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81.
甘肃康县棘腹蛙种群资源调查与分析   总被引:2,自引:0,他引:2  
于2007年4月开始对甘肃陇南市康县分布的棘腹蛙种群数量及其栖息环境进行了为期7个月的初步调查。调查发现:从4月出蜇到8月繁殖高峰期间,种群内成体数量呈现较明显的增加,且距人类生活区越近,种群数量越小。综合调查和走访结果,可以确定棘腹蛙在该地区的种群数量已很少,且各个斑块内均为小种群;影响种群变化的主要因素是人类的活动带来直接和间接影响,如社区居民大量捕捉,农药化肥污染,冶矿企业废水、废渣污染等造成栖息生境退化或丧失;棘腹蛙的生存范围在逐渐地向远离人类活动区域的方向缩减。因此,需要加大保护力度,以确保甘肃南部的这一独特两栖类种群继续生存繁衍。  相似文献   
82.
刘海  魏伟  宋阳  潘杨 《环境科学》2023,44(11):6106-6115
为阐明霍邱县城西湖和城东湖沉积物重金属的环境容量,在城西湖和城东湖各采集了30件沉积物样品,运用综合环境容量指数法(PI),研究了城西湖和城东湖沉积物重金属环境容量特征及空间分布规律,估算了静态和动态环境容量,预测了近百年的变化趋势.结果表明,城西湖和城东湖沉积物中As、 Cd、 Cr、 Cu、 Hg、 Ni、 Pb和Zn含量均值未超过国家规定的土壤风险筛选值;城西湖和城东湖沉积物各重金属元素单项环境容量指数平均值大小分别为:Ni(0.81)相似文献   
83.
Wang C  Yang Y  Zhang Y 《Ambio》2011,40(1):78-87
This article uses a case study in Southeast China to demonstrate how the substantial changes in rural livelihoods have been driven by a combination of “pull” forces from external economic development, and “push” forces from local areas, leading to a shift in rural household economic activities: household outmigration and de-population of the countryside, changes in energy consumption, and most importantly, changes in land uses and eventually, ecological restoration. Such dramatic changes are becoming common across the Chinese countryside. It is pointed out that economic development has generally caused a deterioration of the environment at least at the early period of economic growth, but the positive impacts, especially in some ecosystem in rural areas, have become more apparent.  相似文献   
84.
汤家法  王沁 《灾害学》2015,(1):87-91
北川羌族自治县是2008年汶川8.0级地震的极重灾区之一。2013年7月8-12日,北川县境内普降暴雨,引起地质灾害事件大面积爆发。洪灾之后的灾情普查数据表明,县域内共有1 318个居民点受到各类地质灾害的威胁,这些地质灾害点的类型多样、分布广泛并且所造成的危害严重。根据灾情普查数据,按乡镇单元提取了各自的灾害点数量、受威胁面积、受威胁户数、受威胁人数、受威胁财产以及防治费用等6个指标,采用主成分分析方法来进行地质灾害灾情的综合评价,根据各乡镇的综合得分对乡镇的灾情进行了排序。这个评价结果较好地反映了各乡镇之间的灾情差异,也为上一级政府进行诸如制定乡镇社会经济发展指标、决定防灾减灾资金及技术力量的投向等行政决策提供了直接依据。  相似文献   
85.
通过对四川省沱江乡榨菜种植区土壤和榨菜中重金属的分布特征进行调查分析。结果表明,菜头叶茎中(Zd、Cr、(Zu、Hg、As、Pb6种重金属元素的含量一般随着土壤中此6种重金属元素含量的增加而增多,但分析样品中也有部分样点表现出异样趋势,通过分析此异常主要是人为活动影响造成的。菜头叶茎中对此6种重金属元素均表现出较高富集性,其中尤以cd最为严重,富集系数高达12.14。  相似文献   
86.
