土壤侵蚀模型在黄土高原的应用述评

土壤侵蚀模型是认识和评估水土流失过程及其环境影响的有效工具,目前已有的众多土壤侵蚀模型中,因黄土高原地形和地貌的独特性而使模型的应用受到限制。通过系统整理公开发表的文献,对在黄土高原经过验证的、涵盖不同尺度和过程表达的12个土壤侵蚀模型进行比较分析,依据模型预测精度、过程描述、应用方便程度和情景模拟能力等指标对每个模型进行评估。结果表明:模拟预测精度不随模型复杂程度的提高而提高;经验统计模型有利于土壤流失量的快速评估,物理成因模型尤其是分布式物理成因模型更适用于侵蚀过程和输沙过程的精细评估。指出未来黄土高原土壤侵蚀模型发展应着重于提升数据质量、加强模型开发与模型评估3个方面。     

我国侵蚀产沙数学模型研究评述与展望

随着人们对流域水土保持治理和生态建设的日益重视,土壤侵蚀产沙数学模型作为土壤流失评价预测和流域管理的重要手段之一,已成为水土保持、生态保护与建设、流域管理等领域的研究热点.本文对我国土壤侵蚀产沙数学模型研究成果及进展作了综述,重点介绍近年关于土壤侵蚀产沙模型的理论、方法与应用研究成果,对存在的问题进行了初步思考,展望了土壤侵蚀产沙数学模型研究趋势,提出了土壤侵蚀产沙模型研发中需进一步研究的基础理论和关键技术,包括土壤侵蚀过程与机理,经验模型指标体系,不同区域尺度的土壤侵蚀产沙数学模型设计和开发,土壤侵蚀模拟尺度转换关键技术,现代信息技术应用和水土流失试验观测方法的改进等相关科学与技术问题.     

长江流域土壤侵蚀预报模型研究进展

土壤侵蚀模型是定量评价土壤侵蚀影响,进行土地利 用和水土保持规划的科学工具。总结了长江流域土壤侵蚀模型的主要成果,对长江流域国外 物理模型的应用、USLE模型的应用、经验性模型、物理过程性模型作了详细介绍,以期为今 后长江流域的土壤侵蚀模型研究提供一定的参考意见。     

分布式非点源有毒污染模型构建研究

在分布式水文模型ESSI基础上，以日为时间尺度，以DEM栅格单元为基本模拟单元，构建了区域尺度的长时期连续模拟的分布式非点源污染模型ESSI-2。模型具有完整的产流、汇流、产沙、汇沙、有毒污染物分解、输移及汇聚等完整的模拟过程。采用动态产流方案，即根据降雨特征和下垫面特征之间的动态对比关系动态选取产流方式。采用RUSLE模型计算泥沙剥蚀量，并根据产沙量与径流泥沙输移能力的对比计算泥沙输出量。模型充分描述了农药的降解、吸附、下渗、输移、汇聚等过程，因此可以对农药的输移过程进行模拟和时空分布分析。最后，以临沂流域为研究区，对模型进行了验证和应用。模拟结果表明，ESSI-2模型在临沂流域是适用的，能够应用于土壤侵蚀及农药输移过程研究。     

分布式非点源有毒污染物模型构建研究

在分布式水文模型ESSI基础上,以日为时间尺度,以DEM栅格单元为基本模拟单元,构建了区域尺度的长时期连续模拟的分布式非点源有毒污染物模型ESSI-2。该模型具有产流、汇流、产沙、汇沙、有毒污染物分解、输移及汇聚等完整的模拟功能。模型中根据降雨特征和下垫面特征之间的动态对比关系动态选取产流方式;同时采用RUSLE模型计算泥沙剥蚀量,并根据产沙量与径流泥沙输移能力的对比计算泥沙输出量。该模型充分描述了农药的降解、吸附、下渗、输移、汇聚等过程,可以对农药的输移过程和时空分布进行模拟分析。最后,以临沂流域为研究区,对模型进行了案例分析。计算结果表明,该模型适用于临沂流域,能够分析其土壤侵蚀及农药输移过程。     

