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1.
艾比湖干涸湖底不同地表类型风蚀强度及粉尘输移通量的风洞试验研究 总被引：2，自引：2，他引：0
以新疆准格尔盆地西部艾比湖干涸湖底及相关邻近地区7种不同形态的原状土为研究对象,通过风洞模拟试验,揭示干涸湖底不同地表类型的风蚀强度和沙/盐尘低空输送通量。结果表明：粉状盐漠和含盐量较低的淤泥-粘土混合物临界启动风速最低,硬质盐壳的临界启动风速最大;大于16 m·s-1的大风是造成艾比湖干涸湖底风蚀的主要动力,7种地表类型中湖相沉积物、风积物、粉状盐漠的风蚀率最大,是风蚀尘暴的主要尘源;风蚀过程中颗粒的初始运动主要集中在0~10 cm高度范围内,以近地面跃移为主,风积物、湖相沉积物和粉状盐漠的输移通量最大。 相似文献
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3.
ABSTRACT. Runoff generation and soil erosion were investigated at the Guadalperalón experimental watershed (western Spain), within the land‐use system known as dehesa, or open, managed evergreen forests. Season and type of surface were found to control runoff and soil‐loss rates. Five soil units were selected as representative of surface types found in the study area: hillslope grass, bottom grass, tree cover, sheep trails, and shrub cover. Measurements were made in various conditions with simulated rainfall to gain an idea of the annual variation in runoff and soil loss. Important seasonal differences were noted due to surface cover and moisture content of soil, but erosion rates were determined primarily by runoff. Surfaces covered with grass and shrubs always showed less erosion; surfaces covered with holm oaks showed higher runoff rates, due to the hydrophobic character of the soils. Concentrations of runoff sediment during the simulations confirmed that erosion rates at the study site depended directly on the sediment available on the soil surface. 相似文献
4.
青海共和盆地土壤风蚀的137Cs法研究(Ⅰ)——137Cs分布特征 总被引：3，自引：1，他引：2
土壤风蚀作为土地沙漠化的首要环节,对其准确测定和评估是十分迫切和必要的。放射性核素137Cs作为人类核试验的产物,以其独特的理化性质而成为研究土壤侵蚀和泥沙沉积一种良好的示踪源。137Cs法在水蚀研究领域已取得了显著的进展,而在风蚀研究中的应用却相对不足,目前尚处于探索阶段。作者选择青海共和盆地作为研究区,探讨137Cs法在土壤风蚀研究中应用的可行性。通过对共和盆地不同类型土壤剖面的137Cs取样分析,基本查清了区域137Cs分布的若干特性,测定出不同类型土地137Cs活度的排序为:林地>干湖盆>高寒草原>旱作农田≈干草原>固定沙丘>荒漠草原>流动沙丘>风蚀地,137Cs总量的排序为:干湖盆>林地>流动沙丘>高寒草原>旱作农田≈干草原>固定沙丘>荒漠草原>风蚀地。并分析了一些典型剖面的137Cs深度分布及其机制,将137Cs深度剖面划分为正常剖面、沉积剖面、侵蚀剖面和人为扰动剖面4种型式。沙丘砂由于遭受反复吹失和沉积,其137Cs含量逐渐减小,趋于微量的均匀化;而高寒草原的137Cs含量在区域上也较为均匀,在深度分布上,接近负指数分布曲线保存了相对完好的137Cs初始沉积剖面,是理想的137Cs背景值样点。 相似文献
5.
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
6.
Exploring some relationships between biological soil crusts, soil aggregation and wind erosion 总被引：5，自引：0，他引：5
A portable wind tunnel was used to test the contribution of biological and physical elements to overall soil aggregation on a soil dominated by biological soil crusts in south-eastern Australia. After moderate disturbance and simulated wind erosion, 90% of surface aggregates on the loamy soil and 76% on the sandy soil were dominated by biological elements (cryptogams). Lower levels of biological bonding were observed on the severely disturbed treatment. Linear regression indicated a significant positive relationship (r2=0·72) between biological soil crust cover and dry aggregation levels greater than 0·85mm. To maintain sediment transport below an erosion control target of 5gm−1s−1 for a 65kmh−1 wind at 10m height, a crust cover of approximately 20% is required. When a multiple regression model which sequentially fitted biological crust cover and dry aggregation greater than 0·85mm was applied to the data, dry aggregation accounted for more of the variation in sediment transport rate than biological crust cover. These data were used to develop a conceptual model which integrates crust cover and dry aggregation, and provides a useful framework within which to predict the likely impacts of changes in soil crust cover and aggregation. 相似文献
7.
