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1.
喀斯特生态系统服务主导影响因子识别是科学治理石漠化的前提,然而环境因子对生态系统服务空间分布的解释力受尺度变换的影响,其尺度效应的定量研究仍需进一步加强。为定量厘定环境因子解释力的尺度效应,本文从多尺度视角出发,利用地理探测器定量分析不同空间分辨率下环境因子对土壤侵蚀和产水量的解释力,并探求其在不同地貌形态类型区的差异性规律。结果表明,坡度和植被覆盖度是影响土壤侵蚀空间分布的主导因子,两者的交互作用对土壤侵蚀空间分布的解释力更强。受研究区地形起伏普遍性和景观破碎化的影响,坡度和土地利用类型在低分辨率下解释力最优。降水、海拔和土地利用类型是产水量空间分异的主导因子。降水和土地利用类型的交互作用对产水量的解释力达95%以上,海拔在不同地貌形态类型区的空间变异性影响其最优解释力水平。具体表现为：在台地、丘陵类型区海拔空间变异性较小,在高分辨率下其解释力最优;在山地类型区,海拔空间变异性较大,在低分辨率下其解释力更强。本文通过多尺度分析定量甄别生态系统服务变量的最优解释力,以期为喀斯特山地生态系统服务的主导因子精准辩识和分区优化提供途径和依据。 相似文献
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中国南方岩溶区土地石漠化的成因与过程 总被引：18，自引：2，他引：16
中国南方岩溶区是石漠化广为发展的脆弱生态区域。南方岩溶区土地石漠化的起因既有自然因素,也有人为因素。在地质历史时期其自身环境孕育和存在着自然石漠化过程,在历史时期—现代自然石漠化过程又叠加了人为石漠化过程,人为活动加速、加剧了石漠化的发展。清朝初、中期是人为活动影响石漠化的重要转折时期,此后人为因素作用比重逐渐超过自然因素的作用比重。岩溶区土地石漠化过程是由植被退化丧失过程、土壤侵蚀过程、地表水流失过程、基岩溶蚀侵蚀过程、土地生物生产力退化过程合成的地表生态过程,其实质是形成石质荒漠的土地退化过程。 相似文献
3.
土壤侵蚀模型是定量研究土壤侵蚀的有效工具,探讨土壤侵蚀模型研究中的有关问题对于土壤侵蚀模型的发展及相关研究具有重要意义。从模型的过程模拟、模型时空尺度变异、模型验证和不确定性几方面对模型研究现状及局限进行了归纳和分析,认为:不同过程的模拟及其模拟方法的不同导致了各具特色的土壤侵蚀模型的出现;大多水蚀模型是对不同时空尺度上的水流及相应侵蚀过程进行模拟预测,在不同的时空尺度上,不同的侵蚀过程占主导地位;现实过程和现象的复杂性、观测方法和手段的限制以及模型的自身的局限性是导致土壤侵蚀模型预测的不确定性的主要原因;与GIS结合的强预测力、低数据要求的模型是土壤侵蚀模型发展的趋势。 相似文献
4.
From water to tillage erosion dominated landform evolution 总被引：3，自引：1，他引：3
While water and wind erosion are still considered to be the dominant soil erosion processes on agricultural land, there is growing recognition that tillage erosion plays an important role in the redistribution of soil on agricultural land. In this study, we examined soil redistribution rates and patterns for an agricultural field in the Belgian loess belt. 137Cs derived soil erosion rates have been confronted with historical patterns of soil erosion based on soil profile truncation. This allowed an assessment of historical and contemporary landform evolution on agricultural land and its interpretation in relation to the dominant geomorphic process. The results clearly show that an important shift in the relative contribution of tillage and water erosion to total soil redistribution on agricultural land has occurred during recent decades. Historical soil redistribution is dominated by high losses on steep midslope positions and concavities as a result of water erosion, leading to landscape incision and steepening of the topography. In contrast, contemporary soil redistribution is dominated by high losses on convex upperslopes and infilling of slope and valley concavities as a result of tillage, resulting in topographic flattening. This shift must be attributed to the increased mechanization of agriculture during recent decades. This study shows that the typical topographical dependency of soil redistribution processes and their spatial interactions must be accounted for when assessing landform and soil profile evolution. 相似文献
5.
