水电工程水生态环境效应评价方法与调控措施

围绕水电工程的水生态环境问题，重点梳理了水库运行下关键生源要素生物地球化学循环的变化及其水生态效应、底栖动物生境和鱼类生境以及鱼类洄游通道的影响、水生态环境保护工程与非工程措施等方面的研究进展，剖析了当前科学研究和工程应用中存在的难题，从理论、方法与技术角度阐明了出现这些难题的原因。提出了水电开发水生态环境保护未来需要重点开展的研究：长期系统性观测，揭示库内生源要素的滞留-转化-输送过程与机制及水生态环境累积效应；水库调控导致的鱼类性腺发育有效积温和产卵临界水温节律变化以及两者对鱼类种群繁衍的联合作用。最后特别指出当前针对鱼类保护的部分强制性措施存在的问题，并提出了高坝多环境因子调控的生态调度和支流生境替代等鱼类保护技术以及保护效果量化评价新方法。     

岸堤水库水生态安全调查与评估方案初探

为推进水生态文明建设试点工作,围绕岸堤水库水源地水生态调查、监测与评估三个环节,探讨区域人为活动影响、生态系统状况调查与监测、生态服务功能、生态环境保护调控管理措施、生态安全评估等方案编制所涵盖的内容。建立水生态系统风险监测与评估系统,确保岸堤水库生态安全和长期可持续运行。     

再议水库生态环境调度

从生态调度科学内涵、工程实践以及调度体系3个方面,剖析了诸多学者运用水库生态调度概念所取得的丰硕成果,发现水库生态调度提法得不到共识的原因:对生态调度中的"生态"自然科学的不同认识;水库调度对水库"生态"与"环境"作用机制的不同理解;水库非生物因子与生态系统非生物因子的差异性认识。深入研究和剖析了"水库环境调度"、"水库生态调度"和"水库生态环境调度"的概念及其调度体系内容,明确了"水库生态环境调度"提法的科学性和可操作性,澄清认识,共识提法,有利于在整体分析水库水资源、水库水环境和水库水生态这个复杂系统的基础上来完善水库调度学科体系,有利于在水库生态环境调度科学实践后增加其科学意义和应用价值,有利于在构建水库生态环境调度技术体系、调度规程及其应用平台后提高水库调度的综合效益。     

广义生态水利的内涵及其过程与维度

总结中国工程水利、环境水利、资源水利、生态水利发展沿革，分析国内外生态水利研究进展、发展趋势及其特点，指出生态水利是人类社会发展到生态文明时代水资源利用的一种新途径和方式，以尊重和维护生态环境为主旨，开发水利、发展经济，为人类社会可持续发展服务。阐述了广义生态水利的内涵、定义和发展模式及其过程和维度，并提出以下结论和观点：①生态水利将水资源和水循环调控作为重要生态要素，从流域生态系统能量交换、生物链接、结构平衡、循环转化全视角开展研究，探索既能满足人类社会需求，又能兼顾水生态系统健康和良性发展的生态水利措施和方法。②建立了水利工程"规划设计—建设管理—运行调度"全过程、全生命周期的工程安全和生态安全保障体系，特别是将生态调度纳入水利工程全"服役期"，其中"后坝工时代"实施全流域大尺度生态调度，是生态保护和恢复最有效的措施。③从"生态环境-社会经济-水循环调控"三个维度，在生态文明视野下的国土空间规划治理体系中，科学把控生态水利的空间定位，促进"三生空间"优化布局，保障"三生用水"合理配置，优化"三生关系"耦合协调，实现生态保护和高质量发展，推动生态水利事业创新发展。     

