Quantitative evaluation of soil erosion of land subsided by coal mining using RUSLE

Based on a RUSLE model, we identified the key factors of the impact on soil erosion induced by coal min- ing subsidence. We designed a method for predicting/.S factors of a mining subsidence basin, using ana- lytical GIS spatial technology. Using the Huainan mining area as an example, we calculated the modulus of erosion, its volume and classified the grade of soil erosion for both the original area and the subsidence basin. The results show that the maximum modulus of erosion and the volume of erosion of the subsi- dence basin without water logging would increase by 78% and 23% respectively compared with the ori- ginal situation. The edge of the subsidence basin, where the land subsidence was uneven, is subject to the greatest acceleration in soil erosion. In the situation of water logging after subsidence, the maximum modulus of erosion would decrease if the accumulated slope length were reduced. This maximum mod- ulus around the water logged area within the subsidence basin is equal to that without water logging, while the total volume of erosion decreases. Therefore, mining subsidence aggravates soil erosion espe- cially at the edge of basins where water and soil conservation measures should be taken.

An evaluation method for internal erosion potential of gravelly soil based on particle size distribution

Internal erosion occurs when fine particles escape from the soil driven by seepage flow,which is considered to be the crucial factor causing the failure of earth structures filled with gravelly soil.The objective of this paper is to suggest an appropriate method to assess internal erosion potential of gravelly soil.By analyzing the sensitivity of soil material to internal erosion,the variable(Dc15/df85)max and the content of coarse particles(Pc)are selected as the evaluation indexes(Dc15 and df85 are the diameters of 15%mass passing in the coarse component and 85%mass passing in the fine component,respectively).A series of gravelly soils with different particle size distributions are tested for internal erosion by the self-made permeameter.Based on the test results,an evaluation method for the internal erosion of gravelly soil is proposed.Gravelly soil is prone to internal erosion when 60%≤Pc<95%and(Dc15/df85)max≥9.5.The proposed method shows good accuracy in evaluating the internal erosion of 36 soil samples from other studies,which confirms the reliability of the method.The proposed method makes it possible to accurately assess internal erosion of gravelly soil,and an alternative method is provided for engineers to determine whether there is a risk of internal erosion in earth structures consisting of gravelly soil.

Impoverishment of Soil Nutrients in Gully Erosion Areas in Yuanmou Basin

The impoverishment of soil nutrients of nine gully head areas in Yuanmou Basin is assessed through an integrated evaluation method established on the basis of Fuzzy mathematics and multivariate mathematical theory. Results show that soil erosion of gully erosion area in Yuanmou basin has resulted in severe impoverishment of soil nutrients. All gully head areas are at high leves of impoverishment except for one at middle. By probing into and analyzing the mechanism of impoverishment of soil nutrients, we find that soil erosion has led to impoverishment of soil nutrients in a way of compacting soil, heightening position of obstacle horizon, and reducing the content of organic matter, as well as the direct loss of nutrient elements. Finally, this paper points out that soil and water conservation arming at the prevention of soil erosion is the most effective way against impoverishment of soil nutrients in Yuanmou basin.

Factor value determination and applicability evaluation of universal soil loss equation in granite gneiss region

Six types of runoff plots were set up and an experimental study was carried out to examine natural rate of soil and water loss in the granite gneiss region of northern Jiangsu Province in China. Through correlation analysis of runoff and soil loss during 364 rainfall events, a simplified and convenient mathematical formula suitable for calculating the rainfall erosivity factor （R） for the local region was established. Other factors of the universal soil loss equation （USLE model） were also determined. Relative error analysis of the soil loss of various plots calculated by the USLE model on the basis of the observed values showed that the relative error ranged from -3.5% to 9.9% and the confidence level was more than 90%. In addition, the relative error was 5.64% for the terraced field and 12.36% for the sloping field in the practical application. Thus, the confidence level was above 87.64%. These results provide a scientific basis for forecasting and monitoring soil and water loss, for comprehensive management of small watersheds, and for soil and water conservation planning in the region.

