On the use of multicriteria decision analysis to formally integrate community values into ecosystem‐based freshwater management

Freshwater ecosystems are essential to peoples' economic, cultural, and social well‐being, yet are still among the most threatened ecosystems on the planet. Consequently, a plethora of recent regulations and policies seek to halt the loss of restore or safeguard freshwaters, their biodiversity, and the ecosystem services they provide. Ecosystem‐based management (EBM), an approach that considers human society as an integral part of ecosystems, is increasingly being promoted to help meet this challenge. EBM involves an overarching regulatory framework and local solutions with trade‐offs and compromises—factors that not only make decision processes complex but also provide the means for combining top–down regulation with bottom‐up priorities into collaborative management strategies. Although stakeholder participation is encouraged in most modern freshwater management, community values are often largely neglected. Here, we introduce a well‐known participatory decision support framework based on multicriteria decision analysis (MCDA) to operationalize EBM and promote community‐inclusive decision making in freshwater management. We explain the different steps that this approach comprises, which lead to the prioritization of a management strategy in a collaborative way. We also show how cultural values that inherently embed strong links between the environment and people can be used together with typical ecological and socio‐economic values. We illustrate the MCDA‐based EBM‐approach for New Zealand, one of the few countries in which regional freshwater management is mandated to uphold environmental quality standards, while safeguarding local community values and ecosystem services. Finally, we discuss some of the challenges, which are increasingly emerging as a result of mandated community collaboration in environmental management.     

Assessment and prioritization of eco‐revetment projects in urban rivers

Ecological revetment for slope protection in urban rivers requires consideration of economic and ecological aspects and also of social aspects including recreation. Taking the Hunhe River as an example, our study established an evaluation system and a decision‐making method for evaluating and prioritizing the eco‐revetment projects. The Delphi method was used for collecting the opinions of experts, which include the relative importance of the indicators and the relative preference of the alternatives. The former was surveyed by pair comparison and processed applied analytic hierarchy process (AHP). The latter was described via linguistic variables, which need to be changed into the quantitative values for TOPSIS analysis. For that reason, we introduced the fuzzy set theory and established a fuzzy multi‐attribute decision‐making method based on TOPSIS to assess and prioritize the projects. The evaluation system includes economic, social, environment and ecological several aspects totalling eight indicators. The evaluating and prioritizing result of the projects shows that the three‐dimensional vegetation net is the best slope protection measures in the study area. The sensitivity analyses of indicator weights and different calculation methods were performed to demonstrate the reliability of the results. The sensitivity analyses indicate that construction cost and maintenance cost are dominant factors during the alternatives prioritization. The distance calculation method and normalization technique are insensitive to the prioritization results. The methodology proposed by this paper offers an effective and feasible tool for managers to evaluate and choose the optimal engineering measures of riverbank protection. Copyright © 2008 John Wiley & Sons, Ltd.     

Temporal and spatial dynamics of surface run‐off from Lake Basaka catchment (Ethiopia) using SCS‐CN model coupled with remote sensing and GIS

The Lake Basaka catchment (Ethiopia) has undergone a significant land use–land cover (LULC) change and lake level rise over the past five decades. Significant quantities of water and sediment flow annually into the lake through erosion processes. An appropriate method of estimating the surface run‐off from such ungauged and dynamic catchment is extremely important for delineating sensitive areas (based on run‐off responses) to be protected and for development of suitable measures to reduce run‐off and associated soil loss. Reliable prediction of run‐off, however, is very difficult and time‐consuming for catchments such as that of Lake Basaka. The present study estimated the dynamics of surface (direct) run‐off using the NRCS‐CN model in ArcGIS, assisted by remote sensing and ancillary data. The results indicated the Lake Basaka catchment experienced significant temporal and spatial variability in its run‐off responses, depending on the rainfall (amount and distribution) pattern and LULC changes. A significant run‐off increase occurred after 1973, consistent with significant LULC changes and lake level increments occurring after that period. A reduced vegetation cover also resulted in increased run‐off coefficient of the lake catchment from 0.11 in the 1970s to 0.23 in the 2000s, indicating the important need to consider possible future LULC evolution when forecasting the lake catchment run‐off behaviour.     

