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1.
The accelerated urbanization has resulted in new soil erosion in the Loess Plateau region since the 1980s. A concept of urban erosion and its impacts on environment are discussed. The experimental studies and field investigations show that those loose silt and earth piles formed by urban construction can be eroded seriously: Under stormy rain, the amount of sediment from steep man-dumped slope is 10.8-12.2 times that of from uncovered slope land; the result of experiments with the wind tunnel also shows that the damage to the surface structure of dry loess can cause serious soil erosion by wind in some cities of the region. Even if in the urban built-up area, there are many loose sandy soil, mud and silt, which are washed into rivers by city’s ground flow in the rainy season. So, anthropogenically induced soil erosion has made soil erosion more serious around the urban areas. And the urban eroded environment has several characteristics such as fragility, complexity, seasonality and quick variability. Urban areas witness a quick economic growth and have more construction projects than rural areas, which brings more intensive changes of environments during a short period of time or adds some new elements to the erosion system. Therefore erosion has experienced more intensive impact by human activities. So, the possible impact of urbanization on erosion environment must be taken into consideration when designing or planning to exploit natural resources or to develop urban areas in the Loess Plateau. 相似文献
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1 IntroductionThe Loess Plateau region covers an area of 62.4(104 km2 and lies in the center of northern China. Urbanization and economic development have been quickened in recent decades. Both the number of towns established and scale of cities have increased. Although the pace of urbanization has been accelerated, the eco-environmental control in urban areas still lags behind relatively. Moreover, the construction and development of cities damaged the already vulnerable eco-environment to … 相似文献
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黄土高原侵蚀期研究 总被引：22，自引：12，他引：10
黄土高原在沉积的同时也存在着侵蚀,主要是流水、重力等因素造成的。这种侵蚀会受到气候、构造运动以及人类活动控制。资料显示,黄土高原存在3种基本的侵蚀期,一是气候侵蚀期,二是构造侵蚀期,三是人为因素侵蚀期。此外还有气候与构造共同作用产生的侵蚀期和构造与人类共同作用产生的侵蚀期。温湿期风尘堆积少,降水量增多,流水动力增强,是黄土高原理论上的侵蚀期。构造抬升引起侵蚀基准面下降,进而导致黄土高原加快侵蚀,出现构造侵蚀期。人类活动破坏了黄土高原的植被和土层结构,导致黄土高原侵蚀加剧,从而出现了人类因素引起的现代侵蚀加速期。在黄土发育的冷干期,由于植被稀疏,侵蚀量大于温湿期,但堆积量远大于侵蚀量。要改变现代侵蚀状况,就应当加强黄土高原生态环境治理。 相似文献
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本文基于气象、遥感数据,运用RWEQ模型,结合风蚀季节的植被盖度变化对近30年的土壤风蚀量和植被的防风固沙服务功能的时空变化趋势进行了定量评估,揭示了植被盖度变化对防风固沙服务功能的影响。研究表明:中国北方多年平均土壤风蚀量为160.1亿t,并处于下降趋势,土壤侵蚀强度大的区域主要集中在各大沙漠区和植被盖度较低的草地,且春季为我国土壤风蚀的多发期,占全年风蚀量的45.93%;中国北方多年平均防风固沙量为203.1亿t;防风固沙服务功能保有率的分布特征表现为由东南到西北逐渐降低的趋势;工程实施后春季植被盖度的提升区主要集中在黄土高原、青藏高原、河北北部、内蒙古东部以及东北地区;大部分区域的春季植被盖度减小(提高)与防风固沙的服务保有率的下降(提升)呈显著正相关(r0.7,p0.01);前后两个十年相比较草地生态系统的防风固沙服务功能提升幅度最大(2.02%),其次为林地(1.15%)、农田(0.99%)和荒漠(0.86%)。 相似文献
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山东省聊城市水土流失现状及防治对策 总被引：2，自引：0，他引：2
张重阳 《云南地理环境研究》2004,16(4):10-13
聊城市位于华北平原的西北部，历史上黄河多次决口、改道泛滥冲积，上游携带物质在境内决口扇形地和沙质河槽地处大量沉积。土壤质地均为沙质土，结构疏松，春季常随风飘扬滚动，雨季在地表径流的冲蚀下，水土流失和土地沙化十分严重。针对聊城市的自然环境特点、水土流失和土地沙化现状，提出了以生物措施为主、工程措施为辅，同时结合农业现代技术等综合治理的措施，因害设防，形成水土流失综合防治体系。树立人与自然和谐相处的指导思想，发挥生态的自然修复能力，加快水土流失防治速度。 相似文献
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Soil erosion and its response to the changes of precipitation and vegetation cover on the Loess Plateau 总被引：8，自引：2，他引：6