Land Degradation Evaluation in North Hebei Province Based on Remote Sensing and GIS

Land degradation is one of the serious environmental problems that can lead to poverty, and is especially prominent in eco-fragile areas in developing countries and increases the risk of environmental safety. North Hebei Province belongs to an ecologically fragile region in North China, which has great impact on the eco-safety of Beijing and Tianjin. Using Landsat TM data and GIS, this paper evaluates land degradation in North Hebei province of China from the the 1960′s to 1987 and 2000. Land use/cover change pattern from 1987 to 2000, its regional difference and forest change characteristics will also be analyzed; soil erosion intensity and arable land suitability were also evaluated. Results revealed that land use/cover pattern in this study area did not change greatly from 1987 to 2000. The structure and function of regional land ecosystem was at a level of local improvement and integral deterioration. Land above medium soil erosion intensity reached 21 percent, which was also the area with a serious soil erosion and land degradation problem. Soil erosion and land degradation intensity of grassland was the biggest. For the present arable land, the proportion of high suitability was 13 percent.

三峡库区水土流失遥感监测及治理研究

三峡库区是长江流域生态环境系统的重要环节,库区生态环境问题备受关注。水土流失是影响三峡库区生态安全、制约库区发挥生态屏障功能的关键环境问题之一。2020—2022年,水利部水土保持监测中心的三峡库区水土流失遥感监测站组织实施了基于遥感技术的三峡库区水土流失动态监测,结合野外考察和数值模拟等手段,对库区土壤侵蚀因子与侵蚀模数进行计算,并对水土流失防治效益进行评价。结果显示:(1)林地和耕地是水土流失发生的主要区域;(2)在相同的土地利用模式下,地形较陡的区域更易发生强度较大的水蚀;(3)2020—2022年,库区水土流失面积呈减少趋势,减少速率约为264 km^(2)/年,水土保持措施面积则以865 km^(2)/年的速率增加,取得较好治理效果。在进一步工作中,可针对性地在坡度较大的水蚀区进行合理的水保措施布设,以进一步提高库区水土流失治理成效。本研究可为三峡库区水土流失治理和水保措施规划以及长江流域生态系统建设提供科学依据。

湖北省全口径水土流失治理现状调查及对策研究

当前,湖北省水土流失防治取得了显著成效,但成效仍不稳固,防治任务仍然繁重。建立规划实施监测评估机制,统筹区域全口径水土流失治理情况、跟踪规划实施情况,有利于切实提升区域水土流失治理效益,切实改善区域水土流失情况。收集整理了湖北省8个三级水土保持功能区内的典型县全口径水土流失治理措施实施相关情况以及各类项目图斑、竣工验收图和评估年卫星影像等资料,结合GF-1卫星遥感影像分析及无人机摄影测量等手段踏查治理图斑现场并矢量化治理图斑信息,完成了图斑现场信息化复核校验工作,基本摸清了2020年全口径新增水土流失治理任务分部门、分工程、分措施、分图斑分解落实情况。发现湖北省全口径水土流失治理措施图斑坐标准确率为96.13%、图斑有效率为93.22%、图斑完成率为97.37%,但部分项目进度存在一定滞后、田间配套设施配置不太完善、人为扰动风险仍居高位等实际困难。据此,提出了强化目标责任考核、健全监督检查和监理工作机制、推动防治工作统筹的对策建议,可为湖北省水土流失治理满足《全国水土保持规划(2015~2030年)》中制定的目标任务提供决策依据。

