Assessment of environmental impacts following alternative agricultural policy scenarios.

Abstract Finnish agriculture is likely to undergo major changes in the near and intermediate future. The ifuture policy context can be examined at a general level by strategic scenario building. Computer-based modelling in combination with agricultural policy scenarios can in turn create a basis for the assessments of changes in environmental quality following possible changes in Finnish agriculture. The analysis of economic consequences is based on the DREMFIA model, which is applied to study effects of various agricultural policies on land use, animal production, and farmers' income. The model is suitable for an impact analysis covering an extended time span--here up to the year 2015. The changes in land use, obtained with the DREMFIA model assuming rational economic behaviour, form the basis when evaluating environmental impacts of different agricultural policies. The environmental impact assessment is performed using the field scale nutrient transport model ICECREAM. The modelled variables are nitrogen and phosphorus losses in surface runoff and percolation. In this paper the modelling strategy will be presented and highlighted using two case study catchments with varying environmental conditions and land use as an example. In addition, the paper identifies issues arising when connecting policy scenarios with impact modelling.     

From characterization of sediment to full scale treatment by wet particle separation

Contaminated sediments represent a significant environmental problem in the Netherlands. Dutch policy aims on reusing the sand in the contaminated sediments. The reusable sand can be separated from the sediment by utilizing wet particle separation techniques. The quality and the quantity of the recovered sand product determines whether the application of wet particle separation is economically feasible. Therefore it is important to be able to predict the results of full scale sediment treatment. These predictions can be obtained by thoroughly characterizing the specific contaminated sediment. In the last years several characterization methods have been developed. This paper presents four cases in which the results of the TDG-test and the Fingerprint are compared with results of the full scale treatment of contaminated sediments. The two main factors: sand quality and the quantity of fine grained fraction remaining are well predicted in all four cases. Therefore the conclusion is that both the TDG-test and the Fingerprint are able to predict whether full scale treatment is feasible.     

洪家渡水电站左坝肩高边坡预应力锚索试验分析

洪家渡水电站左坝肩边坡开挖高度达 310m ,是中国水利水电工程史上开挖最高的边坡。为确保边坡稳定 ,设计采用了 15 0t级预应力锚索加固措施。在锚索大规模施工之前 ,先进行了预应力锚索锚固试验 ,以确定和优化初步拟定的锚索设计参数、检验各配套材料及已定施工工艺的可行性等     

Quantifying the Urban Water Supply Impacts of Climate Change

The difference in timing between water supply and urban water demand necessitates water storage. Existing reservoirs were designed based upon hydrologic data from a given historical period, and, given recent evidence for climatic change, may be insufficient to meet demand under future climate change scenarios. The focus of this study is to present a generally applicable methodology to assess the ability of existing storage to meet urban water demand under present and projected future climatic scenarios, and to determine the effectiveness of storage capacity expansions. Uncertainties in climatic forcing and projected demand scenarios are considered explicitly by the models. The reservoir system in San Diego, California is used as a case study. We find that the climate change scenarios will be more costly to the city than scenarios using historical hydrologic parameters. The magnitude of the expected costs and the optimal investment policy are sensitive to projected population growth and the accuracy to which our model can predict spills.     

黄河源区未来气候变化情景预测

在经验正交函数展开的基础上,通过对主分量和大尺度预报因子进行最优回归,确定了流域降尺度统计模式。基于该模式对黄河源区2011—2040年中高排放情景、全球人口不断增加及中低排放情景、全球人口增长较少两种气候情景进行了分析。结果表明:黄河源区未来气温将明显升高,降水量略有增大,水资源压力将趋于增大。     

New technology of mechanical treatment of dredged material from Hamburg Harbour

Harbours and water ways can only fulfil their commercial task if there is always sufficient water depth for navigation. Environmental problems have started to influence dredging methods in recent decades. As a logical consequence of a policy giving high priority to environmental protection, Hamburg built the METHA plant (Mechanical Treatment of Harbour Sediments). METHA produces a clean sand product (grain size>63 μm) which is reused and a contaminated silt fraction (grain size < 150 μm) which is disposed presently. Previous investigations showed that the content of heavy metals and organic contaminants are primarily governed by the grain size. In 1995 Strom- und Hafenbau started a new investigation to produce a further fraction from the METHA silt which can be reused.The result of laboratory- and pilot-scale research showed the possibility of a further separation at 20 μm grain size. The best result was reached through a two-step separation made by hydrocyclons and spirals. The produced fraction (20–150 μm) is mainly quartz material with a low level of contamination. In February 1996 Strom- und Hafenbau decided to built a test plant in a technical scale. The capacity of the test-plant is 50 t/h based on dry substance The technical concept is integrated into the METHA concept. All aspects of technical feasibility, economy, environment and product reuse will be investigated in the test plant. The results of the early test phase will be presented.     

