative module for assessing program impacts by gender and ethnicity. Using four scenarios with various assumptions about types of trees planted, crop incomes by township, CO(2) credit prices, state subsidies, methods for estimating carbon sequestered, and harvesting of trees, we find great variation in the impact of the Grain for Green program on incomes and on carbon sequestered over a 48 year period at both the county and township levels. 相似文献
5.
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. The area of study, the Xaló River catchment
situated in the north of the Alicante Province, has been subjected to a number of LULC changes during the second half of the
20th century such as agricultural abandonment, forest fires, and tourist development. Aerial photographs dating back to 1956
were used for the delineation of historic LULC types; Landsat ETM+ data were used for the analysis and mapping of current
conditions. Two important indicators of land degradation, namely, susceptibility to surface runoff and soil erosion, were
estimated for the two dates using easily parametrizable models. The comparison of 1956 to 2000 conditions shows an overall
“recuperating” trend over the catchment and increased susceptibility to soil erosion only in 3% of the catchment area. The
results also identify potential degradation hot-spots where mitigation measures should be taken to prevent further degradation.
The readily implemented methodology, based on modest data requirements demonstrated by this study, is a useful tool for catchment
to regional scale land use change and land degradation studies and strategic planning for environmental management. 相似文献
6.
7.
k -means nonhierarchical cluster analysis using farm size, slope, and distance to the nearest city center and highway as surrogates
of farmland conversion. Discriminant analysis showed that the two groups derived from the cluster analysis were 98.8% accurate
(P < 0.0000). Results from the statistical analysis may serve as a starting point for the identification of individual farms
prone to residential development. To explain the driving forces of farmland conversion to residential uses, interviews should
be conducted with farmers, landowners, and land buyers. The use of multivariate statistical techniques to identify farms in
jeopardy of residential development, in conjunction with qualitative assessments that explain the probability of development
of individual farms, may prove a useful strategy to understand and predict farmland conversion. 相似文献
8.
TEKLE K 《Environmental management》1999,23(4):419-427
/ Understanding the problems of land degradation and seeking long-lasting solutions to these problems should be one of the central concerns of countries such as Ethiopia where agriculture is the mainstay of no less than 85% of the population. To this end, the collaboration of policy makers, researchers, donor agencies, and the local people is indispensable. In this paper an attempt is made to discuss the causes of land degradation and the reasons for the failure in the endeavors made to solve the problems. Possible solutions, which may help to ameliorate the situation, are also suggested. The study deals with South Wello (a region in northern Ethiopia), but the assessment is, by and large, a reflection of most of the highlands in the country. KEY WORDS: Agroforestry; Donor agencies; Food for work; Hillside closures; Land rehabilitation; Local participation; Population growth; Reforestation 相似文献
9.
Soil erosion is accelerating in developing countries of Asia, Africa, and Latin America. It has threatened the livelihood
of millions of peasants, for agriculture is their economic mainstay. A probe into the forces causing erosion reveals that
the elite’s resolve to accumulate ever more wealth and to maintain, consolidate, or expand their sociopolitical power and
the necessity of the poor to fulfill their requirements of food, fuelwood, and fodder are the two major factors accelerating
soil erosion. Unless the vast masses of poor people are integrated into the national mainstream through the implementation
of equitable and redistributive development policies, it is impossible to control the accelerating rate of soil erosion and
thus to achieve the objective of sustainable development.
In this article, the phenomenon “soil erosion” is studied with the sol e focus on causation through anthropogenic factors. 相似文献
10.
Social, economic, and ecological impacts of the "Grain for Green" project in China: a preliminary case in Zhangye, Northwest China 总被引:4,自引:0,他引:4
This paper provides applications of the integrated assessment (IA) approach in a case study in the Heihe River Basin of Northwest China. Some socio-economic and ecological impact results of forestry land use scenarios are presented in the paper. While seven types of land use scenarios for carbon sequestration purposes were considered for the IA applications, this paper mainly presents impacts of land use scenarios within the Grain for Green (GFG) category [see Yin et al., this volume]. China's national Grain for Green Project was implemented in order to protect and improve ecosystems, while allowing an evolution of agricultural management practices compatible with raising peasants' incomes. Zhangye Prefecture, located in the Heihe River Basin of an arid area in Northwest China, was chosen as the investigation site of the IA case study. Based on fundamental orientation theory, the social sustainability impacts of GFG land use options were assessed. Between 2002 and 2004, the GFG project brought US$23.56 million yuan in net income to the prefecture's peasants. Project implementation resulted in a 1.71 Gg increase in net primary productivity (NPP), as well as a 44.36 Gg rise in net ecosystem productivity (NEP). This suggested that, in Zhangye Prefecture, the Grain for Green Project could enhance the sustainability and stability of the local society, increase peasants' net income, as well as protect and remediate local ecosystems. 相似文献
11.
Keith Hayton 《Journal of Environmental Planning and Management》1989,32(2):115-120
In the past much of the training effort of public agencies was not aimed at specific job vacancies or at areas of skill shortages. In contrast, targeted training aims to provide identified disadvantaged groups with training to enable them to compete for identified job vacancies. This paper looks at the success of targeted training through three examples, at how its effectiveness can be improved, and the role of local government in initiating and developing such training. 相似文献
12.
