A hydrogeomorphic dynamics approach to assess in‐stream ecological functionality using the functional flows model,part 1—model characteristics

The functional flows model integrates hydrogeomorphic processes and ecological functions for stream physical habitat evaluations. Functional flows are discharge values that serve ecological uses. Assessments of functional flows are based on evaluation of shear stress dynamics. The analysis is based on the occurrence of sediment transport regimes defined by threshold values of Shields stress estimated from discharge (Q), a parameter (f) governing depth response to incremental discharge changes, water surface slope (S) and media grain size (D₅₀). As an example, the model was tuned for fall‐run Chinook salmon spawning. Ecological functions studied were bed occupation (spawning, incubation and emergence) and bed preparation (river bed reworking periods)—both reliant on shear stress dynamics. A numerical experiment and sensitivity analysis using a wide range of realistic values of input variables indicated the effect of each variable on flow functionality. Combinations of S = 0.001, 0.005 and 0.01, D₅₀ = 0.02, 0.05, 0.1 m, f = 0.2, 0.3, 0.4, 0.5 and four sediment transport stages produced 144 scenarios. Ranges of functional flows were greater for scenarios for low f (0.2) with low slope (0.001,0.05), for high f (0.5) with small grain size (0.02 m) and for intermediate low f (0.3) with coarse grain size (0.1 m). The functional flows model incorporates in‐stream habitat processes by including metrics of hydrologic, hydraulic, geomorphic and ecologic dynamics. Model uncertainties related to input data, calculation algorithms, and model structure are analysed. Functional flows analysis can be useful in studying water management alternatives to improve habitat conditions for target species and lifestages. Copyright © 2009 John Wiley & Sons, Ltd.     

Differences in river ecological functions due to rapid channel alteration processes in two California rivers using the functional flows model,part 2—model applications

This study applies the functional flows model (FFM) that integrates hydrogeomorphic processes and ecological functions to assess physical habitat. Functional flows are discharge values that serve ecological uses. The model was adjusted to evaluate gravel‐bed riffle functionality for fall‐run Chinook salmon with respect to river rehabilitation on the Mokelumne River and flood‐induced channel change on the Yuba River. The goal was to test if differences in ecological performance were traceable to differences in hydrogeomorphic conditions. Ecological functions studied were bed occupation (spawning, incubation and emergence) and bed preparation (river bed reworking periods)‐ both reliant on shear stress dynamics. Model outputs included number of days that have functional flows, ranges of functional flows that provide favourable sediment transport stages and the efficiency of a site to produce functional flows. Statistical significance of results was tested using non‐parametric tests. Functional flows analyses before and after geomorphic alteration indicate that river rehabilitation on the lower Mokelume River increased the number of days with functional flows, while the Yuba River May 2005 flood increased the functional ranges of flows for the test sites. Reach‐scale analyses indicated similar ecological performance at reference sites in both rivers. A comparison between both rivers showed that despite a greater geomorphic potential of the Mokelumne River sites to have functional flows, Yuba River sites actually experienced better ecological performance for fall‐run Chinook salmon freshwater life stages due to greater flow availability. The FFM provided an objective tool to assess changes in ecological functionality at hydrogeomorphically dynamic sites. Copyright © 2010 John Wiley & Sons, Ltd.     

Spatial Pattern of Phytoplankton Based on the Morphology‐Based Functional Approach along a River–Floodplain Gradient