Soil erosion is a major threat to our terrestrial ecosystems and an important global environmental problem. The Loess Plateau in China is one of the regions that suffered more severe soil erosion and undergoing climate warming and drying in the past decades. The vegetation restoration named Grain-to-Green Program has now been operating for more than 10 years. It is necessary to assess the variation of soil erosion and the response of precipita- tion and vegetation restoration to soil erosion on the Loess Plateau. In the study, the Revised Universal Soil Loss Equation （RUSLE） was applied to evaluate annual soil loss caused by water erosion. The results showed as follows. The soil erosion on the Loess Plateau between 2000 and 2010 averaged for 15.2 t hm-2 a 1 and was characterized as light for the value less than 25 t hm-2 a-1. The severe soil erosion higher than 25 t hm-2 a-~ was mainly distributed in the gully and hilly regions in the central, southwestern, and some scattered areas of earth-rocky mountainous areas on the Loess Plateau. The soil erosion on the Loess Plateau showed a deceasing trend in recent decade and reduced more at rates more than 1 t hm 2 a 1 in the areas suffering severe soil loss. Benefited from the improved vegetation cover and ecological construction, the soil erosion on the Loess Plateau was significantly declined, es- pecially in the east of Yulin, most parts of Yah＇an prefectures in Shaanxi Province, and the west of Luliang and Linfen prefectures in Shanxi Province in the hilly and gully regions. The variation of vegetation cover responding to soil erosion in these areas showed the relatively higher contribution than the precipitation. However, most areas in Qingyang and Dingxi pre- fectures in Gansu Province and Guyuan in Ningxia Hui Autonomous Region were predomi- nantly related to precipitation. 相似文献
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Developing an effective approach to rapidly assess the effects of restoration projects on soil erosion intensity and their extensive spatial and temporal dynamics is important for regional ecosystem management and the development of soil conservation strategies in the future. This study applied a model that was developed at the pixel scale using water soil erosion indicators (land use, vegetation coverage and slope) to assess the soil erosion intensity in the Loess Plateau, China. Landsat TM/ETM+ images in 2000, 2005 and 2010 were used to produce land use maps based on the object-oriented classification method. The MODIS product MOD13Q1 was adopted to derive the vegetation coverage maps. The slope gradient maps were calculated based on data from the digital elevation model. The area of water soil-eroded land was classified into six grades by integrating slope gradients, land use and vegetation coverage. Results show that the Grain-To-Green Project in the Loess Plateau worked based on the land use changes from 2000 to 2010 and enhanced vegetation restoration and ecological conservation. These projects effectively prevented soil erosion. During this period, lands with moderate, severe, more severe and extremely severe soil erosion intensities significantly decreased and changed into less severe levels, respectively. Lands with slight and light soil erosion intensities increased. However, the total soil-eroded area in the Loess Plateau was reduced. The contributions of the seven provinces to the total soil-eroded area in the Loess Plateau and the composition of the soil erosion intensity level in each province are different. Lands with severe, more severe and extremely severe soil erosion intensities are mainly distributed in Qinghai, Ningxia, Gansu and Inner Mongolia. These areas, although relatively small, must be prioritised and preferentially treated. 相似文献
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Soil erosion and management on the Loess Plateau 总被引：1，自引：0，他引：1
CAI Qiang-guo 《地理学报》2001,11(1):53-70
