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1.
《自然地理学》2013,34(1):78-96
Soil erosion has been recognized as one of the major forms of human-induced soil degradation. Due to land use changes in Iran, erosion has increased 800% between 1951 and 2002, calling for urgent action. But erosion research and policy development are hampered by a lack of information on the underlying factors controlling erosion. Soil types vary in their inherent susceptibility to erosion; but, like most countries, Iran lacks a network of field plots where erodibility is measured. A proxy for erodibility based on existing data and supplemented by an easily measured minimum data set is therefore needed. In this study, we use geological mapping and cluster, principal component, and factor analysis to group soils in the Taleghan Drainage Basin in Iran and subsequently determine their erodibility. First, a geological map of the area was prepared by photogeological methods and on-the-ground verification. Then, three soil profiles were investigated within similar landform units of each geological formation, and soil samples were taken. Physical and chemical properties that might impact soil erodibility (soil texture, pH, electrical conductivity, CaCO3, and soil organic matter) were used to create a matrix of soil properties and parent material. Application of cluster analysis and factor analysis to the data allowed identification of three geological (parent material) clusters. To investigate the mutual effect of land use and parent material on soil erodibility, a soil erodibility factor was obtained for three land use types in each cluster: rangeland, cropland (irrigated), and dry-land farming (nonirrigated). Geological cluster 1, consisting of marl, gypsum, and gypsiferous mudstone, was the most erodible; geological cluster 2, consisting of recent alluvium, alluvial fan, and landslip deposits, was of intermediate erodibility; and geological cluster 3, consisting of igneous rocks, dolomite, and conglomerate, was the least erodible. Within each geological cluster, dry-land farming was the most erodible, cropland was medium erodible, and rangeland was least erodible. The study suggests that geological and land use maps provide a useful framework for assessing soil erodibility. This work can guide future soil erosion studies and direct soil conservation policy to areas most susceptible to erosion. 相似文献
2.
Andrew J Dougill Chasca Twyman David S G Thomas & Deborah Sporton 《The Geographical journal》2002,168(3):195-210
Soil degradation assessments for mixed farming systems of the Molopo Basin (North West Province, South Africa and Southern District, Botswana) are provided from farmer–based research, designed to quantify nutrient fluxes across the farming system and to analyze the social, economic, political and environmental factors affecting nutrient management practices. This paper discusses the practical difficulties of how to use participatory farmer–led studies to assess soil degradation extent and its causes, and of then disseminating this information to farming communities and policymakers. Nutrient balance studies show that land degradation is evident on arable fields as soil nutrient depletion (the main threat to poorer manure–reliant farmers) and soil acidification (the main threat to wealthier farmers who have become dependent on inorganic fertilizer additions). Integrated nutrient management strategies involving both compound fertilizer additions and regular manure inputs can mitigate most soil degradation even on the sandy infertile Kalahari soils, but remain infrequently practised. The need to retain nutrient flows through the livestock sector from rangeland to arable land is thus vital to environmental sustainability and offers an applicable entry point for agricultural development initiatives and support. Factors identified as threatening the flow of nutrients from rangelands to arable lands include policy settings in terms of the different support programmes offered to communal farmers, village–level extension advice, household poverty levels and labour constraints. 相似文献
3.
流域土壤侵蚀关键源区的效益评价 总被引：2，自引：0，他引：2
土壤关键源区是指流域内对侵蚀产沙量起决定性作用的区域,控制了关键区域的土壤侵蚀就能有效降低流域的侵蚀量,因此,在关键源区识别的基础上评价基于关键源区的水土流失治理的有效性是流域管理的关键问题.SWAT模型是流域关键源区识别的重要工具,但现有的基于SWAT模型的关键源区识别研究,鲜有对于关键源区水土流失治理效益的评价.本文以黄土高原丘陵沟壑区典型小流域羊道沟流域为例,基于SWAT模型模拟流域内的土壤侵蚀过程,根据HRUs土壤侵蚀模数的排序,将产沙量排在前20％的HRU提取为关键源区.在所提取的关键源区上设置合理的水土保持措施,再基于模型模拟评价水保措施的减沙效果.研究结果表明,SWAT模型能较好地模拟流域的产流产沙过程,所提取的关键源区集中分布在坡度较陡的沟坡和坡耕地.覆盖流域内20％面积的关键源区,其产沙贡献量达到44％.覆盖关键源区的水土保持措施的单位面积减沙量(24115 t km-2 y-1)要显著高于全流域治理的单位面积减沙量(20290 t km-2 y-1),说明基于关键源区布设水土保持措施,能有效提高流域土壤侵蚀控制效率.因此,在关键源区识别的基础上合理布设水土保持措施,是一种有效的流域治理方法. 相似文献
4.
