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阴山北麓不同用地方式下春季土壤可蚀性研究 总被引：1，自引：0，他引：1
阴山北麓位于中国北方农牧交错带内,此区属于生态环境脆弱地带,加之人类对土地资源的不合理利用,导致了严重的土壤风蚀问题,土壤可蚀性是影响土壤侵蚀大小的重要因素之一。本文通过对该区域土壤取样及室内理化分析,结合采样点的地表物质组成、植被覆盖度及土壤有机质含量等因素,分析了其潜在可蚀性。研究结果表明:阴山北麓草地的平均土壤潜在可蚀性最小,为63.82%,耕地的平均土壤潜在可蚀性最大,为66.05%,灌丛和林地居于其中,分别64.58%和64.88%。耕地的平均可蚀性>林地的平均可蚀性>灌丛的平均可蚀性>草地的平均可蚀性。随着春季温度的升高和不断的风蚀,土壤可蚀性也发生相应的变化,但这种变化并不是持续的,当温度达到一定程度时,土壤温度和湿度环境发生了变化,土壤潜在可蚀性反而降低,表现为第二次采样的土壤可蚀性>第三次采样的土壤可蚀性>第一次采样的土壤可蚀性。土地利用方式不同,土壤表层的理化性质、地表状况也会产生一定的差异,从而导致了表层土壤的潜在风蚀性不同。人类活动在土地利用过程中起主导作用,它是叠加在自然因素之上的影响土壤潜在风蚀性的人为因素。所以,应加强对耕地的保护,退耕还林草,减小其潜在风蚀性。 相似文献
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为探明植被恢复对乌兰布和沙漠土壤风蚀可蚀性的影响，以乌兰布和沙漠内不同沙地固 定阶段的 8 种典型植物群落及群落内表土作为研究对象，对土壤物理因子（可蚀性颗粒含量、土壤 含水量、有机质含量）、土壤结皮因子、植被因子 3 类土壤风蚀可蚀性因子指标进行监测，分析土壤 风蚀可蚀性因子在不同植物群落类型间、沙地固定阶段间的差异。结果表明：（1）在乌兰布和沙漠 典型植物群落中，沙蓬、沙生针茅、盐爪爪等草本植物群落的土壤风蚀可蚀性最强，白刺、梭梭、沙 冬青等灌木植物群落土壤风蚀可蚀性弱于草本植物群落，说明灌木林能显著降低土壤风蚀作用。
（2）随着沙地的不断固定，土壤结构不断发育，土壤可蚀性不断降低，土壤风蚀可蚀性强弱表现为 固定沙地<半固定沙地<流动沙地。（3）土壤可蚀性颗粒含量、土壤有机质含量、土壤含水量、土壤结 皮、植被因子与植被类型及沙地固定阶段具有显著相关关系。因此，在沙区生态建设工程中，为了 减少土壤风蚀量，不仅要考虑物种的选择，还要促进人工生态系统的演替和恢复，从而有效降低土 壤风蚀可蚀性。研究结果可为乌兰布和沙区植被生态系统服务功能的科学评价、防沙治沙工程的 建设与管理提供一定参考。 相似文献
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Soil erodibility is an important index to evaluate the soil sensitivity to erosion. The research on soil erodibility is a crucial tache in understanding the mechanism of soil erosion. Soil erodibility can be evaluated by measuring soil physiochemical properties, scouring experiment, simulated rainfall experiment, plot experiment and wind tunnel experiment. We can use soil erosion model and nomogram to calculate soil erodibility. Many soil erodibility indices and formulae have been put forward. Soil erodibility is a complex concept, it is influenced by many factors, such as soil properties and human activities. Several obstacles restrict the research of soil erodibility. Firstly, the research on soil erodibility is mainly focused on farmland; Secondly, soil erodibility in different areas cannot be compared sufficiently; and thirdly, the research on soil erodibility in water-wind erosion is very scarce. In the prospective research, we should improve method to measure and calculate soil erodibility, strengthen the research on the mechanism of soil erodibility, and conduct research on soil erodibility by both water and wind agents. 相似文献
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There is a growing requirement for techniques to assess land susceptibility to wind erosion, i.e. land erodibility, over large geographic areas (>104 km2). This requirement stems from a lack of wind erosion research between the field (101 km2) and regional scales, and a need to evaluate the performance of spatially explicit wind erosion models across these scales. This paper addresses this issue by presenting a methodology for monitoring land erodibility at the landscape scale (103 km2). First, we define criteria suitable for evaluating land erodibility based on empirical relationships between soil texture, vegetation cover, geomorphology, and wind erosion. The criteria were used to visually assess land erodibility over long distances (103 km) using vehicle-based transects run through the rangelands of western Queensland, Australia. Application of the data for testing the performance of a spatially explicit land erodibility model (AUSLEM) is then demonstrated by comparing the visual assessments of land erodibility with the model output. The model performed best in the west of the study area in the open rangelands. In regions with higher woody shrub and tree cover the model performance decreases. This highlights the need for research to better parameterise controls on erodibility in semi-arid landscapes consisting of forested and rangeland mosaics. 相似文献