Wind tunnel test of the influence of moisture on the erodibility of loessial sandy loam soils by wind 总被引：3，自引：0，他引：3
Loessial sandy loam soils are the major soil categories in the northern Loess Plateau, China. Owing to a dry, windy climate and sparse surface cover, wind erosion is a serious problem and dust (sand) storms occur frequently. Soil moisture is one of the most important factors influencing resistance to wind erosion. The influence of moisture content on the erodibility of sandy loam soils was investigated through wind tunnel simulations. Results showed that the threshold velocity for soil particle movement by wind increases with increasing soil moisture by a power function. The intrinsic factor in the increase in soil resistance due to moisture content is the cohesive force of soil water. Cohesive forces of the film and capillary water are different; the influence of soil moisture on threshold velocity was shown to follow a step-like pattern. The wind erosion modulus of sandy loam was directly proportional to the cube of the wind velocity or the square of the effective wind velocity (V−Vt). There existed a negative exponential relationship between the wind erosion rate and soil moisture content. Initially, as soil moisture increased the decrease in the wind erosion rate was rather rapid. When the moisture content reached more than 4%, the rate of decrease in erosion slowed and became almost constant with successive increments of moisture. This suggests that different soil moisture contents can prevent wind erosion at different levels. Four percent soil moisture could only reduce the erodibility of the sandy loam soil by a small degree. 相似文献
8.
小麦玉米田耕作模式的防风蚀效果 总被引：2，自引：0，他引：2
通过风洞实验，在5个风速下对6种耕作方式下农田土壤风蚀速率、0~20 cm风沙流结构进行了模拟研究。结果表明：保护性耕作土壤风蚀速率较传统耕作平均降低20%~40%；保护性耕作和传统耕作条件下土壤风蚀速率均随风速的增大呈幂函数递增，但在传统耕作条件下递增较快；风速14 m·s-1是荒漠绿洲农田土壤风蚀加剧转折点，当风速>14 m·s-1时保护性耕作下风蚀速率较传统耕作明显降低；0~20 cm内，传统耕作和保护性耕作下输沙率与高度分别呈线性和指数关系，保护性耕作下0~4 cm输沙量和输沙量百分比（Q0~4/Q0~20）均低于传统耕作。 相似文献
9.
农田休闲期不同保护性耕作措施的防风效应研究 总被引：5，自引：2，他引：3
保护性耕作是旱作农田土壤风蚀防治的必要措施\.通过野外试验,对深松、浅耕、翻耕覆盖、免耕油菜低茬和高茬、免耕小麦低茬和高茬等7种保护性耕作措施和传统翻耕、草地两种对照下0～4 m的风流场进行了观测,对各种下垫面上空气动力学粗糙度、摩阻速度、风速绝对脉动强度和相对脉动强度进行对比分析。结果显示,不同保护性耕作措施降低风的侵蚀力,防治土壤风蚀的机制不同。留茬主要通过增加地表空气动力学粗糙度和摩阻速度,利用作物残茬和秸秆等粗糙元分解风对地表的剪切应力,降低风蚀强度。而深松、浅耕、翻耕覆盖等措施在增加地表粗糙度和摩阻速度上效果不如留茬,但近地表0\^05 m处风速脉动较弱,相同风速下对地表的剪切应力较小,土壤风蚀速率降低。此外,作物残茬、秸秆和牧草等粗糙元的高度、密度及直立性均对下垫面的空气动力学粗糙度、摩阻速度及风速脉动有一定影响。 相似文献
10.
