浅析珠三角地区有机废气治理技术的开发应用

珠江三角洲地区大气污染最明显的特点就是臭氧浓度的升高导致大气氧化性增强,而挥发性有机化合物(VOCs)和氮氧化物是大气臭氧生成的重要前体物。珠三角地区工业体系发达,VOCs的生产及使用企业众多,由于VOCs的种类繁多,性质各异,排放条件多样,目前已经形成了一系列的VOCs废气实用治理技术。     

Daily Bank Erosion Rates in the Lower Yellow River Before and After Dam Construction

During the period of water impoundment and sediment detention of the Sanmenxia Reservoir, riverbank erosion processes played a key role in the channel evolution of the Lower Yellow River (LYR). However, research into bank erosion rates of the LYR has been neglected due to the lack of direct field monitoring. In this study, an indirect method is proposed to determine bank erosion rates at daily time scales by outlining a detailed calculation procedure using measured hydrological data. A total of 810 data points of daily bank erosion rates before and after the construction of Sanmenxia Dam was calculated at seven hydrometric sections along the LYR, with the corresponding values of the bank stability coefficient and the width‐to‐depth ratio also being calculated. Empirical relations were then developed to estimate the daily bank erosion rates, using these parameters at the sections. Temporal and spatial variability in daily bank erosion rates in the LYR before and after dam construction were also investigated, revealing that: (1) the bank erosion rates had a mean value of 16.7‐29.1 m/day in the braided reach, with a maximum value of 290.0 m/day, while they were relatively low in the meandering reach, with a mean value of 2.5 m/day; (2) the erosion rates before dam construction were slightly greater than those after dam construction, with the difference reaching 5‐10 m/day in the braided reach, decreasing in the transitional reach gradually, and being slight in the meandering reach.     

淮河流域新型城镇化水平的空间差异及其影响因素分析

以淮河流域31个地级市为研究对象,从人口、经济、生活和环境四个方面构建了新型城镇化水平的综合评价指标体系,利用熵值法对其综合城镇化水平及其子系统水平进行评价.结果表明,淮河流域地区新型城镇化发展水平存在较强的空间依赖性,即一个地区城镇化水平的提高通过空间溢出促进周边地区的城镇化发展,地区产业结构的变化是决定其新型城镇化水平的主要因素,尤其是第三产业发展对其影响极大.     

西安市灞河流域水环境现状分析及治理对策

基于大量的技术资料和监测数据,对西安市灞河流域的水环境进行了全面系统的分析,指出了面临的问题及其成因.在此基础上提出了灞河流域水环境治理的新思路、新方法,为流域的综合治理工作提供借鉴.     

龙江县水环境保护基本思路

介绍了龙江县境内的江河流域、泡沼、泉沟及水利工程概况。提出了对一、二、三类河流的水环境保护,水库的改造与利用,泡沼水域的涵养和利用。并提出了相应的保障措施。     

Use of watershed characteristics to select control streams for estimating effects of metal mining wastes on extensively disturbed streams

Impacts of sediments and heavy metals on the biota of streams in the copper-mining district of southwestern Montana were examined by comparing aquatic communities of impacted streams with those of control streams. Control streams were chosen through the use of a technique that identifies similar streams based on similarities in their watershed characteristics. Significant differences between impacted and control sites existed for surface substrate, riparian vegetation, and the number of macroinvertebrate taxa. These results revealed that: (a) chemical and physical habitats at the impacted sites were disrupted, (b) the presence of trout was an inadequate measure of ecological integrity for these sites, and (c) watershed classification based on a combination of mapped terrestrial characteristics provided a reasonable method to select control sites where potential control sites upstream and downstream were unsuitable.     

NITROGEN AND PHOSPHORUS IN SURFACE WATERS OF THE UPPER COLORADO RWER BASIN1

ABSTRACT: As part of a basinwide water-quality study, nitrogen and phosphorus data for the Upper Colorado River Basin from the Colorado-Utah State line to the Continental Divide were analyzed for spatial distributions, concentrations associated with various land uses, and temporal trends. Nitrogen and phosphorus concentrations generally increased in a downstream direction. Some nutrient concentrations were elevated at some sites in the upper parts of the basin in areas influenced by increasing urbanization. Sites were grouped according to land use and site type, and median nutrient concentrations were compared among groups. Sites within the agricultural areas of the basin generally had the highest concentrations of nitrogen and phosphorus; concentrations for main-stem, tributary, and urbanization sites were slightly lower than for the agricultural sites. Background sites, or sites with minimal land-use impacts, had very low median nutrient concentrations. Several sites with long-term data were analyzed for temporal trends in concentrations. Several statistically significant downward trends of low and moderate magnitude were observed for nitrogen and phosphorus species. No upward trends were observed in the data at any site.     

Local Area Quotas for Industrial Emissions along Reaches of the Pearl River in Guangdong

There is an obvious departure from the regional equilibrium of developments between the upper and lower reaches of the Pearl River in Guangdong, which resulted in ＂the effects of contra-geography-grads development＂. It is mainly because the upriver mountainous areas have been deeply stuck in industrialization delay and marginalization plights, so that nearly 40 million local people have conceived a dream to get rid of ＂the vicious circle of poverty＂ by speeding up industrial development. But the problem is that such industrialization efforts on a large scale in mountainous areas are encountering the bottleneck of environmental capacity that strictly limits industrial emissions along the upper reaches of any water system. As a solution, an institutional arrangement called ＂the Local Area Quotas for Industrial Emissions along the Pearl River＂ is put forward supposed to give corresponding compensation to the rights of industrial development yielded by some areas with lower environmental capacity through the distribution and trading of IDQs.     

珠江上游少数民族县域经济活动的累积环境效应研究--以贵州三都水族自治县为例

为了探索珠江上游少数民族区域经济活动的累积环境效应与生态安全，我们选择三都水族自治县作为定位研究基地．对建国以来区域内经济活动变迁进行历史、现状研究和综合评估，揭示历史时期发展政策、发展模式、重大经济活动等人为扰动因素在区域生态环境系统退化过程中的作用．评估少数民族经济活动的累积环境效应与生态安全。     

19世纪是我国特大暴雨洪水发生期

本文用大量资料,论述了我国七个江河历史首位洪水均发生在19世纪。而且,洪水泛滥使得平原地区的水系迁移、湖泊淤缩极为严重。同时,存洪水年前后,伴随着一系列寒冷、干旱的气候异常现象。