Risk early warning of maize drought disaster in Northwestern Liaoning Province,China

This study presents a methodology of risk early warning of maize drought disaster in Northwestern Liaoning Province from the viewpoints of climatology, geography, disaster science, environmental science, and so on. The study area was disaggregated into small grid cells, which has higher resolution than counties. Based on the daily meteorological data and maize yield data from 1997 to 2005, the risk early warning model was built up for drought disaster. The early warning crisis signs were considered from exogenous warning signs and endogenous warning signs. The probability of drought was taken as endogenous warnings sign, which was calculated by logistic regression model. Beside precipitation, wind speed and temperature were taken into consideration when assessing the drought. The optimal partition method was used to define the threshold of each warning grade. Take the year of 2009 as an example, this risk early warning model performed well in warning drought disasters of each maize-growing stage. Results obtained from the early warning model can guide the government to take emergency action to reduce the losses.     

基于功效系数法的泥石流灾害预警研究

泥石流灾害破坏力巨大,预测预报泥石流发生的可能性是防灾减灾的重要手段,也是国内外学者研究的热点。基于功效系数法原理,在综合分析泥石流灾害发生的气象、地质环境影响因素的基础上,选取了山坡坡度、相对高差、植被覆盖率、沿沟松散物储量、5 d累计降雨量、最大小时雨强和当日雨量为评价因子,采用改进后的层次分析法计算评价因子的权重系数,建立了泥石流预测预警模型。以岫岩地区泥石流为例对预警模型进行检验,预测结果较好地反映了实际情况。表明基于功效系数法的泥石流预测预警模型具备较高的可靠性和实用性,研究结果为泥石流预测预警提供了一种新的思路和方法。     

Critical Loads of Heavy Metals in a Highly Polluted Catchment Area in Egypt

Heavy metals in different environmental compartments can be hazardous to ecosystems. Budgets of Cd, Pb and Zn in small ecosystems of the Shubra E1-Kheima area in Egypt are presented. The budgets are not in steady state because they change with time. So the concentrations of the metals are a function of time. The critical loads of heavy metals to soils can be calculated from an inventory of inputs and outputs of the trace components in the catchment area.Critical time is an important parameter for critical load evaluation because it can indicate which of the heavy metals may be the most acute threat to the soils. Egyptian soil in the Shubra ElKheima area seems to be in danger of heavy metal pollution by Zn, Cd and Pb. The calculated critical loads and their exceedances are approximate indicators of the hazards in the soil system.The critical time is a warning signal to initiate an environmental evaluation of possible pollution hazards.     

突发地质灾害气象预警统计模型与应用

通过引入地质灾害潜势度,突发地质灾害气象预警统计模型解决了雨量判据法不能明确表达地质环境条件的问题,在此基础上,提出了潜势度计算、大气降雨变量设计、预警方程优化3方面的改进方法。为提高潜势度计算的准确性,增加了基于卡方检验的地质环境因子独立性判别步骤;对地质环境因子确信程度初始值和权值计算中确信程度变化量初始值设置进行了规定;并将预警模型中累计雨量修正为更为合理的有效累计雨量。在现有的预警方程的基础上提出了基于联合概率分析的预警方程,避免了其与基本地质认识和物理规律存在一定距离、方程系数的意义不明确的局限。以2009年7月2日发布的24 h雨量预报为例,计算结果表明：虽然预报区域面积从101 008 km²减小到27 553 km²,但是地质灾害点落入预报区的比例从44%增加到62%。这说明通过改进的预警模型理论上更加严密,空间准确率有所提高,空报率有所下降。     

Assessment of heavy metal contamination in soils around Manali industrial area, Chennai, Southern India