基于改进型DNDC 模型的小流域非点源氮迁移过程模拟与空间拓展应用

以长江上游紫色土区截流堰小流域和大兴小流域为研究对象,应用改进型DNDC（Enhanced Denitrification Decomposition Model）模型对紫色土区小流域径流、泥沙和氮流失过程进行模拟研究。采用截流堰小流域2007-2009年和2010-2011年径流、泥沙及氮迁移监测数据分别进行模型参数率定和验证,检验模型在紫色土区的适用性,然后利用大兴小流域2011年水文、水质监测数据对该模型进行拓展验证,探讨模型在具相似空间结构特征的小流域尺度拓展的可行性。结果显示：率定期和验证期月径流、土壤侵蚀、氮流失Nash-Sutcliffe效率系数大多超过0.80,相对误差均在16.36%以内。拓展验证期,月径流、土壤侵蚀、总氮（TN）和颗粒态氮（PN）的Nash-Sutcliffe效率系数分别为0.70、0.55、0.76和0.71,相对误差分别为6.2%、31.2%、9.5%和30.4%。改进型DNDC模型能较好模拟紫色土区小流域径流、泥沙和氮迁移过程,但尺度拓展过程中泥沙、颗粒态氮的模拟偏差有所增大。     

基于GeoWEPP的济源市土壤侵蚀研究

根据济源市的DEM、土壤类型、土地利用、气象等数据,运用TOPAZ软件从DEM上提取流域地形参数,采用基于物理过程耦合WEPP和GIS的GeoWEPP模型研究了济源市土壤侵蚀的时空分布特征。利用侵蚀量和径流量监测数据,采用相对误差、相关系数和Nash-Suttcliffe确定性系数对GeoWEPP模型进行识别和验证,结果表明该模型具有较好的适应性。利用经识别验证过的模型,模拟了济源市现状水土保持措施和水土保持生态工程措施下的土壤侵蚀特征。结果表明:相比现状水土保持措施,水土保持生态工程措施条件下,济源市全年土壤侵蚀量和径流量分别减少12.2%和3.2%。     

基于尺度分析的流域土壤侵蚀评估进展与探讨

在分析国内外有关研究成果的基础上，认为解决土壤侵蚀尺度推演问题，需要从尺度转换的角度出发，按照空间、时间和主导过程的差异，将土壤侵蚀细分为典型的几个尺度；按照典型性、代表性以及可尺度转换性分析并提出不同尺度上研究区域和表征指标的选择准则。基于这些准则，引入“3S”技术，对土壤侵蚀定量评估和不同尺度土壤侵蚀研究结果的推演和比较具有现实意义。     

黄土丘陵沟壑区坡长与地形复杂度关系研究

流域分布式土壤侵蚀学坡长作为流域和区域尺度水文模型和土壤侵蚀模型的最基本参数之一,对研究土壤侵蚀的形成和发展有重要影响。从黄土丘陵沟壑区的常用地形因子入手,详细探讨了坡长与地形之间的联系,在此基础上建立了地形要素交互作用的多维复合集成模型,并根据该模型定量计算出研究区各地形要素对坡长的贡献,进而揭示了地形对于水土流失的影响。研究表明:①复杂地形因子对于坡长的贡献率更高,更能揭示地形对于水土流失的影响;②7种复合地形因子,对于坡长的贡献正负不一;③地形因子对坡长的贡献率由高到低依次为坡谱信息熵、粗糙度、高程面积积分、起伏度、海拔标准差、平均坡度、剖面曲率、平面曲率、沟壑密度。     

基于野外调查、遥感信息和CSLE 模型的 土壤侵蚀强度分级

基于野外调查、遥感信息和土壤侵蚀模型等方法的土壤侵蚀强度分级计算,是开展区域土壤侵蚀长期变化监测的重要途径。选取位于西北黄土高原丘陵沟壑区的陕西省靖边县和位于西南土石山区的广西省横县为研究区,基于野外调查数据和遥感信息,应用CSLE土壤侵蚀模型、水利部土壤侵蚀强度面蚀分级指标(三因子法),计算得到30m像元尺度土壤侵蚀模数,据此划分土壤侵蚀强度等级。对比研究结果表明:CSLE土壤侵蚀模型计算结果总体优于三因子法;与三因子法和第二次全国土壤侵蚀遥感调查结果相比,CSLE土壤侵蚀模型计算结果中极强烈侵蚀和剧烈侵蚀所占比例较大;应用土壤侵蚀模型对各因子进行监测和变化分析,有利于对区域土壤侵蚀变化开展长期监测并做出合理解释,但因子赋值对模型模拟结果影响较大。     