湿地土壤水源涵养功能研究进展 总被引：4，自引：0，他引：4
湿地土壤依靠孔隙而发挥水源涵养功能,广义的湿地土壤水源涵养功能是指湿地土壤内多个水文过程及其水文效应的综合表现,而狭义的湿地土壤水源涵养功能仅指湿地土壤蓄水。主要从土壤水源涵养的机制、计算方法、土壤蓄水量及其对径流调节、影响土壤蓄水的因素等几个方面对当前湿地土壤水源涵养功能的研究进行了综述。土壤涵养水源是由于水分能在土壤孔隙中的存储、持留和运转。从力学的角度看,水分主要依赖于吸附力、毛管力和重力作用而持留。湿地土壤蓄水能力的3种计算方法各有优缺点,计算时应结合湿地水文波动的实际情况而选择。不同类型湿地的土壤蓄水能力因土壤本身性质而异。湿地土壤蓄水能力受土壤粒径组成、结构、孔隙、有机质和含水量等因素的影响,同时受自然及人为因素的调控。针对当前湿地土壤蓄水能力研究的不足,指出应加强对湿地蓄水能力的定量研究及计算方法的探讨;同时,土地利用对湿地土壤水源涵养功能影响的研究也需进一步加强。 相似文献
5.
中国生态脆弱带人地关系行为机制模型及应用 总被引：22，自引：2，他引：20
以农牧交错带为研究对象,通过建立人地关系行为机制模型,探讨外部社会经济因素影响土地退化的机制,并重点就当前正在实施的退耕还林还草政策所带来的生态经济效果进行分析。模型拟合结果显示,利用玉米及农作物秸秆作为饲料,扩大舍饲动物饲养,或者扩大种植葵花或油料作物等商品作物以替代自给性作物糜子,将可以在不加剧水土流失的前提下增加农户收入。模型结果还显示,非农就业机会增加时,农户会减少坡地垦殖。这表明推进农村工业化和城镇化发展,增加农民非农就业机会,鼓励农民进城的政策对于黄土高原的水土保持也是有促进作用的。 相似文献
6.
东北黑土区保护性耕作的发展现状与成效研究 总被引：1，自引：0，他引：1
东北黑土区承担着国家粮食安全“稳压器”的重要责任。然而,由于长期超负荷开发利用导致黑土日益退化,黑土资源的永续利用受到严重制约。理论与实践证明,保护性耕作是保护黑土地、推动黑土耕地质量和耕作效益绿色增长的发展模式。综述了保护性耕作的基本内涵及其在东北黑土区的发展现状与技术概况,从保护性耕作在土壤保持、保墒效益、结构改善、固碳培肥和土壤生物多样性增加、节本增效等方面系统评估了东北黑土区实施保护性耕作后的生态与经济效益,提出黑土区实施保护性耕作存在的问题与未来发展方向,以促进黑土地保护与利用协调发展、推动保护性耕作高质量跨越式发展。 相似文献
7.
随着气候变化对农业系统的影响不断加剧,为保障粮食安全,必须掌握变化中的自然与人文因素,判别农 业景观中可调整的关键机制,依据未来的可能情景,尽早订定农业景观优化方案。本研究以土壤侵蚀问题为切入 点,整合相关的环境因子,构建农业景观对土壤侵蚀适应性的研究框架。基本思路为首先通过目前气候变化对土壤 侵蚀的影响研究,为不同时空尺度上土壤侵蚀发生、发展趋势提供理论依据;其次,从增强未来农业景观对土壤侵 蚀适应能力的角度,详细讨论景观类型、空间配置和管理措施等与土壤侵蚀的关系,以提高农业景观优化配置的针 对性;最后,为科学评价农业景观对土壤侵蚀适应的程度,基于Agent 模型原理设计土壤侵蚀模拟模型,通过不同 土壤侵蚀情景下景观类型、结构、空间配置和管理措施等的适应性分析,为有效提升区域农业景观的土壤抗侵蚀能 力提供科学依据。 相似文献
8.
