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Residents' Attitude to Pay for Urban river restoration:Empirical Evidence from Cities in Yangtze Delta

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Chinese Journal of Population,Resources and Environment 2012年第4期10卷 107-115页

作者： Zhang Yifei Li Sheng International Business School Shanghai Institute of Foreign Trade Department of Agricultural Economics Auburn UniversityAuburn36849-5406 USA

Public willingness to pay （WTP） for urban rivers res- toration was investigated in Shanghai, Nanjing and Hangzhou in China with a sample of 1,285. The factors influencing positive WTP against zero WTP are analyzed using a binary logit model. The results indicate that income, Huff （residential registration） status, household size, home property ownership, riverfront access, and attitudes toward current water quality arc statistically signifi- cant in the likelihood of positive WTR It is also found that respon- dents without local Huff are less willingness to pay positively in pooled sample and Shanghai sample. In the group holding property right of house but without local Huff is less willingness to pay positively in Hangzhou. Respondents in Nanjing are more will- ingness to pay positively than those in Hangzhou. Most common arguments against to pay for the restoration are ＂government＇s duty＂, ＂low income＂, ＂non-local-Huji＂ and ＂lack of trust in the government in how it spends money＂. The results are generally consistent with the hypothesis and specific situations in China. The findings make some contributions to the non-market valua- tion studies as well as provide useful information for public policy making in China.

关键词： willingness-to-pay river restoration property rights Huff system

Monitoring river restoration Efforts: Do Invasive Alien Plants Endanger the Success? A Case Study of the Traisen river

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Journal of Environmental Protection 2016年第6期7卷 831-843页

作者： Katharina Lapin Karl-Georg Bernhardt Elisabeth Mayer Stefanie Roithmayr Joachim Neureiter Claudia Horvath Department of Integrative Biology and Biodiversity Research Institute of Botany University of Natural Resources and Life Sciences Vienna Austria

river restoration activities are challenging for the native vegetation and the colonization process. The development of invasive alien plant species (IAS) as well as the development of the pioneer vegetation cover and seed bank were observed in one year prior to construction of a new river bed and within the first two years after construction, along the downstream section of the river Traisen in Austria. One year after completion of the new river channel, the occurrence of IAS above ground decreased while the occurrence of target species increased. Furthermore, no seeds of IAS were detected in the new river bed as a result of proper management of soil movement. Despite the positive impact on the abundance of IAS, the restoration project of the river Traisen shows that the fact that such a restoration activity is a disturbance event must be taken into consideration already during the planning process. Supporting the competitiveness of native plant species is an important tool for reducing the danger of establishment of invasive alien species.

关键词： landscape management Invasive alien plant species vegetation river restoration succession riparian area seed bank

restoration or Rehabilitation of the Faleme river Affected by Mining Activities: What Methods?

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Journal of Water Resource and Protection 2024年第4期16卷 233-263页

作者： Mor Diop Ibrahima Mall Elhadji Mamadou Sonko Tidiane Diop Birane Niane Cheikh Mbow Environmental Sciences Institute (ISE) Cheikh Anta Diop university of Dakar Dakar Senegal Higher School of Mines Geology and Environment Amadou Mahtar Mbow University of Diamniadio (UAM) Dakar Senegal Department of Chemical Cheikh Anta Diop university of Dakar Dakar Senegal Departmentof Engineering Sciences Iba Der Thiam University of Thi&#232s Thi&#232s Senegal

The Faleme river, a West Africa long transboundary stream (625 km) and abundant flow (>1100 million m3) is affected by severe erosion because of mining activities that takes place throughout the riverbed. To preserve this important watercourse and ensure the sustainability of its services, selecting and implementing appropriates restorations techniques is vital. In this context, the purpose of this paper was to present an overview of the actions and techniques that can be implemented for the restoration/rehabilitation of the Faleme. The methodological approach includes field investigation, water sampling, literature review with cases studies and SWOT analysis of the four methods presented: river dredging, constructed wetlands, floating treatment wetlands and chemical precipitation (coagulation and flocculation). The study confirmed the pollution of the river by suspended solids (TSS > 1100 mg/L) and heavy metals such as iron, zinc, aluminium, and arsenic. For the restoration methods, it was illustrated through description of their mode of operation and through some case studies presented, that all the four methods have proven their effectiveness in treating rivers but have differences in their costs, their sustainability (detrimental to living organisms or causing a second pollution) and social acceptance. They also have weaknesses and issues that must be addressed to ensure success of rehabilitation. For the case of the Faleme river, after analysis, floating treatment wetlands are highly recommended for their low cost, good removal efficiency if the vulnerability of the raft and buoyancy to strong waves and flow is under control.