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水蚀风蚀过程中土壤可蚀性研究述评 总被引：4，自引：1，他引：3
1 IntroductionSoil erosion is the process of detachm ent and transport of soil particles caused by w ater andw ind (M organ,1995).Soilerosion by w ater and w ind leads to decline in soilfertility,brings ona series of negative im pacts of land degradation … 相似文献
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黄土丘陵小流域土地利用变化对水土流失的影响 总被引：80，自引：3，他引：80
在土壤侵蚀模型LISEM (Limburg Soil Erosion Model) 校正的基础上,模拟了陕北黄土丘陵沟壑区大南沟小流域5种土地利用方案的水土流失效应,旨在探讨土地利用变化对流域出口水土流失的影响。研究结果表明:流域出口的洪峰流速、径流总量和侵蚀总量的大小顺序为:1975年>1998年>25度退耕>20度退耕>15度退耕。1975年和1998年25度以上的陡坡耕地和休闲地均退耕还林还草,这2种土地利用格局的径流和侵蚀模拟值都显著大于3种退耕方案。在3种退耕方案中,20度和15度以上的陡坡耕地和休闲地逐步转变为果园/经济林地,3种退耕方案之间的水土流失差异不显著。相对于1975年土地利用来说,1998年土地利用能降低洪峰流速、径流量和侵蚀量约5%~10%;3种退耕方案的减流减沙效益更加显著,可以降低洪峰流速、径流量和侵蚀量约40%~50%。 相似文献
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Landsat series multispectral remote sensing imagery has gained increasing attention in providing solutions to environmental problems such as land degradation which exacerbate soil erosion and landslide disasters in the case of rainfall events. Multispectral data has facilitated the mapping of soils, land-cover and structural geology, all of which are factors affecting landslide occurrence. The main aim of this research was to develop a methodology to visualize and map past landslides as well as identify land degradation effects through soil erosion and land-use using remote sensing techniques in the central region of Kenya. The study area has rugged terrain and rainfall has been the main source of landslide trigger. The methodology comprised visualizing landslide scars using a False Colour Composite (FCC) and mapping soil erodibility using FCC components applying expert based classification. The components of the FCC were: the first independent component (IC1), Principal Component (PC) with most geological information, and a Normalised Difference Index (NDI) involving Landsat TM/ETM+ band 7 and 3.The FCC components formed the inputs for knowledge-based classification with the following 13 classes: runoff, extreme erosions, other erosions, landslide areas, highly erodible, stable, exposed volcanic rocks, agriculture, green forest, new forest regrowth areas, clear, turbid and salty water. Validation of the mapped landslide areas with field GPS locations of landslide affected areas showed that 66% of the points coincided well with landslide areas mapped in the year 2000. The classification maps showed landslide areas on the steep ridge faces, other erosions in agricultural areas, highly erodible zones being already weathered rocks, while runoff were mainly fluvial deposits. Thus, landuse and rainfall processes play a major role in inducing landslides in the study area. 相似文献
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Ian Pope Jon Harbor Laura Zanotti Guofan Shao Dawn Bowen Gary R. Burniske 《The Professional geographer》2016,68(1):1-13
Soil erosion threatens long-term soil fertility and food production in Q’eqchi’ communities native to the Sierra Yalijux and Sierra Sacranix mountain ranges in the central highlands of Guatemala. Environmental factors such as steep topography, erodible soils, and intense precipitation events, combined with land subdivision and reduced fallow periods as a consequence of population growth, contribute to severe erosion and strain soil resources. The preservation of the region's cloud forests hinges on enhancing production of staple crops through agricultural intensification while maintaining soil fertility through implementation of soil conservation measures. 相似文献
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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
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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