生态地质调查工程进展与主要成果

为全面支撑山水林田湖草整体保护、系统修复和综合治理,中国地质调查局部署了“生态地质调查工程”。该工程自2019年以来,以地球系统科学理论为指导,重点开展了我国北方林草湿分布区1∶50万生态地质调查以及黄河源区、大凉山区等重点生态功能区1∶5万生态地质调查,采用“空-天-地”一体化调查技术,获取了不同尺度森林、草原、湿地等生态类型分布与变化,成土母岩、水文地质要素、土壤、地形地貌等生态地质条件,以及荒漠化、湖泊萎缩等生态问题分布数据,分析了生态-地质之间相互制约影响关系,剖析了主要生态问题的成因机理,划分了生态地质单元,建立了生态地质图谱,提出了基于地球系统科学的国土空间生态保护修复对策建议,为我国北方地区生态保护与系统修复工作提供了基础数据与技术支撑。     

生态地质调查工程进展与主要成果

为全面支撑山水林田湖草整体保护、系统修复和综合治理,中国地质调查局部署了“生态地质调查工程”。该工程自2019年以来,以地球系统科学理论为指导,重点开展了我国北方林草湿分布区1:50万生态地质调查以及黄河源区、大凉山区等重点生态功能区1:5万生态地质调查,采用“空-天-地”一体化调查技术,获取了不同尺度森林、草原、湿地等生态类型分布与变化,成土母岩、水文地质要素、土壤、地形地貌等生态地质条件,以及荒漠化、湖泊萎缩等生态问题分布数据,分析了生态-地质之间相互制约影响关系,剖析了主要生态问题的成因机理,划分了生态地质单元,建立了生态地质图谱,提出了基于地球系统科学的国土空间生态保护修复对策建议,为我国北方地区生态保护与系统修复工作提供了基础数据与技术支撑。     

水电工程建设对河湖湿地不利影响及对策研究

近年来,辽宁省不断推进水生态环境体系的建设,取得了重要的实践成果,积累了丰富的建设经验。然而,水生态环境体系建设正面临着突出的问题,构建水资源保护与河湖健康保障体系,保护水生态环境,支撑经济社会的可持续发展尤为重要。文章针对全省的水电工程建设对河湖湿地生态环境的不利影响,提出了河湖湿地水生态环境保护措施建设的相应对策,以期为水生态环境体系的发展提供有益借鉴。     

徐州市矿山环境保护与治理工程研究

随着徐州市矿山环境保护与治理工程的实施,徐州市因采煤塌陷及开山采石造成的生态环境问题及景观破坏得到改善,废弃闲置的土地资源得到有效利用。通过分析徐州市矿山环境保护与治理的现状,以生态优先、以人为本及经济效益和示范效应为原则,部署废弃露采矿山治理、采煤塌陷地复垦及绿色矿山建设的重点工程,从资金筹措、技术支撑及政策保障等方面提出重点工程实施的保障措施。     

广义生态水利的内涵及其过程与维度

总结中国工程水利、环境水利、资源水利、生态水利发展沿革，分析国内外生态水利研究进展、发展趋势及其特点，指出生态水利是人类社会发展到生态文明时代水资源利用的一种新途径和方式，以尊重和维护生态环境为主旨，开发水利、发展经济，为人类社会可持续发展服务。阐述了广义生态水利的内涵、定义和发展模式及其过程和维度，并提出以下结论和观点:①生态水利将水资源和水循环调控作为重要生态要素，从流域生态系统能量交换、生物链接、结构平衡、循环转化全视角开展研究，探索既能满足人类社会需求，又能兼顾水生态系统健康和良性发展的生态水利措施和方法。②建立了水利工程"规划设计—建设管理—运行调度"全过程、全生命周期的工程安全和生态安全保障体系，特别是将生态调度纳入水利工程全"服役期"，其中"后坝工时代"实施全流域大尺度生态调度，是生态保护和恢复最有效的措施。③从"生态环境-社会经济-水循环调控"三个维度，在生态文明视野下的国土空间规划治理体系中，科学把控生态水利的空间定位，促进"三生空间"优化布局，保障"三生用水"合理配置，优化"三生关系"耦合协调，实现生态保护和高质量发展，推动生态水利事业创新发展。     

