最小数据方法在舟曲县生态补偿中的应用

弄清补偿标准和新增生态系统服务供给量之间的关系是生态补偿研究中的关键问题.舟曲县现有的补偿是静态补偿,补偿标准低,没有很好地达到改善生态环境的目的.本文基于最小数据方法,以耕地和林地提供的水土保持量的差异表征生态系统服务,通过提供单位水土保持服务的机会成本的空间分布,推导出舟曲县森林水土保持的供给曲线,从而将补偿标准和新增水土保持服务的供给联系起来.同时对比了3种补偿标准下的退耕比例、生态补偿总资金需求和新增水土保持量.研究表明生态补偿在理论上可以提供舟曲县的水土保持能力.随着补偿标准的提高,新增水土保持量也在增加.当补偿标准为250元/亩时,退耕比例仅为8.26%,生态补偿总资金需求为1 930.03万元,新增水土保持量为4.69×104t;当补偿标准提高到518.63 元/亩时,退耕比例增加到49.54%,总资金需求为23 184.26万元,新增水土保持量为2.83×105t;当补偿标准增加到995.65 元/亩时,退耕比例可达到98.79%,总资金需求为87 340.95万元,可新增水土保持量达到5.65×105t.     

两次订购机会下南水北调东线供应链优化

论文研究了准市场条件下南水北调东线供应链两次订购优化决策问题,在降水服从随机分布条件下,分别建立了需求与降水无关、需求与降水相关两种情形下的供应链报童优化模型,并分别考虑了一次订购机会和两次订购机会情形,最后进行了算例分析.研究表明:提高降水利用率,有助于减少系统抽水量,节约能源和水资源.两次订购机会的存在使得外地分销商初次订购的水资源量小于只有一次订购机会情形.两次订购机会情形下,二次订购批发价越高,则外地分销商初次订购的水资源量越大.     

水库温室效应研究进展与主要影响因素分析

温室气体排放导致的全球变暖成为世界各国关注的焦点。目前,关于淡水水库的温室效应在全球气候变化中的作用也成为了科学家争论的问题。已有的研究表明,世界上很多为水力发电或其他目的建造的水库,因水库蓄水所导致土壤和植被的淹没而额外增加碳基温室气体二氧化碳（CO2）和甲烷（CH4）的释放。通过对国内外关于淡水水库温室气体研究方面文献的归纳,综述分析了水库温室效应观测研究案例、〖JP2〗水库温室气体的产生机制、排放过程及其主要影响因素等方面的研究进展。为进一步从事水库温室气体研究、把握水库温室气体排放提供参考     

Background and anthropogenic radionuclide derived dose rates to freshwater ecosystem: nuclear power plant cooling pond: reference organisms

The radiological assessment of non-human biota to demonstrate protection is now accepted by a number of international and national bodies. Therefore, it is necessary to develop a scientific basis to assess and evaluate exposure of biota to ionizing radiation. Radionuclides from the Ignalina Nuclear Power Plant (Lithuania) were discharged into Lake Druksiai cooling pond. Additional radionuclide migration and recharge to this lake from a hypothetical near-surface, low-level radioactive waste disposal, to be situated 1.5 km from the lake, had been simulated using RESRAD-OFFSITE code. This paper uses ERICA Integrated Approach with associated tools and databases to compare the radiological dose to freshwater reference organisms. Based on these data, it can be concluded that background dose rates to non-human biota in Lake Druksiai far exceed those attributable to anthropogenic radionuclides. With respect the fishery and corresponding annual committed effective human dose as a result of this fish consumption Lake Druksiai continues to be a high-productivity water body with intensive angling and possible commercial fishing.     

Knowledge coproduction on the impact of decisions for waterbird habitat in a changing climate

Scientists, resource managers, and decision makers increasingly use knowledge coproduction to guide the stewardship of future landscapes under climate change. This process was applied in the California Central Valley (USA) to solve complex conservation problems, where managed wetlands and croplands are flooded between fall and spring to support some of the largest concentrations of shorebirds and waterfowl in the world. We coproduced scenario narratives, spatially explicit flooded waterbird habitat models, data products, and new knowledge about climate adaptation potential. We documented our coproduction process, and using the coproduced models, we determined when and where management actions make a difference and when climate overrides these actions. The outcomes of this process provide lessons learned on how to cocreate usable information and how to increase climate adaptive capacity in a highly managed landscape. Actions to restore wetlands and prioritize their water supply created habitat outcomes resilient to climate change impacts particularly in March, when habitat was most limited; land protection combined with management can increase the ecosystem's resilience to climate change; and uptake and use of this information was influenced by the roles of different stakeholders, rapidly changing water policies, discrepancies in decision-making time frames, and immediate crises of extreme drought. Although a broad stakeholder group contributed knowledge to scenario narratives and model development, to coproduce usable information, data products were tailored to a small set of decision contexts, leading to fewer stakeholder participants over time. A boundary organization convened stakeholders across a large landscape, and early adopters helped build legitimacy. Yet, broadscale use of climate adaptation knowledge depends on state and local policies, engagement with decision makers that have legislative and budgetary authority, and the capacity to fit data products to specific decision needs.     