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Regional soil erosion risk mapping in Lebanon 总被引：10，自引：0，他引：10
Soil erosion by water is one of the major causes of land degradation in Lebanon. The problem has not yet been treated in detail although it affects vast areas. This study elaborates a model for mapping soil erosion risk in a representative area of Lebanon at a scale of 1:100,000 using a spatial database and GIS. First, three basic maps were derived: (1) runoff potential obtained from mean annual precipitation, soil-water retention capacity and soil/rock infiltration capacity; (2) landscape sensitivity based on vegetal cover, drainage density and slope; and (3) erodibility of rock and soil. Then two thematic maps were derived: potential sensitivity to erosion obtained from the runoff potential and landscape sensitivity maps, and erosion risk based on the potential erosion and erodibility maps. The risk map corresponds well to field observations on the occurrence of rills and gullies. The model used seems to be applicable to other areas of Lebanon, constituting a tool for soil conservation planning and sustainable management. 相似文献
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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
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拉萨地区土地利用变化情景分析 总被引：24，自引：2，他引：22
根据西藏拉萨地区1990年、1995年和2000年3个时点的土地利用数据,应用马尔科夫过程模型分析了未来20年内拉萨地区的土地利用情景变化,并与90年代制定的拉萨地区土地利用规划面积进行了对比研究。研究结果:1)10年间,土地利用类型变化最广泛的是牧草地。变化方向主要由牧草地向耕地、园地、林地、居民点及水域转变,其中变成林地的面积最大,为2338.25hm2(占变化面积的94.093%);2)拉萨地区未来20年中土地利用类型发展趋势是耕地、牧草地、水域和未利用土地面积将进一步减少,林地、园地和居民点面积将进一步增加;3)土地利用规划面积与基于马尔科夫模型的土地利用变化情景分析结果比较吻合,马尔科夫过程模型对制定该区域土地利用规划具有重要的参考价值;4)由于土地利用变化是一个复杂的过程,不仅受到众多自然因素的影响,而且受到未来土地利用政策、社会经济发展、区域内大型工程项目及其他人类活动等不确定因素的影响,从而不同土地利用类型之间的转移概率会发生变化,使得基于马尔科夫过程模型预测的精度有一定的局限性。 相似文献
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贵州猫跳河流域土地利用变化和土壤侵蚀(英文) 总被引：4，自引：2，他引：2
Due to the extremely poor soil cover, a low soil-forming rate, and inappropriate intensive land use, soil erosion is a serious problem in Guizhou Province, which is located in the centre of the karst areas of Southwest China. In order to bring soil erosion under control and restore environment, the Chinese Government has initiated a serious of ecological rehabilitation projects such as the Grain-for-Green Programme and Natural Forest Protection Program and brought about tremendous influences on land-use change and soil erosion in Guizhou Province. This paper explored the relationship between land use and soil erosion in the Maotiao River watershed, a typical agricultural area with severe soil erosion in central Guizhou Province. In this study, we analyzed the spatio-temporal dynamic change of land-use type in Maotiao River watershed from 1973 to 2007 using Landsat MSS image in 1973, Landsat TM data in 1990 and 2007. Soil erosion change characteristics from 1973 to 2007, and soil loss among different land-use types were examined by integrating the Revised Universal Soil Loss Equation (RUSLE) with a GIS environment. The results indicate that changes in land use within the watershed have significantly affected soil erosion. From 1973 to 1990, dry farmland and rocky desertified land significantly increased. In contrast, shrubby land, other forestland and grassland significantly decreased, which caused accelerated soil erosion in the study area. This trend was reversed from 1990 to 2007 with an increased area of land-use types for ecological use owing to the implementation of environmental protection programs. Soil erosion also significantly varied among land-use types. Erosion was most serious in dry farmland and the lightest in paddy field. Dry farmland with a gradient of 6°-25° was the major contributor to soil erosion, and conservation practices should be taken in these areas. The results of this study provide useful information for decision makers and planners to take sustainable land use management and soil conservation measures in the area. 相似文献