Current efforts to yield an appropriate method that would simplify the use of phytoplankton in the ecological evaluation of freshwaters resulted in different approaches based on clustering phytoplankton organisms. In this study, we applied the morphology‐based functional group (MBFG) concept to determine the spatial changes of phytoplankton in the natural riverine floodplain of the alluvial reaches of the Danube River along the horizontal gradient from the river towards the floodplain habitats. The obtained results showed that the magnitude of environmental changes depended on alternations in hydrological variables (hydropattern and water level) that influenced changes in the physical and chemical conditions. High‐intensity flood pulses caused environmental homogenizations and nitrate enrichment of the floodplain habitats. Phytoplankton dynamics were strongly associated with the environmental changes, and using the MBFG approach, two basic hydrological conditions were identified: inundation phase dominated by diatoms (GVI) and isolation phase dominated by filamentous cyanobacteria (GIII). Total diatom biomass decreased along the floodplain gradient with a diminishing of physical constraints, and site‐specific variables became more important in favouring diatom assemblages. The different response of cyanobacterial species to mixing regime was of particular significance for species successions during bloom period. Altogether, classifying very diverse diatoms (centrics and pennates and planktonic and benthic) and cyanobacterial taxa into single groups represents a weakness of the MBFG approach, which might make it impossible to reflect all the ecological differences governed by environmental constraints along river–floodplain gradients. Copyright © 2014 John Wiley & Sons, Ltd.     

Nervous habitat patches: The effect of hydropeaking on habitat dynamics

Alteration in the river flow regime due to intermittent hydropower production (i.e., hydropeaking) leads to biodiversity loss and ecosystem degradation worldwide. Due to the increasing shear of volatile green energy (i.e., wind and solar), hydropeaking frequency is deemed to increase in the coming decades. However, our mechanistic understanding of how the frequency of repeated hydropeaking (i.e., series of multiple events) affects ecological processes is still limited. Here, we reflect on the impacts of altered flow frequency and relative duration on the persistency of aquatic habitats. We focus on the habitats at patch-scale, being this the scale representing what organisms perceive when interacting with their environment. With a showcase we explore a temporally explicit approach to quantify altered habitat dynamics at patch-scale due to hydropeaking. We then review how changes in habitat dynamics and persistency may affect ecological processes. Our findings suggest that (i) a time-series approach allows to account for the inherent multi-event nature of hydropeaking; (ii) hydropeaking can increase the dynamics of single habitat patches by at least one order of magnitude if compared to unregulated rivers; (iii) altered habitat dynamics at the patch scale can affect the survival of more sessile species and life cycle stages (e.g., invertebrates) or the energy budget of mobile species and life cycle stages (e.g., adult fish). However, the ecological significance and potential environmental thresholds of patch-scale dynamics and persistency are still poorly investigated and need further attention. Moreover, methods for the aggregation of habitat dynamics and persistency from the patch to the reach-scale are not available yet.     

基于多维产出ZSG-DEA模型的中国水资源污染综合分配效率测算

利用考虑多维产出的零和收益-数据包络分析(ZSG-DEA)模型测算2000—2017年中国大陆31个省级行政区(以下简称省)在水资源污染排放总量固定下的污染综合分配效率及生产、生活与生态3个维度的产出效率,并基于效率最大化原则对2017年各省污染排放额度进行调整。结果表明:31个省污染综合分配效率的平均值由2000年的0.322上升至2017年的0.364,生产维度产出效率是拉动污染综合分配效率提升的主要动力;2000—2017年31个省污染综合分配效率的平均值为0.341,生态产出过量与生活维度产出不足导致污染综合分配效率处于较低水平;污染综合分配效率、生态维度产出效率与生活维度产出效率受经济发展水平影响较小,而生产维度产出效率受经济发展水平影响较大;污染综合分配效率分布由大到小为东部、西部、中部,生产维度产出效率分布由大到小为东部、中部、西部,生态维度产出效率分布由大到小为西部、中部、东部,生活维度产出效率分布由大到小为西部、东部、中部;各省污染排放调整额度与污染综合分配效率呈正相关关系,北京、天津、上海、浙江、青海与西藏等20个效率较高的省可增加污染排放额度,河北、安徽、河南、江西与湖北等11个效率较低的省需降低污染排放额度。     

