关于全国水土流失问题

全球水土流失属于自然现象,随着人们对丛林的过甚滥用、砍伐,水土流失在我国的影响已达到十分严重的程度,它不仅造成土壤的破坏,导致农业生态的环境变差,,生态不平衡且不断失调,水灾干旱不断发生,而且影响各生产业的发展。     

输变电工程水土保持监测技术及措施

在我国输变电工程建设过程中,工程会穿过许多特殊的地形地貌例如山区、丘陵等,由于工程而导致的水土流失呈现出离散型的特点,虽然水土流失的总体面积不大,但如果它的程度十分严重造成的危害也是非常大的。本文根据以上特点主要针对处于不同地形的输变电工程怎样进行水土保持做出了简要的探讨和研究,大致提出了几项水土保持的技术。     

城市水土保持生态建设模式的探讨

城市出现水土流失的现象通常是由于其城市建设,所以探讨城市水土流失生态建设针对于城市的发展而言有着非常重要的作用。本文作者就首先对水土流失对城市造成了哪些危害进行了分析,而后探讨了几点治理城市水土流失的措施。     

锦郑管道水土保持工程关注的问题和实施措施

长输管道工程是由线型工程和点状工程组成,基本涵盖了各类开发建设项目工程建设造成水土流失的特性,其造成的水土流失形式复杂而多样且治理难度很大。本文以锦州—郑州成品油管道工程(在建)建设要求为例,使管道施工单位明确管道建设水土流失防治责任范围,防治目标;了解各种施工作业对水土流失的影响和危害;采取确实有效地措施使水土流失在工程建设中得到及时有效的控制与治理。     

公路环评中的水土流失预测与防治措施研究——以S304公路改造工程为例

本文以S304公路改造工程为例,以公路通过区的水土流失现状、水土流失防治标准等级、设计水平年为基准,预测公路建设中存在的水土流失的影响程度,提出切实可行的防治措施,并进行投资估算及效益分析,为公路的环境管理提供科学的理论依据,最大限度地降低工程建设对生态环境造成的影响。     

房地产建设水土流失特点及防治

随着经济社会的快速发展,房地产建设也随之扩大,而在大面积大规模的房地产项目建设中产生的水土流失问题,严重的影响了城市居民的日常生活以及城市的生态环境。因此避免房地产建设过程中产生的水土流失是相关单位应该高度重视的问题。本文对房地产建设水土流失的特点进行分析,并提出有效的防治房地产建设水土流失措施和建议。     

浅谈新时期输变电工程水土保持工作重点

首先介绍了水土保持工作的重要性,并以新国标为基础,以输变电工程水土保持工作重点为例,阐述了输变电工程的建设特点和水土流失特点,探讨了输变电工程水土流失的重点区域,提出了水土流失防治措施以及监测方法。     

哲庄煤矿水土保持方案及效益分析

哲庄煤矿矿井属小型开发建设项目,建设项目的实施对周边环境产生一定影响,为了减少水土流失,采取了一系列措施,可有效防治项目区的水土流失,保护和改善生态环境,为防治项目区自然和工程水土流失提供了科学依据,同时更好地维护主体工程安全运行。     

临江市坡耕地水土流失治理试点建设研究

结合坡耕地水土流失综合治理试点工程建设,对临江市坡耕地治理提出相应的治理目标和措施,对其建设必然性和重要性进行分析,旨在为坡耕地的有效开发、保护、整治以及减少水土流失、扩充后备耕地、提高土壤生产力提供参考。     

编制化工类项目水土保持方案的体会

本文以实践为基础,从基础资料收集与分析、主体工程水土保持分析与评价、防治责任范围、水土流失预测、水土流失防治分区及总体布局、防治方案与措施类型等6个方面探讨了如何编制化工类水土保持方案.     

