道光三年（1823年）华北大水初析

1823年华北大水对清王朝盛衰转折变化有很深远的影响。本文根据史料对这次大水的雨情、水情、灾情进行了较全面的分析,并将这次大水同清代其它各次大水进行比较,阐明这场大水影响深远的原因,并指出存在一个多方面因子所组成的自然灾害系统。     

古洪水研究途径及其在减灾中的作用

本文根据史料记载特点,提出了古洪水鉴别原则,并就历史洪水序列的检验、洪水发生频率的划分、洪水演变趋势的定量刻划等问题进行了讨论。     

从基础产业的观点探讨防洪对策

本文从水利是国民经济基础产业的角度阐述了防洪建设是具有战略意义的基础产业.文中提出了未来洪灾损失具有逐步加大的趋势与特点。针对我国防洪现状,提出在国民经济建设中,防洪建设必须超前发展,以及应采取的全面综合防洪对策。     

DESIGN FREEBOARD AND ECONOMIC EFFICIENCY1

Design freeboard is an increment of height added to a dam, floodwall, levee, or channel, above and beyond the design flood height, intended to serve as a safety factor to account for unforeseen errors in design. Current policies of the Corps of Engineers with regard to the handling of design freeboard for local flood protection studies in economic analyses lead to economic inefficiency. An analysis of these policies in the case study of a levee raising plan for Wyoming Valley, Pennsylvania, reveals that a $200 million project which is considered economically justified under anent policies is in fact not justified under strict economic efficiency criteria Congress has directed that water resources development projects be planned for the objective of National Economic Development. Under current policies that is not being done.     

LUMP SUM TAX LOSS REIMBURSEMENT UNDER THE THAMES RIVER FLOOD CONTROL COMPACT1

ABSTRACT: Under the terms of the Thames River Valley Flood Control Compact, Connecticut has been paying Massachusetts 40 percent of the annual property tax losses suffered by seven Massachusetts towns where four flood control structures were located. The permissable alternative of a single lump sum payment was investigated in the study summarized here. The lump sum payment should be the proportion of total benefits (flood control and recreation) from the four structures which Connecticut receives, multiplied by the present value of projected tax losses in the seven tom Flood control benefits and their distribution between the two states were fixed in the Compact, but a survey was necessary to determine recreational benefits and their distribution. Regression analysis of 1957 to 1978 tax loss data provided equations used to project future tax losses. Resent values of projected tax low were calculated using discount rates ranging from 6 to 12 percent. A plausible range of lump sum reinbursements as of 1979 was identified.     

THE IMPACT OF FLOODPLAIN REGULATIONS ON RESIDENTIAL LAND VALUES IN OREGON1

ABSTRACT: The impact of floodplain regulations on mean appreciation rates of residential land values was tested at six study areas in five counties in western Oregon. The study hypothesis that such regulations significantly depress appreciation rates of regulated lands relative to those of similar unregulated lands was in most cases rejected. When the hypothesis was accepted circumstances would render conclusions tenuous. The problems and issues facing this type of research are presented in case studies of two of the research study areas. The following factors challenge investigators seeking to resolve questions about the relationship between land use regulations and land values: varying degrees of stringency with which regulations are enforced; unequal assessment procedures between counties; influences external to floodplain regulations that may affect appreciation rates, including denial of permits for septic tanks, flood damages, and amenity values associated with waterfront locations; and the uncertain effect that the availability of flood insurance, which accompanies floodplain regulations, has on land values.     

SOME TECHNIQUES FOR USING FREQUENCY ANALYSIS AND REALTIME DATA TO INTERPRET FLOOD POTENTIAL DATA1

ABSTRACT: Flood potential data can be effectively interpreted if simple frequency analysis concepts are used to explain the significance of flood potential. Instead of simply presenting data as a quantitative amount or as a percentage of the average condition, predictions can be discussed in terms of their probabilities of exceedance, or return periods. Criteria are presented for evaluating the significance of various return periods. Frequency interpretations are applied to snow course data, peak flow forecasts, and streamflow volume forecasts in northern Utah to illustrate these concepts. In addition, access to realtime data allows tracking of snowmelt progression and identification of any deviations from the forecast flood potential situation. Several data elements, including snowpack, streamfiow volume and peak, and realtime data are jointly evaluated to assess potential hazard and probable risk.     

CORRELATION OF ANNUAL PEAK FLOWS FOR PENNSYLVANIA STREAMS1

A common assumption in flood frequency analysis is that annual peak flows are independent events. This study was undertaken to investigate the validity of this assumption with regard to Pennsylvania streams by statistically analyzing the dependence between annual peak flows and to determine if basin carryover effects relate to the degree of dependence. Five tests of dependence, the autocorrelation test, the median crossing test, the turning points test, the rank difference test, and the Spearman rank order serial correlation coefficient test were applied to the series of annual peak flows for 57 streams. Of the 57 streams analyzed, only two exhibited signs of dependence by at least two of the tests performed, and the baseflow component of annual peak flows was found to be unrelated to the degree of dependence exhibited between annual peak flows. It was concluded that the assumption of independence of annual peak flows is valid in flood frequency analysis for Pennsylvania streams.     

Flood information systems: Needs and improvements in Eastern India

Flood warning systems offer a large potential for reducing human losses and property damage in flood-prone regions. This article illustrates why official organized systems should not be relied on completely in either developing or developed societies. It then discusses an indigenous flood warning system in a rural area of Eastern India, its value, and its importance in providing an alternative means of detecting, interpreting, and relaying flood warning information to the ultimate users of this information, i.e., those populations most at risk from floods.The National Center for Atmospheric Research is operated by the University Corporation for Atmospheric Research and is sponsored by the National Science Foundation.     

UNIVARLATE LEAST SQUARES MUSKINGUM FLOOD ROUTING1

ABSTRACT: The Muskingum method of hydrologic flood routing is based on a graphical bivariate curve fitting procedure. The subjectivity of this procedure may lead to problems of reproducibility and provides no guarantee of model coefficients which minimize the error of estimation. A transformation is developed to express the Muskingum method as a univariate transcendental function suitable for numeric solution. Solution of this function minimizes the sum of the squared deviations between estimated and measured rates of discharge. Five textbook examples of the Muskingum method are evaluated by the univariate transformation. Error reductions range from negligible to tenfold. While the univariate transformation may not improve upon graphically-based results in every case, in no instances are the univariate results inferior; in many cases they are superior.