生态价值评估方法在水电开发环境评价中的应用研究

提出河流生态系统的几种主要生态服务功能价值评估方法,定量评价水电开发影响的河流生态系统服务功能的价值变化量。以广东省紫金县沥口水利枢纽工程为案例,对项目实施后河流生态系统服务功能价值的变化进行了定量分析评价。结果表明:沥口水利开发工程引发的河流生态系统服务功能价值变化的每年正效益为5 941万元,主要来自发电效益、旅游收益和灌溉效益,分别占81%、5%和4%;生态系统服务功能价值损失每年为3 744万元,主要是淹没耕地、有机质生产和水质净化,分别占24%、20%和19%。同时,工程开发引发的负效益占到了正效益的63%,说明该工程开发对东江河流生态系统的负面影响是不容忽视的。     

贵州赤水河流域景观生态安全时空动态分析

土地利用景观生态安全变化对区域生物多样性保护、维持生态平衡,建立可持续的土地利用模式具有重要指导意义.在GIS和RS技术的支持下,从景观生态学的角度,分析贵州赤水河流域1995-2018年土地利用景观生态安全变化特征,结果表明:(1)近23年来研究区土地利用类型发生了较大变化,人为因素对土地利用变化干扰较为严重,建设用...     

Riparian vegetation restoration: Does social perception reflect ecological value?

Social‐ecological contexts are key to the success of ecological restoration projects. The ecological quality of restoration efforts, however, may not be fully evident to stakeholders, particularly if the desired aesthetic experience is not delivered. Aesthetically pleasing landscapes are more highly appreciated and tend to be better protected than less appealing landscapes, regardless of their ecological value. Positive public perception of restoration actions may therefore facilitate stakeholder involvement and catalyse recognition of ecological improvement. Here we aim to contrast aesthetical perception and ecological condition in headwater river reaches restored through passive ecological restoration in study areas in Portugal (Alentejo) and France (Normandy). We recorded structural and functional indicators of riparian vegetation to monitor the ecological condition of study sites along a passive restoration trajectory. Aesthetical perception indicators were assessed through stakeholder inquiries developed under a semantic differential approach. We analysed perception responses to changes in the riparian ecosystems resulting from passive ecological restoration across different geographical contexts and social groups. The analysed social groups comprised stakeholders (environmental managers and landowners) and university students (landscape architecture and geography students). Results indicate that (a) visual preferences often do not reflect changes in ecological condition, (b) perception of the restoration process is strongly context dependent, and (c) experience and cultural background affect perception of ecological condition across the different social groups analysed. Clear identification of relevant stakeholder groups (those interested in or directly affected by restoration), effective communication, and stakeholder engagement are therefore essential for assuring the success of river restoration projects.     

生态敏感区景观安全评价与时空变化研究——以湖北省十堰市为例

以中部生态敏感脆弱区十堰市为研究对象,综合运用GIS技术和景观生态学方法,对研究区进行了景观类型变化特征的分析,并选取与人为干扰密切相关的破碎度、多样性指数、分维数和分离度作为评价指标,构建区域景观生态安全评价模型,对该区域生态安全进行了综合评价与时空变化分析,最后探讨了其变化的驱动因素。结果表明:研究区内景观类型以林地和耕地为主,而其中又以林地为优势景观;各景观之间的相互转换都比较频繁,其中又以耕地和林地两者之间的转换幅度最大;十堰市的景观生态安全整体处于较高的水平,但在空间分布上差异很大;十堰市近20 a来景观生态安全有所变化,且变化的时空差异较大;景观类型变化、经济发展和土地整治政策等共同驱动了研究区景观生态安全变化。研究成果可为该区域土地资源管理、生态环境保护和可持续发展提供参考。     

Large dam removal and early spontaneous riparian vegetation recruitment on alluvium in a former reservoir: Lessons learned from the pre‐removal phase of the Sélune River project (France)