The Loess Plateau is well known to the world for its intense soil erosion. The root cause for river sedimentation of Yellow River (Huanghe) and its resultant "hanging river" in certain section is soil and water loss on the Loess Plateau. The Loess Plateau has a long cultivation history, hence population growth, vegetation degeneration and plugging constitute the chief reason for serious soil and water loss on Loess Plateau. This paper analyses several successful cases and failures in soil conservation, presents practical soil conservation technique and related benefit analysis, and discusses some effective methods adopted in China in soil erosion control, research directions and future perspectives on Loess Plateau. 相似文献
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黄土高原土壤侵蚀规律研究工作回顾 总被引：16，自引：1，他引：16
1950年以来,黄土高原土壤侵蚀规律研究工作已建立了完整的分类系统,进行了侵蚀区划,查明了黄河泥沙及其中的粗泥沙来源。定量评价了各自然因子和人为因子与侵蚀量的关系。黄河自古多沙,而近期更加强烈。指出了过去研究工作中的主要问题。 相似文献
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黄河中游土壤侵蚀与下游古河道三角洲演化的过程响应 总被引：10，自引：7，他引：10
根据黄土高原土壤侵蚀的周期特点，结合华北平原古河道，古三角洲的演化过程，应用泥沙输移的过程响应,分析了晚更新世以来黄河中游黄土高原土壤侵蚀与下游古河道，三角洲演化的关系，在人类历史之前，黄土高原土壤侵蚀基本上遵循自在生态环境演化规律，强裂侵蚀期发生在干冷向湿湿气候转化的过渡期，在强裂侵蚀的初期是古道形成期，强烈侵蚀期发生在干冷向温湿气候转化的过渡期，在强裂侵蚀的期是古河道形成期，强烈侵蚀的外营力迭加了人为作用，黄河下游河游泳以改道，三角洲横向扩展发生在强烈侵蚀的衰退期，人类历史时期，土壤侵蚀的外营力迭加了人为作用，破坏了地质历史时期的规律性，土壤侵蚀强度越来越强，基本上按照旱涝变化频率而演化，干冷期降雨不均匀系数增加，土训侵蚀加重，径流量较少，河床以淤积为主，是古河道形成期，正常年黄河泥少输移比接近于一，是三角洲进积期，温湿期降雨量增加，径流量加大，下游河流改道，三角洲横向发展。 相似文献
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Soil erosion and management on the Loess Plateau 总被引：6，自引：3，他引：3
CAI Qiang-guo 《地理学报(英文版)》2001,11(1):53-70
1 Introduction The Loess Plateau situated in northern China covers the drainage basins in the middle reaches of the Yellow River. It starts from the western piedmont of Taihang Mountains in the east, reaches the eastern slope of the Wushao and Riyue mountains, connects the northern part of the Qinling Mountains in the south and borders the Great Wall in the north, covering an area of about 380,000 km2 (Figure 1). The region is overlain extensively by Quaternary loess in great thickness, … 相似文献
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陕西省渭北矿区地处黄土高原，受到自然环境和煤炭开采等人类活动的双重影响，该地区土壤侵蚀更为严重，生态环境更加脆弱。以渭北矿区为研究对象，基于RUSLE模型对渭北矿区土壤侵蚀进行了评估，并综合植被覆盖度、多年平均降水量、坡度、土地利用类型和煤炭年产量等影响因子，应用地理探测器方法对渭北矿区土壤侵蚀进行定量归因。研究结果对矿区水土流失防治具有一定参考价值。结果表明：（1）渭北矿区土壤侵蚀以微度和轻度侵蚀为主，土壤侵蚀严重的区域主要位于研究区西南部、中部和东南部。（2）植被覆盖度和多年平均降水量是造成研究区土壤侵蚀的主导因子，坡度介于20°~25°的地区、植被覆盖度小于0.3的区域和裸地是发生土壤侵蚀的高风险区。（3）渭北矿区各因子协同作用对土壤侵蚀的解释力均大于单因子解释力，因此多个因子共同作用会对土壤侵蚀造成显著影响。 相似文献
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The spatio-temporal characteristics of net primary productivity (NPP) since implementation of the Grain to Green Program (GTGP) are important for understanding ecological restoration of the Loess Plateau in China. Here, we conduct spatio-temporal analysis of NPP using MODIS datasets (500 m, 8-day intervals) and VPM (Vegetation Photosynthesis Model) from 2000-2015. We found that NPP on the Loess Plateau increased significantly from 2000 to 2015 (p<0.05). Significant increases in NPP were observed in core areas of the GTGP, including northern Shaanxi and Lüliang Mountain in Shanxi. NPP in alluvial plains decreased due to urban expansion into cropland. Significant increases in NPP from 2006-2010 were located north of the area of change in 2000-2005. NPP increased across three vegetation types and four slope gradients. In hilly-gully regions prone to soil erosion, such as central and southeastern parts of the Loess Plateau, obvious vegetation restoration was detected. 相似文献
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不同分辨率DEM提取地面坡度的不确定性模拟:以在黄土高原的试验为例 总被引：1，自引：0，他引：1