Strategies for management of contaminated sediments within the meuse river-system

The sediments in the Meuse valley are contaminated on a large scale by diffuse sources. The project ‘Maaswerken’ aims at the enlargement of the discharge capacity of the river Meuse. In the realization of the project, a full-scale clean-up operation would not be realistic and not effective because of recontamination and the enormous scale and costs involved. The concept of dynamic soil management offers a solution to this problem. This approach to remediation implies putting back contaminated sediments of indigenous quality within the river system. Preconditions are determined by risk assessment and local conditions. The first aim is improvement of the environmental quality of the river system. Other objectives such as the development of natural areas, the mitigation of geohydrological effects and the exploitation of sand and gravel can be realized by several forms of beneficial use of contaminated sediments. Dynamic soil management is expected to be a pragmatic and cost-effective solution for the problem of contaminated sediments.     

Dutch analysis for P-recovery from municipal wastewater.

There is a considerable practical interest in phosphorus recovery from water authorities, elementary P-industry, fertilizer industry and regulators in a number of countries. Due to a handful of full-scale plants worldwide, P-recovery can be seen as technically feasible. However, the economic feasibility of P-recovery from sewage can still be judged as dubious. The most important reason for this is that the prices of the techniques (in euro/tonne P) are much higher compared to the prices of phosphate rock. In this paper an analysis is given to recover phosphate from municipal wastewater for the elementary P-industry Thermphos International B.V. and the fertiliser industry Amsterdam Fertilizers B.V. in The Netherlands. Several scenarios are evaluated and the end products of these scenarios are compared to the quality required by both industries. From a Dutch study it became clear that all end products from the final sludge treatment do not provide a good source of secondary phosphate. As a consequence of this, the most preferred possibility for P-recovery is to extract phosphate before sludge goes to the final sludge treatment. Different scenarios can be selected based on the position of P-recovery in the WWTP configuration, the type of P-recovery product, and the precipitation technique. Local conditions will determine which scenario is the most expedient. Because it is more realistic to judge a practical situation instead of theoretical estimations based on literature, some local situations have to be assessed in sufficient detail to gain more feeling for the expenses and possible savings of P-recovery. One important actor that should be involved in the process management around P-recovery, is the national government. Especially, the Government have the responsibility for sustainable development and should have attention for some stimulation of P-recovery in The Netherlands. Water authorities and the P- and fertilizer industry made already some good steps.     

金沙江溪洛渡水电站工程风险分析

溪洛渡水电站是金沙江开发的第一个巨型工程，工程投资大，技术复杂，存在着政策风险、市场风险、技术风险、环境与移民风险及投资风险。对这些风险因素进行分析和识别，有利于业主在工程建设管理中同避风险，减少损失。溪洛渡水电站可行性研究中用风险评估和风险分析方法，对投资风险进行了量化分析，找出投资风险较大的项目进行重点监控。     

Water Quality Programs In Developing Countries

Abstract

In many developing countries water quality has become the principal limiting factor to water availability. Estimates of future levels of water pollution in many parts of the world under “business as usual” scenarios will be catastrophic for public health, the environment, and national economies in many countries that have limited resources to deal with a contaminated resource. The reality in many developing countries is that political and institutional instability, combined with financial restraint, and poor domestic scientific capacity, means that “western” approaches to water quality management are often inappropriate and unsustainable. Traditional models of technical assistance and technology transfer, including foreign aid and international loans for water quality management, often leave little real change in domestic capacity while generating substantial cash flow for the foreign company. Without a major change in how water quality is managed, including adoption of new paradigms of policy effectiveness, institutional and technical modernization, new methods of knowledge and technology transfer, and innovative investment, the situation can only become more and more serious until the final collapse of major freshwater and coastal ecosystems, and associated economic and public health implications. This paper addresses these various technical, policy, institutional, and financing issues and proposes actions which can lead to sustainability and self-reliance     

Financing the Millennium Development Goals for Water and Sanitation: What Will it Take?