水分是干旱区生态过程中主要限制因子,降水可通过改变土壤的干湿状况直接影响土壤的生态过程,继而引起土壤碳库的变化。生物土壤结皮作为干旱区主要的地表覆盖物,其自身不但可以进行呼吸作用,还能充分利用有限的水分通过光合作用固碳,改变土壤圈与大气圈之间的碳交换通量。通过模拟0、2、5、8、15 mm降雨,利用红外气体分析仪,对腾格里沙漠东南缘人工固沙植被区主要的生物土壤结皮覆盖土壤净CO2通量进行了原位测定,探讨生物土壤结皮覆盖土壤CO2释放和光合固定CO2(吸收)共同作用下的土壤净CO2通量对模降雨的响应特征。结果表明:(1)降雨会迅速激发生物土壤结皮覆盖土壤CO2释放,降雨激发CO2释放速率和有效时间取决于降雨量,降雨量越高,激发程度越低,激增的生物土壤结皮覆盖土壤CO2释放(源)效应有效时间随降雨量的增加而延长;降雨激发的土壤碳释放总量随着降雨量的增加显著增加,且藓类结皮覆盖土壤碳释放总量显著高于藻类结皮(P<0.05)。(2)降雨引起生物土壤结皮覆盖土壤CO2吸收速率在初期呈单峰变化,后逐渐回归到降雨前的水平,随降雨量的增加,CO2吸收的效应的时间越长,峰值越高;降雨量越高,生物土壤结皮光合碳固定量越多,当降雨量增加到15 mm时,藻类结皮光合碳固定量显著低于8 mm时的碳固定量;降雨量<5 mm时,藓类结皮光合碳固定量显著低于藻类结皮(P<0.05),≥5 mm时,藓类结皮光合碳固定量显著高于藻类结皮(P<0.05)。(3)干旱荒漠地区生物土壤结皮覆盖土壤,在无降雨的干旱期表现为较低水平的净碳排放效应,不同程度降雨的初期阶段都有短暂的增加土壤碳的汇效应,且碳汇效应的时间随降雨量的增加而延长;适度的降雨会降低长期干旱藻类结皮覆盖土壤向大气的碳排放量,而过高或过低的降雨都会不同程度地增加藻类结皮覆盖土壤向大气的碳排放,降低土壤碳的储量。不论降雨量大小,降雨都会增加藓类结皮覆盖土壤更多碳向大气排放,但随着降雨量的增加,源效应逐渐减弱。降雨量≤8 mm时,藓类结皮覆盖土壤净碳排放总量显著高于藻类结皮(P<0.05),当降雨量>8 mm时,藓类结皮覆盖土壤净碳排放量显著低于藻类结皮覆盖土壤(P<0.05)。因此,干旱区在估算生物土壤结皮覆盖土壤与大气碳交换对降雨的响应规律时,应该充分考虑降雨量大小对生物土壤结皮碳固定量和土壤碳释放组分的效应,明确降雨事件大小对不同类型生物土壤结皮覆盖土壤与大气之间碳交换的作用。 相似文献
11.
Inappropriate anthropogenic activities such as overcultivation and overgrazing of steppe and excessive collection of fuelwood are largely responsible for current desertification in China. However, quantitative information concerning the impacts of human disturbance on soil erosion remains sparse. This study investigated aeolian sandy soil erodibility under human disturbance by wind tunnel simulation. The fixed aeolian sandy soils were taken from an artificial vegetation protective system on mobile dunes at the southeastern edge of the Tengger Desert. The results indicate that: (1) human disturbance such as cultivation can accelerate the erodibility of the fixed aeolian sandy soil. The ratio between total soil loss from the undisturbed soil and the cultivated soil is about 0.004; (2) surface vegetation and microbiotic crust are the main factors responsible for the natural wind erodibility of the fixed sandy soil. Wind erosion rate increases with decreasing percent of the vegetation and crust cover; (3) the grain size distribution shows a higher percentage of particles in the range >1.0 mm and a lower percentage in the range <0.05 mm for the cultivated sandy soil than for the undisturbed fixed sandy soil. 相似文献
12.
土壤微生物量可敏感指示土壤质量，是衡量荒漠地区生态恢复程度的重要生物学指标，而有关荒漠区人为踩踏生物土壤结皮与土壤微生物量关系的研究相对缺乏。以腾格里沙漠东南缘的人工植被固沙区和天然植被区人为踩踏生物土壤结皮下的沙丘土壤为研究对象，分别采集未踩踏、中度踩踏和重度踩踏结皮下0~5 cm和5~15 cm土样并测定土壤微生物量碳和氮。结果表明：人为踩踏藻-地衣结皮和藓类结皮可减少生物土壤结皮下土壤微生物量碳和氮，且土壤微生物量碳和氮随踩踏程度的增加而减少，重度踩踏显著减少土壤微生物量碳和氮（P<0.05），土壤速效磷、速效氮、全磷和全氮的损失是导致土壤微生物量碳和氮减少的重要因子。除踩踏程度外，土壤微生物量碳和氮也受结皮演替阶段的影响。人为踩踏的藓类结皮下土壤微生物量碳和氮显著高于藻-地衣结皮（P<0.05），表明演替晚期的藓类结皮比演替早期的藻-地衣结皮抗干扰能力更强；无论季节如何更替，土壤微生物量碳和氮均表现为未踩踏 > 中度踩踏 > 重度踩踏；人为踩踏结皮下土壤微生物量碳和氮均表现明显的季节变化，夏季 > 秋季 > 春季 > 冬季。腾格里沙漠人工植被固沙区和天然植被区人为踩踏生物土壤结皮可减少土壤微生物量，表明人为踩踏生物土壤结皮可引起土壤质量下降，导致荒漠生态系统的退化。因此，保护荒漠区生物土壤结皮有利于荒漠生态系统的修复。 相似文献
13.