The long iron line: Water resources development at the United States Military Academy,West Point (1802–1943)

Comprehensive analyses of long-term region-specific water resources developments could offer new insights for contemporary water resources planners and decision makers. The objective of this work was to analyze water supply development at the United States Military Academy (USMA) during the 19th and early 20th Centuries through the lens of selected modern water resources planning and management practices. Analysis of water usage, population, and technological growth revealed that changes in technology had a greater influence on total water withdrawals than an increase in population. The USMA water supply system evolved incrementally over much of the 141-year study period and failure to adequately recognize shortcomings in water supply options resulted in several suboptimal decisions. Communications and enhanced stakeholder participation might have resulted in alternative decisions.     

Use of observed hydroclimatic trends to constrain projections of snowmelt season runoff in the Rio Grande headwaters

A method is developed for choosing 21st Century streamflow projections among widely varying results from a large ensemble of climate model-driven simulations. We quantify observed trends in climate–streamflow relationships in the Rio Grande headwaters, which has experienced warming temperature and declining snowpack since the mid-20th Century. Prominent trends in the snowmelt runoff season are used to assess corresponding statistics in downscaled global climate model projections. We define “Observationally Consistent (OC)” simulations as those that reproduce historical changes to linear statistics of diminished snowpack–streamflow coupling in the headwaters and an associated increase in the contribution of spring season (post-peak snowpack) precipitation to streamflow. Only a modest fraction of the ensemble of simulations meets these consistency metrics. The subset of OC simulations projects significant decreases in headwaters flow, whereas the simulations that poorly replicate historical trends exhibit a much wider range of projected changes. These results bolster confidence in model-based projections of declining runoff in the Rio Grande headwaters in the snowmelt runoff season and offer an example of a methodology for evaluating model-based projections in basins with similar hydroclimates that have experienced pronounced climate changes in the recent historical record.     

Cash and voucher assistance along humanitarian supply chains: a literature review and directions for future research

This study reviews research on cash and voucher assistance (CVA) by applying a humanitarian supply chain management perspective. A systematic literature review was conducted to identify, analyse, and synthesise past academic research. The content, context, and process framework was used to structure the content analysis. The findings reveal that the outcomes of CVA programmes are dependent on critical context-specific variables that influence feasibility and operability. Humanitarian actors must consider factors that are external (the nature of disaster, politics, economy, and infrastructure) and internal (local market availability and accessibility, supplier/donor interest, supplier/vendor selection and contracting, and beneficiary preference) to the supply chain. The delivery process is influenced by them, impacting on programme responsiveness and cost-efficiency. The results provide insights that humanitarian practitioners can utilise to reconsider their supply chain strategies when deciding on the selection and implementation of CVA programmes. Potential literature gaps are identified, and recommendations for further research are provided.     

空气幕对抑制收费亭内污染物侵入作用的数值模拟

针对高速公路收费亭内空气质量差、污染严重的问题,为改善收费亭内工作环境、保障作业人员的身体健康,采用空气幕隔断方式抑制污染物进入亭内.运用Airpak软件对空气幕不同送风速度和送风角度下的抑制效果进行数值模拟,计算结果表明:空气幕可以有效抑制污染物侵入收费亭内;竖直向下送风时,随着送风速度的增加,抑制效果有所增加,当送...     

基于CAS视角的供应链环境协同治理研究

为探究供应链环境协同治理问题,本文从复杂适应系统视角分析了供应链环境协同治理中内部主体之间以及内外部主体间的协同作用机理,以此为基础构建了供应链环境协同治理模型。为探究协同治理机制在该模型中的实际成效,本文运用多主体仿真技术,对二级供应链模型进行仿真模拟,验证了协同治理在企业运营发展以及供应链整体环境绩效方面的提升作用,并针对协同模型中制造商零售商间减排成本分担系数进行调整,检验上下游企业间减排成本分担系数变化对供应链环境治理效果的影响。仿真结果显示,虽然供应链整体利润随着制造商承担的减排成本增加而增加,但供应链单位产值排放量却随之呈现先下降后上升的趋势,进一步验证了协同治理的效果。