城镇景观水体水质控制技术分析

本文针对上海城镇小型景观水体水质污染特征，分析了充氧曝气、人工湿地、曝气生物滤池等工艺技术在小型景观水体水质净化中的应用，提出各种小型景观水体水质控制技术的特点和适用范围，为2010年上海世博会园区内景观水体水质控制方法提供参考，也为其他小型景观水体的建设和运行提供借鉴。     

成都市景观水体污染防治问题探讨

随着城市建设的快速发展,越来越多的城市景观水体美化了城市,同时也改善了城市居民的居住环境,然而城市景观水体易受污染的问题也较为突出.在各种现有城市景观水体污染治理技术的基础上,提出了适宜成都市景观水体污染防治的几种策略.     

城市景观水体的开发与利用研究——以中国江北水城（聊城）为例

城市景观水体是城市中重要的自然组分,具有多种服务功能,对维持城市生态系统的持续、稳定和健康发展起着积极作用。在介绍城市景观水体内涵的基础上,简要阐述了城市景观水体的服务功能,最后以中国江北水城（聊城）为例,对城市景观水体的开发与利用进行了具体分析。     

基于Cite Space的中国湿地公园景观研究知识图谱分析

运用Cite Space文献计量法,分析2001—2018年湿地公园景观研究领域的主要理论、方法和成果。结果表明:2001—2018年湿地公园景观研究发文量递增,刊物以高校学报为主,作者群相对分散,相关研究的数量和质量有待提升;研究内容侧重于湿地公园景观格局演变、驱动机制分析以及景观保护与恢复、生态旅游评价与评估等方面;景观格局指数、景观模型分析、GIS和RS技术、数理模型与统计分析等定量化方法是湿地公园景观研究的重要手段。     

城市景观水体的生态修复技术研究

城市景观水体对于城市发展和居民生活具有重要意义,当前城市景观水体污染问题尤其是富营养化现象比较突出,影响了水体生态环境和城市景观。文章综述了近年来景观水体的生态治理技术及其机理,重点介绍了人工浮岛、生物操纵等技术在景观水体修复中的应用和发展,以期对景观水体的治理和修复有一定的借鉴作用。     

校园景观水体富营养化现状及修复对策

以黄山学院上塘为例,通过对上塘周围污染源的详细调查和4个季度的水质分析,采用综合营养状态指数法评价了上塘富营养化现状,提出了对上塘实行修复的可行性措施,以改善校园生态环境,为校园景观水体的规划提供依据。     

中国湿地公园景观生态健康研究进展

以中国知网关于湿地公园景观生态健康的相关研究成果为样本,系统梳理我国湿地公园景观生态健康研究内容与方法,发现该主题研究内容倾向性大,偏重于景观生态健康的评价研究。同时,研究方法借助于软件技术手段,以实证研究为主。在此基础上,认为湿地公园景观生态健康研究应跨学科、多样化,以丰富湿地公园研究体系,推动湿地公园建设。     

城区富营养化景观水体的生物修复技术

生物修复技术在富营养化景观水体中有其独特的应用价值,本文综述了生物操纵控藻技术、植物控藻技术和微生物控藻技术的研究现状,讨论和展望了不同生物修复技术相互结合在水体修复中的作用.     

荒漠生态旅游资源及开发模式研究

对荒漠旅游资源的特殊性进行分析,总结了荒漠景观观光、荒漠文化遗产考古开发、荒漠探险开发、小众荒漠生态旅游开发、荒漠度假体验开发、沙漠体育公园开发、荒漠主题城市开发等7种模式,有益于荒漠旅游的开发管理实践.     

郊野游憩资源开发背景下的上海城市森林景观格局动态

以上海郊野森林为研究对象,共选择森林样地64个,通过解译判读2000年、2006年和2012年的相航空遥感影像,分析了上海郊野森林12年来的景观空间格局及其动态变化特征。结果表明:林地始终是上海郊野森林的主体景观类型,且林地面积一直呈增加趋势,其他各景观类型面积随着时间的推移呈不同程度的增减;非林地景观类型的主要转出类型均为林地,且主要发生在新建的外环林地、外环公园和森林公园区域;森林景观的破碎化程度减弱,景观异质性下降,景观优势度和连接性增加,景观多样性降低。     

