基于影响因子分析的滑坡位移预测模型研究

将滑坡的影响因索引入到滑坡的位移预测模型中．从滑坡的位移动态变化特征和响应组成组分研究入手,将滑坡的位移分解为趋势项、周期项、脉动项和随机项．针对每一项进行研究,分别选取合适的影响因子变量和函数关系来模拟,并将各项耦合在一起得到位移的初步预测模型。通过对监测数据进行非线性多元统计回归分析,得到位移的最终预测模型。以长江三峡库区的新滩滑坡为实例,通过验证研究,发现将滑坡的影响因子引入滑坡的预测预报模型中的思路是有效可行的,而且可以明显地改善预测预报的时间尺度。     

有机磷农药污染对金龟子幼虫呼吸强度的影响

有机磷农药对金龟子幼虫呼吸强度影响的实验研究表明,金龟子幼虫对有机磷农药污染的反应十分敏感,4种有机磷农药处理组动物呼吸强度均明显大于对照组,并且由于不同种农药的毒性不同,对呼吸强度影响的程度也明显不同,其中以甲胺磷影响最大,灭杀毙最小,呼吸强度分别为4.9528mL/g·h和2.1557mL/g·h。染毒历时和农药浓度的影响则表现为随染毒时间的延长和农药浓度的降低,动物呼吸强度逐渐减弱。     

叶片大气颗粒物滞纳能力评估方法的定量对比

为探究基于相同实验材料和叶面积测定方法的前提下,5 种评估叶片滞尘能力方法的差异,并在此基础上归纳总结各方法的优缺点,本研究以北京市常见、叶片特征区别较大的4个城市绿化树种油松(Pints tabuliformis)、侧柏(Platycfadus orientalis)、银杏(Ginkgobiloba)和一球悬铃木(P...     

Incorporating detectability of threatened species into environmental impact assessment

Environmental impact assessment (EIA) is a key mechanism for protecting threatened plant and animal species. Many species are not perfectly detectable and, even when present, may remain undetected during EIA surveys, increasing the risk of site‐level loss or extinction of species. Numerous methods now exist for estimating detectability of plants and animals. Despite this, regulations concerning survey protocol and effort during EIAs fail to adequately address issues of detectability. Probability of detection is intrinsically linked to survey effort; thus, minimum survey effort requirements are a useful way to address the risks of false absences. We utilized 2 methods for determining appropriate survey effort requirements during EIA surveys. One method determined the survey effort required to achieve a probability of detection of 0.95 when the species is present. The second method estimated the survey effort required to either detect the species or reduce the probability of presence to 0.05. We applied these methods to Pimelea spinscens subsp. spinescens, a critically endangered grassland plant species in Melbourne, Australia. We detected P. spinescens in only half of the surveys undertaken at sites where it was known to exist. Estimates of the survey effort required to detect the species or demonstrate its absence with any confidence were much higher than the effort traditionally invested in EIA surveys for this species. We argue that minimum survey requirements be established for all species listed under threatened species legislation and hope that our findings will provide an impetus for collecting, compiling, and synthesizing quantitative detectability estimates for a broad range of plant and animal species. Incorporación de la Capacidad de Detectar una Especie Amenazada a la Evaluación de Impacto Ambiental     

超高速活性污泥法的试验研究

吸附活性污泥法是一种高效率的污水处理方法，曝气池停留时间约４０ｍｉｎ、ＣＯＤ、ＢＯＤ５和ＳＳ的去除率可达到６０－７０％。本文以试验结果为基础，探讨了停留时间，污泥浓度，污泥回流比和污浓度对处理效果的影响，也探讨了该方法对氮，磷的去除效果。     

APPLICATION OF INFILTRATION THEORY FOR THE DETERMINATION OF EXCESS RAINFALL HYETOGRAPH1

ABSTRACT: The purpose of this paper is to show through the use of numerical examples that modern infiltration theory can be used in everyday hydrologic practice. The actual use of four methods of calculation of infiltration rates and of excess rainfall rates is demonstrated for the case when simultaneous data of rainfall and stream flow are available for a watershed. The four methods are: (1) the well known Π-index method, (2) the traditional Horton's infiltration capacity formula, (3) the less traditional Green and Ampt infiltration capacity formula, and (4) a ponding time approach. It is recommended that hydrologists become at least familiar with the numerical procedures involved in the ponding time and postponding infiltration approach. This approach, though not flawless, should be preferred to the other three methods if use of the other three is at all considered.     

SOME SIMPLE MODELS FOR CONTINUOUS VARIATE TIME SERIES1

ABSTRACT: A survey is given of recently developed models for continuous variate non–Gaussian time series. The emphasis is on marginally specific models with given correlation structure. Exponential, Gamma, Weibull, Laplace, Beta and Mixed Exponential models are considered for the marginal distributions of the stationary time series. Most of the models are random coefficient, additive linear models. Some discussion of the meaning of autoregression and linearity is given, as well as suggestions for higher–order linear residual analysis for non–Gaussian models.     

THE OPPORTUNITY COST OF TIME AND AVERTING EXPENDITURES FOR SAFE DRINKING WATER1

ABSTRACT: A survey of individuals during a Giardia contamination incident provided data to calculate the cost of boiling, hauling, or purchasing water to avoid infection. Three different approaches to the valuation of time were used to assess the implications of the opportunity cost of time for the measurement of averting costs. Mean monthly household averting costs were $33.47 using family income to value time, $13.07 using the minimum wage to value time, and $5.60 using zero opportunity cost of time. Comparisons of the mean costs for different sources and household characteristics indicated the value of time from family income was too high and that the other methods of valuing time were superior.     

GOALS AND DATA COLLECTION DESIGNS FOR WATER QUALITY MONITORING1

ABSTRACT: Water quality monitoring cannot address every information need through one data collection procedure. This paper discusses the goals and related procedures for designing water quality monitoring programs. The discussion focuses on the broad information needs of those agencies operating water quality networks. These information needs include the ability to assess trends and environmental impacts, determine compliance with objectives or standards, estimate mass transport, and perform general surveillance. Each of these information needs has different data requirements. This paper outlines these goals and discusses factors to consider in developing a monitoring plan on a site by site basis.     

陕西省近10年自然灾害的损失规律

本文主要根据自然灾害损失资料,对陕西近10a自然灾害损失时空规律、各灾种特点、损失结构进行了较详尽讨论,并进行了损失强度分区。