川西北山水林田湖草生态保护技术研究

山水林田湖草生命共同体是现代生态保护思想的重要部分。以川西北阿坝生态示范区为研究对象,调查了该地区生态环境现状及其受人类活动的影响。采用综合调查等手段,重点研究了水环境、草原及矿山环境生态保护措施及恢复技术。结果表明：川西北阿坝州主要面临生态环境退化、水土流失和森林破坏等生态问题,人类工程活动是影响生态环境的主要因素;严格的水资源管理措施以及增加水污染相关政策是水环境生态保护的基础;通过建设处理湿地、生态漂浮浮岛,以及使用再生水进行补给等手段能够有效恢复草原水质;提出了矿山采空区土地处理措施和植被恢复措施,复垦监测是评价矿山环境恢复效果重要手段。本研究成果为推进山水林田湖草生命共同体的整体保护、系统修复、综合治理提供理论与技术支撑。     

Impact of control structures on assimilative capacity of rivers and fish habitat

This research studies the impact of water level control structures on self-assimilative capacity of rivers and on fish habitat. Constructing a water level control structure in a river reach will alter its hydraulics as well as its water quality, thermal regime and fish habitat. A mathematical model is developed to simulate river hydraulics, water quality, temperature and fish habitat. Diurnal dissolved oxygen concentrations are investigated to show their impact on fish. A case of a Nile River reach was studied to investigate the impact of the existence of the Esna barrage on the water quality and fish in its upstream reach. The barrage has negative impacts on the upstream self-assimilative capacity of the rivers. The waste load that the river could absorb was only 54 % (at low flow) and 78 % (at high flow) of the entire load if no barrage was present. Including in the simulation of the effects of photosynthesis and respiration, the above mentioned percentages were raised to 54 % and 91 %, respectively. Although water level control structures have negative impacts on the upstream self-assimilative capacity of the rivers, they have positive effect on downstream dissolved oxygen concentrations due to reaeration that happens across them. Downstream dissolved oxygen concentration increased by 6 % from its upstream concentration value. The barrage has a positive effect on fish habitat in the upstream section. The weighted usable area of Tilapia fish is doubled in case of barrage existence. The barrage causes a slight decrease in water temperature that reaches an average of 0.13 degree in the month of June.     

Impacts of soil conservation on groundwater recharge in the semi-arid Loess Plateau, China

Soil conservation measures undertaken to address land degradation can alter the hydrologic cycle by changing partitioning of water fluxes at the land surface. While effects on runoff are well documented, impacts of soil conservation activities on fluxes to groundwater are poorly understood. The goal of this study was to examine fluxes to groundwater in a semi-arid area of China’s Loess Plateau that has been subject to extensive soil conservation activities. Unsaturated zone pore-water pressures and concentrations of chloride show that impacts on deep drainage differ between ecological and structural soil conservation approaches. High matric potentials and low chloride beneath cultivated terrace and gulley sites are consistent with deep drainage occurring at these sites. Estimated recharge rates for dryland cultivated upland sites were approximately 55??0?mm/year (11??8% of mean annual rainfall) based upon chloride mass balance. In contrast, results suggest that mature tree and shrub plantations prevent deep drainage. Stable isotope signatures of unsaturated-zone moisture and groundwater indicate that focused infiltration through gullies and other topographic lows is likely to be the primary recharge mechanism. The results of this study highlight the potential for inadvertent effects of some soil conservation approaches on regional water resources.     