地球化学示踪在现代土壤侵蚀研究中的应用 总被引：4，自引：1，他引：4
土壤侵蚀导致土地退化、农产品产量和品质下降、水环境污染等诸多问题 ,引起各方面的广泛关注 ,而且这个问题随着持续增长的人口压力和农业生产方式深刻变革的影响而日益严重。由于目前广泛使用的高差法、遥感研究法、RUSLE、野外调查法、水土流失监测点法等土壤侵蚀研究方法存在着一些不足 ,因此 ,核素地球化学示踪法、稀土元素示踪法、土壤地球化学指标法等地球化学示踪方法应运而生 ,在土壤侵蚀研究中发挥其独特作用。在比较了各种传统的土壤侵蚀研究方法的优势和不足的基础上 ,作者认为 :1 137Cs、 2 10 Pb可用于研究 30、 40年左右平均土壤侵蚀速率 ,7Be可用于示踪季节性土壤侵蚀和一次降雨事件的土粒运移 ,并说明这些核素的示踪原理和侵蚀速率的定量依据 ;2人为施放稀土元素 ( REE)示踪法适合定量一次或多次降雨事件的侵蚀速率 ,可用于土壤侵蚀理论的研究 ,尤其适合于室内模拟实验的研究 ;3土壤磁化率法和土壤理化性质指标法研究土壤侵蚀是一种处于起步阶段的侵蚀研究方法 ,适用于土壤质量退化研究 ,但要用于土壤侵蚀研究特别是侵蚀速率的定量研究还很不成熟。 相似文献
14.
Theoretical expressions for soil particle detachment rate due to saltation bombardment in wind erosion 总被引：1，自引：0，他引：1
Saltation bombardment is a dominate dust emission mechanism in wind erosion. For loose surfaces, splash entrainment has been well understood theoretically. However, the mass loss predictions of cohesive soils are generally empirical in most wind erosion models. In this study, the soil particle detachment of a bare, smooth, dry, and uncrusted soil surface caused by saltation bombardment is modeled by means of classical mechanics. It is shown that detachment rate can be analytically expressed in terms of the kinetic energy or mass flux of saltating grains and several common mechanical parameters of soils, including Poisson's ratio, Young's modulus, cohesion and friction angle. The novel expressions can describe dust emission rate from cohesive surfaces and are helpful to quantify the anti-erodibility of soil. It is proposed that the mechanical properties of soils should be appropriately included in physically-based wind erosion models. 相似文献
15.
Simon J. van Donk Xuewen Huang Edward L. Skidmore Alan B. Anderson Dick L. Gebhart Valerie E. Prehoda Elizabeth M. Kellogg 《Journal of Arid Environments》2003,54(4):687-703
Military training activities reduce vegetation cover, disturb crusts, and degrade soil aggregates, making the land more vulnerable to wind erosion. The objective of this study was to quantify wind erosion rates for typical conditions at the Marine Corps Air Ground Combat Center, Twentynine Palms, CA, U.S.A. Five Big Spring Number Eight (BSNE) sampler stations were installed at each of five sites. Each BSNE station consisted of five BSNE samplers with the lowest sampler at 0·05 m and the highest sampler at 1·0 m above the soil surface. Once a month, sediment was collected from the samplers for analysis. Occurrence of saltating soil aggregates was recorded every hour using Sensits, one at each site. The site with the most erosion had a sediment discharge of 311 kg m−1 over a period of 17 months. Other sites eroded much less because of significant rock cover or the presence of a crust. Hourly sediment discharge was estimated combining hourly Sensit count and monthly sediment discharge measured using BSNE samplers. More simultaneously measured data are needed to better characterize the relationship between these two and reconstruct a detailed time-series of wind erosion. This measured time-series can then be used for comparison with simulation results from process-based wind erosion models such as the Wind Erosion Prediction System (WEPS), once it has been adapted to the unique aspects of military lands. 相似文献
16.