The restoration of ecological continuity along the Sélune River (Normandy, France) involves the removal of two tall hydroelectric dams (36 m removed in 2019 and 16 m in 2021), a project without precedent in Europe. During the pre‐removal phase (2014–2018), we performed scientific monitoring of the vegetation that was colonizing alluvium in the former dam reservoir (length: 19 km; surface area: 151 ha). Our study aimed to analyse if spontaneous vegetation could ecologically restore the riparian zone and help maintain fine sediment after dam removal. We used colonization indicators related to vegetation structure, taxonomic richness and diversity, and composition. These indicators were calculated at two spatial scales (local, at a single site, and broad, along the reservoir). The aim was to (a) characterize the spontaneously established species pool; (b) analyse longitudinal patterns in vegetation colonization; and (c) assess temporal changes in the species community. Our results show that diverse plant communities have developed. Slight differences in longitudinal and lateral patterns existed; they were linked with habitat heterogeneity and the reservoir's slow pace of draining. We observed fast spontaneous terrestrialization, which has resulted in cover stabilization, decreased diversity, and the development of herbaceous riverbank communities, with very few invasive species. This finding suggests stabilization potential is high and passive ecological restoration could occur, at least locally. Further analyses focusing on functional traits could help inform future management decisions regarding revegetation on reservoir alluvium.     

塔里木河流域水资源-经济社会-生态环境耦合系统和谐程度量化分析

为科学评价塔里木河流域水资源-经济社会-生态环境耦合系统和谐程度,明晰影响其和谐发展的主要因素,系统考虑水资源禀赋、地区发展水平、生态环境状况等多个方面,构建了水资源-经济社会-生态环境耦合系统和谐程度评价指标体系,运用组合权重SMI-P法定量测算了 2007-2016年塔里木河流域5地州各子系统及耦合系统的和谐程度....     

三峡库区水资源生态足迹及承载力时空演变研究

三峡库区流域水资源可持续承载力的评价研究,对区域实现高质量发展具有重要意义。将淡水生态足迹和水污染生态足迹纳入核算,构建水资源生态足迹模型,综合评价建库以来三峡库区水资源生态足迹与水资源生态承载力时空演变。结果表明,2002～2016年三峡库区整体水资源生态足迹呈波动的先上升后下降趋势,水环境安全及水资源利用效率均有所提高;受年际间降雨量不均影响,水资源生态承载力波动较大,历年均大于水资源生态足迹,水资源呈可持续利用的生态盈余状态。三峡库区水资源利用分布极不均衡,位于重点生态功能区、对水资源需求量较小的库首,水资源生态承载力大,生态盈余较大;位于重点开发区,对水资源需求量较大的库尾,水资源生态承载力小,生态盈余较低,在渝中、渝北区等11个区县出现生态赤字,水资源利用呈不健康状态。水资源生态足迹变化与社会经济发展密切关联,应充分考虑三峡库区水资源时空分布情况,调整产业结构,提升用水效率,合理调度利用水资源,促进三峡库区流域社会经济环境的可持续发展。     

Is fish biomass controlled by abiotic or biotic factors? Results of long-term monitoring in a large eutrophic lake

Relationships between biomass and ecological factors including trophic interactions were examined to understand the dynamics of six fish species in Lake Võrtsjärv, a large shallow eutrophic lake located in Estonia (north-eastern Europe). The database contained initially 31 predictive variables that were monitored in situ for nearly forty years. The strongest predictive variables were selected by three parallel approaches: single correlation (Pearson), a multivariate method (Co-inertia analyses), and a machine learning algorithm (Random Forests), followed by a Generalized Least Squares model to determine meaningful relationships with fish biomass. Models with both additive and interactive effects were constructed. The results revealed that the indicators of degraded ecological conditions (high cyanobacteria biomass and their proportion in total phytoplankton, high summer temperature, high nutrient concentration) were negatively correlated to fish biomass. Benthic macroinvertebrates and other biotic predictors (biomass of specific fish prey and predators) were also important contributors to fish biomass dynamics. Together, abiotic and biotic factors explained 40–60% of the variance of fish biomass, depending of the species. Our findings suggest that both abiotic and biotic factors control fish biomass changes in this eutrophic lake.     