The concentrations of heavy metals (As, Ba, Co, Cr, Cu, Ni, Mo, Pb, Sr, V and Zn) were studied in soils to understand metal contamination due to industrialization and urbanization around Manali industrial area in Chennai, Southern India. This area is affected by the industrial activity and saturated by industries like petrochemicals, refineries, and fertilizers generating hazardous wastes. The contamination of the soils was assessed on the basis of geoaccumulation index, enrichment factor (EF), contamination factor and degree of contamination. Soil samples were collected from the industrial area of Manali from the top 10-cm-layer of the soil. Soil samples were analyzed for heavy metals by using Philips MagiX PRO-2440 Wavelength dispersive X-ray fluorescence spectrometry. The data revealed elevated concentrations of Chromium (149.8–418.0 mg/kg), Copper (22.4–372.0 mg/kg), Nickel (11.8–78.8 mg/kg), Zinc (63.5–213.6 mg/kg) and Molybdenum (2.3–15.3 mg/kg). The concentrations of other elements were similar to the levels in the earth’s crust or pointed to metal depletion in the soil (EF < 1). The high-EFs for some heavy metals obtained in the soil samples show that there is a considerable heavy metal pollution, which could be correlated with the industries in the area. Contamination sites pose significant environmental hazards for terrestrial and aquatic ecosystems. They are important sources of pollution and may result in ecotoxicological effects on terrestrial, groundwater and aquatic ecosystems. In this perspective there is need for a safe dumping of waste disposal in order to minimize environmental pollution.     

基于模糊物元的城市化生态预警模型及应用

根据模糊物元理论建立了城市化的生态预警模型,将警报级别分为无警、轻警、中警、重警和巨警5级,并从资源预警、生态预警和环境预警3个方面构建河西走廊城市化进程中的生态环境预警指标体系,设立了预警参照标准与预警界限、警灯、警度,对河西走廊进行了实证分析。结果发现,河西走廊及五大地市按照预警指数从大到小的顺序依次为：张掖市、武威市、金昌市、河西走廊、嘉峪关市和酒泉市。其中,河西走廊的生态用水比重、植被覆盖率、人均环境保护费用和万元产值工业SO2排放量的景气指数最高,处于重警状态;城市工业用地定额、城市居住用地定额、万元产值工业废水排放量和万元产值工业粉尘排放量的景气指数最低,均处于轻警状态;其它指标均处于中警状态。可见,相对于土地资源和环境污染因素而言,水资源和生态条件已经对河西走廊的城市化产生了较强的束缚作用。     

Evacuation behaviour of households and drivers during a tornado

With increasing concerns over the possibility of tornadoes in highly populated areas in Canada, emergency managers are looking into ways to mitigate the impacts of tornadoes. Given that tornadoes can cause enormous destruction, early warnings and proper evacuation actions are critically important in helping save lives. In this paper, a survey was conducted to analyse the evacuation behaviour of households and drivers during a hypothetical tornado warning situation in the city of Calgary, Alberta. Nearly 500 Calgarians took part in the online survey and provided information on how they would respond to tornado warnings after receiving them. This paper presents the results of the survey. Using probit models, the factors influencing these evacuation decisions are identified and discussed in detail. The results of the household evacuation model show the importance of improving awareness about the safest locations during a tornado. It further highlights the need for targeting the population under the age of 30, who are more likely to take unsafe evacuation actions. The model for evacuation of drivers shows that several factors, such as knowing the difference between a watch and a warning, awareness of safe cover, receipt of warnings through natural environmental cues and the level of education, trigger evacuation actions in avoiding a tornado threat.     

基于显式统计原理的地质灾害区域预警方法初步研究

区域预警是提高防灾减灾意识、有效减轻地质灾害造成损失的重要手段。地质灾害显式统计预警理论考虑了地质环境变化与降雨参数等多因素的耦合作用,克服了传统单一临界雨量判据方法的局限。笔者应用地质灾害显式统计预警的基本原理,以中国的东南区为例开展应用研究。选取岩土体类型、地形起伏等12个基础地质环境因素.通过确定性系数模型(CF)综合分析了地质灾害分布与地质环境基础因素的关系.选取地质灾害"潜势度"作为地质环境优劣的指标,并进行了定量计算。选取当日雨量和一个降雨过程的前期累计雨量作为降雨激发因素的指标.采用多元回归的统计分析方法,分析了地质环境因素、降雨激发因素的耦合作用与地质灾害发育情况之间的关系.建立了显式统计的地质灾害预警预报模型。以2006年5月18日台风"珍珠"登陆期间的实况预警情况对模型进行了应用校验。验证了显式统计预警原理及模型方法的可行性和实用性。     