不同侵蚀部位微生物变异性研究

土壤是一个由生物和非生物组成的复杂综合体,肥力是土壤的本质和属性。土壤养分含量和土壤微生物特征是表示土壤肥力高低的重要指标,水土流失不仅导致土壤养分含量下降,而且对土壤微生物特征产生明显的影响,进而影响到土壤养分的循环和转化。本研究对华南赤红壤丘陵坡地不同侵蚀部位微生物特性的变异性进行了对比分析。结果表明：随着土壤侵蚀程度的加剧和植被的破坏,土壤微生物总数逐渐减少,土壤基础呼吸和土壤诱导呼吸显著下降。在没有草本植物的情况下,仅有人工荷木并不能起到明显的水土保持作用,近地表覆盖的草本植物应是水土保持植被建设必不可少植物类群。以此为华南赤红壤丘陵区土壤生态环境修复和水土保持提供科学依据。     

水泥改性膨胀土在侵蚀环境下的干湿循环效应研究

为了研究水泥改性膨胀土在复杂环境条件下的稳定性及耐久性,设计了室内模拟试验,探讨了纯净水、不同浓度及不同种类的化学溶液在干湿循环作用下对水泥改性膨胀土的侵蚀效应.从初始至破坏状态,记录了试样的宏观裂隙开展过程及体积的变化情况,对比分析了相应的荷载位移曲线及峰值强度,得到了水泥改性膨胀土在不同侵蚀环境下的力学特性随干湿循环次数的变化规律,并对相应的作用机理进行了分析.试验结果表明,侵蚀环境的干湿循环作用对水泥改性膨胀土的力学特性有明显的影响,且随着侵蚀溶液的浓度和干湿循环次数的递增而变得愈加显著.     

聊城市20m以浅地下空间开发地质问题分析

当前聊城市地下空间开发利用程度较低,随着城市化进程的不断发展,其对地下空间的需求日趋明显。本文从地下水水位、水质、软土、砂性土及土质腐蚀性等方面出发,分析了影响聊城市地下空间开发的主要地质问题。软土、砂性土的地基液化及承压水突涌、水土腐蚀等工程地质问题因素对聊城市20m以浅的地下空间开发影响不大,影响其地下空间开发的其主要地质问题为地下水引起的流砂、边坡失稳、地基承载力下降、土体位移等问题及砂性土引发的流砂与管涌问题。通过对聊城市20m以浅地下空间开发的主要地质问题分析,为今后城市地下工程选址及建设提供基础依据。     

包膜肥料控制释放速率的测定

分别用水浸泡法和土壤溶出率法测定了3种包膜肥料氮素的释放速率,研究了这两种测试方法的特点以及应用范围。结果表明：同一肥料在水中以及土壤中氮素的释放速率和释放模式有所不同;水浸泡法适用于水田用或者释放速率小的包膜肥料释放速率的测定,而土壤溶出率法适用于旱地上用或者释放速率大的包膜肥料释放速率的测定;水浸泡法可以快速比较不同包膜肥料的缓／控释性能,但与肥料在土壤中的实际释放期有偏差;土壤溶出率法能较好地模拟施肥的情况,但测试时间长。     

Nylon matting: A textile structure used for soil and civil engineering applications

A new type of interlaced mat made of heavy denier nylon monofilaments has been developed, and has been under evaluation for the past few years. Due to its combination of unique properties—high strength, great porosity, chemical stability—it is finding uses in many varied applications. Its current greatest use is in soil erosion control, where the product, when placed on steep banks, traps soil particles caused by runoff water, thus preventing erosion and providing a good seed bed for grasses and other ground cover. Placed under turf and sods, the structure provides a porous, open structure which holds moisture and enhances root growth, while the mechanical strength of this material reduces packing of the soil, thus making a superior base for athletic fields and playgrounds. The product, its properties, and its applications are described.     