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R. A. SHAKESBY C. J. CHAFER S. H. DOERR W. H. BLAKE P. WALLBRINK G. S. HUMPHREYS 《The Australian geographer》2003,34(2):147-175
Soil water repellency can enhance overland flow and erosion and may be altered by fire. The Christmas 2001 bushfires near Sydney allowed investigation of the relationship between fire severity, water repellency and hydrogeomorphological changes. For two sub-catchments with differences in fire severities in Nattai National Park, south-west of Sydney, this paper considers: (1) the links between fire severity based on SPOT image analysis and ground observation of fire severity and repellency; (2) the textural and organic/minerogenic characteristics of eroded sediment; and (3) erodibility, erosion and deposition of soils in both catchments. Ground surveys show that image analysis reflects well the degree of vegetation consumption by fire, but cannot adequately predict the degree of ground litter consumption, associated soil heating and repellency effects. Fire had varying effects on repellency, leaving it unchanged, destroying it or enhancing it, depending on the soil temperature reached. The main post-fire hydrogeomorphological changes have been widespread erosion and colluvial and alluvial deposition of topsoil in foot-slope locations and river systems, but only localised redistribution of the highly erodible, repellent sandy subsurface layer. The fire did not trigger major geomorphological change in the study area, but fires probably cause important topsoil and nutrient depletion and may also affect water quality. 相似文献
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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
19.
土壤斥水性（Soil Water Repellency，SWR）指水分不能或很难湿润土壤颗粒表面的现象，对农业水管理、土壤水入渗、农化污染物运移及土壤侵蚀有重要影响，土壤斥水性在绿洲化过程中的变化特征及其影响因素尚不明确。在甘肃临泽绿洲分别选取未开垦的沙地（0年）及开垦10、30、50、100年绿洲农田表层土壤（0~5 cm），分别测定土壤有机碳含量、土壤质地（砂粒、粉粒、黏粒）和土壤pH，并用毛管上升法测定土壤斥水性。结果表明：土壤斥水性随着开垦年限的增加而不断增加。不同开垦年限土壤的“土-水”接触角58°~89°，差异显著（P<0.001）。土壤有机碳含量、土壤质地和土壤pH均与“土-水”接触角存在显著的回归关系（P<0.001）。逐步回归分析的结果表明，绿洲化过程中土壤有机碳含量和pH共解释了土壤斥水性72.1%的变异。因此，在绿洲农田进一步研究土壤斥水性对土壤水运动的影响应更多关注土壤有机碳和pH两大因素。 相似文献
20.
Cultivation, overgrazing, and overharvesting are seriously degrading forest and grassland ecosystems in the Taurus Mountains of the southern Mediterranean region of Turkey. This study investigated the effects of changes on soil organic carbon (SOC) content and other physical soil properties over a 12-year period in three adjacent ecosystems in a Mediterranean plateau. The ecosystems were cropland (converted from grasslands in 1990), open forest, and grassland. Soil samples from two depths, 0–10 and 10–20 cm, were collected for chemical and physical analyses at each of cropland, open forest, and grassland ecosystems. SOC pools at the 0–20 cm depth of cropland, forest, and grassland ecosystems were estimated at 32,636, 56,480, and 57,317 kg ha−1, respectively. Conversion of grassland into cropland during the 12-year period increased the bulk density by 10.5% and soil erodibility by 46.2%; it decreased SOM by 48.8%, SOC content by 43%, available water capacity (AWC) by 30.5%, and total porosity by 9.1% for the 0–20 cm soil depth (p<0.001). The correlation matrix revealed that SOC content was positively correlated with AWC, total porosity, mean weight diameter (MWD), forest, and grassland, and negatively with bulk density, pH, soil erodibility factor, and cropland. The multiple regression (MLR) models indicated that any two of the three ecosystems and one of the two soil depths accounted for 86.5% of variation in mean SOC values ((p<0.001). 相似文献