本文以成渝城市群、长江中游城市群和长三角城市群为研究对象,解析不同空间尺度下绿色发展与生态足迹时空变化特征,并结合耦合协调度模型、环境库兹涅茨曲线(EKC)理论探究绿色发展与生态足迹的关联特征。研究表明,长江经济带城市群2000—2015年绿色发展水平逐年提升,约16.44%的城市达到较高水平,空间上呈现“东部高、西部低”的特征。人均三维生态足迹增长逐渐趋缓,成渝城市群达到峰值(5.21hm2)后逐年稳定下降。长江经济带绿色发展与生态足迹处于良好协调状态,绿色经济的快速发展带动了耦合协调度的提高。绿色发展与生态足迹存在倒“ U”形EKC曲线关系,由于自然资源基础和产业结构差异,成渝城市群(拐点出现在2008年)绿色发展与生态足迹协调关系好转早于中下游城市群(拐点分别在2019年、2012年)。四川、安徽应作为降低资源消耗的重点对象,未来应进一步加强区域中心城市的辐射带动作用,拉动周围城市提高绿色发展水平。研究成果能为区域绿色发展与生态环境协同管理提供思路与理论支持。 相似文献
13.
Environmental and economic analysis of switchgrass production for water quality improvement in northeast Kansas 总被引:2,自引:0,他引:2
The primary objectives of this research were to determine SWAT model predicted reductions in four water quality indicators (sediment yield, surface runoff, nitrate nitrogen (NO(3)-N) in surface runoff, and edge-of-field erosion) associated with producing switchgrass (Panicum virgatum) on cropland in the Delaware basin in northeast Kansas, and evaluate switchgrass break-even prices. The magnitude of potential switchgrass water quality payments based on using switchgrass as an alternative energy source was also estimated. SWAT model simulations showed that between 527,000 and 1.27 million metric tons (Mg) of switchgrass could be produced annually across the basin depending upon nitrogen (N) fertilizer application levels (0-224 kg N ha(-1)). The predicted reductions in sediment yield, surface runoff, NO(3)-N in surface runoff, and edge-of-field erosion as a result of switchgrass plantings were 99, 55, 34, and 98%, respectively. The average annual cost per hectare for switchgrass ranged from about 190 US dollars with no N applied to around 345 US dollars at 224 kg N ha(-1) applied. Edge-of-field break-even price per Mg ranged from around 41 US dollars with no N applied to slightly less than 25 US dollars at 224 kg N ha(-1) applied. A majority of the switchgrass produced had an edge-of-field break-even price of 30 Mg(-1) US dollars or less. Savings of at least 50% in each of the four water quality indicators could be attained for an edge-of-field break-even price of 22-27.49 US dollars Mg(-1). 相似文献
14.
从区域经济发展的角度出发,系统研究待开发区域主导产业选择的基本思路.依据主导产业选择原则(发展基础原则、战略分工原则、区域适宜性原则),通过比较研究确定区域发展的产业方向,构建区域主导产业选择的指标体系,采用AHP分析方法对指标进行衡量,最终得出主导产业推荐方案.同时,对营口经济技术开发区进行实证研究,运用上述方法选择适合该区域发展的产业为:港口物流业、冶金钢材业、输变电设备制造业、重型装备制造业、电子信息业和休闲旅游业.本研究为我国待开发区域的主导产业选择提供了一种新思路,其实证分析结果也为营口经济技术开发区的主导产业选择提供了科学依据. 相似文献
15.
Marie-Claire Cordonier Segger 《Natural resources forum》2004,28(1):61-74
This article develops a practical proposal for progress on sustainable development law. It examines the prospects for an international sustainable development law to provide a framework for more effective, coherent governance. Sustainable development law is briefly defined and an analytical framework is provided. Different degrees of integration between economic, social and environmental law are described. Certain principles of international law related to sustainable development are also highlighted. It is argued that these principles may serve to guide law‐makers and jurists where social, economic and environmental law and policy conflict or overlap. Continuing, underlying questions of sustainable development governance are addressed and its global frameworks analysed. The article also focuses on the 2002 World Summit on Sustainable Development, held in Johannesburg in August‐September 2002, and its specific mandate for the United Nations Commission on Sustainable Development (UNCSD) to take related legal developments into account. The article advances a proposal: that governments, economic, social and environmental intergovernmental organizations and other actors establish a ‘network of inquiry’ with members from relevant groups, including legal and academic organizations, and other expert groups, in order to follow, research, analyse and debate legal developments in a balanced way. 相似文献
16.
Gerzabek MH Barceló D Bellin A Rijnaarts HH Slob A Darmendrail D Fowler HJ Négrel P Frank E Grathwohl P Kuntz D Barth JA 《Journal of environmental management》2007,84(2):237-243
The integrated project "AquaTerra" with the full title "integrated modeling of the river-sediment-soil-groundwater system; advanced tools for the management of catchment areas and river basins in the context of global change" is among the first environmental projects within the sixth Framework Program of the European Union. Commencing in June 2004, it brought together a multidisciplinary team of 45 partner organizations from 12 EU countries, Romania, Switzerland, Serbia and Montenegro. AquaTerra is an ambitious project with the primary objective of laying the foundations for a better understanding of the behavior of environmental pollutants and their fluxes in the soil-sediment-water system with respect to climate and land use changes. The project performs research as well as modeling on river-sediment-soil-groundwater systems through quantification of deposition, sorption and turnover rates and the development of numerical models to reveal fluxes and trends in soil and sediment functioning. Scales ranging from the laboratory to river basins are addressed with the potential to provide improved river basin management, enhanced soil and groundwater monitoring as well as the early identification and forecasting of impacts on water quantity and quality. Study areas are the catchments of the Ebro, Meuse, Elbe and Danube Rivers and the Brévilles Spring. Here we outline the general structure of the project and the activities conducted within eleven existing sub-projects of AquaTerra. 相似文献