LAWRENCE S. GROSSMAN 《Geographical review》1997,87(3):353-374
ABSTRACT. A political-ecological perspective is used to analyze soil erosion, conservation, and the peasantry on Saint Vincent in the Eastern Caribbean. Peasants farm areas most susceptible to erosion because of the historical development of property relationships. A soil-conservation effort begun in the late 1930s was part of a broader, British Empire-wide program. Local political-economic conditions and the environmental and technical characteristics of the cropping systems influenced the nature of soil conservation on Saint Vincent. Official colonial discourse about erosion reflected a complex mixture of blaming peasants and recognizing their political-economic constraints. 相似文献
9.
Michael Stocking 《Applied geography (Sevenoaks, England)》1983,3(1):63-77
Farming and environmental degradation are inextricably linked through a complex of political, social, economic and physical forces. A connection is drawn between the initiation and maintenance of distinct farming systems (commercial, emergent and subsistence) by largely human influences, and the effect these farming systems have in turn on the environment. There are important implications for the environment through indirect effects on plant cover, cultivation methods and systems of bush fallowing. In many respects subsistence cultivation is probably the safest.A case study from Mkushi District, Central Province exemplifies the influence of external factors on environmental degradation in general, and soil erosion in particular. In the survey, traditional practices show fewer signs of soil erosion than commercial farming because of rational decisions taken by each group of farmers. The implication for conservation strategies is briefly reviewed. 相似文献
10.
Soil and water conservation technology plays an important role in soil and water loss control and the construction of the ecological civilization in vulnerable areas. Here, soil and water conservation technology use over 70 years for the Zhifanggou watershed is summarized and ecological, economic and social backgrounds are determined through consultation with experts and reference to published literature. We found that soil and water conservation technology use includes soil and water conservation engineering technology, soil and water conservation cultivation technology and soil and water conservation biotechnology. Soil and water conservation technology utilization varied with people’s demands and core problems at different developmental stages of the agricultural eco-economic system. The coupling process of the agricultural eco-economic system at Zhifanggou went through three stages. In stages I and II, soil and water conservation cultivation technology was applied to meet farmers’ basic life demands. In stage III, all three technologies were applied comprehensively to solve eco-environmental problems and adjust industrial structure. To facilitate regional ecological civilization construction and sustainable development of the ecological economy and society, more emphasis should be given to research and development, implementation of soil and water conservation technology, stand structure improvement, forest grass quality enhancement, biodiversity, ecosystem functional improvement, development of soil and water conservation ecological resources, the coupling of soil and water conservation, and agricultural industry-resource optimization. 相似文献
11.
Analysis of the development of research and technical application is a critical basis for the identification and evaluation for suitable soil and water conservation ecological technology (SWCET) in China. Among instruments for analyzing the development of research and technical application, bibliometric statistics and visualization tools such as CiteSpace have been widely applied. To analyze the domestic development of SWCET, we applied CiteSpace to the CNKI (China National Knowledge Infrastructure) database on Chinese research literature (from Jan 1985 to Mar 2017) and patents (Jan 2002 to Feb 2017). The circulation of research after 2002 and quantity of patents after 2010 increased rapidly. Research institutions, people and interests were dispersed, a strong center of research has not been formed and cooperation among research institutions is weak. The number of patented inventions in western regions of China suffering serious soil erosion is far lower than that in eastern regions such as Jiangsu, Beijing, Shandong and Guangdong. Vegetation restoration, ecological slope protection and protective cultivation are relative hotspots according to technical measures: the Loess Plateau, stony desertification (area) and dry-hot valley according to research area, and expressway, side slope and sloping cropland according to application area. Research hotspots mainly appeared several years after the number of published papers increased in 2002. In the past five years, only stony desertification has emerged as a focus. We argue that further studies on the identification and evaluation of SWCET should be focused on certain technical measures, regions and areas. 相似文献
12.