A spatially explicit methodology to quantify soil nutrient balances and their uncertainties at the national level

A soil nutrient balance is a commonly used indicator to assess changes in soil fertility. In this paper, an earlier developed methodology by Stoorvogel and Smaling to assess the soil nutrient balance is given a major overhaul, based on growing insights and advances in data availability and modelling. The soil nutrient balance is treated as the net balance of five inflows (mineral fertilizer, organic inputs, atmospheric deposition, nitrogen fixation and sedimentation) and five outflows (crop products, crop residues, leaching, gaseous losses and erosion). This study aims to improve the existing methodology by making it spatially explicit, improving various transfer functions, and by modelling explicitly the uncertainties in the estimations. Spatially explicit modelling has become possible through a novel methodology to create a simulated land use map on the basis of the principles of traditional qualitative land evaluation. New literature data on the various inputs and outputs allowed improvement of the estimations of deposition, sedimentation, leaching, and erosion. Moreover, the uncertainty of the calculated soil nutrient balances was assessed. To illustrate the improved methodology, we applied it to Burkina Faso and revealed that nutrient depletion is occurring throughout the country at rates of , and . The resulting spatial soil nutrient balances at the national level can constitute the basis for targeting soil fertility policies at lower levels.     

盐水与冻融耦合作用对玄武岩纤维水泥土性能影响研究

冻融循环作用与外界环境的侵蚀是影响水泥土强度的主要因素,探索如何提高水泥土在寒冷地区盐水侵蚀环境下的强度及其发展规律是一个重要的课题。通过盐冻试验和无侧限抗压强度试验,研究了玄武岩纤维水泥土在不同溶液(3.5%(质量分数,下同)NaCl溶液、3.5%Na₂SO₄溶液、3.5%(NaCl+Na₂SO₄)混合溶液、清水)与冻融循环作用耦合下的力学性质与表观特征,探讨了养护温度、侵蚀溶液类型、冻融循环次数等变量对水泥土性能的影响。在此基础上,采用Logistic生长模型,对不同环境下水泥土试块的强度进行回归分析。研究结果表明:低温养护环境会抑制水泥土强度的发展;随着冻融次数的增加,试块出现了不同程度的质量损失、表面破坏,以及无侧限抗压强度降低的现象;在相同冻融次数下,玄武岩纤维水泥土的破坏程度由强到弱依次为硫酸盐冻＞混合盐冻＞氯盐冻＞水冻;而掺入玄武岩纤维可使水泥土经历更多次的冻融循环,有效降低强度损失率,提高水泥土的抗冻性;通过回归分析,得到不同试验组的强度衰减模型和预期强度。     

Available soil phosphorus, phosphorus buffering and soil cover determine most variation in phosphorus concentration in runoff from pastoral sites

Phosphorus (P) runoff from agricultural land contributes to elevated P concentrations in surface water. Although P concentrations in runoff are often higher when soil P is increased, attempts to quantify this relationship in field studies have been inconclusive, either because of confounding within experiments or methodological differences between experiments. The present study attempted to address these issues using simulated rainfall at 15 pastoral locations with varied lithology, land-use intensity, plant cover and soil-P properties in SE Australia, at a total of 38 on-farm sites, each with paired plots. At 27 sites, one of each pair was covered with 70?% shade-cloth to reduce rainfall energy. Although these were uncultivated pastoral sites and surface soil erosion rates were all relatively low, eroded surface soil had sufficiently high concentrations of P to make a major contribution to total P in runoff from some sites, even when plant-available soil P was low. We conclude that greater vegetative cover is required to manage P in runoff than to manage soil erosion. When soil was adequately protected against erosion by either high vegetative cover or shade-cloth, greater than 90?% of the variation in both dissolved reactive P and total P was explained by two commonly measured soil variables: soil-test P (bicarbonate extract) and P-buffering index (where P was in the range where plants may respond to fertiliser). It appears that available soil P can be raised with fertiliser to improve agronomic production without fear of significantly increasing P losses in runoff provided soil test P remains below the agronomic critical concentration defined by the soil P-buffering index. These findings have broad relevance for environmental risk assessment and management where the data required for more complex procedures are unavailable.     

长输管道土壤腐蚀特性分析

基于长输管道658处土壤取样点的腐蚀等级及变化趋势,选取30处典型土壤腐蚀点开展埋片试验,建立土壤腐蚀数据样本。采用BP神经网络评价法,进行多因素分析30处埋片点的测试结果,并预测其他628处取样点的土壤腐蚀特性。该方法可为今后长输管道土壤腐蚀特性分析提供依据和标准。