关键词： Faleme river river restoration Constructed Wetlands Dredging Floating Treatment Wetlands Coagulation-Flocculation

Nutrient distribution within and release from the contaminated sediment of Haihe river

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Journal of Environmental Sciences 2011年第7期23卷 1086-1094页

作者： Min Wu Suiliang Huang Wei Wen Xueming Sun Xianqiang Tang Miklas Scholz Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education Nankai University Tianjin 300457 China Numerical Simulation Group for Water Environment Tianjin Key Laboratory of Environmental Remediation and Pollution Control College of Environmental Science and Engineering Nankai University Tianjin 300071 China Civil Engineering Research Centre School of Computing Science and Engineering The University of Salford Newton Building Salford M5 4WT England United Kingdom

We assessed nutrient characteristics, distributions and fractions within the disturbed and undisturbed sediments at four sampling sites within the mainstream of Haihe river. The river sediments contained mostly sand （ 60%）. The fraction of clay was 3%. Total nitrogen （TN） and total phosphorus （TP） concentrations ranged from 729 to 1922 mg/kg and from 692 to 1388 mg/kg, respectively. Nutrient concentrations within the sediments usually decreased with increasing depth. The TN and TP concentrations within the fine sand were higher than for that within silt. Sediment phosphorus fractions were between 2.99% and 3.37% Ex-P （exchangeable phosphorus）, 7.89% and 13.71% Fe/Al-P （Fe, Al oxides bound phosphorus）, 61.32% and 70.14% Ca-P （calcium-bound phosphorus）, and 17.03% and 22.04% Org-P （organic phosphorus）. Nitrogen and phosphorus release from sediment could lead to the presence of 21.02 mg N/L and 3.10 mg P/L within the water column. A river restoration project should address the sediment nutrient stock.

关键词： total nitrogen and phosphorus calcium-bound phosphorus organic phosphorus undisturbed aquatic sediment disturbed aquatic sediment river restoration

A New Method of Assessing Environmental Flows in Channelized Urban rivers

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Engineering 2018年第5期4卷 590-596页

作者： Xin-An Yin Zhifeng Yang Enze Zhang Zhihao Xu Yanpeng Cai Wei Yang State Key Laboratory of Water Environment Simulation School of Environment Beijing Normal University Beijing 100875 China

Assessing environmental flows （e-flows） for urban rivers is important for water resources planning and river protection, Many e-flow assessment methods have been established based on species＇ habitat pro- vision requirements and pollutant dilution requirements, To avoid flood risk, however, many urban rivers have been transformed into straight, trapezoidal-profiled concrete channels, leading to the disappearance of valuable species, With the construction of water pollution-control projects, pollutant inputs into rivers have been effectively controlled in some urban rivers, For these rivers, the e-flows determined by tradi- tional methods will be very small, and will consequently lead to a low priority being given to river pro- tection in future water resources allocation and management, To more effectively assess the e-flows of channelized urban rivers, we propose three e-flow degrees, according to longitudinal hydrological con- nectivity （high, medium, and low）, in addition to the pollutant dilution water requirement determined by the mass-balance equation, In the high connectivity scenario, the intent is for the e-flows to maintain flow velocity, which can ensure the self-purification of rivers and reduce algal blooms; in the medium connectivity scenario, the intent is for the e-flows to permanently maintain the longitudinal hydrological connectivity of rivers that are isolated into several ponds by means of weirs, in order to ensure the exchange of material, energy, and information in rivers; and in the low connectivity scenario, the intent is for the e-flows to intermittently connect isolated ponds every few days （which is designed to further reduce e-flows）, The proposed methods have been used in Shiwuli river, China, to demonstrate their effectiveness, The new methods can offer more precise and realistic e-flow results and can effectively direct the construction and management of e-flow supply projects,

关键词： Environmental flow Urban river Channelized rivers river restoration

Identifying and mitigating dam-induced declines in river health:Three case studies from the western United States

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International Journal of Sediment Research 2012年第3期27卷 271-287页

作者： Ellen WOHL Department of Geosciences Colorado State UniversityFort CollinsColorado 80523-1482 USA Prof.Dr.

river health can be defined as the degree to which riverine energy source,water quality,flow regime, habitat and biota match the natural *** a healthy river,physical process and form remain actively connected and able to mutually adjust,and biological communities have natural levels of diversity and are resilient to environmental *** physical diversity and biodiversity influence river *** diversity is governed by hydrology,hydraulics,and substrate,as reflected in the geometry of the river channel and adjacent floodplain,which create habitat for aquatic and riparian *** is governed by biological processes such as competition and predation,but biodiversity also reflects the diversity,abundance and stability of habitat,as well as connectivity. Connectivity within a river corridor includes longitudinal,lateral,and vertical *** health declines as any of these interacting components is compromised by human *** cumulative effect of dams and other human alterations of rivers has been primarily to directly reduce physical diversity and connectivity,which indirectly reduces *** and maintenance of physical diversity and biodiversity on rivers affected by dams requires quantifying relations between the driver variables of flow and sediment supply,and the response variables of habitat,connectivity,and biological *** relations can take the form of thresholds(e.g., entrainment of streambed sediment) or response curves(e.g.,fish biomass versus extent and duration of floodplain inundation).I use examples from Wyoming,Colorado,and Arizona in the western United States to illustrate how to quantify relations between driver and response variables on rivers affected by dams.