SPATIAL AND TEMPORAL WATER QUALITY VARIABILITY IN AQUATIC HABITATS OF A CULTIVATED FLOODPLAIN

The floodplains of lowland rivers contain diverse aquatic habitats that provide valuable ecosystem services but are perturbed when intensively cultivated. Hydrologic, water chemistry and biological (fish) conditions in five aquatic habitats along the Coldwater River, Mississippi, were measured for more than 4 years: the river, two severed meanders that functioned as backwaters, a managed wetland and an ephemeral channel draining cultivated fields. Off‐channel habitats were connected to downstream regions 0.10% to 32% of the dry season and 24% to 67% of the wet season. The median temperatures for the five monitored sites ranged from 18°C to 23°C, the median total solids concentration for all sites was 135 mg L^?1, the median total phosphorus was 0.29 mg L^?1 and the median total nitrogen was 1.56 mg L^?1. Chemical and physical water quality displayed strong seasonal differences between the wet winter/spring and the dry summer/fall periods so that temporal variation consisted of gradual seasonal trends superimposed on strong diurnal variations. All off‐channel habitats exhibited periods of hypoxia and temperatures >30°C during the dry season. Between‐site gradients of water and habitat quality were strongly coupled to water depth and runoff loading. The rehabilitation of one backwater by increasing water depth and diverting agricultural runoff was associated with improved water quality and fish species richness relative to an adjacent untreated backwater. The diversion of polluted runoff and the use of water control structures to maintain greater water depth were observed to be effective management tools, but the former reduces the water supply to habitats that tend to dry up and the latter reduces connectivity. Published in 2011 by John Wiley & Sons, Ltd.     

Spatio‐temporal variation of gross CO2 and CH4 diffusive emissions from Australian reservoirs and natural aquatic ecosystems,and estimation of net reservoir emissions

Carbon dioxide (CO₂) and methane (CH₄) diffusive emissions were measured during two field surveys in Queensland and Tasmania, Australia, using the floating chamber method. Bubbling and degassing emissions in 2010 were estimated in Koombooloomba Dam reservoir using only inverted funnels and gas concentrations, respectively. A total of 14 reservoirs and 16 rivers and lakes were sampled from 2006 to 2010. Spatial variation was substantial within each water body, as well as between them. The main drivers of diffusive emission variation were physiographic region and climate, with a clear demarcation being observed between diffusive emissions from tropical Queensland and temperate Tasmania, and between the humid West Coast Range (Tasmania) and dry Central Plateau (Tasmania). Higher CO₂ and CH₄ diffusive emissions were observed during the dry season, when long water residence times would promote organic matter degradation. Estimated total gross emissions, including diffusive, bubbling and degassing emissions, for Koombooloomba Dam reservoir were about 1.5 × 10⁶ t CO₂eq km² per year, or 24 × 10⁶ t CO₂eq per year. This corresponds to a plant emission factor of 3.18 kg CO₂eq MWh^?1. Using an estimate of terrestrial emissions derived from literature data for the Tully River catchment area, rough estimated net emissions from the catchment area are about 44 kt CO₂eq per year, or 5.83 kg CO₂eq MWh^?1, which is in the lower range of the studied reservoirs.     

Call for Papers

正As the eldest and most distributed professional journal of water industry,Water Wastewater Engineering(W WE)gained very wide acceptance from the colleagues working in this field in this country since start publication in 1964.Now it is administrated by the Ministry of Construction of the People’s Republic of China and sponsored by the China Civil Engineering Society etc.     

Serial discontinuities in a Rocky mountain river. II. Distribution and abundance of trichoptera

River regulation in the headwaters and middle reaches of the Gunnison River, Colorado, significantly altered distributions and abundances of Trichoptera fauna. Twenty-five species were collected from mainstream samples, with the greatest species richness occurring at an unregulated, rhithron segment above the central reach dams. At sites immediately below the three hypolimnial-release dams and a reregulation dam, species richness was reduced 35–90 per cent and abundance > 95 per cent. Net-spinning caddisflies were the dominant trichopterans at unregulated sites; Arctopsyche grandis in the upper reaches (218 organisms, 586 mg dry mass m^?2) and Hydropsyche cockerelli, H. occidentalis and Cheumatopsyche pettiti in the lower river (9041 total organisms, 6621 mg m^?2), downstream from the last dam. The observed distributional pattern of low trichopteran densities in dam tailwaters and high hydropsychid densities at sites 60–80 km below the central reach dams is a classic expression of continuum resets and adjustments in response to stream regulation as predicted by the Serial Discontinuity Concept.     

Surveying for Water Resources

Abstract

A professional Land Surveyor (Geomatician) describes the Hydrogeologists' survey requirements of a major water resources assessment for the government of The Sultanate of Oman (1992 to 1996). The need for objective specifications is stated. Specialist terms like geoid, spheroid, Mean Sea Level are explained and how to relate spheroidal levels to the geoid. Methods like traditional survey, satellite survey, and photogrammetry are introduced. The paper encourages coordinated working for the benefit of water resource assessment and recommends employment of the professional land surveyor for major studies.     