基于TM影像的石羊河流域土地利用变化研究

根据1999年和2010年两期影像数据,在遥感软件EDARS IMAGINE9.1的支持下对图像进行技术处理,通过计算机自动分类方法提取土地利用信息,将石羊河流域土地利用类型分为耕地、草地、林地、建筑用地、水域及未利用地,同时利用数学模型和景观生态学理论,分析了石羊河流域土地利用变化的时空特征和格局变化。研究结果表明,1999-2010年间耕地和未利用地的面积变化最大,变化量占到总流域面积的比例分别为3.94%和2.42%;水域、林地、耕地的土地利用动态度明显,依次为3.06%,1.82%和1.12%;11年间草地、耕地和水域的流转较为剧烈,变化速率较快;11年间石羊河流域的土地利用偏离度为持续缓慢下降的趋势,下降幅度达到0.04,土地利用活动对自然景观的干预趋于缓和;景观优势度增大,景观多样性和景观均匀度有所减少,人类活动对景观格局影响明显;人口、经济因素和政策因素在短时间尺度上对土地利用变化的影响较为显著。     

大气干湿沉降对城市景观水体水质影响的评价

选择上海城市化地区的绿地、水体、道路、工地及空中5个类型的环境区域,定期收集大气干湿沉降。测定其大气沉降通量及CODCr、TN、TP的沉降量,并计算分析了其对城市景观水体水质的影响。研究结果表明：在仅受大气干湿沉降影响的条件下,水质处于地表水V类中值、水深为0.5m、1.0m、1.5m和2.0m的城市景观水体,经过28d、54d、83d和214d即可转变为劣V类水体。通过实例分析,提出了应对大气干湿沉降影响的水质保持措施。研究成果为城市景观水体的水质保育提供了评价依据与借鉴。     

Denitrification enzyme activity of fringe salt marshes in New England (USA)

Coastal salt marshes are a buffer between the uplands and adjacent coastal waters in New England (USA). With increasing N loads from developed watersheds, salt marshes could play an important role in the water quality maintenance of coastal waters. In this study we examined seasonal relationships between denitrification enzyme activity (DEA) in salt marshes of Narragansett Bay, Rhode Island, and watershed N loadings, land use, and terrestrial hydric soils. In a manipulative experiment, the effect of nutrient enrichment on DEA was examined in a saltmeadow cordgrass [Spartina patens (Aiton) Muhl.] marsh. In the high marsh, DEA significantly (p < 0.05) increased with watershed N loadings and decreased with the percent of hydric soils in a 200-m terrestrial buffer. In the low marsh, we found no significant relationships between DEA and watershed N loadings, residential land development, or terrestrial hydric soils. In the manipulation experiment, we measured increased DEA in N-amended treatments, but no effect in the P-amended treatments. The positive relationships between N loading and high marsh DEA support the hypothesis that salt marshes may be important buffers between the terrestrial landscape and estuaries, preventing the movement of land-derived N into coastal waters. The negative relationships between marsh DEA and the percent of hydric soils in the adjacent watershed illustrate the importance of natural buffers within the terrestrial landscape. Denitrification enzyme activity appears to be a useful index for comparing relative N exposure and the potential denitrification activity of coastal salt marshes.     

Hydrology of Clay Settling Areas and Surrounding Landscapes in the Phosphate Mining District,Peninsular Florida1

Abstract: The objective of this study was to use applied and naturally occurring geochemical tracers to study the hydrology of clay settling areas (CSAs) and the hydrological connectivity between CSAs and surrounding hydrological landscapes. The study site is located on the Fort Meade Mine in Polk County, Florida. The CSA has a well‐developed, subangular‐blocky, clay‐rich surface layer with abundant desiccation cracks and other macropores, and a massive, clay‐rich sublayer that is saturated below ～1.0‐2.5 m. A bromide tracer was applied to study hydrological processes in the upper part of the CSA. Bromide infiltrated rapidly and perched on a massive, clay‐rich sublayer. Bromide concentrations decreased in the upper part of the profile without being transported vertically down through the lower part of the profile suggesting that bromide was lost to lateral rather than to vertical transport. Infiltration and lateral flow were rapid suggesting that preferential flow through desiccation cracks and other macropores likely dominates flow in the upper part of the CSA. Naturally occurring solute and stable isotope tracers were used to study the hydrological connectivity between the CSA and the surrounding hydrological landscape. Three‐end mass‐balance mixing model results indicate that shallow and/or deep CSA water can be found in all downgradient waters and must be as much as ～50% of some downgradient waters. Discharge from the CSA to the surrounding surface water‐bodies and surficial aquifer occurs laterally through the berms and/or vertically through the massive, clay‐rich sublayer. However, the precise flow paths from the CSA to the surrounding hydrological landscape are unclear and the fluxes remain unquantified, so the precise effects of CSAs on the hydrology of the surrounding hydrological landscape also remain unquantified.     