关键词： river health Dams river restoration

Numerical simulation of low-flow channel evolution due to sediment augmentation

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International Journal of Sediment Research 2012年第3期27卷 351-361页

作者： Hiroshi MIWA Gary PARKER Department of Civil Engineering Maizuru National College of Technology Department of Civil and Environmental Engineering University of Illinois at Urbana-Champaign

For the conservation and restoration of river environment,a sediment replenishment technique, which conveys a part of the sediments excavated and/or dredged from reservoirs to the river below dams is developed and has been implemented tentatively in several *** placed as replenishment can be flushed out and transported downstream by floodwater or dam *** flushed sediments are expected to contribute to the control of degradation and the variation of the low-flow ***,this technique is in the development stage because there are many unknown ***,systematic investigations are necessary for practical management of the *** this study,the effects of the location of replenishment sediment on sediment flushing and on control of degradation were investigated by means of flume experiments.A two-dimensional numerical model was also developed to further investigate the effects of sediment augmentation on river *** numerical model treats bank erosion and sediment transport over fixed beds. The simulation results were verified against the experimental *** flushing process of replenishment sediment was investigated first,and then its effect as a countermeasure for river bed degradation was *** are summarized as follows:(1) Augmentation at upper riffles is effective for flushing of replenishment sediment and variation of low-flow channel.(2) Amelioration of degradation can be found in the cases of two types of *** amelioration effect of upper riffle placement was larger than that of lower riffle placement(3) Aggradation rate of the bed near the replenishment site in the fixed bed is large in the lower riffle placement compared with the upper riffle placement.(4) The numerical model was found to be generally successful as a predictive tool.

关键词： river restoration Low-flow channel Degradation Sediment replenishment Numerical simulation

Suitable Weir Heights to Improve the Provision of Environmental Flows in Urban rivers

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Engineering 2021年第2期7卷 187-194页

作者： Yuanyuan Sun Xin’an Yin Xianqiang Mao Enze Zhang Yanwei Zhao State Key Laboratory of Water Environment Simulation School of EnvironmentBeijing Normal UniversityBeijing 100875China

Many studies have been conducted on environmental flow(e-flow)assessment and supply,but e-flow shortages remain common in many urban *** addition to known reasons such as ever-increasing competition among water users and inadequate execution of designed e-flow supply plans,we propose that designing weir heights without explicitly considering e-flows is another major cause of this *** this paper,we suggest that the measures for satisfying e-flows be extended from the water supply stage to the river channel design *** establish a new weir height determination framework that would more effectively satisfy the required *** new framework differs from previous frameworks,in which flood control and water retention are the major concerns and the flow during floods is set as the *** the new framework,e-flow provision and flow velocity maintenance are added concerns and the actual flows for e-flow supply are set as the *** a case study of the new framework’s effectiveness,we applied it to the Shiwuli river,a typical channelized urban river in Hefei,*** old framework specified too-high weir height to meet the e-flow requirements,whereas the new framework offered more reasonable heights that improved e-flow provision.

关键词： Environmental flow Urban rivers river restoration

Sampling-Based Approaches to Estimating Two-Dimensional Large Wood Area from UAS Imagery

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Journal of Geographic Information System 2022年第6期14卷 571-588页

作者： Matthew I. Barker Jonathan D. Burnett Francisco Mauro Gutiérrez Steven M. Wondzell Michael G. Wing Forest Engineering Resources and Management Department College of Forestry Oregon State University Corvallis OR USA USDA Forest Service Pacific Northwest Research Station Corvallis OR USA EiFAB—iuFOR Campus Duques de Soria s/n Universidad de Valladolid Soria Spain

Large in-stream wood (LW) is a critical component of riparian systems that increases heterogeneity of flow regimes and provides high quality habitat for salmonids and other fishes. We present four sampling-based methods to estimate two-dimensional LW for a 61-hectare river restoration project on the South Fork McKenzie river near Rainbow, OR (USA). We manually delineated LW area, from unoccupied aircraft systems (UAS) multispectral imagery for 40 randomly selected 51.46 m2 hexagonal plots. Seven auxiliary variables were extracted from the imagery and imagery derivatives to be incorporated in four estimators by summarizing spectral statistics for each plot including Random forest (RF) classification of segmented imagery (Cohen’s kappa = 0.75, balanced accuracy = 0.86). The four estimators were: difference estimator, simple linear regression estimator with one auxiliary variable, general regression estimator with seven auxiliary variables, and simple random sample without replacement. We assessed variance of the estimators and found that the simple random sample without replacement produced the largest estimate for LW area and widest confidence interval (17,283 m2, 95% CI 10,613 - 23,952 m2) while the generalized regression approach resulted in the smallest estimate and narrowest confidence interval (16,593 m2, 95% CI 13,054 - 20,133 m2). These methods facilitate efficient estimates of critical habitat components, that are especially suited to efforts that seek to quantify large amounts of these components through time. When combined with traditional sampling methods, classified imagery acquired via UAS promises to enhance the temporal resolution of the data products associated with restoration efforts while minimizing the necessity for potentially hazardous field work.

关键词： UAS Large in-Stream Wood Sampling Image Classification river restoration