Multiple criteria rainfall–runoff model calibration using a parallel genetic algorithm in a cluster of computers / Calage multi-critères en modélisation pluie–débit par un algorithme génétique parallèle mis en œuvre par une grappe d'ordinateurs     

《水文科学杂志》2013,58(6)

Abstract

Genetic algorithms are among of the global optimization schemes that have gained popularity as a means to calibrate rainfall–runoff models. However, a conceptual rainfall–runoff model usually includes 10 or more parameters and these are interdependent, which makes the optimization procedure very time-consuming. This may result in the premature termination of the optimization process which will prejudice the quality of the results. Therefore, the speed of optimization procedure is crucial in order to improve the calibration quality and efficiency. A hybrid method that combines a parallel genetic algorithm with a fuzzy optimal model in a cluster of computers is proposed. The method uses the fuzzy optimal model to evaluate multiple alternatives with multiple criteria where chromosomes are the alternatives, whilst the criteria are flood performance measures. In order to easily distinguish the performance of different alternatives and to address the problem of non-uniqueness of optimum, two fuzzy ratios are defined. The new approach has been tested and compared with results obtained by using a two-stage calibration procedure. The current single procedure produces similar results, but is simpler and automatic. Comparison of results between the serial and parallel genetic algorithms showed that the current methodology can significantly reduce the overall optimization time and simultaneously improve the solution quality.  相似文献   

基于PLUS和InVEST模型的渭河流域土地利用与生境质量时空变化及预测   总被引：4，自引：0，他引：4       下载免费PDF全文

胡丰  张艳  郭宇  张盼盼  吕帅  张长春 《干旱区地理》2022,45(4):1125-1136

生境质量是关系人类福祉和实现可持续发展的重要基础,对区域生态保护和土地资源可持续利用具有重大意义。以渭河流域为研究对象,基于2000、2010年和2020年的土地利用数据,应用斑块生成土地利用变化模拟（Patch-generating land use simulation,PLUS）模型、生态系统服务和权衡的综合评估（Integrated valuation of ecosystem services and trade-offs,InVEST）模型预测并评价了土地利用与生境质量时空变化特征。结果表明：（1） 2000—2020年渭河流域建设用地和草地面积逐年增加,林地面积略微增长,耕地面积持续减少;2020—2050年土地利用变化趋势同2000—2020年基本一致但剧烈程度显著下降,建设用地扩张趋势减缓,耕地减少幅度下降,草地面积占比超过耕地跃居流域第一。（2） 2000—2020年流域内生境质量两极分化趋势明显,低生境质量和高生境质量区域面积有所增加,中等生境质量的面积减少,整体生境质量水平呈上升趋势;2020—2050年生境质量水平继续保持逐年上升趋势但增幅放缓,生境质量变化强度下降,低生境质量区域面积逐渐减少,中等生境质量面积保持稳定,高生境质量面积有所增长。研究结果可为渭河流域土地资源可持续利用和高质量发展提供相应科学依据和决策参考。  相似文献   

工程造价计价特点与方法研究     

闫添 《中国煤炭地质》2010,(2):71-74

现行工程造价的计价方式,与市场竞争机制和价格调节机制存在许多不协调之处,诸如工程定额的结构、工程利润模式、工程取费方式、人工单价、机械台班单价的制定、材料价格信息的发布等方面尚有待改进。依据我国工程造价的特点,提出工程造价计价方式改革的基本思路应该是:在计价依据上,实现根本上的"量价分离";在管理方式上,实现控制"量",指导"价"、竞争"费",即统一工程计量,政府间接调控,市场形成价格,企业根据竞争原则依法结算;进而实现"四化",即工程量计算规则统一化,工程量计算方法标准化,工程造价的确定市场化,资源管理信息化。  相似文献   

Marine biological valuation mapping of the Basque continental shelf (Bay of Biscay), within the context of marine spatial planning     

Marta Pascual  Angel Borja  Sarah Vanden Eede  Klaas Deneudt  Magda Vincx  Ibon Galparsoro  Irati Legorburu 《Estuarine, Coastal and Shelf Science》2011

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Improving the recreational value of Ireland's coastal resources: A contingent behavioural application     

Luke Barry  Tom M. van RensburgStephen Hynes 《Marine Policy》2011

This paper measures willingness to pay (WTP) for public access to additional beach area and trail improvements to a coastal recreational site in the west of Ireland. The Contingent Behaviour model is used to measure the increased number of trips associated with improved public access using a connecting trail between two beach areas along a stretch of Irish coastline. Results show that improving access through the use of the connecting trail increases consumer surplus by €111.15 per person per annum. It is argued that in designing new regulation such as Marine Protected Areas (MPAs) for the management of Ireland's coastline, an understanding of the values the Irish public place on coastal recreational access will be important to manage the resource in a sustainable manner.  相似文献   

Economic valuation of suspended sediment and phosphorus filtration services by four different wetland types: A preliminary assessment for southern Ontario,Canada     