A review of runoff generation and soil erosion across scales in semiarid south-eastern Spain 总被引：3，自引：0，他引：3
Y. Cantón A. Solé-Benet J. de Vente C. Boix-Fayos A. Calvo-Cases C. Asensio J. Puigdefábregas 《Journal of Arid Environments》2011,75(12):1254-1261
Climate, lithology, soil and especially, intense land use/cover changes, make SE Spain very vulnerable to runoff generation and water erosion leading to loss of nutrients and organic matter and to infrequent but devastating floods, reservoir siltation and mass failures. This susceptibility has led to heavy economic investment and research efforts since the 1980s, making this region a worldwide reference for understanding the hydrology and geomorphology of semiarid ecosystems. Runoff and soil erosion have been intensively studied throughout the last decades in various natural ecosystems as well as in abandoned farmlands. Research has considered a wide range of methods and spatial and temporal scales. This paper reviews the methods and data describing runoff generation and water erosion, synthesising the key processes involved, rates, thresholds and controlling factors from a scale-dependent perspective. It also identifies the major gaps in current knowledge to provide recommendations for further research towards solutions that reduce the negative impacts of erosion. Research in SE Spain has contributed significantly to a better understanding of the effect of spatial and temporal scale on runoff and sediment yield measurements, and highlighted the important role of distinct erosion and sediment transport processes, hydrologic connectivity, spatial and temporal patterns of rainfall, the occurrence of extreme events and the impacts of land use changes. The most effective ways and challenges to predict runoff, soil erosion and sediment yield at the catchment scale are also discussed. 相似文献
6.
以石羊河流域下游——民勤绿洲为研究区域,通过野外采样、实地调查和实验分析,对不同土地利用类型下（耕地、林地、草地、湿地、盐碱地、撂荒地和荒漠）土壤的水盐特征进行研究,结果表明研究区土壤含水率整体偏低,范围为5.35%~20.58%,土壤含盐量的平均值为47.02 g·kg-1,盐渍化程度严重。土壤含水率和含盐量表现为中等变异性,说明其易受到气候、地形、水文地质以及人为活动的影响。不同土地利用类型下土壤水盐的垂直分布差异显著,土壤含水率在垂直方向上的变化特征较为复杂,但含盐量在垂直方向上主要表现为“表聚型”和“振荡型”。民勤绿洲各土层土壤水盐的水平分布均呈条带状分布,土壤含水率整体表现出西高东低,南高北低,而土壤含盐量则表现出相反的趋势。 相似文献
7.
黑河下游地下水波动带土壤盐分空间变异特征分析 总被引：18，自引：3，他引：15
以黑河下游地下水波动带为研究区,根据64个样点的实验数据,采用地统计分析法对区域土壤盐分空间变异函数理论模型进行了选择,同时还利用GIS交叉验证(Cross-Validation)对目前较为薄弱的空间插值方法的适用性选择问题进行了分析.并在此基础上对整个区域土壤盐分空间分布进行了模拟,进而分析了其空间变异特征.结果表明:(1) 受地下水影响,黑河下游地下水波动带土壤盐分含量整体较高,且其空间分布具有明显的变异特征.在沿河流流向及垂直于河流流向方向上,各盐分要素在整体规律性变化基础上都存在局部性变异,且这种局部性变异在垂直于河流流向方向上比河流流向方向更显著;(2) 各盐分要素的变程为本研究今后合理布置采样点提供了参考依据,同时也为黑河下游地区水文及生态研究提供了有关研究尺度的参考信息;(3) 研究区土壤盐分空间分布模拟也为该区植被恢复提供了必要的土壤盐分信息,这对本区乃至整个黑河下游植被恢复及生态重建工作都具有重要指导意义. 相似文献
8.
