黄土丘陵沟壑区坡体稳定性影响因素分析     

张庚  王志强  朱喆 《水土保持学报》2022,36(3):107-114,121

选取黄土丘陵沟壑区纸坊沟小流域为研究区,利用高精度遥感影像(分辨率0.068 m)和DEM (分辨率0.34 m)数据,结合野外调查,对崩塌、滑塌、滑坡、脱落和陷穴等失稳体进行识别,通过统计学、敏感系数方法,利用识别失稳体数据,分析不同类型失稳体空间分布状况,定量研究不同类型失稳体的影响因子敏感程度,揭示不同类型失稳体的主控因子,进一步阐明流域坡体失稳体的空间分布规律和影响坡体稳定性的主控因子。结果表明:(1)利用高精度遥感影像,获取流域失稳体,主要是以小规模和浅层的脱落、崩塌和滑塌为主,三者面积合计为0.417 km²,占流域总面积的5.04%。(2)评价因子内部中,土壤母质的红黏土、土地利用的天然灌木林地和草地、地貌部位的沟坡、坡度＞35°、地形起伏度为0.74~3.34 m是坡体失稳发生的高敏感区域,也是崩塌、滑塌、脱落和陷穴发育共有的敏感区域。(3)影响坡体稳定性主控因子权重由大到小为土壤母质、地形起伏度、坡度、土地利用和坡向。崩塌、滑塌和脱落的主控因子与整体坡体稳定性的主控因子相同,但因子内部权重存在差异。崩塌与整体坡体稳定性影响因子顺序分布一致。滑塌主控因子权重由大到小为土壤母质＞地形起伏度＝坡度＞土地利用＞坡向＞地貌部位。脱落主控因子权重由大到小为土壤母质＞土地利用＞地形起伏度＞坡度＝坡向＞地貌部位。滑坡的主控因子为坡度和地形起伏度。陷穴的主控因子权重由大到小为土壤母质＞地形起伏度＞坡度＞坡向。  相似文献   

Gully erosion and environmental change: importance and research needs   总被引：29，自引：0，他引：29  

J. Poesen  J. Nachtergaele  G. Verstraeten  C. Valentin   《CATENA》2003,50(2-4):91-133

Assessing the impacts of climatic and, in particular, land use changes on rates of soil erosion by water is the objective of many national and international research projects. However, over the last decades, most research dealing with soil erosion by water has concentrated on sheet (interrill) and rill erosion processes operating at the (runoff) plot scale. Relatively few studies have been conducted on gully erosion operating at larger spatial scales.Recent studies indicate that (1) gully erosion represents an important sediment source in a range of environments and (2) gullies are effective links for transferring runoff and sediment from uplands to valley bottoms and permanent channels where they aggravate off site effects of water erosion. In other words, once gullies develop, they increase the connectivity in the landscape. Many cases of damage (sediment and chemical) to watercourses and properties by runoff from agricultural land relate to (ephemeral) gullying. Consequently, there is a need for monitoring, experimental and modelling studies of gully erosion as a basis for predicting the effects of environmental change (climatic and land use changes) on gully erosion rates.In this respect, various research questions can be identified. The most important ones are:

What is the contribution of gully erosion to overall soil loss and sediment production at various temporal and spatial scales and under different climatic and land use conditions?

What are appropriate measuring techniques for monitoring and experimental studies of the initiation and development of various gully types at various temporal and spatial scales?

Can we identify critical thresholds for the initiation, development and infilling of gullies in different environments in terms of flow hydraulics, rain, topography, soils and land use?

How does gully erosion interact with hydrological processes as well as with other soil degradation processes?

What are appropriate models of gully erosion, capable of predicting (a) erosion rates at various temporal and spatial scales and (b) the impact of gully development on hydrology, sediment yield and landscape evolution?

What are efficient gully prevention and gully control measures? What can be learned from failures and successes of gully erosion control programmes?