Macroinvertebrate Functional Trait Responses to Chemical Pollution in Agricultural–Industrial Landscapes

Both physical–chemical and biological indicators are used to assess the ecological health of ecosystems. The functional trait composition of communities has the potential to predict the impact of environmental change on ecosystems, yet, we miss evidence that information on pollution can be used to forecast the functional responses of freshwater communities. We used chemical and ecological data collected in the Nestore river basin (Central Italy) to test whether (i) there are generalities in the response of macroinvertebrate functional diversity to river pollution; (ii) water pollution filters certain functional traits and (iii) traits do better than chemical analyses at revealing ecological stress in rivers. Due to interactions with hydrology, chemical variables showed higher seasonal variation at impacted sites, so occasional water samples represented snapshots. Functional traits did well at detecting water pollution by various chemicals, and there was a clear shift of trait combinations from unimpacted to impacted sites. Anthropogenic disturbances homogenized benthic communities in terms of taxonomic and functional composition, both in space (impacted sites) and time (seasons). Traits related to feeding habits (mainly reliance on fine particulate organic matter) and tolerance to organic pollution were prevalent at impacted reaches, and functional trait compositions were more stable than water chemistry over seasons because they integrate environmental conditions over longer time periods. Functional traits can play a relevant role in the bioassessment of polluted river ecosystems, even under low to moderate disturbance. Trait‐based assessment can be complemented by chemical analyses, notably at highly polluted sites where biological diversity drops to its lowest levels. Copyright © 2016 John Wiley & Sons, Ltd.     

Investigation of aquaculture dynamics at a Ramsar site,using earth observation systems in conjunction with a socio‐economic assessment

This study presents a comprehensive site‐scale analysis conducted within the global wetland inventory and mapping (GWIM) project. GWIM was developed and promoted by the International Water Management Institute (IWMI) through global partnerships to investigate wetland analyses at multiple scales. The present study investigates the complexity of an inland freshwater wetland system, presenting a conceptual framework for mapping and monitoring the dynamics of Lake Kolleru (a wetland of international importance, as defined by the Ramsar Convention), utilizing a geospatial platform. Illustrating the pace of land use changes leading to the progressive elimination of the wetland ecosystem of freshwater Lake Kolleru, this study also highlights the impacts of such changes on the socio‐economic system. A comprehensive temporal analysis (1977–2007) provided a structural base to schematically analyse the dynamics of biophysical and ecological changes to the wetland by effectively using a spectrum of remote sensing data. The present status and changing trends in ecological dimensions of Lake Kolleru were illustrated, utilizing information from spatial analyses, complimented with socio‐economic assessment. Attention is drawn to the potential of utilizing earth resources systems in exploring space–time interactions in freshwater ecosystems heavily modified through aquaculture interventions. Further, the spatial derivatives are meant as reference material for local authorities and decision‐makers to rehabilitate the economic livelihood activities to the social community dependent on the lake ecosystem. The disseminated message emphasizes the applicability of geospatial tools to enhance the efficacy of the decision‐making process by facilitating regular monitoring of ecosystem dynamics and providing updated information on wetland patterns and uses.     

Ecological changes and the drivers in the Nu River basin (upper Salween)

The Nu-Salween River is one of the most important international rivers in Southeast Asia. Ecological changes in the Nu River in China are of concern given China's increasing development. This paper uses a great deal of data to analyse the ecological changes of the Nu River basin over 40 years. Key conclusions are: policies were the primary driver of ecological changes; population growth was the secondary driver, leading to an increase in the sown area of 29.88%; in 1968–2000, sediment load showed an obvious increasing tend, and it was mainly influenced by natural elements first, then by human activities second.     