Soil erosion is a complex process determined by mutual interaction of numerous factors. The aim of erosion research at regional scales is a general evaluation of the landscape susceptibility to soil erosion by water, taking into account the main factors influencing this process. One of the key factors influencing the susceptibility of a region to soil erosion is land cover. Natural as well as human-induced changes of landscape may result in both the diminishment and acceleration of soil erosion. Recent studies of land-cover changes indicate that during the last decade more than 4.11% of Slovak territory has changed. The objective of this study is to assess the influence of land-cover and crop rotation changes over the 1990–2000 period on the intensity and spatial pattern of soil erosion in Slovakia. The assessment is based on principles defined in the Universal Soil Loss Equation (USLE) modified for application at regional scale and the use of the CORINE land cover (CLC) databases for 1990 and 2000. The C factor for arable land has been refined using statistical data on the mean crop rotation and the acreage of particular agricultural crops in the districts of Slovakia. The L factor has been calculated using sample areas with parcels identified by LANDSAT TM data. The results indicate that the land-cover and crop rotation changes had a significant influence on soil erosion pattern predominately in the hilly and mountainous parts of Slovakia. The pattern of soil erosion changes exhibits high spatial variation with overall slightly decreased soil erosion risks. These changes are associated with ongoing land ownership changes, changing structure of crops, deforestation and afforestation. 相似文献
9.
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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由于不同的环境背景下环境机制不同,所以导致了水盐（主要指水分、盐分）空间变异存在很大差异,在此背景下分析艾比湖地区含水量与含盐量空间变异,有助于更加合理的了解土壤含水量与含盐量一体化规律。以艾比湖为中心把艾比湖区域分为三个靶区：绿洲、荒漠、湖区,运用统计学方法,分析三个区域的土壤水分、盐分差异性特征。结果表明：绿洲、荒漠、湖区这三个区域表层土壤盐分积聚严重,其含盐量大小依次为：荒漠→绿洲→湖区,而含水量却相反;绿洲、荒漠和湖区土壤含盐量的变异系数均在85%～150%之间,属高强度变异,含水量变异系数均介于55%～75%之间,属中强度变异。说明荒漠区域盐分含量的水平分布不均匀,空间异质性较强;而水分含量的水平相对较为均匀,空间异质性较弱。绿洲、荒漠、湖区土壤层10～20 cm与20～40 cm土壤层含盐量的存在显著性相关性（p<0.01）,即绿洲的相关系数0.913,荒漠的相关系数0.966,湖区的相关系数0.941,绿洲与湖区土壤表层与亚层含水量存在显著性相关性（p<0.01）相关系数分别为0.851 和0.908。说明绿洲与湖区土壤层0～10 cm与10～20 cm土壤含水量存在水分转移现象,荒漠区域这种现象不明显,可能与沙漠炎热地表环境和土壤性质等因素有关。研究结果揭示了艾比湖地区不同环境背景下秋季的土壤含水量与含盐量分布特征,为艾比湖地区农作物灌溉管理及土壤盐渍化治理提供了科学依据。 相似文献
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山区土地利用/覆被变化对土壤侵蚀的影响 总被引：42，自引：6，他引：36
本文以福建省山区为例,在对福建省水土保持实验站、建瓯市牛坑龙水土保持试验站长期观测、实验资料深入分析对比的基础之上,探讨了土地利用/土地覆被变化对土壤侵蚀的影响规律。分析结果表明,土地利用/土地覆被变化对径流的产生和土壤侵蚀有重要影响,植被的覆盖度的变化直接影响着径流系数和土壤侵蚀模数;植被的覆盖度和径流系数呈负线性关系,随着覆盖度的增加径流系数逐渐减小;植被覆盖度和土壤侵蚀模数为负指数关系,随着植被覆盖度的增大,土壤侵蚀模数急剧下降。 相似文献
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黄河三角洲多尺度土壤盐分的空间分异 总被引：20，自引：5，他引：15
本文利用多尺度采样数据,探索了两个深度土壤盐分的空间分异,分析了不同尺度、深度土壤盐分的变异系数和空间相关性(结构方差与基台值之比)的变化,揭示了形成这种空间变异的地貌因素,最后利用普通克立格(ordinary kriging)方法对土壤盐分的分布进行了估测。分析发现,研究区土壤盐分的空间变异具有三个尺度。随着采样间隔的增加和区域的扩大,盐分分布空间相关性增强,且下层比上层具有更高的空间相关性。地貌因素(微地貌类型、坡度和高程)均具有较高的空间相关性,当与地貌因素关系密切时,该尺度及深度的土壤盐分空间相关性就大;反之,则小,这时可能主要受具有较小空间相关性其他因子的影响(如人为活动)。最后对合理的土壤采样提出了建议。 相似文献