These questions need to be answered first if we want to improve our insights into the impacts of environmental change on gully erosion. This paper highlights some of these issues by reviewing recent examples taken from various environments.  相似文献   

黄土高原丘陵沟壑区放牧林草地团聚体水稳性的研究     

范春梅  廖超英  孙长忠  许喜明  刘恒柏 《勤云标准版测试》2005,(11)

以黄土高原丘陵沟壑区——山西偏关县为例,对不同放牧植被类型、不同放牧强度、不同放牧畜种条件下表层土(0-10cm)的团聚体水稳性进行分析研究。结果表明,放牧草地较之放牧林地的土壤结构及结构稳定性要好;重度放牧下土壤团聚体含量最小,其结构稳定性亦最差;从畜牧羊种选择来看,绵羊相对于山羊来说对土壤结构破坏较小,土壤中团聚体含量较多、团聚体水稳性也较好。  相似文献   

放牧对黄土高原丘陵沟壑区林草地土壤特性的影响   总被引：1，自引：1，他引：1       下载免费PDF全文

范春梅  廖超英  孙长忠  许喜明  李培玉 《西北农业学报》2006,15(1):24-28

在黄土高原丘陵沟壑区——山西偏关县通过放牧试验研究了草地和柠条林地在不同放牧强度、不同放牧畜种条件下表层土(0~10 cm)的物理和化学性质。结果表明,放牧强度直接影响着草地和柠条林地土壤的物理结构。随放牧强度的增加,牲畜对土壤的践踏加剧,导致土壤紧实度增加,容重上升,含水量下降。草地和柠条林地的水解氮含量都随放牧强度的增加而增加,速效钾含量则都表现为中度放牧>重度放牧>轻度放牧;速效磷的含量草地随放牧强度的增加而减少,柠条林地的速效磷含量则随放牧强度的增加而增加。从畜牧羊种选择来看,绵羊相对于山羊来说对放牧地践踏较轻,土壤容重较小,土壤含水量、水解氮、速效磷和速效钾含量则较高。  相似文献   

李家大沟泥石流与三峡库区奉节县新城建设     

郑建国  李天斌  沈军辉  张志龙 《水土保持通报》2005,25(3):84-87,96

三峡库区奉节县新城建设大大改变了李家大沟中下游的地质环境,泥石流将直接威胁到新城区的建设和人民财产的安全。从工程地质角度出发,对李家大沟泥石流的形成环境(地层岩性条件、构造条件、地貌条件、气象条件、植被发育及人类工程活动)、基本特征(形成区和流通区特征)和形成机制进行了详细的系统研究,对泥石流的危害性和发展趋势做了预测评价,并提出了合理科学的建议。  相似文献   

