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41.
长江上游小流域土壤侵蚀动态模拟与分析 总被引：1，自引：0，他引：1
以长江上游甘肃省尚沟流域为研究区,在遥感影像和GIS空间分析技术支撑下,根据USLE因子算法生成各因子栅格图,借助地图代数运算,估算了尚沟流域1998年和2004年的土壤侵蚀量,并对2004年土壤侵蚀与其环境背景因子进行叠加和空间统计分析。在此基础上,构建了与GIS软件平台集成的地理元胞自动机,模拟了该流域2004年、2010年和2020年土壤侵蚀空间演化情形。结果表明:研究区平均侵蚀量从1998年的6598.1t/km2下降到2004年的5923.3t/km2,侵蚀面积净减少172.3hm2,输沙量减少9.15×104t;1300～1400m的海拔高程带、25～35°坡度带、南坡和旱耕地是发生水土流失的主要区域;经模拟,2010年总侵蚀面积为93.49km2,侵蚀总量73.15×104t,侵蚀模数为5126t/km2,土壤侵蚀状况总体上将有所减缓。 相似文献
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基于GIS和USLE的东圳库区土壤侵蚀量预测研究 总被引：13，自引：1，他引：12
运用GIS、遥感技术与USLE模型相结合预测东圳库区流域土壤侵蚀量,利用GIS平台建立东圳库区基础地理数据库,以10×10m为栅格单元对库区进行离散化,在GIS空间分析功能支持下,结合USLE土壤侵蚀预测模型,根据合适的USLE因子算法生成栅格图层,通过图层运算,预测了东圳库区土壤侵蚀量,进而标识库区土壤侵蚀严重区域,为库区非点源污染控制及水土流失治理提供定量依据,并通过建立实用的泥沙输移比模型结合水文监测数据,对预测结果进行验证。根据USLE方程,采用改进后的SDR方程,预测的渡里流域年输沙量与流域实际监测得到的年输沙量仅相差14.08%,说明本文采用USLE方程模拟流域土壤侵蚀结果可信,可定量评价、拟定水土保持措施方案。 相似文献
43.
Testing assumptions and procedures to empirically predict bare plot soil loss in a Mediterranean environment 
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下载免费PDF全文 Empirical prediction of soil erosion has both scientific and practical importance. This investigation tested USLE and USLE‐based procedures to predict bare plot soil loss at the Sparacia area, in Sicily. Event soil loss per unit area, Ae, did not vary appreciably with plot length, λ, because the decrease in runoff with λ was offset by an increase in sediment concentration. Slope steepness, s, had a positive effective on Ae, and this result was associated with a runoff coefficient that did not vary appreciably with s and a sediment concentration generally increasing with s. Plot steepness did not have a statistically detectable effect on the calculations of the soil erodibility factor of both the USLE, K, and the USLE‐M, KUM, models, but a soil‐independent relationship between KUM and K was not found. The erosivity index of the USLE‐MM model performed better than the erosivity index of the Central and Southern Italy model. In conclusion, the importance of an approach allowing soil loss predictions that do not necessarily increase with λ was confirmed together with the usability of already established and largely applied relationships to predict steepness effects. Soil erodibility has to be determined with reference to the specific mathematical scheme and conversion between different schemes seems to need taking into account the soil characteristics. The USLE‐MM shows promise for further developments. The evolutionary concept applied in the development of the USLE should probably be rediscovered to improve development of soil erosion prediction tools. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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The main goal of this study was to assess the prediction reliability, the quantitative differences and the spatial variations of the Morgan––Morgan–Finney (MMF) and the Universal Soil Loss Equation (USLE) erosion prediction models along the 442-km-long and 44-m-wide Right-of-Way of Baku–Tbilisi–Ceyhan oil and South Caucasus gas pipelines. USLE performed better than MMF erosion model by the accurate prediction of 61% of erosion occurrences. Paired-samples T-test with p-value less than 0.05 and bivariate correlation with the Pearson's correlation coefficient equal to 0.23 showed that the predictions of these two models were significantly different. MMF model revealed more clustered patterns of predicted critical erosion classes with a soil loss of more than 10 ton/ha/year in particular ranges of pipelines rather than USLE model with the widespread spatial distribution. The average coefficients of variation of predicted soil loss rates by these models and the number of accurately predicted erosion occurrences within the geomorphometric elements of terrain, vegetation cover and landuse categories were larger in the USLE model. This supported the hypothesis that larger spatial variations of erosion prediction models can contribute to the better soil loss prediction performance and reliability of erosion prediction models. 相似文献
45.
