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数字高程模型是进行地学研究的重要基础数据,SRTM、DEM是公众可以免费获取的精度达90m的DEM数据.以我国1:5万DEM为参考数据,以巢湖流域为研究区,利用高程中误差模型和单位面积土地填挖方对SRTM、DEM进行高程精度研究,并分析了高程误差的空间分异规律.结果表明,SRTM、DEM的高程中误差和单位面积土地填挖方随着地貌类型的变化呈现明显的空间分异性,这主要由于SRTM像元精度不高所致.在研究区内的33块样区中,绝大部分都是在二级精度评价标准之内,可见SRTM、DEM整体精度较高. 相似文献
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以福州市主城区1988年和2008年的TM影像为基础,对福州市主城区土地利用/覆被变化特征进行分析.结果表明:研究区1988-2008年期间土地利用结构发生了很大的变化,不同土地利用类型之间相互转化,其中建设用地面积剧增,导致不透水层的大面积增加.结合土地利用/覆被变化的水文效应分析表明,主城区土地利用/覆被变化对洪水的产流、汇流过程及河网水系结构产生很大的影响. 相似文献
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《新疆环境保护》2018,(4)
采用乌伦古河出山口水文站二台站与河流尾闾水文站福海站1957-1961年的河道径流数据,分析了两站间年径流量以及丰、平、枯水期月径流量关系,得到乌伦古河平原耗散区河道自然耗散水量,并对不同频率水文年的平原区河道人工可取用水量阈值进行了探讨,结果表明:福海站与二台站年径流量及丰、平、枯水期径流量均成不同的线性关系;不同频率水文年二台至福海间河道的自然耗散量在1.0~9.0×108m3之间,人工可取用的阈值在0.70~17.0×108m3之间,年际变化极大;由月径流关系估算的人工最大可用水量均小于用年径流关系计算值,是更为严格与合理的河道断流判断依据;平水年人工可取用水量的最大值在4.56~5.04×108m3之间,6-8月的最大取用水量为0.08~1.21×108m3之间;枯水年人为可用水的阈值更小,为1.728~2.562×108m3之间,一旦二台-福海水文站间区间取用水量超过人工耗散阈值,就可导致河道断流情况发生。研究结果可为进一步分析和探讨乌伦古河不同时期的断流规律及成因提供基础。 相似文献
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姚北平原河网水体榨菜废水污染严重,根据废水的排放特点,分卤水落水前、卤水落水期和卤水落水后3个典型时段对河网水质进行监测,结果表明,其污染类型为有机污染。基于榨菜废水排放的分散性和不定期的特点,提出人工湿地系统治理榨菜废水污染的方案设想,并就工艺流程、耐盐型水生植物等进行了初步探讨。 相似文献
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以新疆喀什噶尔河流域克孜河卡拉贝利水利枢纽工程为例,采用水均衡模型计算方法,从工程建成后区域荒漠河岸林草耗水量变化、荒漠河岸林草区地下水位变化情况、工程建成后洪水过程变化等方面分析工程建设对工程影响区荒漠河岸林草的影响。评价结果显示,工程建成后,与现状相比荒漠河岸林草植被的耗水量有所增加,区域平均地下水埋深仍能维持现状,在河岸林草生长和繁殖的6-9月,区域地下水位较现状略有上升,可满足大部分荒漠河岸林草植被的正常生长需求,水库对5年一遇标准以下洪水不调蓄,不会对荒漠河岸林草的繁衍存活产生明显不利影响。 相似文献
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Benjankar R Egger G Jorde K Goodwin P Glenn NF 《Journal of environmental management》2011,92(12):3058-3070
The Kootenai River floodplain in Idaho, USA, is nearly disconnected from its main channel due to levee construction and the operation of Libby Dam since 1972. The decreases in flood frequency and magnitude combined with the river modification have changed the physical processes and the dynamics of floodplain vegetation. This research describes the concept, methodologies and simulated results of the rule-based dynamic floodplain vegetation model "CASiMiR-vegetation" that is used to simulate the effect of hydrological alteration on vegetation dynamics. The vegetation dynamics are simulated based on existing theory but adapted to observed field data on the Kootenai River. The model simulates the changing vegetation patterns on an annual basis from an initial condition based on spatially distributed physical parameters such as shear stress, flood duration and height-over-base flow level. The model was calibrated and the robustness of the model was analyzed. The hydrodynamic (HD) models were used to simulate relevant physical processes representing historic, pre-dam, and post-dam conditions from different representative hydrographs. The general concept of the vegetation model is that a vegetation community will be recycled if the magnitude of a relevant physical parameter is greater than the threshold value for specific vegetation; otherwise, succession will take place toward maturation stage. The overall accuracy and agreement Kappa between simulated and field observed maps were low considering individual vegetation types in both calibration and validation areas. Overall accuracy (42% and 58%) and agreement between maps (0.18 and 0.27) increased notably when individual vegetation types were merged into vegetation phases in both calibration and validation areas, respectively. The area balance approach was used to analyze the proportion of area occupied by different vegetation phases in the simulated and observed map. The result showed the impact of the river modification and hydrological alteration on the floodplain vegetation. The spatially distributed vegetation model developed in this study is a step forward in modeling riparian vegetation succession and can be used for operational loss assessment, and river and floodplain restoration projects. 相似文献