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塔里木河源流区绿洲土壤含盐量空间变异和格局分析——以岳普湖绿洲为例 总被引：18，自引：0，他引：18
基于区域变量理论,在GPS和GIS技术支持下,通过地统计学的半变异函数和Kriging空间插值,以岳普湖绿洲为例,定量分析塔里木河源流区绿洲不同层次土壤盐分的空间异质性。结果表明:0~30cm、30~60cm和60~100cm土壤盐分半方差函数的理论分布模型属于指数模型,100~200cm属于球状模型。不同土层之间的空间自相关范围具有明显的差异,由表层至深层,土壤盐分的自相关范围逐渐增大。土壤盐分的空间格局分析表明,在水平方向上,研究区各层土壤盐分的高值区主要集中分布在人类活动强烈、靠近河渠水源和地势较为低洼区域;在垂直方向上,土壤表层盐分含量最高,向深层逐渐减少。 相似文献
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天山南麓山前平原土壤盐分空间异质性对植物群落组成及结构的影响 总被引：2，自引：1，他引：1
将轮台天山南麓山前平原中下部自北至南分为4个地貌带:洪水剥蚀带、溢出带、三角洲带及两河交汇区带。并以土壤电导作为积盐程度的指标,分析了天山南麓山前平原4个地貌带土壤盐的分布特征:溢出带和三角洲带土壤盐分含量高,两端洪水剥蚀带和两河交汇区带盐分含量低。物种多样性及物种组成分析结果表明,自北至南物种多样性及物种数量都在下降,洪水剥蚀带主要为柽柳群落、琵琶柴群落,溢出带主要为柽柳群落、盐节木群落、盐角草群落,三角洲带及两河交汇区均为柽柳群落。通过相关性分析,土壤盐分与群落物种多样性相关性不显著。但是,土壤盐渍化的变化明显影响到植物群落物种组成的变化、群落类型的空间分布和演替。 相似文献
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黑土侵蚀速率及其对土壤质量的影响 总被引：35，自引：3，他引：32
利用137Cs示踪法,研究了东北黑土耕作土壤的流失厚度和速率,探讨了水土流失对土壤机械组成、有机质、土壤水分、容重及其N、P含量的影响。结果表明:研究区侵蚀坡面137Cs的分布深度在0～25cm,137Cs的活度在1246.05±85.90～1499.45±101.73Bq/m2,侵蚀厚度可达0.316～0.433mm/a,侵蚀强度3033.6～3940.3t/km2·a,已属于中度侵蚀水平。水土流失造成土壤质地粗化,从坡顶向坡底,耕层土壤有机质增加、容重变化不大,含水量增加,土壤养分的“贫化”现象明显。 相似文献
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基于土壤侵蚀控制度的黄土高原水土流失治理潜力研究 总被引：11，自引：1，他引：10
以整个黄土高原为研究对象,首先将水土保持措施容量定义为某一区域能容纳的最大适宜水土保持措施量。根据梯田、林地和草地的适宜布设区域,在地理信息系统（GIS）软件的支持下,确定了黄土高原的水土保持措施容量。使用修正通用土壤流失方程（RUSLE）,计算了最小可能土壤侵蚀模数和2010年现状土壤侵蚀模数,并将水土保持措施容量下的最小可能土壤侵蚀模数与现状土壤侵蚀模数之比定义为土壤侵蚀控制度。随后使用土壤侵蚀控制度,对黄土高原水土流失治理潜力进行了研究。结果显示：黄土高原2010年现状土壤侵蚀模数为3355 t·km-2·a-1,最小可能土壤侵蚀模数为1921 t·km-2·a-1,土壤侵蚀控制度为0.57,属于中等水平。相比于现状条件,在水土保持措施容量条件下,微度侵蚀区比例从50.48%提高至57.71%,林草覆盖率从56.74%增加至69.15%,梯田所占比例由4.36%增加到19.03%,人均粮食产量可从418 kg·a-1提高至459 kg·a-1。研究成果对于黄土高原生态文明建设具有一定的指导意义。 相似文献
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Techniques for simultaneous quantification of wind and water erosion in semi-arid regions 总被引：3，自引：0，他引：3
Wind and water erosion are usually studied as two separate processes. However, in semi-arid zones both processes contribute significantly to soil degradation. Whereas for water erosion the direction of sediment transport is controlled by topography, in wind erosion the direction of transport is controlled by the wind direction. Furthermore, the spatial pattern of erosion and deposition for wind erosion is determined by the spatial distribution of source material, soil erodibility factors and non-erodible roughness elements. Given this difference in dependence on topography, different approaches are needed to determine the mass balance for a given area. For water erosion, the research area has to be defined such that no input of sediment occurs, whereas in wind erosion the input and output fluxes of sediment should be measured, or a non-eroding boundary should be created.In semi-arid regions, wind erosion events are often followed immediately by heavy rain. As wind and water erosion occur almost simultaneously at the same