Land use change scenarios and associated groundwater impacts in a protected peri-urban area

Land use changes in peri-urban areas are usually associated with significant impacts on groundwater resources due to alteration of the recharge regime as well as through the establishment of pollution sources. Quantifying the aforementioned impacts and assessing the vulnerability of the groundwater resources is an important step for the better management and protection of the aquifers. In the present study, a physically based, distributed hydrologic model has been used to identify the impacts from specific land use change scenarios in the protected area of Loutraki catchment. A vulnerability assessment method has been also implemented to provide a decision support tool to the land planning authorities and also hydrologic mitigation measures for the sustainable development of the area have been proposed. The hydrologic impacts of the land use scenarios include a 5% reduction in the annual recharge of the study aquifer for scenario 1 (doubling of the current urban areas) and 7% decrease for scenario 2 (tripling of the current urban areas). Nevertheless, these impacts can be minimised if small-scale artificial recharge infrastructure is developed and the land planning measures suggested through the vulnerability and recharge maps will be followed.     

Response of Tidal Creek Fish Communities to Dredging and Coastal Development Pressures in a Shallow-Water Estuary

To investigate the effects of dredging and associated development pressures (i.e., shoreline armoring, developed land use) on fish, three sets of paired dredged and undredged tidal creeks were surveyed within Lynnhaven River, Virginia. Fish species diversity, community abundance, biomass, and size structure were compared among creeks and related to watershed, shoreline, and physicochemical characteristics. Mean fish community characteristics (e.g., abundance) were similar among creeks; however, species-specific analysis revealed subtle differences. Species biomass differed between dredged and undredged creeks, though species abundance was similar. Turbidity highly influenced differences in species abundance among creeks, while organic matter, dissolved oxygen, turbidity, and shoreline hardening may be influencing biomass patterns. The most recently dredged creek appeared to provide less suitable nursery habitat for some species than historically dredged creeks, suggesting initial adverse effects with eventual recovery. Protective measures, such as preservation of marshes, dredge depth, and time-of-year restrictions, may be moderating development and dredging pressures.     

应用流量历时曲线分析黄土高原水利水保措施对河川径流的影响

流量历时曲线（Flow Duration Curve,FDC）是用于分析流域径流特征及其变化的有效方法之一。以长序列日流量为基础,采用FDC方法并结合各流域的径流量时间变化趋势分析方法,研究了黄土高原佳芦河、秃尾河、延河和湫水河等4条流域流量变化的基本特征;通过临界年份前后两个时段序列及不同年代序列的流量历时曲线变化的比较,分析了流域径流过程对大面积水土保持措施的响应。结果表明：随水土保持措施累积面积的不断增大,佳芦河、湫水河、秃尾河的径流量逐年减少,且水土保持措施对高流量部分径流减少的程度较低流量部分大,尤以工程措施为主的湫水河流量减少最明显。在延河流域,与临界年份前的时段相比,后期的高流量部分的径流量减小,而常水和低流量部分的径流量相对增大。尽管流域水土流失综合治理并未使河川径流量增加,但由于高流量部分流量的减少程度较低流量部分径流量减少程度大,从而使流域年内日径流量变化过程趋于均匀化。     

Food habits of red drum and spotted seatrout in a restored mangrove impoundment

Benthic resource utilization by, red drum (Sciaenops ocellatus) and spotted seatrout (Cynoscion nebulosus) was studied in a restored, mangrove-rimmed impoundment (Cabbagehead Bayou) of Upper Tampa Bay, Florida, and in a nearby, natural site of unaltered tidal regime (Double Branch Bay). Diets of fish captured from August 1990 to May 1992 were determined from stomach content analysis. Simultaneously, food availability was evaluated by sampling benthic macroinvertebrates, mobile decapods, and small fish. Red drum and spotted seatrout utilized the restored habitat 1 yr after it was opened to tidal influence. Both species also were collected in the natural mangrove. Although there were noted differences in benthic assemblages between the two sites, red drum and spotted seatrout exhibited flexibility in diet, feeding on abundant and accessible prey. The high abundance of microcrustacea, such as amphipods, on detritus accumulated in the restored habitat constituted a main food resource for both fish species. Major food items in the diet of small (<200 mm) red drum were amphipods, mysids, and nereid and arenicolid polychaetes. Large (200–590 mm) red drum fed on polychaetes, xanthid crabs, palaemonid shrimp, and small fishes. Spotted seatrout preyed primarily upon mysids, shrimp, and small fishes, and to a lesser extent, upon a nereid polychaete. Our findings on fish feeding in a restored mangrove impoundment indicated that the detrital-associated benthic community is utilized by reinvading fish within a short time period, suggesting that not only habitat but food resources were augmented by the reopening of this wetland.     

