长江流域水土流失及其对洪灾的影响

人口的持续增长和区域开发规模的扩大,导致流域生态环境恶化,水土流失加剧.目前长江流域水土流失面积达56.2万km2,占流域总面积的31.2%,每年土壤侵蚀量达24亿t .严重的水土流失使土层减薄,水源涵养能力下降,土壤水库容减少,造成暴雨径流加速汇集;同时大量泥沙下泄,淤积江河湖库,降低调蓄和行洪能力,抬高洪水水位,加剧了洪灾的发展.综合分析了长江流域水土流失的历史变化和现状,探讨了水土流失对洪灾的影响, 在此基础上因地制宜的提出了水土流失的防治对策.     

水土流失对长江流域洪灾的影响分析

2010年入汛以来,长江流域在降雨量仅比常年同期偏多14.7%的情况下发生了严重的洪水灾害。为了进一步认识水土流失与长江流域洪灾的关系,从源头和根本上综合防治洪灾,分析了人为因素对长江流域洪水的影响。结果发现:长江流域森林植被系统受损,蓄水拦洪能力减弱;土壤侵蚀严重,土壤水库功能弱化;水库蓄水能力低,河系湖泊失调;开发建设项目造成新的水土流失,加剧了河道淤积等都与洪灾有着十分密切的联系。在此基础上提出了长江流域洪灾综合防治的对策和相关建议。     

长江流域水土流失与洪涝灾害关系剖析

首先从水土流失加剧、森林破坏、坡耕地面积增多、工程活动增加产沙量等方面,分析了人为活动对长江流域生态环境恶化的影响;其次,从剥蚀与堆积的关系和土壤水库容减少与洪水量增加两个方面,深入探讨了水土流失对洪涝灾害的叠加效应及负面影响;指出水土流失导致了流域环境承受和抗御自然灾害的能力下降,在同量降雨条件下,是诱发和加剧洪涝灾害的重要原因;最后,从技术和政策方面,提出了防治水土流失和洪涝灾害的策略性意见和途径。     

长江流域水土流失生态化治理模式探讨

长江流域中上游的水土流失十分严重,已严重威胁到全流域的社会、生态、经济的可持续发展。虽然“长治”、“天保”、“退耕”三大工程的实施在一定程度上遏制了水土流失的加剧,但其本身仍有许多局限与不足。由于治理长江流域水土流失十分重要和紧迫,本文在详细分析的基础上提出了开征生态税、发展生态经济农业、实施生态移民、加大生态进口和发展生态旅游等一系列长江流域水土流失生态化治理的新模式。     

长江流域生态环境与可持续发展

1998年长江发生了自1954年最大洪水以来历史上又一次全流域特大洪大,生态环境严重恶化,严重的水土流失是这次洪灾的主因,如何尽快治理长江流域水土流失,整治生态环境,确保长江流域的可持续发展是“科教兴国”的重要组成部分。     

长江流域水土流失面积10年减少27.5%

<正>本刊讯据长江水利委员会发布的《2006—2015年长江流域水土保持公报》,经过10年的治理和预防,长江流域水土流失面积减少了14.62万km~2,较全国第二次水土流失遥感调查结果减少了27.5%,水土保持成效显著,为流域生态环境改善打下了坚实基础。长江流域面积约180万km~2,涉及19个省(自治区、直辖市)。流域内水土流失主要分布在长江上中     

对长江上游水土流失重点治理的回顾与思考

长江流域在我国国民经济和社会发展中的战略地位极为重要,但长江上游水土流失是严重影响长江和长江经济带生态文明建设的主要因素之一。新中国成立以来,特别是改革开放以来,长江流域在国家的支持下开展了水土流失重点治理,到2018年水土流失面积减少12.34万km~2,水土流失严重、生态恶化的局面得到彻底扭转,实现了水土流失面积由增到减、生态环境总体向好的历史性转变,并探索总结了一套具有长江流域特色的水土保持技术路线和不同类型区的治理开发模式。在新的历史时期和新的发展阶段,我们既要总结和发扬成功的经验做法,更要贯彻新发展理念和《中华人民共和国长江保护法》,针对存在的问题和不足,进一步做好顶层设计,聚焦重点地区治理;提高投资标准,加大对严重流失区的重点治理投入;注重科学,高质量治理水土流失;强化管理,有效提升水土流失治理成效。     

