How Accurate are Disaster Loss Data? The Case of U.S. Flood Damage

Policy makers need accurate disaster loss data for decisions about disaster assistance, policy evaluation, and scientific research priorities. But loss estimation is difficult in a disaster situation, and initial loss estimates are seldom evaluated in comparison with actual costs. This paper uses the example of historical flood damage data in the U.S. to evaluate disaster loss data. It evaluates the accuracy of historical flood damage estimates from two federal agencies. The U.S. National Weather Service (NWS) has compiled annual flood loss estimates for each state since 1955. Comparison of the NWS data with similar estimates from five state emergency management agencies reveals substantial disagreement between estimates from different sources. The Federal Emergency Management Agency (FEMA) began in the 1990s to systematically collect damage estimates and cost data associated with its disaster assistance programs. Comparison of early damage estimates with actual expenditures in a California flood disaster reveals large errors in some estimates for individual counties, but no statistically significant tendency to underestimate or overestimate. Positive and negative errors tend to average out and the total damage estimate for the state approximates the final expenditures. Both comparisons indicate that damage estimates for small events or local jurisdictions often are extremely inaccurate. On the other hand, estimates aggregated over large areas or long time periods appear to be reasonably reliable; that is, this study finds that independent estimates for events with losses greater than $500 million disagree by less than 40. The paper suggests ways of interpreting and using such loss estimates to reduce the likelihood of misinterpretation.The National Center for Atmospheric Research is sponsored by the National Science Foundation.     

婺源县森林景观游憩价值的经济评价

文章在简要分析森林游憩价值经济评价方法的基础上，采用旅行费用法（TCM）对婺源县森林景观游憩价值进行了经济评价。采用整群随机抽样的方法对研究区的游客进行半访谈式问卷调查，根据调查资料，将婺源县游客来源划分为15个出发区，建立了游林率-旅行费用回归模型。结果表明，旅行费用与游林率呈极显著的负相关，文化程度与游林率呈显著的正相关；在此基础上制定了游憩需求曲线，计算得出研究区2002年森林景观游憩经济价值为1．02亿元。     

影子价格在竞争厂商配置资源中的应用

根据线性规划对偶理论中影子价格的经济含义和竞争厂商对多生产要素(资源)的使用原则,利用资源的影子价格和市场价格的差异性,探讨在完全竞争和不完全竞争条件下竞争厂商资源配置的决策问题,对竞争厂商实现资源的最优配置具有重要的指导意义。     

关于气象服务产品消费问题的讨论

在人类即将进入知识经济和信息经济的时代,在经济发展需要进入可持续性发展轨道的宏观背景下,研究气象服务产品的消费具有重大理论与实践意义。气象服务产品的消费极具特殊性,风险性等五方面的性质;其消费主体结构与消费客体结构也极为复杂;气象服务产品的消费成本在气象服务产品消费中具有十分重要的地位,决定消费成本有两个经济量,它是制约消费的基本经济变量。     

Air quality and view degradations due to copper mining and milling: Preliminary analysis and cost estimates for Green Valley,Arizona

Green Valley, Arizona is a retirement community located near major open-pit copper mines. Mining and milling activities create dust, which degrades air quality, and mine dumps and tailings banks, which degrade the viewscape. Although the tailings banks are highly visible, this study found that consumer surplus lost from dust-polluted air is more than twice that from degradation of viewscape. Consumer surplus lost from both air quality and viewscape degradation is estimated to be between $116,000,000 and $169,000,000. These preliminary estimates are based upon two studies: hedonic property values, and a contingent valuation survey of willingness to pay.     

Optimum seismic zoning for multiple types of structures

We consider zoning for the design criterion that minimizes the expected present value of the total cost, including the initial cost as well as losses due to damage and failure. The problem consists of the following: given the number of zones, their boundaries and design coefficients must be such that they minimize the expected present value of all structures built in the region. We will refer to solutions in one or more dimensions, depending on the number of the types of structures built in the region to be zoned. Two methods are proposed to solve the problems. The first method is based on the different combinations performed in order to attain optimum zoning. The second method uses an analogy to the evolution of biological systems. The work ends by applying the methods developed to a region of known seismicity. Copyright © 2003 John Wiley & Sons, Ltd.     

我国数字城市建设的经济分析

数字城市是我国国民经济信息化的重要环节。如何发挥其效益，尽快回收投资和获得利润一直是进行数字城市研究的重点之一。与信息支持经济活动有关的理论主要是博弈论、交易费用理论等，结合地球信息的应用，笔者提出了图谱理性的观点。对数字城市的效益分析，强调了数字化和货币化管理的重要性，建立全社会的信用机制；主张推动信息定价和信息服务，通过市场价格信号的有效传递，实现市场的监管和高效发展，从而发展信息产品市场尤其是消费品市场。     

甘肃省不同气候条件下退耕还林(草)成本及对策研究

通过实地调查和科学计算 ,分析退耕还林 (草 )的成本和影响成本的因素 ,提出有效利用气候资源降低成本 ,使退耕还林 (草 )工作取得更大效益的建议 ,供决策部门参考     

顾及风向和风速的气温空间插值方法

当前气温插值方法多将高程、经纬度等作为影响因素,无法解决风向、风速对气温空间分布的影响问题。该文提出一种顾及风向和风速的气温空间插值方法:1)根据气象观测站点的风向、风速数据进行插值,生成连续的风场表面;2)基于该风场数据利用高斯扩散模型构建成本表面;3)利用Dijkstra最短路径算法计算观测点与待求点的累计移动成本最短路径(SPOCMC);4)将SPOCMC作为协变量进行薄盘光滑样条插值以实现气温插值。为验证该方法的有效性和可靠性,选取山东省109个气象观测点样本数据,以SPOCMC、DEM和SPOCMC-DEM分别作为协变量对气温数据进行薄盘光滑样条插值,结果显示:SPOCMC-DEM法的MAE和RMSE均值(分别为0.517、0.779)略低于SPOCMC法(0.583、1.016),显著低于DEM法(0.809、1.231),表明添加SPOCMC作为协变量可有效提高气温空间插值的准确性。在江苏省与贵州省的插值实验结果证明了该方法的普适性。