Exploring and Evaluating Scenarios for a River Catchment in Northern Australia Using Scenario Development,Multi-criteria Analysis and a Deliberative Process as a Tool for Water Planning

Water catchments worldwide are experiencing increasing pressure on the quantity and quality of ground and surface water resources. Water managers are increasingly consulting community and stakeholder groups to ensure their decisions reflect the values and preferences of water users. Growing tensions between different water users require the use of techniques that can enable stakeholders to learn about each others’ positions and deliberate about the costs and benefits of alternative water allocation scenarios. This paper describes the use of scenario development, a small group deliberative process (citizens’ jury) and multi-criteria analysis to assist in water planning for the Howard River catchment in the Northern Territory (NT) of Australia. Water planning processes in the NT are in their infancy. As such, this research provides information about stakeholder preferences where none was previously available and demonstrates the use of a new water planning tool. The research found that the process in this case was most useful in providing information to stakeholders, dispelling some unhelpful myths about water use in the catchment, and coalescing opinion about important criteria for assessing future options.     

Use of multi‐criteria decision‐making for selecting spillway type and optimizing dimensions by applying the harmony search algorithm: Qeshlagh Dam Case Study

Economic considerations are significantly important in designing a dam and its related hydraulic structures. Considering the methods used for economic design of hydraulic structures such as a spillway, they are also dependent on the construction costs of the spillway. In addition to the spillway type and capacity being associated with the magnitude of floods. Selecting different options of a spillway, considering all their aspects, has always been one of the biggest issues in decision‐making. The present study determined the best spillway type (free‐flow, stepped, semicircular and cylindrical) for Qeshlagh Dam, Iran, by considering different aspects (costs, time and performance) and using the TOPSIS method. The obtained dimensions of the spillway from multi‐criteria decision‐making were then optimized using meta‐heuristic Harmony Search Algorithm (HSA). The results identified a free‐flow spillway was the best option in terms of cost and time, whereas a cylindrical spillway is the best choice in terms of performance. The optimal free‐flow spillway length is 31.8 m, and height is 3.45 m, being capable of passing a flood discharge of 452 m³/s. This discharge was calculated by a reservoir routing method. Moreover, the obtained solution led to reducing the spillway construction costs, one of the most important issues in civil engineering projects.     

Tradeoffs associated with sediment‐maintenance flushing flows: a simulation approach to exploring non‐inferior options

Sediment‐maintenance flushing flows designed to mimic the action of natural floods in removing the accumulated fine sediments from the channel and loosening the gravel bed have been increasingly proposed as an effective alternative in dam management and a required component of riverine restoration programmes. However, reservoir releases are generally associated with financial and environmental costs, thus it is highly desirable to specify flushing flows as accurately as possible. In this paper we present a simulation approach to evaluating flushing flows and exploring the tradeoffs associated with non‐inferior flushing options. A two‐fraction sediment routing model is used to simulate the gravel‐sand bed response to flushing flows. The results reveal that the sand cleansing effect propagates from upstream to downstream and from surface to subsurface. Under a steady gravel supply from upstream, an equilibrium state of gravel transport and bed degradation is eventually reached in the simulation reach. The flushing flow and sediment transport system investigated in this study involves a transient state variable (bed sand content), a decision variable (flushing flow discharge), a flushing goal (ultimate bed sand content), and three outcomes to be minimized (flushing duration, released water volume, and total gravel loss). A series of numerical simulations are carried out with a range of flows and pre‐flushing bed sediment conditions. The results reveal that the flushing efficiency is higher for the larger flow. However, for flows greater than ～100 m³/s the flushing duration is less sensitive to the flow discharge, thus the system may be simplified as a bi‐objective one. The gravel loss and water volume are two conflicting outcomes within the non‐inferior flow region. Under a worse bed sediment condition, the feasible flushing options are constrained in a narrower range and also associated with higher costs. The tradeoffs between the conflicting outcomes are quantitatively displayed with the transformed feasible solutions in the objective space. We provide here a general and practical approach permitting a quantitative evaluation of the different flushing options that is appropriate to the level of data typically available. Copyright © 2004 John Wiley & Sons, Ltd.     