Tariq Aziz  Philippe Van Cappellen 《水文研究》2021,35(12):e14442

Wetlands are known for their water filtration (or purification) function. Although different wetland types differ in their filtration capacity, they are usually aggregated together in economic valuation studies. Here, we explicitly separate the valuation of the suspended sediment and phosphorus (P) filtration services of the four major wetland types—bogs, fens, marshes and swamps—found in southern Ontario, Canada. The areal extents of the four wetland types are derived from the Canadian Wetland Inventory (CWI) progress map, while the sediment accretion rate is used as the key variable regulating the suspended sediment and P filtration functions. Based on available literature data, we assess the relationship of the sediment accretion rate to wetland size. Because only weak positive correlations are found, we assign a mean (average) sediment accretion rate to each wetland type. The sediment accretion rates are combined with mean soil P concentrations to estimate Pretention rates by the wetlands. The replacement cost method is then applied to valuate the sediment and P filtration services. The unit values for both sediment and P retention decrease in the order: marshes > bogs ≈ swamps > fens. The total value of sediment plus phosphorus removal by all wetlands in southern Ontario amounts to $4.2 ± 2.9 billion per year, of which about 80% is accounted for by swamps. We further assess the costs of different options to offset the additional P loading generated in a hypothetical scenario whereby all wetlands are converted to agriculture. The results demonstrate that replacing the P filtration function of existing wetlands with conventional land management and water treatment solutions is not cost-effective, hence reinforcing the importance of protecting existing wetlands.  相似文献   

条件价值评估法的发展与应用   总被引：115，自引：2，他引：115  

张志强  徐中民  程国栋 《地球科学进展》2003,18(3):454-463

环境物品或生态系统服务的经济价值评估是国际上生态经济学、环境经济学研究的前沿领域。由于绝大多数环境物品或生态系统服务的公共物品特性，其经济价值的评估需要运用非市场的价值评估技术。条件价值评估法（CVM）是非市场价值评估技术中应用最广、影响最大的一种方法。详细介绍了国际上CVM及其发展与应用研究的现状，分析了CVM在环境价值评估技术中的地位及其理论基础，总结了最大支付意愿（WTP）的各种引导技术，全面归纳了CVM研究中可能出现的各种偏差及其相应的解决方法，简要介绍了最大支付意愿的数据统计分析方法。  相似文献   

条件价值评估法在公众气象效益评估中的应用研究   总被引：1，自引：0，他引：1  

王桂芝  李廉水  黄小蓉  夏平嵩  李洁 《气象》2011,37(10):1309-1313

条件价值评价法（CVM）是目前生态（环境）经济学中最重要的和应用最为广泛的公共所有物价值的一种评估方法,对自然资源价值进行量化评估方面具有独特的优势,通过问卷调查反映环境影响下的价值问题,是一种理论化极强的评价方法。现将该方法应用到公共气象服务效益评估建模中,在考虑CVM不确定性因素的前提下,对公众气象服务效益进行评估,构建公众气象服务效益评估二分Logistic模型,并与传统的自愿付费法进行比较。采用全国抽样问卷调查数据量化结果比较表明,用二分Logistic模型对全国公众气象服务效益进行定量评估会更客观。  相似文献   

Cost-benefit analysis in the context of the EU Marine Strategy Framework Directive: The case of Germany     

《Marine Policy》2014

The Marine Strategy Framework Directive (MSFD) requires EU member states (MS) to develop and implement marine strategies containing programs of measures to protect and preserve the marine environment. Prior to their implementation, impact assessments, including Cost-Benefit-Analyses (CBA), need to be carried out. While the costs of introducing such measures are often relatively easy to determine, the economic valuation of the benefits derived from environmental improvements is much more challenging, particularly in the marine context. Still, it remains an important prerequisite for conducting CBA. The aim of this paper is to evaluate to what extent benefits can be quantified for use in CBA focusing on the German marine waters. The results indicate that there are still considerable gaps in the scientific knowledge about many of the pressures mentioned in the MSFD. Moreover, few economic studies exist that evaluate the benefits of marine protection measures, and many of them are not applicable in the German context. In addition, there is the risk that some benefits accruing from marine protection measures are systematically omitted in CBA. This raises the question to what extent comprehensive CBAs as required by the MSFD are possible in Germany, but also in other EU MS.  相似文献   

Developing a co-management financing mechanism to enhance the financial sustainability of marine protected areas in Taiwan     

《Marine Policy》2014

Marine Protected Areas (MPAs) are a cost-efficient and management-effective tool. Fishery Resource Conservation Zones (FRCZs) are one type of MPA in Taiwan, and they were designated to ensure the sustainability of fishery resources since 1976; however, government appropriations are the only financing source for FRCZs, leading to manpower and equipment shortages for FRCZ management. This study selected the Touching and Suao FRCZs in Yilan County of Taiwan as cases studies. To assess the feasibility of establishing a sustainable financing mechanism for MPAs, the Contingent Valuation Method (CVM) was applied to examine respondents׳ willingness to pay (WTP) to setup a fund for FRCZ management. The empirical results indicated that approximately 90% of respondents would be willing to donate funding for MPAs, and the WTP per respondent is NT$586.51 (US$19.6). Thus, establishing an MPA fund is a feasible way to operate Taiwanese MPAs through a co-management framework involving the central government, local government, local communities and stakeholders. However, based on our empirical results, a co-management financing mechanism for MPAs should be established to ensure stable and diverse financing sources.  相似文献