What kind of intensification? Agricultural practice, soil fertility and socioeconomic differentiation in rural Burkina Faso 总被引：1，自引：0，他引：1
LESLIE C GRAY 《The Geographical journal》2005,171(1):70-82
In rural Burkina Faso, intensification has been an uneven process that has resulted in social costs, particularly in the form of uneven distribution of assets and disparate environmental trade-offs. This study examines the effects of wealth status on agricultural practice and soil fertility, arguing that differences in the practices of wealthier and poorer farmers lead to differential social and environmental outcomes. Two concerns are highlighted. First is the role of poverty in environmental degradation. Much of the debate about the role of wealth and poverty in environmental outcomes in developing countries has pinpointed poverty as the main causal explanation. Using studies of agricultural practices and soil fertility from several villages in southwestern Burkina Faso, this paper will counter this dominant view by showing that wealthier farmers farm much larger areas, have fewer trees in their fields, and use higher levels of animal traction which, in turn, has led to lower levels of soil fertility. A second concern is that while poorer farmers may have agricultural practices that minimize environmental degradation, their exclusion from key institutions that provide access to resources has serious livelihood consequences and potentials for increasing socioeconomic differentiation. The agricultural practices of wealthier farmers, while not optimal environmentally, result in higher levels of household wealth. A paradox emerges that while poorer farmers are conserving environmental resources, they are doing so at the expense of economic development and well-being. 相似文献
13.
农户水土保持行为与生态环境变化关系密切，分析农户水土保持行为响应机理对退耕还林政策的实施具有重要意义。通过对江西省丰城市梅林镇多元回归模型分析，结果表明：（1）农户水土保持行为与退耕还林实施力度、退耕地收入与退耕还林后补偿比重成正相关，与退耕补偿年限成负相关；（2）农户水土保持投入减少反映农户家庭收入结构发生变化：从农业为主的收入阶段向以非农业或农业与非农业收入为主的阶段转变；（3）退耕还林政策实施农户水土保持行为响应以效益引导型为主。据此，提出相关建议。 相似文献
14.
In 2015 China’s Ministry of Agriculture introduced two Actions that seek to achieve zero growth in the use of chemical fertilizer and pesticides by 2020. Success in reaching these targets will help control agricultural non-point source pollution, increase cost efficiency, energy conservation and emission reductions, help to ensure the safety and quality of the national grain supply and agricultural products and the safety of the ecological environment, and realize the sustainable development of agriculture. However, successful implementation will be crucial. This article considers the main contents of the Actions and analyzes their feasibility from the perspectives of policy formulation, local practices, technical support and achievements. We identify problems and challenges and suggest that zero growth of chemical fertilizer and pesticide use can be achieved by undertaking basic research on the factors that shape the use of farm chemicals, making improvements to the monitoring and statistical system for chemical fertilizer and pesticide use, setting up demonstration projects and enhancing policies formulated to reduce chemical fertilizer and pesticide use. 相似文献
15.
社会—生态系统视角下农户对禁牧政策的适应性——以宁夏盐池县为例 总被引：2，自引：2，他引：0
为了保护草原生态环境,2002年起国家全面实施“退牧还草”工程,在草原破坏严重的地区实施禁牧政策。政策实施后,草地生态明显恢复。作为草原最主要的经济活动主体和禁牧政策的最直接承受者,农户对政策的适应性直接影响政策的顺利进行以及生态环境恢复的可持续性。基于宁夏盐池县入户调查资料,研究了不同类型农户对禁牧政策的生态环境效应感知以及对禁牧政策适应能力感知,分析了不同类型农户对禁牧政策的应对策略,探讨了影响农户适应策略选择的主要因素。结果表明：（1）盐池县社会-生态系统尚处于不理想的系统稳态,生态系统恢复明显,但社会系统的适应性较低。农户普遍认为禁牧政策实施对生态环境有很大的改善,但对禁牧政策满意度感知处于中等水平,对禁牧政策适应能力的感知处于较低水平。由于生计方式和收入水平的差异,不同类型农户对禁牧政策的适应性感知差异较大。（2）不同类型农户采取不同适应策略应对禁牧政策实施造成的影响。纯农户适应策略以收缩型为主,兼业户和非农户以调节型为主,低收入和中等收入农户以收缩型为主,高收入农户以调节型为主。（3）农户对禁牧政策的适应成本、自我效能和农户拥有的人力资本、金融资本是影响农户适应性策略类型选择的主要因素。 相似文献
16.
