长江上游森林植被变化对削洪减灾功能的影响

长江上游具有形成暴雨洪水的地形与气候条件，森林植被削洪减灾功能的提高必须着眼于森林植被—土壤生态系统结构的改善，削洪减灾功能的提高是通过林冠层、枯枝落叶层和土壤层对雨水的截留拦蓄作用实现的。研究区森林植被—土壤生态系统区域差异明显，不同地区该系统林冠层、枯枝落叶层和土壤层的最大截持水量不同，该系统削洪减灾功能的大小不仅与降雨特点有关，而且与系统各水文层前期持水量有关。在连续长时间暴雨情况下，森林植被—土壤生态系统除对第一次洪峰有削减作用外，对后续暴雨洪水的削减作用不明显，甚至会使洪峰增高。根据宜昌站30d洪水量的地区组成和森林植被—土壤生态系统截留持水功能的特点，提出了长江上游森林植被恢复、重建与保护的宏观调控对策。     

NUTRIENT CONCENTRATIONS IN WASTEWATER TREATMENT PLANT EFFLUENTS,SOUTH PLATTE RWER BASIN1

ABSTRACT: Accurate data about nutrient concentrations in wastewater treatment plant effluents are needed for river basin water-quality studies. As part of the U.S. Geological Survey's National Water-Quality Assessment Program in the South Platte River Basin, nutrient data were requested from 31 wastewater-treatment plants located in the basin. This article describes the types of nutrient data available from the plants, examines the variability of effluent nutrient concentrations, and discusses methods for estimation of nutrient concentrations where data are lacking. Ammonia was monitored at 88 percent of the plants, nitrite plus nitrate was monitored at 40 percent of the plants, and organic nitrogen and phosphorus were monitored at less than 25 percent of the plants. Median total nitrogen concentrations and median total phosphorus concentrations were small compared to typical literature estimates for wastewater-treatment plants with secondary treatment. Nutrient concentrations in effluent from wastewater-treatment plants varied widely between and within plants. For example, ammonia concentrations varied as much as 5 mg/L during a day, as much as 10 mg/L from day to day, and as much as 30 mg/L from summer to winter within a plant. In the South Platte River Basin, estimates of median annual ammonia and nitrite plus nitrate concentrations can be improved based on plant processes; and nitrite plus nitrate and organic nitrogen concentrations can be estimated based on ammonia concentrations. However, to avoid large estimation errors, more complete nutrient data from wastewater-treatment plants are needed for integration into river basin water quality studies. The paucity of data hinders attempts to evaluate the relative importance of point source and nonpoint source nutrient loadings to rivers.     

论灾害管理与经济发展的辩证关系

本文以ＡＢＣ分类法说明了减轻地震灾害的重要意义，指出了地震灾害绝对损失数额一般会随社会经济发展而逐渐增大这一客观事实。文中提出了表达地震灾害危险性、防抗灾工程投资和社会经济发展关系的一般数学模型，对灾害管理与经济发展的辩证关系进行了讨论。     

山东省城市灾害与减灾对策

通过分析山东省城市化现状以及带来的城市灾害特点，总结出适合山东特点的城市减灾对策。     

The economics of tire remanufacturing

The world market for tires is described to identify the current material flow from raw materials to tires and the used tire disposal problem. Then, I describe the value-adding operations in the tire production process and in the tire retreading process. Once retreading is identified as the only recovery alternative that maximizes tire utilization, I explain why heat generation is the only recovery alternative, when retreading is not technically feasible. The economic values of heat generation in electric plants and in cement kilns are discussed. The paper culminates with the case of retreading, the tire remanufacturing process and the recommendation of a simple decision rule for selecting the number of times a tire should be retreaded to maximize its utilization.     

旱涝灾害的一些基本问题初探

首先就旱涝灾害对人类的作用进行了分析，认为它影响范围最大，危害程度最深．其次．对旱涝灾害的成因、确定旱涝灾害的定量指标以及评估旱涝灾害的指标体系进行分析探讨；最后对国内防御旱涝灾害的能力做了总体评价，并对其所采取的预防，救抗灾措施等进行分析．     

SCR反应塔入口段烟气速度场的数值模拟

使用商业计算软件CFX5．7．1，采用标准k-ε湍流模型，模拟了SCR脱硝反应塔入口段烟气速度场，并分析比较了导流板对烟气速度场的影响及均匀SCR反应塔进口处烟气速度场的作用。     

海啸预警系统及我国海啸减灾任务

2004年12月26日印度洋海啸引发了新一轮海啸预警系统的研究。简述了地震海啸预警的原理，分析了海啸数值模拟的一些基本方法，综述了目前世界上多个国家海啸预警系统的建设情况，通过对我国海啸灾害研究现状的分析，明确了我国当前海啸防灾减灾工作的主要任务。     

城市绿地系统建设与城市减灾防灾

自然灾害往往给城市造成重大损失.在城市综合防灾减灾体系中,城市绿地系统占有十分重要的位置.城市绿地系统是城市规划和建设中的重要组成部分,它不仅具有美化城市环境、净化空气、平衡城市生态系统、为城市居民提供休憩游乐场所等作用,同时还具有防震、防火、防洪、减轻灾害的功能.从城市绿地的定义和分类人手,分析了城市绿地系统在城市综合防灾减灾中的作用,并通过介绍和分析日本防灾公园的规划建设,探讨了城市避灾绿地系统的规划方法.     

NUTRIENT CONCENTRATION CRITERIA AND CHARACTERIZATION OF PATTERNS IN TROPHIC STATE FOR RIVERS IN HETEROGENEOUS LANDSCAPES1

ABSTRACT: A method is demonstrated for the development of nutrient concentration criteria and large scale assessment of trophic state in environmentally heterogeneous landscapes. The method uses the River Environment Classification (REC) as a spatial framework to partition rivers according to differences in processes that control the accrual and loss of algae biomass. The method is then applied to gravel bed rivers with natural flow regimes that drain hilly watersheds in New Zealand's South Island. An existing model is used to characterize trophic state (in terms of chlorophyll a as a measure of maximum biomass) using nutrient concentration, which controls the rate of biomass accrual, and flood frequency, which controls biomass loss. Variation in flood frequency was partitioned into three classes, and flow data measured at 68 sites was used to show that the classes differ with respect to flood frequency. Variation in nutrient concentration was partitioned at smaller spatial scales by subdivision of higher level classes into seven classes. The median of flood frequency in each of the three higher level classes was used as a control variable in the model to provide spatially explicit nutrient concentration criteria by setting maximum chlorophyll a to reflect a desired trophic state. The median of mean monthly soluble reactive phosphorus and soluble inorganic nitrogen measured at 68 water quality monitoring sites were then used to characterize the trophic state of each of the seven lower level classes. The method models biomass and therefore allows variation in this response variable to provide options for trophic state and the associated nutrient concentrations to achieve these. Thus it is less deterministic than using reference site water quality. The choice from among these options is a sociopolitical decision, which reflects the management objectives rather than purely technical considerations.