长江流域水土流失面积较全国第一次水利普查结果减少近10%

<正>本刊讯长江水利委员会近日发布的《长江流域水土保持公告(2018年)》显示,与2011年第一次全国水利普查结果相比,长江流域水土流失面积减少3.79万km2,减幅接近10%。公告显示,根据水利部2018年全国水土流失动态监测成果,长江流域水土流失面积34.67万km2,占流域总面积的19.36%。水土流失主要分布在金沙江下游、嘉陵江和岷江沱江中下游、乌江赤水河上中游及三     

中国的水土流失及其对区域环境的影响

中国是一个水土流失十分严重的国家,根据最新的普查资料,20世纪90年代末全国水土流失总面积356万km2,其中水蚀165万km2,风蚀191万km2。在水蚀和风蚀面积中,水蚀风蚀交错区水土流失面积为26万km2。严重的水土流失导致耕地减少,土地退化;泥沙淤积,加剧了洪涝灾害;影响水资源的分配和有效利用,加剧了干旱的发展;破坏湿地生态系统,调洪能力下降;污染水资源环境;提高了大气中CO2浓度,对周边环境造成巨大的影响。     

《长江流域水土保持》公开出版发行

<正>2015年8月,长江流域第一部系统而全面的流域性水土保持书籍——《长江流域水土保持》,由长江出版社公开出版发行。《长江流域水土保持》系统总结了长江流域自新中国成立以来特别是1988年国务院批准实施"长治"工程以来水土保持的成功经验,集合了长江流域水土流失区广大人民群众长期与水土流失作斗争的丰富成果,以及水土保持工作者和相关科技工作者的艰辛劳     

Time and scale of gully erosion in the Jedliczny Dol gully system, south-east Poland

Key catchments of the Roztocze loess area in south-east Poland have a great potential of revealing the history of long-term soil erosion and changes in land use. The knowledge of how and when soil erosion took place in the past helps one understand the impact of land use changes on the landscapes [Bork, H.-R., 1989. Soil erosion during the past Millennium in Central Europe and its significance within the geomorphodynamics of the Holocene. Catena 15, 121–131]. The Jedliczny Dol gully system near the town Zwierzyniec in south-east Poland was investigated by using detailed field stratigraphy and radiocarbon dating of charcoal and wood.In connection with new settlements which were established between the 14th and 16th centuries, arable land was cultivated and forests were used much more intensively. As a consequence, the loess soils were strongly eroded during heavy rainfalls. Up to 4 m of colluvial sediments were deposited in the gully system during the 15th and/or 16th centuries. The thickness of the colluvial sediments indicate severe erosion which might be related to excessive timber exploitation for the local glass and iron production. With the foundation of the so-called Ordinariat Zamoyski at the end of the 16th century, some parts of the area were presumably reforested. High pressure on the land at the beginning of the 19th century enabled a second main phase of gulling before 1900.Since 1890 at the latest, almost the whole catchment is used as a forest, however, concentrated runoff on compacted forest roads can still be high after heavy rainfalls.In loess areas soil erosion caused by intensive land use, triggered by heavy rainfalls, can change the landscape drastically. These changes will continue to influence how catchments react, even if land use gets less intensive again. This knowledge should be considered regarding future, sustainable land use and recent changes in land use in the south-eastern Polish loess regions.     