基于2000年、2005年、2010年和2015年土地利用现状遥感监测数据,分别采用景观格局指数和当量因子法测度了黄河流域多尺度景观破碎化和土壤保持服务的时空特征,并且综合运用热点分析工具、普通最小二乘法和空间回归分析模型,探索了2000—2015年黄河流域多尺度土壤保持服务时空演变特征及景观破碎化对土壤保持服务的影响机制。结果如下：① 黄河流域土壤保持服务低值区主要集中分布在黄河流域上游青海-甘肃-宁夏-陕西-内蒙古沿线地区以及流域下游河南和山东,另外省会城市以及周边地区同样是土壤保持服务低值区,土壤保持服务具有显著的尺度依赖性;② 研究期间黄河流域土壤保持服务变化的热点区域主要分布在流域上游黄土高原地区,冷点区域主要分布在黄土高原的周边地区,不同尺度下土壤保持服务变化冷热点差异显著;③ 回归结果显示,经济社会因子与土壤保持服务具有显著的负相关;自然本底因子中海拔和林地面积比重与土壤保持服务具有显著的正相关;景观破碎化指数对土壤保持服务的影响差异性显著。未来黄河流域不同分区土壤保持和土地利用政策的制定不仅需要考虑自然本底和经济社会驱动因子,还应考虑多尺度景观格局破碎化以及空间溢出效应,跨区域协同治理对于黄河流域土地利用政策制定和生态系统保护具有重要现实意义。 相似文献
17.
Geomorphological research has played an important role in the development and implementation of soil erosion assessment tools. Because policy and management approaches include the use of soil erosion assessment tools, soil erosion research directly affects the public in terms of providing information on natural hazards and human impacts, and also as the basis for regulatory policy on land management. For example, soil loss calculations and geomorphological expertise are used to support soil conservation planning, both through agricultural legislation that defines maximum tolerable soil loss rates, and through federal and local legislation that requires soil erosion controls on many construction sites.To be useful for decision makers, soil erosion models must have simple data requirements, must consider spatial and temporal variability in hydrological and soil erosion processes, and must be applicable to a variety of regions with minimum calibration. The growing use of erosion models and Geographic Information Systems (GIS) in local to regional scale soil and water conservation raises concerns about how models are used. This has prompted interest in methods to assess how models function at management scales and with the types of data that are commonly available to users. A case study of a GIS-based soil erosion assessment tool using the process-based Water Erosion Prediction Project (WEPP) shows that using commonly available data rather than research grade data can have (predictably) a significant impact on model results. If model results are then used in management decisions, it is critical to assess whether the scale and direction of variation in results will affect management and policy decisions. Geomorphologists provide unique perspectives on soil erosion and can continue to affect policy through soil erosion research. This research should focus on fundamental processes, but equally important is continued development and evaluation of models that are matched to real world data availability, geomorphic settings, and information needs. 相似文献
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Land use changes from natural ecosystems to industrial agriculture have impacted water quality and wildlife populations in the Mississippi River basin. Government programs providing technical assistance and monetary incentives have not resulted in adequate adoption rates of conservation practices. While there has been a plethora of research examining the factors associated with conservation adoption, significantly less is understood about the relative importance of these factors. Using the Analytic Hierarchy Process (AHP) with agricultural producers in three Midwestern watersheds, we assess the relative importance of environmental and production decision criteria when making decisions to adopt conservation practices. Although AHP provides insight into how decisions may be made at the watershed scale, this methodology also provides insight into how individuals make conservation decisions and may also provide a method for delivering tailored conservation advice and communications. 相似文献
20.
农户保护性耕作技术采纳行为及其影响因素研究综述 总被引：1，自引：0，他引：1
保护性耕作对于防止水土流失、改善土壤质量、保障国家粮食安全等具有重要意义。农户作为保护性耕作技术采纳的直接决策者,研究其采纳行为及其影响因素有助于促进保护性耕作技术的推广应用。基于此,论文系统梳理了国内外农户保护性耕作技术采纳行为及其影响因素的相关研究,以期为更有效的技术推广提供参考。结果发现：不同类型农户的保护性耕作技术采纳行为存在较大差异;农户保护性耕作技术采纳的研究区域较为集中;影响农户保护性耕作技术采纳行为的因素主要包括基本因素(个体特征和家庭特征)和差别因素(社会网络、风险偏好与风险感知、政府政策、心理认知及区位特征)2类。基于上述分析,论文提出了未来重点的研究方向：技术推广要考虑农户群体内的异质性;应注重各种研究理论间的融合;未来可进一步加强多学科交叉的系统研究。 相似文献