Macro‐invertebrate Community Response to Multi‐annual Hydrological Indicators

Flow is widely considered one of the primary drivers of instream ecological response. Increasingly, hydroecological models form the basis of integrated and sustainable approaches to river management, linking flow to ecological response. In doing so, the most ecologically relevant hydrological variables should be selected. Some studies have observed a delayed macro‐invertebrate (ecological) response to these variables (i.e. a cumulative inter‐annual effect, referred to as multi‐annual) in groundwater‐fed rivers. To date, only limited research has been performed investigating this phenomenon. This paper examines the ecological response to multi‐annual flow indicators for a groundwater‐fed river. Relationships between instream ecology and flow were investigated by means of a novel methodological framework developed by integrating statistical data analysis and modelling techniques, such as principal component analysis and multistep regression approaches. Results demonstrated a strong multi‐annual multi‐seasonal effect. Inclusion of additional antecedent flows indicators appears to enhance overall model performance (in some cases, goodness of fit statistics such as the adjusted R‐squared value exceeded 0.6). These results strongly suggest that, in order to understand potential changes to instream ecology arising from changing flow regimes, multi‐annual and multi‐seasonal relationships should be considered in hydroecological modelling. © 2017 The Authors River Research and Applications Published by John Wiley & Sons Ltd.     

Interval-parameter Two-stage Stochastic Semi-infinite Programming: Application to Water Resources Management under Uncertainty

In this study, an interval-parameter two-stage stochastic semi-infinite programming (ITSSP) method was developed for water resources management under uncertainty. As a new extension of mathematical programming methods, the developed ITSSP approach has advantages in uncertainty reflection and policy analysis. In order to better account for uncertainties, the ITSSP approach is expressed with discrete intervals, functional intervals and probability density functions. The ITSSP method integrates the two-stage stochastic programming (TSP), interval programming (IP) and semi-infinite programming (SIP) within a general optimization framework. The ITSSP has an infinite number of constraints because it uses functional intervals with time (t) being an independent variable. The different t values within the range [0, 90] lead to different constraints. At same time, ITSSP also includes probability distribution information. The ITSSP method can incorporate pre-defined water resource management policies directly into its optimization process to analyze various policy scenarios having different economic penalties when the promised amounts are not delivered. The model is applied to a water resource management system with three users and four periods (corresponding to winter, spring, summer and fall, respectively). Solutions of the ITSSP model provide desired water allocation patterns, which maximize both the system’s benefits and feasibility. The results indicate that reasonable interval solutions were generated for objective function values and decision variables, thus a number of decision alternatives can be generated under different levels of stream flow. The obtained solutions are useful for decision makers to obtain insight regarding the tradeoffs between environmental, economic and system reliability criteria.     

FISH HABITAT OPTIMIZATION TO PRIORITIZE RIVER RESTORATION DECISIONS

This paper examines and ranks restoration alternatives for improving fish habitat by evaluating tradeoffs between fish production and restoration costs. Optimization modelling is used to maximize out‐migrating coho salmon (Oncorhynchus kisutch) from a natal stream and is applied as a case study in California's Shasta River. Restoration activities that alter flow and water temperature conditions are the decision variables in the model and include relocating a major diversion, increasing riparian shading, increasing instream flow, restoring a cool‐water spring and removing a dam. A budget constraint limits total restoration expenditures. This approach combines simple fish population modelling with flow and water quality modelling to explore management strategies and aid decision making. Previous fish habitat optimization research typically uses single restoration strategies, usually by altering reservoir releases or modifying outlet structures. Our method enlarges the solution space to more accurately represent extensive and integrated solutions to fish habitat problems. Results indicate that restoration alternatives can be prioritized by fish habitat improvement and restoration cost. For the Shasta River case study, considerable habitat restoration investments were required before fish productivity increased substantially. This exercise illustrates the potential of ecological optimization for highlighting promising restoration approaches and dismissing poor alternatives. Copyright © 2011 John Wiley & Sons, Ltd.     

基于鲁棒规划方法的农业水资源多目标优化配置模型

在干旱半干旱地区,调整种植结构可以促进农业水资源的高效利用。农业水资源配置需要在多个目标间权衡博弈,对各目标的偏好和赋权直接影响着优化模型的输出和决策方案的制定,但以往研究往往忽略了权重确定过程中因主观等因素的影响而普遍存在的不确定性。针对农业水资源多目标规划中存在的权重不确定性难题,建立了基于鲁棒优化方法的农业水资源多目标优化配置模型方法(MRPWU)。该方法可以把权重中蕴含的复杂不确定性信息纳入建模过程,产生可靠的模型结果;并能提供效益值及风险值均定量化的方案集,便于决策者在权衡效益与风险后确定最优方案。模型以作物种植经济收益和碳吸收量最大化为目标、以水土资源供需平衡等为约束条件,并应用于农业水资源供需矛盾突出的甘肃省民勤县。优化结果表明,随着保护度水平的提高,生态效益上升,经济效益和综合效益下降,系统面临的风险也随之下降。相比于权重为确定参数的模型,MRPWU模型可以在综合效益下降3.7%的同时,较大地提高系统应对权重不确定性以及风险的能力。与2017年的实际情况相比,MRPWU模型可以减少种植面积1.6%、节省灌溉用水3.9%,同时提高生态效益1.6%。     