Application of the USLE in a Savannah Environment: Comparative Experiences from East and West Africa
The use of empirical models for predicting erosion hazard in Africa is widespread. One of the most commonly used models is the Universal Soil Loss Equation (USLE). This paper explores the applicability of the USLE in the East and West African Savannah environments, using both primary and secondary data. The results show that the USLE can be applied to Savannah conditions if some level of instrumentation is provided to enable model calibration and validation. The rainfall erosivity factor (R) is one variable which is calculated differently in both the East and the West African Savannah, reflecting differences in the storm characteristics between the two regions. The soil erodibility factor (K) is applied to cultivated soils with relatively high organic matter but does not adequately predict soil loss if the soils have large quantities of stone cover or if they exhibit surface sealing properties. The topographic factors (LS) are transferable, but in some parts of the Savannah, very steep slopes are cultivated, limiting the accuracy of the LS factor. The crop and management factor (C) is applicable for single stand crops, but more studies are required to develop C factors for multiple cropping and rangelands as these are more prevalent in the Savannah. The conservation practices factors (P) as described in the USLE routines do not adequately cater for soil conservation structures found in Africa, such as trash lines and stone lines. Thus, local indices need to be developed. In general, the USLE tends to underestimate soil erosion in East Africa while overestimating it in the West African Savannah. User‐friendly Geographical Information Systems (GIS) applications that depict the uncertainty of model estimates should be explored in the future. 相似文献
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47.
James V. Bonta 《国际泥沙研究》2000,(2)
1INTRODUCTIONSediment-yieldestimatesarerequiredforsurfacec0al-minepermitsunderFederalandStatelaws-Estimatesareneededfordeterminingtheimpactsofminingandreclamationduringmine0Peration,fordiversi0nandsmallimpoundmentdesigns,andforsizingsedimentpondstocontrolsedimenttransporteddownstfeam0faproposedminesite.Technologiesavailablef0rsediment-yieldestimationsincludetheUniversalSoilLossEquati0n(USLE,WischmierandSmith,l978);theWaterErosionPredictionPr0ject(WEPP,FlanaganandLivingst0n,l995),… 相似文献
48.
通用土壤流失方程最新研究改进分析 总被引：4，自引：0，他引：4
通用土壤流失方程(USLE)是水动力土壤侵蚀研究领域应用广泛的经验模型。其结构简单,所需输入数据量少,计算结果可满足一定精度下,土壤侵蚀预测的要求。模型的改进使其应用范围扩大,适用性增强,计算精度提高。通用土壤流失方程的发展趋势:其一,传统方法,不改变模型的结构,通过引进合理的新参数或优化参数的取值来提高模型的预测能力;其二,非传统方法,通过模糊逻辑或人工神经网络方法来改变模型的结构,使土壤侵蚀影响因子的确定更加灵活合理,土壤流失量的计算结果更加精确可信。 相似文献
49.
Derege Tsegaye MESHESHA Atsushi TSUNEKAWA Mitsuru TSUBO Nigussie HAREGEWEYN 《国际泥沙研究》2012,27(1):84-99
Most of the lowland in the central rift valley of Ethiopia is arid or semiarid and in degradation,with frequent occurrence of droughts.Soil erosion by water during the rainy season is a serious problem... 相似文献
50.
安徽省土壤侵蚀空间分布及其与环境因子的关系 总被引：10，自引：1，他引：9
基于USLE和GIS空间分析技术,对安徽省土壤侵蚀空间分布进行了定量研究,分析了土壤侵蚀空间分布与地形、土壤类型、土地利用方式的关系。结果表明:安徽省2002年平均土壤侵蚀模数为249.5t/km2·a,土壤侵蚀总量为33599148t/a。土壤侵蚀空间分布呈块状分布特征。淮北平原地区土壤侵蚀较弱,皖南丘陵山区和皖西大别山区土壤侵蚀较严重。在不同高程带上,200~500m高程带土壤侵蚀最强;不同坡度等级中,15°~25°坡度上的土壤侵蚀最强,>35°坡地上则较弱;不同坡向中,东南坡土壤侵蚀最强,其次是东坡;不同用地类型的土壤侵蚀程度不同,草地的土壤侵蚀最为严重,其次是林地;在各种土壤类型中,紫色土和黄褐土的土壤侵蚀最为突出,棕壤的土壤侵蚀微弱。 相似文献