Slope is one of the crucial terrain variables in spatial analysis and land use planning,especially in the Loess Plateau area of China which is suffering from serious soil erosion. DEM based slope extracting method has been widely accepted and applied in practice. However slope accuracy derived from this method usually does not match with its popularity. A quantitative simulation to slope data uncertainty is important not only theoretically but also necessarily to applications. This paper focuses on how resolution and terrain complexity impact on the accuracy of mean slope extracted from DEMs of different resolutions in the Loess Plateau of China. Six typical geomorphologic areas are selected as test areas, representing different terrain types from smooth to rough. Their DEMs are produced from digitizing contours of 1:10,000 scale topographic maps. Field survey results show that 5 m should be the most suitable grid size for representing slope in the Loess Plateau area. Comparative and math-simulation methodology was employed for data processing and analysis. A linear correlativity between mean slope and DEM resolution was found at all test areas,but their regression coefficients related closely with the terrain complexity of the test areas. If taking stream channel density to represent terrain complexity, mean slope error could be regressed against DEM resolution (X) and stream channel density (S) at 8 resolution levels and expressed as (0.0015S2+0.031S-0.0325)X-0.0045S2-0.155S+0.1625, with a R2 value of over 0.98. Practical tests also show an effective result of this model in applications. The new development methodology applied in this study should be helpful to similar researches in spatial data uncertainty investigation. 相似文献
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TANGGuoan ZHAOMudan LITianwen LIUYongmei ZHANGTing 《地理学报(英文版)》2003,13(4):387-394
Slope is one of the crucial terrain variables in spatial analysis and land use planning, especially in the Loess Plateau area of China which is suffering from serious soil erosion. DEM based slope extracting method has been widely accepted and applied in practice. However slope accuracy derived from this method usually does not match with its popularity. A quantitative simulation to slope data uncertainty is important not only theoretically but also necessarily to applications. This paper focuses on how resolution and terrain complexity impact on the accuracy of mean slope extracted from DEMs of different resolutions in the Loess Plateau of China. Six typical geomorphologic areas are selected as test areas, representing different terrain types from smooth to rough. Their DEMs are produced from digitizing contours of 1:10,000 scale topographic maps. Field survey results show that 5 m should be the most suitable grid size for representing slope in the Loess Plateau area. Comparative and math-simulation methodology was employed for data processing and analysis. A linear correlativity between mean slope and DEM resolution was found at all test areas, but their regression coefficients related closely with the terrain complexity of the test areas. If taking stream channel density to represent terrain complexity, mean slope error could be regressed against DEM resolution (X) and stream channel density (S) at 8 resolution levels and expressed as(0.0015S2 0.031S-0.0325)X-0.0045S2-0.155S 0.1625, with a R2 value of over 0.98. Practical tests also show an effective result of this model in applications. The new development methodology applied in this study should be helpful to similar researches in spatial data uncertainty investigation. 相似文献
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硬化地面与黄土高原水土流失 总被引：3，自引：2，他引：1
在界定硬化地面概念的基础上,进一步将硬化地面分为道路、城镇街区、农家场院三大类。并利用黄土高原400~600mm集流能力试验公式,对甘肃省陇东黄土高原沟壑区不同硬化地面的集流能力、侵蚀量进行分类实例分析研究,发现硬化地面集流能力远大于自然地面,因此城镇、道路、村庄附近的土壤侵蚀尤其严重。在黄土高原地区,不仅与之相关的沟壑的形成和发育,而且相关沟谷和河流的溯源侵蚀之力度大小也要受其影响。随着人口的增加,硬化地面面积越来越大,受其影响水土流失更加严重,这是历史时期黄土高原水土流失日益加剧的重要原因之一。今后黄土高原的水土保持工作,须将防治水土流失与解决水资源紧缺有机结合起来。其最佳解决途径,就是用硬化地面所集中的雨水,作为工农业生产和生活用水,以解决黄土高原水资源之不足。 相似文献