不同时间尺度下农田土壤风蚀可蚀性的变化 总被引：1，自引：1，他引：0
土壤风蚀可蚀性（简称土壤可蚀性）作为风蚀模型的必要输入参数之一,会随风蚀事件过程、耕作措施以及气象气候等因素发生显著变化,但目前对其变化趋势尚认识不足。本文采用野外观测、采样分析与空间换时间的方法,就次风蚀事件、风蚀月、风蚀季、多年4个时间尺度下坝上地区农田土壤可蚀性变化问题进行研究。结果表明：严重风蚀事件过程中,地表土壤中粒径<0.85 mm干团聚体颗粒的含量明显降低,临界起沙摩阻风速明显升高,输沙率明显减弱,三者均显示土壤可蚀性出现明显降低的趋势。风蚀月、风蚀季和多年3个时间尺度下,农田特别是翻耕农田土壤可蚀性均呈下降的趋势,并且时间尺度越长,土壤可蚀性的下降幅度越大。强烈的风蚀搬运作用可能是造成各时间尺度下坝上地区农田土壤可蚀性普遍下降的主因。为了降低坝上地区农田风蚀的危害,应减少新农田的开垦并尽量避免在风蚀事件高发期进行农田翻耕。 相似文献
17.
Carlos E. Cordova 《自然地理学》2013,34(6):538-567
Soils and alluvial sediments in two wadi systems provide preliminary evidence of intense prehistoric soil erosion in the Plateau of Central Jordan. Magnetic susceptibility, color, secondary carbonate morphology, and soil structure suggest that, at the end of the Pleistocene, red Mediterranean soils (terra rossa soils) extended into areas that today are dry steppes on desert fringes. The chronological correlation between alluvial depositional events and cultural phases in the context of climatic change in the Levant suggests that climatic fluctuations at the end of the Pleistocene, which were characterized by gradual drying and warming, triggered several consecutive cycles of soil erosion. There is also evidence to suggest that the advent of early farming in the early Holocene played an important role in the continuation of soil erosion processes. The results of this preliminary research suggest that studies of ancient soil erosion in this region, red Mediterranean soils are a useful chronological and pedological datum to be correlated with alluvial and colluvial deposits. [Key words: soil erosion, alluvial sequences, red Mediterranean soils, Levant, Jordan, Middle East, soil properties.] 相似文献
18.
《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
19.
黄河内蒙古段土壤风蚀特征模拟 总被引：1，自引：0，他引：1
采集黄河内蒙古段风沙土、灰漠土、棕钙土和灌淤土，在室内进行土壤理化性质测定和风洞模拟试验。对比分析了4种土壤的理化性质和不同风速及含水量条件下的风蚀特征，并量化了不同土壤的风蚀强度与土壤理化性质间关系。结果表明：（1）相对于棕钙土和灌淤土，风沙土和灰漠土易蚀性颗粒含量较大，团聚体、有机质和碳酸钙含量较低，但相同风速和含水量条件下平均风蚀强度风沙土>棕钙土>灰漠土>灌淤土。（2）不同土壤风蚀强度与风速均呈较好的幂函数关系（R2≥0.85，P<0.05），尤其是风沙土和棕钙土，幂函数关系明显优于指数函数。（3）除灰漠土，土壤风蚀强度与土壤含水量均呈较好指数函数关系（R2>0.90，P<0.05），风沙土和灰漠土的风蚀强度突降的含水量临界点在4.5%左右，灌淤土和棕钙土无明显临界点。（4）不同土壤输沙率均随距地表高度的增加而急剧减少。在距地表10 cm范围内，不同土壤输沙率占总输沙率比例风沙土（82.67%）>灰漠土（80.77%）>灌淤土（74.07%）>棕钙土（73.77%），当距地表大于30 cm后，集沙仪中基本收集不到风沙土和灰漠土风蚀颗粒。当轴心风速为16 m·s-1时，不同土壤风沙流结构均表现为单峰曲线。（5）不同土壤风蚀强度与风速、含水量、团聚体、易蚀性颗粒和黏粒含量均呈较强的非线性相关关系（R2=0.76，P<0.05）。易蚀性颗粒含量是影响风蚀强度最主要的土壤属性，其次是干团聚体和黏粒含量。 相似文献
20.
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