Gully erosion: Impacts, factors and control   总被引：21，自引：1，他引：21  

C. Valentin  J. Poesen  Yong Li 《CATENA》2005,63(2-3):132

Gully erosion attracts increasing attention from scientists as reflected by two recent international meetings [Poesen and Valentin (Eds.), Catena 50 (2–4), 87–564; Li et al., 2004. Gully Erosion Under Global Change. Sichuan Science Technology Press, Chengu, China, 354 pp.]. This growing interest is associated with the increasing concern over off-site impacts caused by soil erosion at larger spatial scales than the cultivated plots. The objective of this paper is to review recent studies on impacts, factors and control of gully erosion and update the review on ‘gully erosion and environmental change: importance and research needs’ [Poesen et al., 2003. Catena 50 (2–4), 91–134.]. For the farmers, the development of gullies leads to a loss of crop yields and available land as well as an increase of workload (i.e. labour necessary to cultivate the land). Gullies can also change the mosaic patterns between fallow and cultivated fields, enhancing hillslope erosion in a feedback loop. In addition, gullies tend to enhance drainage and accelerate aridification processes in the semi-arid zones. Fingerprinting the origin of sediments within catchments to determine the relative contributions of potential sediment sources has become essential to identify sources of potential pollution and to develop management strategies to combat soil erosion. In this respect, tracers such as carbon, nitrogen, the nuclear bomb-derived radionuclide 137 Cs, magnetics and the strontium isotopic ratio are increasingly used to fingerprint sediment. Recent studies conducted in Australia, China, Ethiopia and USA showed that the major part of the sediment in reservoirs might have come from gully erosion.Gullies not only occur in marly badlands and mountainous or hilly regions but also more globally in soils subjected to soil crusting such as loess (European belt, Chinese Loess Plateau, North America) and sandy soils (Sahelian zone, north-east Thailand) or in soils prone to piping and tunnelling such as dispersive soils. Most of the time, the gullying processes are triggered by inappropriate cultivation and irrigation systems, overgrazing, log haulage tracks, road building and urbanization. As exemplified by recent examples from all over the world, land use change is expected to have a greater impact on gully erosion than climate change. Yet, reconstructions of historical causes of gully erosion, using high-resolution stratigraphy, archaeological dating of pottery and ¹⁴C dating of wood and charcoal, show that the main gully erosion periods identified in Europe correspond to a combination not only of deforestation and overuse of the land but also to periods with high frequency of extreme rainfall events.Many techniques have proved to be effective for gully prevention and control, including vegetation cover, zero or reduced tillage, stone bunds, exclosures, terracing and check dams. However, these techniques are rarely adopted by farmers in the long run and at a larger spatial scale because their introduction is rarely associated with a rapid benefit for the farmers in terms of an increase in land or labour productivity and is often contingent upon incentives.  相似文献   

The impact of environmental change on the intensity and spatial pattern of water erosion in a semi-arid mountainous Andean environment     

Veerle Vanacker  Gerard Govers  Jean Poesen  Jozef Deckers  Gerd Dercon  George Loaiza 《CATENA》2003,51(3-4):329-347

Aerial photographs taken in 1976 and 1989 and a field survey in 1999 showed that land use in a 900-ha catchment in the southern part of the Ecuadorian Andes is highly dynamic. Over 23 years, ca. 83 ha of arable land was abandoned and ca. 70 ha was taken into agricultural production. Changes in land use were not spatially homogeneous. Parcels on unstable geologic formations and close to village centres were preferably set-aside. Land taken into cultivation was preferably located on gently sloping areas close to newly built sites and arterial roads. The area with bush vegetation increased by regeneration of natural vegetation on fields set-aside in the late 1970s and early 1980s. There was a complex interaction between water erosion and environmental change in the study area. Land taken into production was levelled for furrow irrigation: this led to a net reduction in the area susceptible to water erosion. However, one quarter of the area affected only by sheet and rill erosion 23 years ago has since become incised by deep gullies. This increase in gully density was related to inadequate construction and management of irrigation infrastructure, rather than to change in vegetation cover and/or soil erodibility caused by agricultural practices. This factor is often overlooked in studies of the effects of environmental change on geomorphologic processes.  相似文献   

黑土区坡耕地侵蚀沟发育机理   总被引：3，自引：0，他引：3  

唐莉  孟令钦  张锋 《安徽农业科学》2012,40(2):819-821,827

对黑土区5个小流域开展侵蚀沟调查,分析了侵蚀沟的分布和形态特性,发现侵蚀沟主要发生在坡耕地上。通过对垄作的汇流进行计算,发现造成沟蚀快速发展的原因之一是坡耕地实行单一的横坡垄作。因此,在东北黑土区采取水土保持综合措施可防止坡耕地水土流失。  相似文献   