site, the effect of wind and water erosion at a given site should be studied concurrently. To do so, a number of measurement techniques with different spatial and temporal scales are necessary. The research should be started at the scale of a Sahelian field. For a complete insight into the processes at a site, the research should include measurement techniques that quantify the impact of wind and water erosion separately and techniques that quantify their combined effect. 相似文献
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20.
Hydrological responses and soil erosion potential of abandoned cropland in the Loess Plateau, China 总被引：17，自引：0，他引：17
Recent changes in hydrological processes and soil erosion in the Loess Plateau, China, are immediate responses to cropland abandonment for revegetation, which lead to a long-term decrease in runoff generation and soil erosion. However, detailed hydrological responses and soil erosion changes have not been clearly evaluated. In this study, two issues were focused on the plot scale. The first issue relates to changes in vegetation cover and soil properties during the early stages of revegetation. Given the occurrence of soil compaction, it was hypothesized that runoff increased during this period and the soil erosion did not significantly decline, even though vegetation increased. The second issue is the effect of scale on runoff and soil erosion. Three plot groups of three vegetation types and two restoration stages were established for comparative experiments. The results from these experiments confirmed that the soil compaction occurred during revegetation in this region. Greater runoff was produced in plot group that experienced both a longer restoration time and with higher vegetation cover (such as Groups 2 and 3 in this study) than that with a shorter restoration time and lower vegetation cover (Group 1). In addition, the total soil loss rates of all plot groups were rather low and did not significantly differ from each other. This indicates that a reduction in runoff generation and soil erosion, as a result of revegetation, was limited in the early stages of restoration following the cropland abandonment. With increasing plot area, the runoff coefficient decreased for the plot group with a longer revegetation time (Groups 2 and 3), but gently increased for the one with a shorter restoration time (Group 1). In Groups 2 and 3, soil loss rate decreased when plot area enlarged. In Group 1, it decreased before a plot area threshold of 18 m2 was exceeded. However, the increase occurred when plot area crossed the threshold value. In conclusion, the high vegetation cover alone did not lead to reduction in the runoff coefficient during the early stages of revegetation. When evaluating hydrological and soil erosion responses to revegetation, the soil compaction processes should be considered. Additionally, the effect of scale on runoff and soil erosion was found to be dependent on restoration extent, and thus on restoration time. 相似文献