The Role of Headwater Streams in Downstream Water Quality1

Abstract: Knowledge of headwater influences on the water‐quality and flow conditions of downstream waters is essential to water‐resource management at all governmental levels; this includes recent court decisions on the jurisdiction of the Federal Clean Water Act (CWA) over upland areas that contribute to larger downstream water bodies. We review current watershed research and use a water‐quality model to investigate headwater influences on downstream receiving waters. Our evaluations demonstrate the intrinsic connections of headwaters to landscape processes and downstream waters through their influence on the supply, transport, and fate of water and solutes in watersheds. Hydrological processes in headwater catchments control the recharge of subsurface water stores, flow paths, and residence times of water throughout landscapes. The dynamic coupling of hydrological and biogeochemical processes in upland streams further controls the chemical form, timing, and longitudinal distances of solute transport to downstream waters. We apply the spatially explicit, mass‐balance watershed model SPARROW to consider transport and transformations of water and nutrients throughout stream networks in the northeastern United States. We simulate fluxes of nitrogen, a primary nutrient that is a water‐quality concern for acidification of streams and lakes and eutrophication of coastal waters, and refine the model structure to include literature observations of nitrogen removal in streams and lakes. We quantify nitrogen transport from headwaters to downstream navigable waters, where headwaters are defined within the model as first‐order, perennial streams that include flow and nitrogen contributions from smaller, intermittent and ephemeral streams. We find that first‐order headwaters contribute approximately 70% of the mean‐annual water volume and 65% of the nitrogen flux in second‐order streams. Their contributions to mean water volume and nitrogen flux decline only marginally to about 55% and 40% in fourth‐ and higher‐order rivers that include navigable waters and their tributaries. These results underscore the profound influence that headwater areas have on shaping downstream water quantity and water quality. The results have relevance to water‐resource management and regulatory decisions and potentially broaden understanding of the spatial extent of Federal CWA jurisdiction in U.S. waters.     

Effects of watershed configuration and composition on downstream lake water quality

We evaluated the relationships between landscape characteristics and lake water quality in receiving waters by regressing four water quality responses on landscape variables that were measured for whole watersheds and three different buffer distances (30, 60, and 120 m). Classical percolation theory was used to conceptualize nutrient pathways and to explain nonlinear responses. The response variables were total nitrogen (TN), total phosphorus (TP), chlorophyll-a (Chl-a), and Secchi transparency (SD). Landscape data were obtained from satellite image-derived maps of 130 watersheds in Iowa using geographic information systems software. We developed regression models with a stepwise protocol selecting the optimal number of significant explanatory variables. Configuration variables such as contagion, the cohesion of cropland and urban land, and the aggregation index of forest were very important and more important than variables assessing landscape composition (e.g., percentage farmland). Whole watershed models predicted between 15 and 67% of the variability in TN, TP, Chl-a, and SD. Proximity-explicit data offered only slightly improved statistical power over land cover data derived from the entire watershed for variables TN, Chl-a. and SD, but not for TP.     

Application of SPARROW Modeling to Understanding Contaminant Fate and Transport from Uplands to Streams

Understanding spatial variability in contaminant fate and transport is critical to efficient regional water‐quality restoration. An approach to capitalize on previously calibrated spatially referenced regression (SPARROW) models to improve the understanding of contaminant fate and transport was developed and applied to the case of nitrogen in the 166,000 km² Chesapeake Bay watershed. A continuous function of four hydrogeologic, soil, and other landscape properties significant (α = 0.10) to nitrogen transport from uplands to streams was evaluated and compared among each of the more than 80,000 individual catchments (mean area, 2.1 km²) in the watershed. Budgets (including inputs, losses or net change in storage in uplands and stream corridors, and delivery to tidal waters) were also estimated for nitrogen applied to these catchments from selected upland sources. Most (81%) of such inputs are removed, retained, or otherwise processed in uplands rather than transported to surface waters. Combining SPARROW results with previous budget estimates suggests 55% of this processing is attributable to denitrification, 23% to crop or timber harvest, and 6% to volatilization. Remaining upland inputs represent a net annual increase in landscape storage in soils or biomass exceeding 10 kg per hectare in some areas. Such insights are important for planning watershed restoration and for improving future watershed models.     