基于尖点突变模型与D-S证据融合理念的地下矿山岩体失稳预警方法

地下矿山岩体失稳预警一直是矿山灾害防治研究的重要课题。为了提高岩体失稳预警的准确性和可靠性,本文提出一种基于尖点突变理论和D-S证据融合理论的综合性预警方法。首先通过建立尖点突变分析模型和D-S证据融合模型得到两种独立预警判据。然后借助风险矩阵融合两种独立预警判据形成综合性预警判据。最后利用矿山实测的微震数据分别对三种预警判据的预警效果进行检验。结果表明:尖点突变模型对岩体失稳的预警效果较差;D-S证据融合模型的鲁棒性较差;综合性预警判据的预警结果与工程实际高度吻合且鲁棒性较好,预测准确性和可靠度明显提高。     

地质灾害区域预警原理与显式预警系统设计研究

通过总结分析国内外经验和新认识,文章把地质灾害区域预警原理初步划分为隐式统计预警、显式统计预警和动力预警三种类型。隐式统计预警是把地质环境因素的作用隐含在降雨参数中,仅仅考虑降雨参数建立模型的方法。显式统计预警是一种把地质环境因素变化与激发因素相迭加耦合而后建立判据模型的预警方法。动力预警是一种考虑地质体在降雨过程中自身动力变化过程而建立数学物理判据方程的方法,实质上是一种解析预警方法。本文以系统工程思想为指导,比较全面地架构了显式统计预警系统的设计方法,包括需求分析、问题表述、目标设定、设计原则、图层设计、系统建模、系统运算、预警等级确定、产品生成、产品会商、产品发布、预警校验、预警决策、应急行动、成本收益分析和系统完善升级等内容。这项设计研究为具体研发设计某个地区的预警系统提供了思想平台,为建立国家、省和市(县)分层级联动的地质灾害区域预警体系提供了技术路线。     

Quaternary palaeoecology and nature conservation: a general review with examples from the neotropics

Palaeoecology, as an ecological discipline, is able to provide relevant inputs for conservation science and ecosystem management, especially for issues involving long-term processes, such as ecological succession, migration, adaptation, microevolution, and extinction. This use of palaeoecology has been noted for several decades, and it has become widely accepted, especially in the frame of ongoing and near-future global warming and its potential biotic consequences. Selected palaeoecological insights of interest for conservation include the following: 1) species respond in an individualistic manner to environmental changes that lead to changes in community composition, suggesting that future ecosystems would have no modern analogues; 2) in the short-term, acclimation is more likely a response of species that are expected to persist in the face of global warming, but the possibility of evolutionary change linked to the existence of pre-adapted genomes cannot be dismissed; 3) species unable to acclimate or adapt to new conditions should migrate or become extinct, which has been observed in past records; 4) current extinction estimates for the near-future should be revised in light of palaeoecological information, which shows that spatial reorganisations and persistence in suitable microrefugia have been more common than extinction during the Quaternary; 5) biotic responses to environmental changes do not necessarily follow the rules of equilibrium dynamics but depend on complex and non-linear processes that lead to unexpected “surprises”, which are favoured by the occurrence of thresholds and amplifying positive feedbacks; 6) threshold responses can cause the movement of ecosystems among several potentially stable states depending on their resilience, or the persistence of transient states; 7) species and their communities have responded to environmental changes in a heterogeneous fashion according to the local and regional features, which is crucial for present and future management policies; 8) the global warming that occurred at the end of the Younger Drays cold reversal (ca 13.0 to 11.5 cal kyr BP) took place at similar rates and magnitudes compared to the global warming projected for the 21st century, thus becoming a powerful past analogue for prediction modelling; 9) environmental changes have acted upon ecosystems in an indirect way by modifying human behaviour and activities that, in turn, have had the potential of changing the environment and enhancing the disturbance effects by synergistic processes involving positive feedbacks; 10) the collapse of past civilisations under climate stress has been chiefly the result of inadequate management procedures and weaknesses in social organisation, which would be a warning for the present uncontrolled growth of human population, the consequent overexploitation of natural resources, and the continuous increase of greenhouse gas emissions; 11) the impact of fire as a decisive ecological agent has increased since the rise of humans, especially during the last millennia, but anthropic fires were not dominant over natural fires until the 19th century; 12) fire has been an essential element in the development and ecological dynamics of many ecosystems, and it has significantly affected the worldwide biome distribution; 13) climate–fire–human synergies that amplify the effects of climate, or fire alone, have been important in the shaping of modern landscapes. These general paleoecological observations and others that have emerged from case studies of particular problems can improve the preservation of biodiversity and ecosystem functions. Nature conservation requires the full consideration of palaeoecological knowledge in an ecological context, along with the synergistic cooperation of palaeoecologists with neoecologists, anthropologists, and conservation scientists.     