基于LSTM神经网络模拟的陇中黄土高原沟壑区保护性耕作下土壤贮水量变化     

王钧  李广  刘强 《中国生态农业学报》2019,27(8):1226-1237

为分析陇中黄土高原沟壑区不同保护性耕作措施的贮水效果,本研究利用春小麦/豌豆（W/P）、豌豆/春小麦（P/W）轮作的长期定位试验,分别设置传统耕作（T）、免耕（NT）、传统耕作秸秆覆盖（TS）和免耕覆盖（NTS）4种耕作措施,以当地月平均气温、月降水量、月平均辐射量、月平均蒸发量、月作物耗水量为输入因子,以月土壤贮水量为输出,建立基于长短期记忆（Long Short-Term Memory,LSTM）神经网络的土壤贮水量预测模型,并对该模型的有效性进行评估。研究结果表明：1）基于LSTM神经网络建立的土壤贮水量模型对陇中黄土高原沟壑区保护性耕作下土壤贮水量预测具有较好的适用性,模型模拟结果的平均均方根误差为7.76 mm,平均绝对误差为6.95 mm,相对误差控制在-5%~+5%的范围内。2） P/W轮作序列中各处理的土壤贮水量均比W/P轮作序列增加1.09%~1.43%。3）不同轮作序列,NTS处理的贮水效果均优于其他3种耕作措施,在W/P轮作序列中,NTS处理的年均土壤贮水量比T、NT和TS分别增加2.89%、1.70%和2.46%;在P/W轮作序列中,NTS处理的年均土壤贮水量比T、NT和TS分别增加3.03%、1.91%和2.57%。4）不同降水年型,NTS处理的土壤贮水量最高,且干旱年效果更加显著,其中丰水年NTS处理的土壤贮水量比T、NT和TS平均增加2.71%、1.48%和2.19%,而干旱年平均增加3.97%、2.54%和3.64%。5）保护性耕作措施的贮水效果随季节发生变化,作物生长前期（3-5月）保护性耕作措施的贮水优势较为明显,进入作物生长旺盛期（5-6月）保护性耕作措施与传统耕作的贮水效果差异不显著,而作物生长后期（7月）保护性耕作措施较传统耕作土壤贮水量明显增加。基于LSTM神经网络模拟环境下免耕覆盖的贮水保墒效果最好,为陇中黄土高原沟壑区最适宜的保护性耕作措施。  相似文献   

Gully and sheet erosion on subtropical mountain slopes: Their respective roles and the scale effect   总被引：2，自引：0，他引：2  

L. Descroix  J.L. Gonzlez Barrios  D. Viramontes  J. Poulenard  E. Anaya  M. Esteves  J. Estrada 《CATENA》2008,72(3):325-339

As most mountains in tropical and subtropical zones, the Western Sierra Madre suffers active present erosion, which may create some constraints to the social and economic development in the area.The objectives of this study of soil degradation in the Western Sierra Madre, are to determine the respective roles of gully and sheet erosion. This research is based on field observations, field measurements of runoff and, soil losses at the plot, as well as the watershed scales as an analysis of an exhaustive census of the few gullies located in an experimental area.Measured soil losses in the Western Sierra Madre are high although there are few gullies. Most of the sediment yield seems to originate in widespread degraded areas where stoniness is the main evidence of a previous stage of erosion. Previously overgrazing and deforestation were determined as the factors of the appearance of new soil surface characteristics which explain the high runoff and sediment productions. The soil compacted by cattle trampling reduces infiltration. The decrease of the vegetation cover triggers a rise in the splash effect and thus, a soil sealing.These processes induce an increase in runoff and soil losses. The main erosion type has been described as sheet erosion: it is characterised by the removal of fine soil particles and the remains of gravels, pebbles and blocks, which constitute a pavement on the soil. Gullies generally appear on the bottom of wide valleys and depressions, where soils are thick. It is shown that sheet erosion is two orders of magnitude higher than gully erosion at the hillslope scale.Due to the spatial distribution of land use and the geological context such as the heavily degraded areas close to the main rivers, the reduction of runoff and soil loss rates within the extension of a considered area, commonly observed in hydrology, only applies up to the elementary catchments scale (1 to 50 km²). Above this area, runoff coefficient and soil loss rates increase.  相似文献