A detailed reconstruction of changes in the factors and parameters of soil erosion over the past 250 years in the forest zone of European Russia (Moscow region)

Accelerated soil erosion is a major threat to soil, and there are great variations in the rate of soil erosion over time due to natural and human-induced factors. The temperate forest zone of Russia is characterized by complex stages of land-use history (i.e. active urbanization, agricultural development, land abandonment, etc.). We have for the first time estimated the rates of soil erosion by the WaTEM/SEDEM model (rainfall erosion) and by a regional model (snowmelt erosion) over the past 250 years (from 1780 to 2019) for a 100-km² study site in the Moscow region of Russia. The calculations were made on the basis of a detailed historical reconstruction of the following factors: the location of the arable land, crop rotation, the rain erosivity factor, and the maximum snow water equivalent. The area of arable land has decreased more than 3.5-fold over the past 250 years. At the end of the 20th century, the rates of gross erosion had declined more than 5.5-fold (from 28 × 10³ to 5 × 10³ t?ha^?1?yr^?1) in comparison with the end of the 18th century. Changes in the boundaries of arable land and also the relief features had led to a significant intra-slope accumulation of sediments. As a result of sediment redeposition within the arable land, the variation in net soil erosion was significantly lower than the variation in gross soil erosion. The changes in arable land area and in crop composition are the factors that have to the greatest extent determined the changes in soil erosion in this territory.     

子午岭林区林地和开垦地土壤侵蚀特征研究

利用大型坡面径流场和小流域的观测资料研究了子午岭林区林地开垦前后土壤侵蚀特征,其结果为林地土壤侵蚀很轻微,侵蚀强度小于15t/（km²·a）,径流模数小于2400m³/（km²·a）。地形和降雨特征对土壤侵蚀的影响不甚明显,植被和土壤成为影响土壤侵蚀的决定性因子。而当林地被开垦后,土壤侵蚀由自然植被覆盖下的自然侵蚀转变为人为加速侵蚀,侵蚀模数达1000t/（km²·a）以上,径流模数在27480m³/（km²·a）以上。降雨和地形特征对土壤侵蚀的影响非常明显。土壤加速侵蚀量与10min 或15min 最大雨强（Ⅰ₁₀或Ⅰ₁₅）的关系最为密切,坡面汇流增加,谷坡侵蚀产沙系数为27.7%。     

辽宁省土壤侵蚀空间尺度效应初探

土壤侵蚀的空间尺度效应和不同空间尺度土壤侵蚀定量评价的分析与研究是目前土壤侵蚀研究中的热点问题之一。通过对辽宁省34个典型水文站长序列水文资料和2000年辽宁省遥感资料进行汇总,运用沙量平衡分析方法,对辽宁省小流域-中尺度流域-区域大尺度3种尺度土壤侵蚀量进行不同空间尺度的对比研究。研究表明,辽宁省土壤侵蚀的空间尺度效应随着研究尺度的增大,主要表现在：1）通过对辽河流域的研究表明,研究区土壤流失量随流域面积的增大表现出递次减小的规律;2）通过对辽宁省9大流域的水文资料和遥感资料对比研究表明,随着研究尺度增大,土壤侵蚀的宏观特征表现更为显著。通过沙量平衡分析方法,沉积泥沙存蓄变化量是造成尺度效应的重要因素之一。深入研究沙量平衡计算的理论与方法,以沙量平衡计算辅助土壤侵蚀监测工作,是进一步促进土壤侵蚀监测工作的重要方法之一。     

我国亚热带土壤侵蚀的生物工程治理

我国亚热带具有丰富的水热资源,物产丰富,但由于不合理的土地利用使土壤侵蚀仍有不断增加的趋势。其原因是由于这一地区降雨侵蚀力大;地貌以丘陵和山地为主,坡度较大;土壤的可蚀性较高以及在本世纪经历了四次较大规模的森林毁坏。本区按土地利用不当引起的土壤侵蚀类型可划分成农用耕地侵蚀和裸地稀疏林地侵蚀。按土壤侵蚀程度、独特的成土母质以及土地利用分别阐述了各种生物工程治理措施。     

广东省水土流失的生物治理途径

治理广东省水土流失的指导原则是水利工程措施与生物措施相结合。治理崩岗的技术经验是改进修坡技术;充分利用植物资源;实行草木并举,以草保树促林;实施促生长措施,用“以快制胜”技术战略实现植被覆盖。     