Estimation of ecological flow requirement in Zoige Alpine Wetland of southwest China

In many vulnerable wetlands, water is the most crucial factor for sustaining human development, economic growth, as well as existence and evolution of various indigenous ecosystems. This has led to intensive competitions against limited water resources and caused a number of potentially adverse effects on local ecosystems and human society. As water demand by human activities is increasing, balancing water demands between human society and ecosystems is desired to improve economic development without causing too much disturbance on the environment and ecosystems within a wetland. In this study, a computationally efficient quantitative method was developed to calculate the ecological flow requirement (i.e., water demand by ecosystems) in an alpine wetland of western China. The proposed method was also carried out by means of remote sensing images interpretation. Through this method, variations in water demands by human beings and ecosystems could be reflected and analyzed, which would be useful in helping formulate water allocation strategies under multiple objectives such as environmental protection, economic development, and ecological conservation. The method was then applied to assess ecological flow requirements in Zoige Wetland of western China. The results indicated that to maintain the basic ecological structure and integrity of the wetlands, the minimum reserve of 6.218 billion m³/a and a suitable reserve of 6.639 billion m³/a of water would be required. Also, the application results indicated that the method is applicable and can be expanded to other similar wetlands for balancing water demands between ecosystems and human beings.     

Earthquake early warning for earth dams: concepts and objectives

In the geotechnical field, the risk related to slope instabilities or collapse of geotechnical structures are increasingly being faced by early warning systems, capable of: (1) predicting the incipient collapse based on the interpretation of a continuous monitoring of the structure and (2) spreading alarm promptly to reduce people exposure. Compared with structural approaches, early warning systems have two important advantages: a faster, simpler and less expensive implementation and environmental compatibility. Past experience indicates that vulnerability of earth dams is generally low under both static and seismic loading conditions. In spite of this, earth dams are characterized by a high-risk level, due to the high exposure factor. Nowadays, the application of early warning systems to dams is fully supported by the technological progress achieved in the telecommunication field, since it is possible to install and automate recordings and transmission of all physical variables significant to check dam safety: accelerations, displacements, pore-water pressures, total stresses, seepage flows. A considerable lack still arises in the predictive models for interpreting monitoring data and providing indicators on dam safety soon after a strong earthquake. The present work illustrates the basic concepts of an earthquake early warning (EEW) system for earth dams and the main features that should characterize a predictive model to such a scope. An application to a real case is finally provided, enhancing the role played by each monitored physical variable for the aims of EEW.     

Excessive reliance on afforestation in China's arid and semi-arid regions: Lessons in ecological restoration

Afforestation is a primary tool for controlling desertification and soil erosion in China. Large-scale afforestation, however, has complex and poorly understood consequences for the structure and composition of future ecosystems. Here, we discuss the potential links between China's historical large-scale afforestation practices and the program's effects on environmental restoration in arid and semi-arid regions in northern China based on a review of data from published papers, and offer recommendations to overcome the shortcomings of current environmental policy. Although afforestation is potentially an important approach for environmental restoration, current Chinese policy has not been tailored to local environmental conditions, leading to the use of inappropriate species and an overemphasis on tree and shrub planting, thereby compromising the ability to achieve environmental policy goals. China's huge investment to increase forest cover seems likely to exacerbate environmental degradation in environmentally fragile areas because it has ignored climate, pedological, hydrological, and landscape factors that would make a site unsuitable for afforestation. This has, in many cases, led to the deterioration of soil ecosystems and decreased vegetation cover, and has exacerbated water shortages. Large-scale and long-term research is urgently needed to provide information that supports a more effective and flexible environmental restoration policy.     