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为了充分认识再生水用于城市河道补水后的潜在正面环境价值,构建了案例区规划水系的水量水质模型,并筛选了7项景观生态河流的生态服务价值指标,对案例区的河流生态服务价值进行了评估.以规划补水量为基础条件,规划水系的潜在服务价值总量约为1.995亿元,每增加1倍补水量可增加约0.4~0.5亿元的服务价值.气候调节、洪水调蓄和水... 相似文献
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河长制是由各级党政主要负责人担任河长、负责辖区内河湖全面管理的机制性安排。福建生态文明试验区在全面推行河长制过程中,面临部分改革工作进展缓慢、效果不如预期等问题,亟待进行全面评估。本文剖析了河长制在生态文明试验区建设中的地位和作用,甄别了河长制与相关政策的逻辑联系,从政策过程的制定和执行阶段出发,通过指标法进行评估。所构建的指标体系包括一级指标2个、二级指标5个、三级指标39个,并给出各级指标权重,制定相应的评估标准。从得分情况来看,福建省全面推行河长制总分为0.90分,评估结果为优秀;从一级指标评估结果来看,政策执行阶段总体好于政策制定阶段;从二级指标得分来看,长效执行机制评估结果为良好,方案制定的评估结果为合格,其余为优秀;从三级指标得分来看,优良率达71.79%。在此基础上,从法律法规、政策协同、跨省协调、任务统筹、管护手段、社会参与等方面指出了存在的问题,并提出了有针对性的对策建议。 相似文献
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Adam B. Munson Joseph J. Delfino 《Journal of the American Water Resources Association》2007,43(2):522-532
Abstract: Regulation of river flows can result in decreased stage fluctuations and alteration of inundation patterns of floodplain wetlands. However, floodplain inundation has historically not been addressed in most minimum flow determinations. Florida law requires the water management districts of the state to establish minimum flows and levels to protect water bodies from significant harm associated with water withdrawals. The Southwest Florida Water Management District utilizes a 15% reduction in habitat criterion as a threshold for defining significant harm to freshwater segments of rivers. Utilizing a multi‐parameter approach and different habitat measures for seasonal flow periods, the District has recommended minimum flow compliance standards for the Alafia, Myakka and middle Peace rivers. For the high‐flow period, the District utilized a 15% reduction in the number of days of floodplain inundation (a temporal loss) as a significant harm threshold. This approach yielded allowable flow reductions of 8% for the Alafia and Peace rivers during the high‐flow season and a 7% allowable reduction of natural flows on the Myakka River. Comparison of changes in flows associated with temporal and spatial loss thresholds indicated that flow reductions required to effect a 15% spatial loss of habitat on the Alafia, Myakka and middle Peace rivers are higher than those that would yield a 15% temporal loss. This indicates that with respect to natural flow protection, the District’s consideration of temporal reductions in habitat for establishing minimum river flows for seasonal high‐flow periods is more conservative than the use of a spatial loss criterion. 相似文献
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Thayer Scudder 《Natural resources forum》1994,18(2):101-113
This paper utilizes experiences gained since the first United Nations studies were prepared on river basin planning and development in 1958. The author's experiences, mainly in the tropical and subtropical areas of Africa and Asia, set the stage for a brief consideration of the role of institutions in achieving a process of integrated river basin development. In emphasizing these experiences, this paper has three purposes. First, the author assesses the influence and adequacy of the vision expressed in the earlier United Nations reports. Second, he examines the experience with attempts to implement river basin development, including resettlement problems. Third, he suggests ways in which lessons learned can be applied to future development. The case studies utilized in this paper draw more on the author's experience than on the literature. While the focus is on transnational river basin development, experiences within states are also included when they provide relevant insights. 相似文献