Both permit requirements and ecological assessments have been used to evaluate mitigation success. This analysis combines these two approaches to evaluate mitigation required under Section 404 of the United States Clean Water Act (CWA) and Section 10 of the Rivers and Harbors Act, which allow developers to provide compensatory mitigation for unavoidable impacts to wetlands. This study reviewed permit files and conducted field assessments of mitigation sites to evaluate the effectiveness of mitigation required by the US Army Corps of Engineers for all permits issued in Orange County, California from 1979 through 1993. The 535 permit actions approved during this period allowed 157 ha of impacts. Mitigation was required on 70 of these actions, with 152 ha of enhanced, restored, and created habitat required for 136 ha of impacts. In 15 permit actions, no mitigation project was constructed, but in only two cases was the originally permitted project built; the two cases resulted in an unmitigated loss of 1.6 ha. Of the remaining 55 sites, 55% were successful at meeting the permit conditions while 11% failed to do so. Based on a qualitative assessment of habitat quality, only 16% of the sites could be considered successful and 26% were considered failures. Thus, of the 126 ha of habitat lost due to the 55 projects, only 26 ha of mitigation was considered successful. The low success rate was not due to poor enforcement, although nearly half of the projects did not comply with all permit conditions. Mitigation success could best be improved by requiring mitigation plans to have performance standards based on habitat functions.  相似文献   
87.
/ Whereas habitat conservation plans (HCPs) have been intended to provide comprehensive environmental mitigation for multiple species, they often narrow in focus to one species and either one mitigation site or unspecified sites. We developed an indicators framework from which to rate land units for their ecological integrity, collateral values (nonbiological qualities that can improve conservation), and restoration and conservation opportunities. The ratings of land units were guided by the tenets of conservation biology and principles of landscape and ecosystem ecology, and they were made using existing physical and floral information managed on a GIS. As an example of how the indicators approach can be used for HCPs, the 29 legally rare species targeted by the Yolo County HCP were each associated with vegetation complexes and agricultural crops, the maps of which were used for rating some of the landscape indices. The ratings were mapped so that mitigation can be directed to the places on the landscape where the legally rare species should benefit most from conservation practices. The most highly rated land units for conservation opportunity occurred along streams and sloughs, especially where they emerged from the foothills and entered the Central Valley and where the two largest creeks intersected the Sacramento River flood basin. We recommend that priority be given to mitigation or conservation at the most highly rated land units. The indices were easy to measure and can be used with other tools to monitor the mitigation success. The indicators framework can be applied to other large-area planning efforts with some modifications.KEY WORDS: Ecosystem; Indicators; Landscape; Mitigation; Planning; Yolo County; California  相似文献   
88.
Minimisation is the top priority of the waste management hierarchy, which is one of the guiding principals for national solid waste management planning throughout the developed world. As such it should be encouraged as a means for reducing wastes which require treatment and disposal, whether they be household, commercial or industrial in source. This paper suggests that minimisation is not being given the necessary policy frameworks or legislation within which to develop in the UK, and questions whether minimisation is being afforded the respect and attention, from all levels, that is due the most preferable waste option according to the hierarchy. This theme is investigated by surveying the county councils of England as a representative sample of waste disposal authorities in England, and former waste regulation authorities. They are responsible for guiding local and district waste policy and are the regional waste planners in the UK. If they are not seriously taking on board the message of minimisation, then there is little chance that it will succeed without further legislative developments. Some 59% of English counties have a minimisation policy, whilst only 47% have participated in and supported a minimisation programme or trial within their region. The majority of these developments have occurred within the last three years, and 78% of counties who have participated in a programme have found it a successful venture. By 1999 79% of English counties will have been actively involved in a minimisation programme in their region, which is a positive scenario. This trend must continue if waste minimisation is to become the key theme of future sustainable waste management in the UK as was intended by declarations at the Rio '92 conference and in subsequent UK Government policy and strategy.  相似文献   
89.
概述了目前县(市)环保执法中存在的问题,提出了加强县(市)环保执法的对策。  相似文献   
90.
达县百节"水保生态园区"水土流失治理与生态环境保护   总被引:1,自引:1,他引:1  
张敏 《四川环境》2005,24(2):63-64,75
本文反映了严重的水土流失是导致达县百节河小流域生态环境恶化的主要原因。阐述了通过实施水土流失治理三大措施:工程措施、生物措施、农耕措施,有效地控制了水土流失等生态问题,极大地改善了当地生态环境,取得了显著的三大效益:经济效益、生态效益和社会效益。同时陈述了百节河小流域生态园区的建设特色:组织协调部门资金捆绑使用,集中投入:业主参与,责、权、利统一,投资渠道多元化,为水土保持和生态环境建设注入了生机与活力。  相似文献   
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