Ecosystem Management Along Ephemeral Rivers: Trading Off Socio‐Economic Water Supply and Vegetation Conservation under Flood Regime Uncertainty

In ecosystems driven by water availability, plant community dynamics depend on complex interactions between vegetation, hydrology, and human water resources use. Along ephemeral rivers—where water availability is erratic—vegetation and people are particularly vulnerable to changes in each other's water use. Sensible management requires that water supply be maintained for people, while preserving ecosystem health. Meeting such requirements is challenging because of the unpredictable water availability. We applied information gap decision theory to an ecohydrological system model of the Kuiseb River environment in Namibia. Our aim was to identify the robustness of ecosystem and water management strategies to uncertainties in future flood regimes along ephemeral rivers. We evaluated the trade‐offs between alternative performance criteria and their robustness to uncertainty to account for both (i) human demands for water supply and (ii) reducing the risk of species extinction caused by water mining. Increasing uncertainty of flood regime parameters reduced the performance under both objectives. Remarkably, the ecological objective (species coexistence) was more sensitive to uncertainty than the water supply objective. However, within each objective, the relative performance of different management strategies was insensitive to uncertainty. The ‘best’ management strategy was one that is tuned to the competitive species interactions in the Kuiseb environment. It regulates the biomass of the strongest competitor and, thus, at the same time decreases transpiration, thereby increasing groundwater storage and reducing pressure on less dominant species. This robust mutually acceptable strategy enables species persistence without markedly reducing the water supply for humans. This study emphasises the utility of ecohydrological models for resource management of water‐controlled ecosystems. Although trade‐offs were identified between alternative performance criteria and their robustness to uncertain future flood regimes, management strategies were identified that help to secure an ecologically sustainable water supply. Copyright © 2014 John Wiley & Sons, Ltd.     

水资源使用权初始分配协商模型研究

针对用水主体以平等的身份参与水资源使用权初始分配的协商具有多目标群决策的特征,从水资源使用权初始分配协商的要素分析出发,结合其协商的特点,构建了以综合满意度最大为目标的协商模型.并基于决策论原理,分析了模型的算法以及协商的流程.最后以宁夏为例对模型进行了验证,结果显示模型是可行性.     

Communicating (nature‐based) flood‐mitigation schemes using flood‐excess volume

As interest mounts in nature‐based solutions (NBS) for flood mitigation as complementary options to civil‐engineering measures, possible flood‐protection strategies have become more diverse and hence complicated to assess. We offer a straightforward and educational protocol targeted for effectiveness analysis and decision making involving stakeholder participation. It is based on the concept of flood‐excess volume (FEV), the volume exceeding a threshold and generating flood damage, and explores what fraction of FEV is reduced, and at what cost, by particular flood‐mitigation measures. Quantification and interpretation of cost scenarios are facilitated using a graphical display that is easy to understand and encapsulates concepts of flood magnitude, FEV and protection‐measures efficacy. It is exemplified for two recent extreme‐flood events on the River Calder in Mytholmroyd (Yorkshire, United Kingdom) and the River Brague in Biot (Alpes‐Maritimes, France). Each case has different flood‐mitigation measures such as natural water‐retention measures, tree planting, river‐bed widening, or use of reservoirs and floods walls. Our straightforward protocol enables fast, quantifiable and easy‐to‐understand exploration of protection strategies using multiple measures, and in doing so highlights the issue of NBS scalability.     

引黄灌区水资源调配模型及和谐评估

基于引黄灌区普遍特征及存在的水资源问题,构建考虑水资源、经济社会和生态环境多维目标的水资源优化调配模型,建立引黄灌区水资源和谐评估指标体系,并将模型和评估体系应用到赵口引黄灌区二期工程。基于模型解集中选取的4种代表性优化调配方案进行水资源、经济社会、生态环境的效益分析,选定P₄方案为赵口二期水资源多目标优化调度方案,并基于该方案开展和谐评估和多方案调控研究。结果表明：模型优化后灌区和谐度明显提高,通过对和谐度较低的地下水开采率、农业用水比例、城镇化率、人均粮食产量、绿化覆盖率等指标调控后,和谐度可进一步提高到0.790。     