基于降雨过程自动识别的泥石流实时预警技术

本文结合对雨量数据的分析, 总结了泥石流自动实时监测预警中的一些关键技术, 并提出一种基于降雨过程的泥石流实时监测预警的解决方案。在泥石流的监测预警工作中, 目前多采用雨强与累计雨量作为主要参数, 如何正确识别一场降雨过程, 对于提高监测预警的精度具有重要的意义。结合监测数据特征, 本文采用詹钱登对降雨过程的划分标准, 基于数据库技术实现对降雨过程的自动识别, 为后续预警参数的获取提供支撑。由于受雨量计工作模式的影响, 其原始数据的时间间隔是随机的, 不能直接用于预警模型的计算, 因此对雨量监测数据进行等时间间隔的处理。在预警流程方面, 如何实现预警过程无人工干预的完全自动、实时与稳定运行, 一直是预警工作中的难点, 本研究中引入“系统服务”这一技术, 将整套预警系统作为系统级别的后台服务运行于服务器上, 能够保证整个预警过程稳定地运行, 真正意义上实现了泥石流监测预警过程的自动化与实时化。本文研究成果应用于走马岭沟泥石流监测预警中, 成功对2013年7月8日的泥石流事件进行预警。     

Impacts of Coastal Development on the Ecology of Tidal Creek Ecosystems of the US Southeast Including Consequences to Humans

Upland areas of southeastern United States tidal creek watersheds are popular locations for development, and they form part of the estuarine ecosystem characterized by high economic and ecological value. The primary objective of this work was to define the relationships between coastal development, with its concomitant land use changes and associated increases in nonpoint source pollution loading, and the ecological condition of tidal creek ecosystems including related consequences to human populations and coastal communities. Nineteen tidal creek systems, located along the southeastern US coast from southern North Carolina to southern Georgia, were sampled in the summer, 2005 and 2006. Within each system, creeks were divided into two primary segments based upon tidal zoning—intertidal (i.e., shallow, narrow headwater sections) and subtidal (i.e., deeper and wider sections)—and then watersheds were delineated for each segment. Relationships between coastal development, concomitant land use changes, nonpoint source pollution loading, the ecological condition of tidal creek ecosystems, and the potential impacts to human populations and coastal communities were evaluated. In particular, relationships were identified between the amount of impervious cover (indicator of coastal development) and a range of exposure and response measures including increased chemical contamination of the sediments, increased pathogens in the water, increased nitrate/nitrite levels, increased salinity range, decreased biological productivity of the macrobenthos, alterations to the food web, increased flooding potential, and increased human risk of exposure to pathogens and harmful chemicals. The integrity of tidal creeks, particularly the headwaters or intertidally dominated sections, was impaired by increases in nonpoint source pollution associated with sprawling urbanization (i.e., increases in impervious cover). This finding suggests that these habitats are valuable early warning sentinels of ensuing ecological impacts and potential public health and flooding risk from sprawling coastal development. The results also validate the use of a conceptual model with impervious cover thresholds for tidal creek systems in the southeast region.     

Residence time distribution in the Kirkgoz karst springs (Antalya-Turkey) as a tool for contamination vulnerability assessment

Lumped parameter modeling of environmental tracer (tritium, CFCs and tritiogenic helium-3) transport in the Kirkgoz karst springs (Antalya-Turkey) appears to be a useful tool for assessing the vulnerability to contamination. Based on tritium observations between 1963 and 2000, the springs revealed a mean residence time (MRT) of 120 years. This suggests an active transport volume of 71 billion cubic meters for the aquifer, a value that is coherent with the estimated void volume of karst aquifer based on the mass of associated travertine deposits. The CFC-11 and CFC-12 MRTs are in agreement with tritium-based MRT, after correcting for excess air effect. Excess crustal and mantle helium flux hindered the use of tritiogenic helium-3 as a potential tracer. The residence time distribution (RTD) indicates a groundwater transport system that is fed by recharges extending back to past several hundred years. This wide RTD suggests that any recent contamination that may have entered the system could progress slowly within the entire aquifer but would be unnoticed in the early period because of the dilution effect of uncontaminated past recharge waters. Once the contamination is recognized, it may last for many centuries ahead even if the contamination practice is stopped. Thus, control of contaminant release to aquifer and monitoring of contaminant level in Kirkgoz springs is an immediate task for the associated public health authorities.     