Hydrological changes and ecological impacts associated with water resource development in large floodplain rivers in the Australian tropics

The majority of rivers in the Australian tropics possess near‐natural flow regimes and are an ecological asset of global significance. We examined flow variability in large floodplain rivers in the Gulf of Carpentaria, northern Australia, and the potential ecological impacts of future water resource development (WRD). Flow metrics based on long‐term records were used to classify flow regimes and predict hydrological drivers of ecological function. Flow regimes of selected rivers were then compared with those simulated for pre‐ and post‐WRD flows in the Darling River, a highly modified river in Australia's south‐east. Generally, rivers were classified as typically ‘tropical’ (more permanent, regular flows) or ‘dryland’ (more ephemeral, with greater flow variability). In addition, all rivers displayed wet–dry seasonality associated with changes in flow magnitude or number of zero‐flow days. We propose that these features (flow permanence and regularity; flow variability and absence; wet–dry seasonality) are the key hydrological drivers of biodiversity and ecological function in the floodplain rivers of Australia's north. In terms of WRD, inter‐annual flow variability was predicted to increase or decrease depending on rivers' natural flow regimes, specifically their tendency toward lower or higher flow magnitudes. Either outcome is expected to have adverse effects on the biodiversity and ecological function of these relatively pristine rivers and floodplain habitats. In particular, reduced and homogenized habitat, loss of life‐history cues, inhibited dispersal and shifts in community composition, as a result of WRD, threaten the ecological integrity of rivers adapted to the three hydrological drivers above. These findings serve as a caution for careful consideration of WRD options for rivers in the Australian tropics and for those with similar flow regimes the world over. Copyright © 2008 John Wiley & Sons, Ltd.     

智慧水利解析

智慧水利是水利高质量发展的显著标志,是运用大数据、人工智能、物联网、云计算、移动互联等新一代信息通信技术,基于自然水系、水利工程体系和水利管理体系,智慧地将适量适质的水适时送到适地,为实现长久水安澜、优质水资源、宜居水环境、健康水生态提供支撑。智慧水利包括目标、对象、时空、技术、价值、成效等六个维度的内涵。目标维度包括问题识别与目标制订,对象维度包括服务主体与水利业务,时空维度包括监控环节与决策过程,技术维度包括赋能体系与核心技术,价值维度包括概念模型与推进路径,成效维度包括功能表征与建设愿景。在智慧水利建设中,数据是基础,要高度重视水利数据的收集、开放和共享;信息是关键,要高度重视监测数据的信息提取和分析;知识是核心,要加强水利知识的挖掘、提升和知识的积累;智能和智慧是目的,要重视人工智能的使用和标准化管理体系的构建。     

湖北省水生态足迹时空动态分析

随着人口增长和经济发展,自然环境面临的压力显著增加,与人类生存息息相关的水首当其冲,对水这种人类赖以生存的自然资源进行评价具有重要意义。搜集了湖北省2005—2018年的水文和社会经济发展资料,利用生态足迹法,分析湖北省水资源生态足迹、生态承载力、生态盈余/赤字、水资源负载指数和万元GDP生态足迹的年际变化,探讨了丰、平、枯水3个典型年湖北省水生态足迹的空间分布特征。结果显示:湖北省2005—2018年水资源生态足迹逐年增大,而水资源生态承载力不呈显著增大或减小趋势,年际变化较大,湖北省在2005—2018年间均为生态盈余,水资源负载指数年际变化较大,万元GDP生态足迹呈逐年下降趋势;从空间分布上看,武汉、襄阳、孝感水资源负载指数较大,而恩施、咸宁、神农架水资源负载指数较小。这说明湖北省水资源总体上较为丰富,足以维持该地区可持续性发展,但水资源地区分布不均匀,对于工业型城市而言用水压力仍然较大。     

基于能值分析的生态供水效益量化方法

为了能够客观、真实地反映生态供水系统中供水效益的影响,弥补传统间接计算法不能全面考虑所有效益的缺点,利用能值分析方法,将生态生产系统的投入和产出转化为同一量纲,对生态供水效益进行量化研究,绘制生态生产系统能量图并建立能值分析表,计算生态供水效益分摊系数,从而计算生态供水总效益和单方水供水总效益。以南水北调东线应急供水受水区——京津冀地区为例,利用2015年的数据,计算得出该地区的生态供水效益分摊系数为4.08%,单方水供水效益为5.48元/m~3。