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S. N. Kulshreshtha J. A. Gillies 《Journal of the American Water Resources Association》1993,29(2):257-266
ABSTRACT: Presence of a river in an urban setting may contribute positively to an aesthetically pleasing environment. Such aesthetic effects are not typically linked to specific economic activities and occur, for example, when residents are exposed to a river-view. Qualities enhancing the aesthetic value of the river include the presence of parks, trails, and vegetation along the riverbanks. The value of aesthetic amenities provided by the South Saskatchewan to the City of Saskatoon residents was estimated in this study using non-market methods. The implicit price of the river view was estimated using the Hedonic Price Model, whereas value through willingness to pay for property taxes or higher rents were also estimated using actual market data. The total annual value of the river to the City of Saskatoon through addition of aesthetic amenities was estimated at $1.2 million in 1989 dollars. 相似文献
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Spatial Differentiation of Landscape Values in the Murray River Region of Victoria, Australia 总被引:3,自引:0,他引:3
Xuan Zhu Sharron Pfueller Paul Whitelaw Caroline Winter 《Environmental management》2010,45(5):896-911
This research advances the understanding of the location of perceived landscape values through a statistically based approach
to spatial analysis of value densities. Survey data were obtained from a sample of people living in and using the Murray River
region, Australia, where declining environmental quality prompted a reevaluation of its conservation status. When densities
of 12 perceived landscape values were mapped using geographic information systems (GIS), valued places clustered along the
entire river bank and in associated National/State Parks and reserves. While simple density mapping revealed high value densities
in various locations, it did not indicate what density of a landscape value could be regarded as a statistically significant
hotspot or distinguish whether overlapping areas of high density for different values indicate identical or adjacent locations.
A spatial statistic Getis–Ord Gi* was used to indicate statistically significant spatial clusters of high value densities
or “hotspots”. Of 251 hotspots, 40% were for single non-use values, primarily spiritual, therapeutic or intrinsic. Four hotspots
had 11 landscape values. Two, lacking economic value, were located in ecologically important river red gum forests and two,
lacking wilderness value, were near the major towns of Echuca-Moama and Albury-Wodonga. Hotspots for eight values showed statistically
significant associations with another value. There were high associations between learning and heritage values while economic
and biological diversity values showed moderate associations with several other direct and indirect use values. This approach
may improve confidence in the interpretation of spatial analysis of landscape values by enhancing understanding of value relationships. 相似文献
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河流治理问题不仅关乎国家经济问题,而且涉及人民根本利益,所以在面对严峻的河流问题,探寻其症结所在,探索河流治理价值取向则显得尤为重要。河长制作为新时代治理河流的治河政策,对于缓解我国河流治理困境以及对河流治理价值取向转向研究有着极其重要的作用。基于河长制的实施背景,从维护河流生态价值的角度出发,通过总结梳理河流治理体制现状,强调研究河流治理价值取向的重要性,通过对河流治理价值取向及其实现路径的理论的研究,辨析河流治理的价值取向,并从意识层面出发、从保障与监督机制以及立法协调角度对河流治理价值取向实现路径进行深入探索,得出其对维护河流生态功能、维持河流生态价值等具有重要意义,为河流管理发展规划提供参考。 相似文献