An assessment of landscape characteristics affecting estuarine nitrogen loading in an urban watershed

Exploring the quantitative association between landscape characteristics and the ecological conditions of receiving waters has recently become an emerging area for eco-environmental research. While the landscape-water relationship research has largely targeted on inland aquatic systems, there has been an increasing need to develop methods and techniques that can better work with coastal and estuarine ecosystems. In this paper, we present a geospatial approach to examine the quantitative relationship between landscape characteristics and estuarine nitrogen loading in an urban watershed. The case study site is in the Pensacola estuarine drainage area, home of the city of Pensacola, Florida, USA, where vigorous urban sprawling has prompted growing concerns on the estuarine ecological health. Central to this research is a remote sensor image that has been used to extract land use/cover information and derive landscape metrics. Several significant landscape metrics are selected and spatially linked with the nitrogen loading data for the Pensacola bay area. Landscape metrics and nitrogen loading are summarized by equal overland flow-length rings, and their association is examined by using multivariate statistical analysis. And a stepwise model-building protocol is used for regression designs to help identify significant variables that can explain much of the variance in the nitrogen loading dataset. It is found that using landscape composition or spatial configuration alone can explain most of the nitrogen loading variability. Of all the regression models using metrics derived from a single land use/cover class as the independent variables, the one from the low density urban gives the highest adjusted R-square score, suggesting the impact of the watershed-wide urban sprawl upon this sensitive estuarine ecosystem. Measures towards the reduction of non-point source pollution from urban development are necessary in the area to protect the Pensacola bay ecosystem and its ecosystem services.     

A Method for Comparative Analysis of Recovery Potential in Impaired Waters Restoration Planning

Common decision support tools and a growing body of knowledge about ecological recovery can help inform and guide large state and federal restoration programs affecting thousands of impaired waters. Under the federal Clean Water Act (CWA), waters not meeting state Water Quality Standards due to impairment by pollutants are placed on the CWA Section 303(d) list, scheduled for Total Maximum Daily Load (TMDL) development, and ultimately restored. Tens of thousands of 303(d)-listed waters, many with completed TMDLs, represent a restoration workload of many years. State TMDL scheduling and implementation decisions influence the choice of waters and the sequence of restoration. Strategies that compare these waters’ recovery potential could optimize the gain of ecological resources by restoring promising sites earlier. We explored ways for states to use recovery potential in restoration priority setting with landscape analysis methods, geographic data, and impaired waters monitoring data. From the literature and practice we identified measurable, recovery-relevant ecological, stressor, and social context metrics and developed a restorability screening approach adaptable to widely different environments and program goals. In this paper we describe the indicators, the methodology, and three statewide, recovery-based targeting and prioritization projects. We also call for refining the scientific basis for estimating recovery potential.

Management Relevance of Benthic Biogeography at Multiple Scales in Coastal Waters of the Northeast U.S.

Continuing pressures from human activities have harmed the health of ocean ecosystems, particularly those near the coast. Current management practices that operate on one sector at a time have not resulted in healthy oceans that can sustainably provide the ecosystem services humans want and need. Now, adoption of ecosystem-based management (EBM) and coastal and marine spatial planning (CMSP) as foundational principles for ocean management in the United States should result in a more holistic approach. Recent marine biogeographical studies and benthic habitat mapping using satellite imagery, large-scale monitoring programs, ocean observation systems, acoustic and video techniques, landscape ecology, geographic information systems, integrated databases, and ecological modeling provide information that can support EBM, make CMSP ecologically meaningful, and contribute to planning for marine biodiversity conservation. Examples from coastal waters along the northeast coast of the United States from Delaware Bay to Passamaquoddy Bay, Maine, illustrate how benthic biogeography and bottom seascape diversity information is a useful lens through which to view EBM and CMSP in nearshore waters. The focus is on benthic communities, which are widely used in monitoring programs and are sensitive to many stresses from human activities.