库水波动下库岸边坡地下水浸润线解析解及误差分析

解析法是库岸边坡地下水浸润线计算中便于实际应用的方法,但该方法须基于若干假定并对潜水运动基本方程线性化后才能求解。针对各假定和线性化过程建立不同的地下水渗流数学模型,用解析法和有限元法解答上述数学模型,分析各误差大小及其规律。结果表明：库岸垂直处理带来的误差要小于方程线性化处理和不考虑非饱和渗流带来的误差,而且它们都随渗透系数变大而减小;在三峡库区库水调度情况下,假定库水位等速变化带来的误差对大多岸坡而言可以忽略;计算库岸边坡地下水浸润线时,解析法只适用于水位变化幅度相比含水层厚度较小,且几何边界规则、岩土结构简单、岩土体渗透性较好时的情况。     

Changes in Summer Irrigated Crop Area and Water Use in Southeastern Turkey from 1993 to 2002: Implications for Current and Future Water Resources

Changes in summer irrigated cropland acreage and related water use are estimated from satellite remote sensing and ancillary data in semi-arid Southeastern Turkey where traditionally dry agricultural lands are being rapidly transformed into irrigated fields with the help of water from the Euphrates-Tigris Rivers. An image classification methodology based on thresholding of Landsat NDVI images from the peak summer period reveals that the total area of summer irrigated crops has increased three-fold (from 35,000 ha to over 100,000) in the Harran Plain between 1993 and 2002. Coupled analysis of annual irrigated crop area from remote sensing and potential evapotranspiration based estimates of irrigation water requirements for cotton indicate a corresponding increase in agricultural water use from about 370 million cubic meters to over one billion cubic meters, a volume in accordance with the state estimates. These estimates have important implications for understanding the rapid changes in current agricultural withdrawals in Southeastern Turkey and form a quantitative basis for exploring the changes in future water demands in the region. For example, expansion of irrigated lands have led to a steady decrease in potential evaporation due to increased roughness and decreased humidity deficit in the Harran Plain. Assuming that the changes in future evaporation conditions will be of similar nature, water use for irrigation is expected to decrease over 40 percent in future irrigation sites. Incorporating this decrease in overall planning of the irrigation projects currently under construction should lead to improved management, and by extension, sustainability of water resources in the region.     

The Impact of Economic Development on Water Pollution: Trends and Policy Actions in Malaysia

The paper examines the impact of development activities on water pollution in Malaysia. Hence, the main objective of this paper is not just to examine the trends of development-induced water pollution around the region of the country but to know where the problems are and the policy measures taken by the government. It evaluates the probable causative relationship between problems introduced due to technology employed in water pollution control and governmental policy measures. It examines the relationship between development indicators as sources of pollution and polluted rivers over a period of 12 years. The findings of the paper have shown that despite the policy enforcement actions against the identified sources of water pollution, all the three development indicators (chosen based on those identified sources) still accounted for high percentage of river pollution in Malaysia. The findings of the paper were used to identify the central fact of the location of the problem. Some crucial conclusions of where the problems likely to be, as reflected in the findings, are: (a) the issue of interactive-effects between pollutants that many policy-makers are not aware of. This is when policy measures concentrate only on one source of water pollution; (b) the enforcement strength and/or effectiveness of policy measures themselves; (c) financial constraints to invest in appropriate technology especially sewerage systems for controlling human source of water pollution in the country; as well as those confronting small polluting industries (d) finally, lack of cooperation between government and private business firms to comply with regulatory policies for water pollution control.     

浅淡溢洪道改扩建方案与选择

溢洪道改扩建和进行溢洪道方案布置，要择优选取溢洪道进口型式、防冲消能工，以使其工程量省、施工快、运行管理方便     

Intangible Flood Damage Quantification

Flooding is a natural disaster that may cause tremendous tangibleand intangible damage to the national economy. The tangible damage assessment, i.e. the monetary value of all direct and indirect physical damages, has already been studied, whileintangible damages have not yet been taken into account. Thisarticle, therefore, is the first systematic attempt to assess bothtangible and intangible damages. The new proposed Anxiety-Productivity and Income Interrelationgship Approach (API) has been developed to quantify the intangible damage in monetary terms. The Bangkok area has been selected as the research area because several severe flood events have occurredthere over the last two decades. The 1983 Bangkok flood caused 6600 million baht in damage, according to estimates by the National Statistical Office (NSO). This article examines the totalflood damage (including the intangible damage) at different flood magnitudes. Case studies with and without flood mitigation projects are studied and compared. Furthermore, thisarticle also discusses the improvements over the conventional approach offered by the new API methodology.