Assessment of trace element contamination in soils around Chinnaeru River Basin, Nalgonda District, India

Concentrations of trace elements such as As, Ba, Co, Cr, Cu, Ni, Pb, Rb, Sr, V, Y, Zn and Zr were studied in soils to understand metal contamination due to agriculture and geogenic activities in Chinnaeru River Basin, Nalgonda District, India. This area is affected by the geogenic fluoride contamination. The contamination of the soils was assessed on the basis of geoaccumulation index, enrichment factor (EF), contamination factor and degree of contamination. Forty-four soil samples were collected from the agricultural field from the study area from top 10–50 cm layer of soil. Soil samples were analyzed for trace elements using X-ray fluorescence spectrometer. Data revealed that soils in the study area are significantly contaminated, showing high level of toxic elements than normal distribution. The ranges of concentration of Ba (370–1,710 mg/kg), Cr (8.7–543 mg/kg), Cu (7.7–96.6 mg/kg), Ni (5.4–168 mg/kg), Rb (29.6–223 mg/kg), Sr (134–438 mg/kg), Zr (141.2–8,232 mg/kg) and Zn (29–478 mg/kg). The concentration of other elements was similar to the levels in the earth’s crust or pointed to metal depletion in the soil (EF < 1). The high EFs for some trace elements obtained in soil samples show that there is a considerable heavy metal pollution, which could be due to excessive use of fertilizers and pesticides used for agricultural or may be due to natural geogenic processes in the area. Comparative study has been made with other soil-polluted heavy metal areas and its mobility in soil and groundwater has been discussed. A contamination site poses significant environmental hazards for terrestrial and aquatic ecosystems. They are important sources of pollution and may result in ecotoxicological effects on terrestrial, groundwater and aquatic ecosystems.     

对滑坡监测预警相关问题的认识与思考

近年来,随着科技的迅猛发展,监测预警已成为主动防范地质灾害的重要手段,国家每年投入大量的人力物力财力开展滑坡预警工作。但调查发现,不少相关从业人员(主要是专业技术人员和管理人员)对滑坡监测预警方面的一些基本问题还存在误区甚至错误的认识,严重影响其防灾减灾效果。结合近年来在滑坡监测预警实践中的研究成果和经验教训,本文重点就滑坡监测和预警方面的一些问题提出了自己的认识。其主要观点包括:并不是监测点和监测手段越多就越有效,滑坡监测应突出针对性、实用性和目的性,监测方案设计及具体监测内容都应为滑坡预警提供依据。不少滑坡的发生具有一定的突发性,应采用具自动变频功能的监测设备才能获取滑坡全过程尤其是临滑阶段完整的数据,为科学预警提供保障。监测仅是手段,预警才是目的,不仅要重视滑坡的监测工作,更应高度重视预警工作,且应同时加强区域性气象预警和单体滑坡预警工作。目前常用的阈值预警方法误报、漏报率较高,应将预警的重心转移到对历史数据的统计分析和基于变形、地下水位、雨量等关键指标的预警模型和判据研究,据此提高滑坡预警的准确性和实用性。     

Contamination of the environmental ecosystems by trace elements from mining activities of Badao bone coal mine in China

Bone coal, as a main mining object, can be used by local inhabitants as daily fuel and by local industrial enterprises as industrial fuel in Pinglin County, Shaanxi Province, China. This study reports how the environmental ecosystems have been polluted around the Badao bone coal mine. Geochemical samples (e.g. rock, water, soil, edible plant and animal) were collected. Bone coal from the Badao mine contains Se up to 75 µg/g Se and 28 µg/g Se in ashes after its combustion, with higher contents of other trace elements. Bone coal and its ash seem to be the main geochemical source of trace elements in soils and plants, which may cause contamination of the local environmental ecosystems. Three ways by which soils have been contaminated by these trace elements derived from bone coal are proposed in this paper. Radishes and beans have the ability to accumulate Mo and Se from soils. There is no obvious difference in concentrations of Cu, Cr and F in each plant from the two areas.