特大暴雨下残垣丘陵沟壑区水土流失与梯田措施效益评价

[目的]开展场次暴雨水土流失评估与措施效益评价,分析暴雨造成的土壤侵蚀状况,评价梯田措施效益,为常规水土流失动态监测提供有效补充。[方法]以甘肃“2022·7·15”特大暴雨发生地庆城县和暴雨中心湫沟小流域为研究区,利用日降雨量数据与全国水土流失动态监测项目相关成果,基于次暴雨降雨侵蚀力,采用改进的CSLE模型计算土壤侵蚀模数,分析暴雨降雨侵蚀力与多年均降雨条件下全年降雨侵蚀力的关系,以及次暴雨条件下不同土地利用类型土壤侵蚀强度等级的空间分布,探讨梯田对区域水土流失的影响。[结果]庆城县该次暴雨产生的降雨侵蚀力达到多年均降雨条件下全年降雨侵蚀力的1.85倍,暴雨中心降雨侵蚀力达到多年均降雨条件下全年降雨侵蚀力的4.88倍。暴雨造成的强烈级以上土壤侵蚀面积是2021年全年强烈级以上土壤侵蚀面积的3.46倍,暴雨中心达6.93倍。场次特大暴雨造成的强烈以上等级土壤侵蚀主要分布在旱地、草地和灌木林地。庆城县现状梯田面积325 km^(2),相较于无梯田措施情景,县域土壤侵蚀量减幅达72.87%。[结论]加强退耕还林还草、坡耕地综合整治、旱作梯田建设等水土保持工作,是特大暴雨条件下水土流失灾害防治的有效手段。

黑龙江省冻融侵蚀强度分级评价及空间分布特征

黑龙江省肩负维护国家生态安全、保障国家粮食安全的重任,近年来因冻融侵蚀影响,自然环境和黑土资源受到严重威胁。为了定量揭示黑龙江省冻融侵蚀强度的空间异质性及其影响因素,该研究选取10个冻融侵蚀强度评价指标,并确定其权重。通过构建多元回归模型得到冻融侵蚀下限,将权重和赋值结果代入综合评价指数模型,利用自然断点法对冻融侵蚀强度进行分级。研究结果表明:1)黑龙江省冻融侵蚀总面积为1.917×10~5 km^(2),占全省面积的40.53%,其中强烈和极强烈侵蚀分别占冻融侵蚀总面积的20.66%和10.54%。2)黑龙江省中度冻融侵蚀以上的区域呈现三区一带的特征。三区分别为大兴安岭地区、小兴安岭地区和张广才岭地区;一带为西北—东南走向的“三岭一平原”廊道。3)黑龙江省冻融侵蚀强度在空间上表现出明显的正相关和集聚性特征,强度相近的冻融侵蚀区在空间上积聚,高强度和低强度的冻融侵蚀区在空间上分异,产生了多个高强度和低强度的冻融侵蚀区。4)植被覆盖度的增加可以降低冻融侵蚀强度,在植被覆盖度小于20%的地方,冻融侵蚀尤为剧烈;冻融侵蚀主要发生在土壤含水量为0.2~0.3 m^(3)/m^(3)的区域,而极少发生在土壤水分含量小于0.2 m^(3)/m^(3)的区域。研究结果通过对比验证显示出较高的可靠性,可为该地区冻融侵蚀的防护和管理提供依据,并为类似区域提供借鉴方法和技术参考。

小型河道流域整治工程水土流失危害分析及防治措施评价

针对小型河道流域整治工程的水土流失问题展开研究,首先分析了水土流失的现状和危害,然后对流域进行了水土流失防治分区划分,并提出了相应的水土保持措施和防治措施。通过对民田涌流域的实例分析和评价,提出了一些有效的防治措施,以提高防治效果和生态环境的稳定性。研究表明,采取合适的水土流失防治措施可以有效减少水土流失,改善生态环境,提高流域的可持续发展能力。

基于DL和GKDE的松花江流域土壤侵蚀类型的概率评价研究

[目的]为科学判别流域尺度土壤侵蚀类型并给出相应的发生概率。[方法]构建基于深度学习(deep learning,DL)的松花江流域土壤侵蚀模数(erosion modulu,EM)计算模型,并计算不同类型的侵蚀模数。以降雨、气温、风速3个侵蚀模数影响因子为随机变量,利用数值模拟和高斯核密度估计法(gaussian kernel density estimation,GKDE)构建EM概率评价方法,给出不同土壤侵蚀强度组合的发生概率。[结果]EM计算模型验证期的R^(2)均>0.86。流域内平均每年有74.47%发生微度水蚀与微度风蚀;12.86%的面积发生轻度及以上水蚀与微度风蚀;12.56%的面积发生轻度及以上风蚀与微度水蚀;0.11%的面积水蚀强度与风蚀强度均在轻度及以上。36个典型像元中,发生微度水蚀与微度风蚀的平均概率为57.45%;发生微度水蚀与轻度风蚀的平均概率为30.26%;发生微度水蚀与中度风蚀的平均概率为8.03%;发生轻度水蚀与微度风蚀的平均概率为2.11%;发生微度水蚀与重度风蚀的平均概率为2.08%;发生其余强度组合的平均概率在0.05%以下。[结论]构建的松花江流域EM计算模型精度较高,揭示了松花江流域土壤侵蚀类型空间分布特征,并给出不同土壤侵蚀强度组合的发生概率,为松花江流域土壤侵蚀治理提供依据。