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Slope is one of the crucial terrain variables in spatial analysis and land use planning, especially in the Loess Plateau area of China which is suffering from serious soil erosion. DEM based slope extracting method has been widely accepted and applied in practice. However slope accuracy derived from this method usually does not match with its popularity. A quantitative simulation to slope data uncertainty is important not only theoretically but also necessarily to applications. This paper focuses on how resolution and terrain complexity impact on the accuracy of mean slope extracted from DEMs of different resolutions in the Loess Plateau of China. Six typical geomorphologic areas are selected as test areas, representing different terrain types from smooth to rough. Their DEMs are produced from digitizing contours of 1:10,000 scale topographic maps. Field survey results show that 5 m should be the most suitable grid size for representing slope in the Loess Plateau area. Comparative and math-simulation methodology was employed for data processing and analysis. A linear correlativity between mean slope and DEM resolution was found at all test areas, but their regression coefficients related closely with the terrain complexity of the test areas. If taking stream channel density to represent terrain complexity, mean slope error could be regressed against DEM resolution (X) and stream channel density (S) at 8 resolution levels and expressed as (0.0015S2+0.031S-0.0325)X-0.0045S2-0.155S+0.1625, with a R2 value of over 0.98. Practical tests also show an effective result of this model in applications. The new development methodology applied in this study should be helpful to similar researches in spatial data uncertainty investigation. 相似文献
19.
Soil erosion assessment and prediction play critical roles in addressing problems associated with erosion control or soil
conservation. The past dynamics of soil erosion can provide valuable information for us to understand the relations of soil
erosion to environmental change and anthropogenic activity. The present paper has compared Holocene climatic changes in northwestern
China with those in southern Norway, and investigated the past dynamics of erosion activity during the Holocene. Modern soil
erosion on the Loess Plateau is a combination of the intensive natural erosion and human-induced erosion, the latter being
four times greater than the former. Because of global warming and increasing human activities, climate on the Loess Plateau
is becoming dryer and more unstable, causing an enhanced erosion problem and water scarcity. In the arctic-alpine region of
southern Norway, however, the global warming and regional wetting caused expansion of the largest European ice cap. This has
accentuated the erosion in that region, with a higher frequency of avalanches and debris flows. 相似文献
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Soil erosion assessment and prediction play critical roles in addressing problems associated with erosion control or soil conservation. The past dynamics of soil erosion can provide valuable information for us to understand the relations of soil erosion to environmental change and anthropogenic activity. The present paper has compared Holocene climatic changes in northwestern China with those in southern Norway, and investigated the past dynamics of erosion activity during the Holocene. Modern soil erosion on the Loess Plateau is a combination of the intensive natural erosion and human-induced erosion, the latter being four times greater than the former. Because of global warming and increasing human activities, climate on the Loess Plateau is becoming dryer and more unstable, causing an enhanced erosion problem and water scarcity. In the arctic-alpine region of southern Norway, however, the global warming and regional wetting caused expansion of the largest European ice cap. This has accentuated the erosion in that region, with a higher frequency of avalanches and debris flows. 相似文献