Historical Comparison of Fish Community Structure in Lower Chesapeake Bay Seagrass Habitats

Seagrass beds provide important habitat for fishes and invertebrates in many regions around the world. Accordingly, changes in seagrass coverage may affect fish communities and/or populations, given that many species utilize these habitats during vulnerable early life history stages. In lower Chesapeake Bay, seagrass distribution has contracted appreciably over recent decades due to decreased water clarity and increased water temperature; however, effects of changing vegetated habitat on fish community structure have not been well documented. We compared fish community composition data collected at similar seagrass sites from 1976–1977 and 2009–2011 to investigate potential changes in species richness, community composition, and relative abundance within these habitats. While seagrass coverage at the specific study sites did not vary considerably between time periods, contemporary species richness was lower and multivariate analysis showed that assemblages differed between the two datasets. The majority of sampled species were common to both datasets but several species were exclusive to only one dataset. For some species, relative abundances were similar between the two datasets, while for others, there were notable differences without directional uniformity. Spot (Leiostomus xanthurus) and northern pipefish (Syngnathus fuscus) were considerably less abundant in the contemporary dataset, while dusky pipefish (Syngnathus floridae) was more abundant. Observed changes in community structure may be more attributable to higher overall bay water temperature in recent years and other anthropogenic influences than to changes in seagrass coverage at our study sites.     

Large-Scale Differences in Community Structure and Ecosystem Services of Eelgrass (<Emphasis Type="Italic">Zostera marina</Emphasis>) Beds Across Three Regions in Eastern Canada

Eelgrass (Zostera marina) forms extensive beds in temperate coastal and estuarine environments worldwide and provides important ecosystem services, including habitat for a wide range of species as well as nutrient cycling and carbon storage. However, little is known about how eelgrass ecosystem structure and services differ naturally among regions. Using large-scale field surveys, we examined differences in eelgrass bed structure, carbon and nitrogen storage, community composition, and habitat services across three distinct regions in Eastern Canada. We focused on eelgrass beds with low anthropogenic impacts to compare natural differences. In addition, we analyzed the relationships of eelgrass bed structure with environmental conditions, and species composition with bed structure and environmental conditions, to elucidate potential drivers of observed differences. Our results indicate that regional differences in eelgrass bed structure were weakly correlated with water column properties, whereas differences in carbon and nitrogen storage were mainly driven by differences in eelgrass biomass. There were distinct regional differences in species composition and diversity, which were particularly linked to temperature, as well as eelgrass bed structure indicating differences in habitat provision. Our results highlight natural regional differences in ecosystem structure and services which could inform spatial management and conservation strategies for eelgrass beds.     

岩盐沉淀对咸水层二氧化碳地质封存注入过程的影响:以江汉盆地为例

依托江汉盆地基础地质和水文地质数据,通过建立新沟嘴组一维、二维径向数值模型,对该储层进行CO2封存注入数值模拟研究,分析二氧化碳注入储层后,咸水层中发生的地球物理化学作用.以CO2的溶解作用和岩盐的沉淀作用为主,分析它们对储层压力和注入性的影响.模拟结果表明,二氧化碳注入储层后,近井周围会形成3个分区,即纯液相区、两相混相区、盐沉淀区;盐沉淀会导致压力积累严重,影响CO2可注入性;对盐度的敏感性分析表明,咸水含水层盐度越大,压力积累会越严重.因此,江汉盆地CO2地质封存应考虑盐度的影响,采取相关缓解压力积累的措施.