Early soil knowledge and the birth and development of soil science

Soils knowledge dates to the earliest known practice of agriculture about 11,000 BP. Civilizations all around the world showed various levels of soil knowledge by the 4th century AD, including irrigation, the use of terraces to control erosion, various ways of improving soil fertility, and ways to create productive artificial soils. Early soils knowledge was largely based on observations of nature; experiments to test theories were not conducted. Many famous scientists, for example, Francis Bacon, Robert Boyle, Charles Darwin, and Leonardo da Vinci worked on soils issues. Soil science did not become a true science, however, until the 19th century with the development of genetic soil science, led by Vasilii V. Dokuchaev. In the 20th century, soil science moved beyond its agricultural roots and soil information is now used in residential development, the planning of highways, building foundations, septic systems, wildlife management, environmental management, and many other applications in addition to agriculture.     

垦植方式对山地果园水土流失的影响

应用径流小区法,长期（1996-2006）定位研究福建中部尤溪县垦植方式对山地果园水土流失的影响,结果表明：1）该地区11年平均年降雨量1575.5mm,平均年蒸发量1461.1mm,5月、6月、8月是强降雨高发期,也是水土流失防治的关键期;2）在山地果园开发中,平台开垦的径流系数为0.0688,明显小于顺坡开垦（0.2865）;3）植草能使果园0-30cm土层的土壤含水量提高0.8％-0.9％;4）顺坡清耕区侵蚀模数为2388.2t／（km^2·a）,梯台清耕区土壤侵蚀量达10.3kg/m,土壤侵蚀主要源于台壁受冲刷,顺坡植草区、梯台植草区基本不发生土壤侵蚀。     

黄土高原土壤侵蚀垂直分带性研究

土壤侵蚀垂直分带是黄土高原土壤侵蚀分布的重要规律。本文通过野外细沟、浅沟侵蚀实测,航片判读和量算,小区域调查与制图等方法,对黄土高原土壤侵蚀垂直分带作了系统研究和划分,并提出两个水土保持重点带。通过系统的测量发现了以往被忽视但很重要的一个侵蚀带:细沟、浅沟侵蚀过渡带。提出浅沟、切沟侵蚀混交带的新概念。本文对塬区与丘陵区分别进行研究与划分,补充了塬区分带研究这一薄弱环节,对黄土高原土壤侵蚀制图和水土保持措施布设具有指导意义。     

Soil moisture,stressed vegetation and the spatial structure of soil erosion in a high latitude rangeland

Soil erosion has been a persistent problem in high-latitude regions and may worsen as climate change unfolds and encourages increased anthropogenic exploitation. We propose that soil moisture is likely to shape future erosion trends, as moisture stress reduces the capacity of vegetation cover to retard erosive processes. However, the spatial variability of soil moisture in high-latitude soils—and the ways in which this variability drives the spatial distribution of erosion features—is poorly understood. We addressed this knowledge gap with a study of andosol erosion in southern Iceland. Our study used a combination of high-resolution (<3 cm) remote sensing data (using normalised difference vegetation index (NDVI) and normalised difference red edge as metrics of plant vitality) and long-term, in situ measurements of soil moisture to unpick the relationship between moisture stress, vegetation vitality and patchy soil erosion. Mean NDVI increased with distance from eroded areas, varying from ~0.6 in vegetated areas on the margins of erosion patches to ~0.8 in areas >10 m from eroded terrain. We found lower moisture availability close to existing erosion features: mean volumetric soil moisture content varied from 17% (proximal to erosion patch) to 36% (distal to erosion patch). We also found that variability in soil moisture decreased with distance from eroded areas: the coefficient of variation (CV) in soil moisture varied from 0.33 (proximal to erosion patch) to 0.13 (distal to erosion). Our findings indicate that the margins of erosion patches have a stressful soil environment due to exposure to the atmosphere. The vegetation in these locations grows less vigorously, and the exposed soil becomes more vulnerable to erosion, leading to erosion patch expansion and coalescence. If these conditions hold more generally, they may represent a feedback mechanism that facilitates the lateral propagation of soil erosion in high-latitude regions.