喀斯特槽谷区侵蚀坡面的土壤质量评价及障碍因子

[目的]为准确评价喀斯特槽谷区顺/逆层坡侵蚀坡面的土壤质量特征,筛选出适用于该地区的土壤质量评价方法,探析限制其土壤质量的障碍因子。[方法]以重庆市青木关喀斯特槽谷区顺/逆层坡面的5种典型土地利用类型(林地、草地、裸地、玉米地、辣椒地)为研究对象,利用主成分分析法结合Norm值建立评价指标最小数据集(minimum data set,MDS),并通过非线性土壤质量评价方法和隶属度函数对喀斯特槽谷区顺/逆层坡面的土壤质量进行评价。[结果](1)喀斯特槽谷区土壤质量评价指标最小数据集(MDS)包括毛管持水量、毛管孔隙度和全磷;(2)通过非线性土壤质量评价方法得出,逆层坡土壤质量(0.519)优于顺层坡(0.451),其中逆层坡林地土壤质量最优(0.653),辣椒地土壤质量最差(0.426);(3)非线性评价方法在顺/逆层坡的决定系数(R 2)均高于隶属度函数,因此喀斯特槽谷区更适合采用非线性评分模型;(4)顺/逆层坡侵蚀坡面的土壤质量障碍因子差异显著,仅有全氮为共同的障碍因子。[结论]适当增加草地和乔木林的覆盖能提高喀斯特槽谷区土壤质量,研究结果可因地制宜地为喀斯特槽谷区顺/逆层坡侵蚀坡面的土壤质量调控和生态恢复提供依据。

农户在水土流失治理中的获得感评价分析——以福建省长汀县为例

本文基于公共产品、公众满意度理论,构建长汀县农户在水土流失治理中的获得感评价指标体系进行测度分析,结论可为政府后续治理提供参考。运用因子分析法探索验证评价指标体系的科学性并对获得感进行测度分析。结果表明:(1)长汀县农户获得感由政治、经济、环境、公共服务及文化技术5个维度构成,其中经济和公共服务维度的获得感是农户获得感的主要构成部分;(2)长汀县农户的获得感总体水平较为一般,有较大的增强空间,在性别、是否为村干部/党员、学历、婚姻状况、健康情况等方面存在差异。

基于AHP-Delphi法的黄河山西段水土流失治理生态效益评价研究

针对黄河山西段水土流失问题,对山西采取的水土流失治理措施进行梳理。基于AHP法与Delphi法构建起包含三个评价层次、十二个指标层的水土流失治理生态效益综合评价体系,详细分析各指标含义及计算方法,并对该体系的一致性进行检验,计算各指标的权重,对无量纲化处理过后的各指标进行分值量化,结合评价等级标准,最终得出结论:治理后总体评分为81.61分,评价等级为Ⅳ级。说明山西多年来对省内水土流失问题的整治取得了良好效益,有效缓解了水土流失问题。

鹿鸣关灌区节水改造水土流失问题与防治对策分析研究

对鹿鸣关灌区节水改造过程中的水土流失问题进行深入研究,提出了一系列有效的防治对策。通过对工程建设区水土流失现状的调查和分析,发现该区域存在以轻度侵蚀为主的水土流失现象;通过对水土流失的预测和分析,确定了未来可能出现的水土流失状况;根据不同防治区的划分,提出了一系列切实可行的水土保持措施,包工程措施和植物措施,并对其防治效益进行了综合评价。