多目标水资源系统运行决策优化的遗传算法

针对一多目标水资源系统优化运行问题，本文阐述了多目标决策遗传算法(MODGA)的应用。按遗传算法原理，采用浮点向量表达解的结构；并依据多目标决策协调规划法定义适应度为任一目标点与理想点的距离。对构建的模型，文中使用的计算方法的收敛过程相当有效，计算结果合理。     

Assessment of the Ecological Reservoir Operation in the Yangtze Estuary Based on the Salinity Requirements of the Indicator Species

In conventional reservoir operations, energy and economic benefits are typically optimized, and ecosystem values are only addressed as constraints. To reduce the negative influence of reservoir operation on the downstream ecological environment, ecological targets should be incorporated into reservoir operations. The concept of environmental flow was developed to define the quantity, quality and timing of water flows that are required to sustain freshwater and estuarine ecosystems. Based on the salinity requirements of the indicator species and the relationship between salinity and the freshwater inflows, environmental flows for the Yangtze Estuary were determined. Subsequently, an ecological reservoir operation model was established that incorporated the ecological target for the protection of the Qingcaosha water source; the Non‐dominated Sorting Genetic Algorithm II was applied to the model. Three typical periods of wet, normal and dry years were selected, and the operation results were analysed for the downstream Datong cross‐section and the environmental flows. The results showed that joint scheduling should be performed for the reservoirs upstream of the Yangtze Estuary. In June of wet and normal years, the current run‐off of the Datong should be reduced by 13.5% and 5%, respectively. In July and September of wet years, current run‐off should be reduced by 30.6% and 25.5%, respectively, as these reductions will not negatively affect the drinking‐water sources. The results of this study should provide guidance in decision‐making to improve the operation of the Three Gorges Reservoir. Copyright © 2015 John Wiley & Sons, Ltd.     

Integrated irrigation development planning by multi‐objective optimization

A multi‐objective linear‐programming‐based planning model for irrigation development, incorporating the integrated use of surface and groundwater resources, is presented. Applicability of the model is illustrated by a case study of the Bagmati River Basin, Nepal. Alternative plans for irrigation development are identified by analysing trade‐offs between the specified objectives of maximizing total net economic benefits from agriculture (economic efficiency) and total irrigated cropped area (balanced regional development). Evaluation of the alternatives by compromise programming is carried out in order to indicate the optimal scale of development, cropping plans, system design capacities and water allocation policies.     

基于二元水循环及系统熵理论的城市用水配置

基于二元水循环理论,在分析城市水资源配置系统结构基础上,构建了考虑水资源质、量均衡的城市用水优化配置模型,并运用多目标求解方法获得水资源分配的可行方案;对信息熵进行改进,构建了系统熵,并将其应用于可行方案的评价中。对昆明市水资源的优化配置计算结果表明,当重视生态效益或者综合考虑生产、生活、环境及生态效益时,系统熵值较小,这将有利于水资源系统的长期健康运行;该方法不仅能对城市用水系统进行简洁有效的分析评价,亦能对用水系统的结构调整、系统发展提供参考意见。     

Enhancing institutional dynamics for multiple uses of water amidst climate‐related risks: The case of Lake Buhi,Philippines

This study examined the current governance system for Lake Buhi, Philippines. It describes stakeholder patterns of decision‐making, their roles in the decision‐making process based on their legal mandates, the manner of interactions, the sources of conflict and how these various issues are currently resolved. Stakeholders represent diverse interests, including irrigation, hydropower generation, fishery management and navigation. This study uses data generated from ten key informant interviews of the different stakeholders, information from five round table discussions, and secondary data and reports of various agencies. The results indicate that Lake Buhi and its watershed present classic man‐in‐nature governance challenges. The interplay of internal and external uncertainties regarding multiple uses results in a complex system that is difficult to effectively manage. Climate‐related hazards aggravate the pressures from activities within the lake watershed, complicating water allocation issues. The institutional arrangements that have emerged to address these challenges, however, appear to be fraught with overlaps, fragmentation and a lack of communication. It is thought these deficiencies could be addressed by establishing a lake basin council with representation from all the involved organizations, as well as any stakeholder groups not represented by organizations. The system of governance over the lake must address issues concerning water uses and access to the resource. The capacity of the organizations to participate in such an arrangement is weak, however, and capacity building is needed. The availability and sharing of data and information among stakeholders are also weak and must be strengthened if the work of the lake basin council is to be based on the best available information.