The key financing challenge in meeting the Millennium Development Goals (MDGs) is to arrive at consensus-based, viable and sustainable country-level financing strategies that are integrated into the overall national planning and expenditure process. This requires an assessment of various policy scenarios taking into account economic capacity (as defined by GDP) as well as (plausible) level of public expenditures and affordability at a household level. This paper is prepared to guide the discussions on the characteristics of financing requirements, affordability and feasibility of the MDGs on water and sanitation in Africa. It argues that for African countries to meet the targets, they will need to implement cost recovery policies (leverage more resources into the sector) and use public resources better so as to increase sector performance and help the poor gain access to water and sanitation.     

System Dynamics Analysis for Managing Iran’s Zayandeh-Rud River Basin

Within river basins different social, economic, political and physical subsystems interact. When making decisions, policy makers should be aware of such interactions as any new policy will affect more than one subsystem. To determine the adequacy of a specific management policy, an integrated study is needed of a complicated water management system in the basin considering major physical, social, economic and political aspects. The Zayandeh-Rud river basin, in central Iran with a semi-arid climate and large agricultural, industrial and domestic water uses, is an example of a complicated watershed system where the lack of complete knowledge about all the interacting subsystems has led to failure of the policy makers in addressing the water shortage in the basin. Although water shortages occur fairly soon after completion of each new water source, transbasin water diversion is still the major policy of water planners to address ongoing shortages. System dynamics provides a unique framework for integrating the disparate physical, socio-economic and political systems important to watershed management. This approach is used to comprehend the interactions of different drivers of the problem and to convey the experiences, lessons learned, and perceptions gained during the model development process. A simulation model, built based on causal loop diagrams of the problem, shows that transbasin diversion is not the best and only solution to the problem. The results of the model for different scenarios suggest that various options of demand management and population control can be more effective in addressing the water crisis of the basin when combined with transbasin water diversions, increasing water storage capacity and controlling of groundwater withdrawal.     

Sustainable Management for Minimizing Land Subsidence of an Over-Pumped Volcanic Aquifer System: Tools for Policy Design

Groundwater management scenarios for the Toluca Valley, Mexico, are examined with a three dimensional groundwater flow model coupled to a one dimensional compaction module. The objective of this study is to establish a management policy for the sustainable development and management of the Toluca aquifer system for minimizing land subsidence. Several scenarios are tested by varying 4 main parameters: recharge, exports to other basins, local consumption, and relocating pumping centers. It is apparent that continuing at current rates of water consumption will lead to subsidence of more than 1.6 m over a 40 year period (2010–2050). Completely stopping exports to Mexico City is not the most important factor in controlling subsidence because the pumping system is mostly located in regions with low clay content, where subsidence is lower. However, decreasing exports by half and relocating the pumping centres to low-clay-content areas does have a positive effect on the overall water budget and subsidence. Based on simulation results, it appears that much of the land subsidence could have been avoided had water policies been applied to restrict pumping in regions with compressible materials. The approach taken in this study could be applied to other locations with similar problems in order to determine the most viable option for water supply.     

混凝土面板堆石坝筑坝材料工程特性研究

水布垭工程正在进行可行性研究。混凝土面板堆石坝方案，坝高２３３ｍ，大大超过国内外已建和在建的同类坝型中的是高面板堆石坝设计工作中的关键工作之一。为此，针对水布垭工程的具体情况，对筑坝材料的级配，压实密度孔隙率，压缩模一，排水性能，强度和应力应变等特性进行了大量的室内外试验研究。     

察汗乌苏水电站坝基覆盖层土料的动强度特性

通过大型与中型动三轴试验，对新疆察汗乌苏水电站混凝土面板堆石坝坝基土料动强度与动孔压特性进行了试验研究。根据试验结果和以往成果中坝基动剪应力比分布规律初步估计，在该工程给定的地震设计烈度条件下，该坝基覆盖层可以满足建坝要求，不会发生液化破坏。研究成果可为深厚覆盖层地基上高土石坝的抗震稳定性计算和安全性评价提供科学依据，为深厚覆盖层工程特性的进一步研究提供参考。     

Remediation of polluted soil and sediment: perspectives and failures

Experience gained with the remediation of contaminated sites over the last 10 to 15 years has strongly increased the insight into the problem and how it can be tackled. A large number of remediation techniques, most of which focus on clean-up, are now available, and some of them are intensively applied in practice. However, the experiences gained with them show that they are not capable of solving all problems. Furthermore, each case of soil pollution is different and the way to manage it requires, within the limits set by policy and the finances available, a careful weighing of all relevant factors. Increased knowledge about the problem has resulted in potential new techniques, such as extensive in-situ treatment, the use of special treatment walls, phytoremediation and intrinsic natural degradation.     