大涌水系整治工程水土流失分析及防治措施探究

随着城市化进程的加速和经济的快速发展,河流、湖泊等水体的整治工程日益增多。在水系整治过程中,往往会导致河道两侧土地开挖、水体岸线变化等情况,从而引发水土流失问题。以伦教大涌水系整治工程为背景,结合工程背景分析了项目所在区域的水土流失现状,结合工程背景分析水土流失情况,并提出相应的防治措施。通过对水系整治工程水土流失的分析与防治,项目在施工期间和后期采取了有效的水土保持措施,水土保持现状良好,无明显水土流失现象,可以有效地保护环境和生态。

小流域水土流失综合治理提质增效项目建设经验探讨

总结分析浙江省江山市新塘边小流域综合治理提质增效示范项目的相关经验,包括提质增效示范项目如何选择小流域选择,水土流失治理措施的布局等,并提供小流域提质增效综合效益评价方法,通过建立数学模型,量化提质增效的相关指标,评价其是否达到提质增效的目标,为其他地区的小流域综合治理提质增效示范项目提供参考。

建立水土保持信用评价制度提升人为水土流失监管效能

中共中央办公厅、国务院办公厅印发的《关于加强新时代水土保持工作的意见》,对建立以信用监管为基础的新型监管机制、全面实施水土保持信用评价提出了明确要求。水土保持信用评价是推进人为水土流失监管的重要方式,有利于完善水利行业信用制度建设,提升水土保持监管效能。建立水土保持信用评价制度要加快明确信用评价主客体、建立评价标准、规范评价程序等,并根据评价结果科学开展分级分类监管,加强水土保持信用评价结果运用。通过顶层政策设计和地方试点先行相结合,共同推动建立完善水土保持信用评价制度。

基于土地适宜性评价的小流域土地规划和利用

为实现小流域土地的可持续利用,以晋西南王家沟小流域为典型黄土丘陵区,借助GIS技术构建了流域土地栅格属性数据库,利用加权和叠加相结合的算法实施了区域土地适宜性评价。评价结果表明:王家沟小流域的土地利用差异性较大,高度宜农、高度宜林和高度宜牧的土地面积分别占小流域总面积的11.11%、70.04%和95.30%;对宜农地、宜林地、宜牧地较差的区域可经过适当的水土保持措施、营造水土保持林、种植灌木和土地改良等措施后进行规划使用。研究结果对小流域土地的可持续利用和区域生态环境的建设具有重要的实践意义。

岷江上游土壤侵蚀时空演变特征及其成因分析

为研究岷江上游流域土壤侵蚀动态变化情况,使用通用土壤流失方程(USLE)和统计学、空间分析等方法探讨了该区域2001—2017年土壤侵蚀时空演变特征及其成因。结果表明:(1)岷江上游流域土壤侵蚀主要发生在西部、西南部、东北部和东南部。(2)土壤侵蚀模数显著减小区域主要分布在流域西部和西南部,从地形、降水和土地利用看,主要分布于海拔2500~5000 m、坡度大于15°、年均降水量800~1200 mm的区域和林地侵蚀区。土壤侵蚀显著增加区域主要分布在北部和东南部,其中以中山、亚高山区域和年均降水量400~800 mm的干旱河谷区域为主。(3)土壤侵蚀状况与海拔、坡度、年降水量和植被类型在空间上呈显著正相关关系(p<0.05),随着海拔、坡度、年降水量增加,土壤侵蚀现象越明显。(4)未利用地、草地和林地土壤侵蚀较明显,侵蚀占比(轻度及以上侵蚀面积占该类型的比例)分别为87.11%,39.75%和9.49%。(5)不同类型林地侵蚀占比由大到小为疏林地(15.04%)>针叶林(13.50%)>混交林(4.41%)>阔叶林(0.97%)。林地土壤侵蚀主要受降水和植被覆盖度影响;而灌木和草地土壤侵蚀主要受制于降水。综上,未来该区域生态恢复需要重点加强对高海拔带(>2500 m)、坡度大于25°以及草地区域的植被恢复研究,进一步提高各类型植被水源涵养功能,开展流域土壤侵蚀分类治理,提高区域土壤侵蚀防治效果。