城市防灾救灾计算机集成管理系统初论

本文通过分析现代城市灾害的特点和城市灾害管理的原则，提出了城市减灾集成管理的思想，并按此思想初步分析和设计了一个城市防灾救灾计算机集成管理系统。     

活性污泥处理系统的计算机模拟

介绍了以活性污泥1号模型(ASMI)和固体通量沉淀模型为基础．结合反应器原理．用VB6．0计算机语言建立城市污水活性污泥模拟器的方法,探讨了生物反应器和二沉池的模拟工艺流程、各组分的物料平衡关系和欧拉法数值积分的步长选取等问题。模拟器的校准结果表明,该模拟器建立的思路和方法是可靠的．可以用于城市污水生物处理系统的模拟和预测。     

破碎机高效、安全运行的计算机控制

介绍了矿石破碎安全生产中的主体设备——液压圆锥破碎机的计算机控制,对系统的组成、功能、软件编制作了简述,构成的系统在矿山极具通用性。     

Can Repeated Fertilizer Applications to Young Norway Spruce Enhance Avian Diversity in Intensively Managed Forests?

Repeated fertilization of forests to increase biomass production is an environmentally controversial proposal, the effects of which we assessed on breeding birds in stands of young Norway spruce (Picea abies), in an intensively managed forest area in southern Sweden. Our results show that fertilized stands had 38% more species and 21% more individuals than unfertilized stands. Compared with stands under traditional management, the further intensification of forestry by repeated applications of fertilizers thus seemed to enhance species richness and abundance of forest birds. We cannot conclude at this stage whether the response in the bird community was caused by changes in food resources or increased structural complexity in the forest canopy due to the skid roads used for the application of the fertilizers. Future studies should focus on structural and compositional effects of fertilization processes during the entire rotation period and at assessing its effects in a landscape context.     

Forest Value Orientations in Australia: An Application of Computer Content Analysis

This article explores the expression of three forest value orientations that emerged from an analysis of Australian news media discourse about the management of Australian native forests from August 1, 1997 through December 31, 2004. Computer-coded content analysis was used to measure and track the relative importance of commodity, ecological and moral/spiritual/aesthetic forest value orientations. The number of expressions of these forest value orientations followed major events in forest management and policy, with peaks corresponding to finalization of Regional Forest Agreements and conflicts over forest management. Over the time period analyzed, the relative share of commodity value orientation decreased and the shares of the ecological and moral/spiritual/aesthetic value orientations increased. The shifts in forest value orientations highlight the need for native forests to be managed for multiple values and the need for continued monitoring of forest values. Research carried out while employed by the Bureau of Rural Sciences, Department of Agriculture, Fisheries, Forestry, Canberra, Australia.     

Re‐thinking water scarcity: Can science and technology solve the global water crisis?

This paper provides examples from the last fifty years of scientific and technological innovations that provide relatively easy, quick and affordable means of addressing key water management issues. Scientific knowledge and technological innovation can help open up previously closed decision‐making systems. Four of these tools are discussed in this paper: a) the opportunities afforded by virtual water trade; b) the silent revolution for beneficial use of groundwater; c) salt water desalination; and finally, d) the use of remote sensing and geographic information systems (GIS). Together these advances are changing the options available to address water and food security that have been predominant for centuries in the minds of most water decision‐makers.     

Risk-based Decision Process for Arsenic in Soils: Implications of Conservative Protocols

Making defensible risk-based decisions is a complex process that incorporates risk assessment into a risk management framework. Many site investigations require additional study, negotiations and/or actions for arsenic detected in soil samples, in many cases where no process related sources are identified and no other chemicals of concern are identified. Regulatory agencies develop guidance to standardize approaches to risk-based site investigations that focus on achieving "safe" concentrations. For arsenic, the action level is frequently in the "gray region", a U.S. Environmental Protection Agency (USEPA) term associated with a region of high uncertainty for risk management decisions in the "decision performance curve" associated with the data quality objective (DQO) process. Recognizing the conservative nature of the risk-based screening value for arsenic, approaches to enforce this level (or proof of comparability to natural background) may have numerous consequences including ineffective use of resources, stigmas on properties or actions at industrial or hazardous sites that are inconsistent with their regional setting. Florida has developed regulations and guidance on investigation of brownfield sites and has supported a study by the University of Florida (UF) to evaluate natural background concentrations in Florida soils. This paper discusses the sources of uncertainty near the soil cleanup target levels (SCTLs) in the Florida decision-making framework.     

Net drift in an atypical estuary,Long Island Sound

Long Island Sound is an estuary with two-layered flow at the eastern opening to the ocean and a salinity gradient of about 5 parts per thousand between the eastern and western extremes. Tidal currents, wind-driven circulation, and river inflow and fresh water influx are investigated as factors affecting the net drift. Current measurements in eastern Long Island Sound indicate that the tidal circulation features that predominate there do not normally affect the net drift at the New Haven dump site. Drifter returns and a numerical model indicate that seasonal prevailing winds seem to be the primary cause of the net drift in central Long Island Sound.     

Simulating the effects of Glen Canyon Dam releases on Grand Canyon river trips

The Shechter-Lucas wilderness use simulation model (WUSM) has been modified to quantify the effects of fluctuating Glen Canyon Dam releases on Grand Canyon river trips. The model now simulates changes in flow as predicted by the Streamflow Synthesis and Reservoir Regulation computer model for the Colorado River. This revised WUSM provides data on several flow-related effects, including delays at rapids, encounters with other parties, and the time available for visiting attraction sites. Nine flow alternatives are evaluated and compared. Analysis of these outputs provides useful information to the Bureau of Reclamation on how the operation of Glen Canyon Dam effects river trips through Grand Canyon National Park.