Trends and issues in delivery of integrated catchment scale river restoration: Lessons learned from a national river restoration survey within Scotland

This paper provides data on the changing character of river restoration within one country within a single policy and legislative framework. The information gathered was based on web searches, meetings and questionnaire responses with organizations and individuals working as environmental policy developers, stakeholders and practitioners of catchment management and river restoration. The paper utilizes this information to explore generic issues promoting and constraining a move to integrated catchment scale river restoration. Catchment scale river restoration was defined as ‘any river restoration activity that singly, or in combination, restores natural catchment processes and a naturally functioning ecosystem and brings benefit or environmental services to the whole catchment and not just to the site of restoration’. The river restoration project data compiled showed that the number of projects in Scotland is on a strong upward trajectory, but the number of catchment scale projects is still limited. The data also showed a trend towards a range of underpinning reasons for river restoration. Traditionally the reasons for river restoration in Scotland have been strongly fisheries focussed, with another key driver being biodiversity conservation. Sustainable flood management and climate change adaptation are seen as emerging drivers of river restoration. In terms of the individuals interviewed, most appreciated that river restoration can bring about multiple benefits and should be underpinned by a good understanding of catchment processes. Our overall assertion based on our study is that unless there is a fundamental paradigm shift, a change in the nature and level of funding for river restoration and a single organization is given overall authority to direct river restoration. ‘business as usual’ will continue and the benefits of catchment scale river restoration will be limited. Copyright © 2010 John Wiley & Sons, Ltd.     

Water Quality in the Future Alcolea Reservoir (Odiel River,SW Spain): A Clear Example of the Inappropriate Management of Water Resources in Spain

The Odiel River is located in southwestern Spain; the greater portion of its basin is composed of materials from the Iberian Pyrite Belt (IBP), an area with numerous massive sulfide deposits that have been highly exploited since the third millennium BC. As sulfides come into contact with the atmosphere due to mining activity, oxidation occurs, generating a highly toxic acidic leachate with large concentrations of sulfates and metals, a process which is known as acid mine drainage (AMD). As a result, the Odiel River and most of its tributaries are severely contaminated. The construction of two large dams in the Odiel River basin is planned. The most advanced project is that of the Alcolea reservoir, with a storage capacity of 274 hm³, whose construction has already begun, with a total budget of around €164 million. There are reasonable doubts about the final quality of the reservoir water, as this dam will regulate a river with a mean pH close to 3.5 and large concentrations of toxic elements. This paper analyzes the data of water quality in the Alcolea reservoir. The results show that the reservoir water will be acidic and not useful at all, although more specific studies are necessary to obtain the exact estimation of its hydrochemical characteristics. It seems unwise to start building the dam, which requires a large economic investment and will have a vast environmental impact, without first conducting these studies. This proves that water management in Spain is still based on political motivation rather than on technical criteria and good management of natural and economic resources.     

Identifying Optimal Water Resources Allocation Strategies through an Interactive Multi-Stage Stochastic Fuzzy Programming Approach

In this study, an interactive multi-stage stochastic fuzzy programming (IMSFP) approach has been developed through incorporating an interactive fuzzy resolution (IFR) method within an inexact multi-stage stochastic programming framework. IMSFP can deal with dual uncertainties expressed as fuzzy boundary intervals that exist in the objective function and the left- and right-hand sides of constraints. Moreover, IMSFP is capable of reflecting dynamics of uncertainties and the related decision processes through constructing a set of representative scenarios within a multi-stage context. A management problem in terms of water resources allocation has been studied to illustrate applicability of the proposed approach. The results indicate that a set of solutions under different feasibility degrees (i.e., risk of constraint violation) has been generated for planning the water resources allocation. They can not only help quantify the relationship between the objective-function value and the risk of violating the constraints, but also enable decision makers (DMs) to identify, in an interactive way, a desired compromise between two factors in conflict: satisfaction degree of the goal and feasibility degree of constraints. Besides, a number of decision alternatives have been generated under different policies for water resources management, which permits in-depth analyses of various policy scenarios that are associated with different levels of economic penalties when the promised water-allocation targets are violated, and thus help DMs to identify desired water-allocation schemes under uncertainty.