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71.
A conceptual framework for assessing cumulative impacts on the hydrology of nontidal wetlands 总被引:2,自引:0,他引:2
Thomas C. Winter 《Environmental management》1988,12(5):605-620
Wetlands occur in geologic and hydrologic settings that enhance the accumulation or retention of water. Regional slope, local relief, and permeability of the land surface are major controls on the formation of wetlands by surface-water sources. However, these landscape features also have significant control over groundwater flow systems, which commonly play a role in the formation of wetlands. Because the hydrologic system is a continuum, any modification of one component will have an effect on contiguous components. Disturbances commonly affecting the hydrologic system as it relates to wetlands include weather modification, alteration of plant communities, storage of surface water, road construction, drainage of surface water and soil water, alteration of groundwater recharge and discharge areas, and pumping of groundwater. Assessments of the cumulative effects of one or more of these disturbances on the hydrologic system as related to wetlands must take into account uncertainty in the measurements and in the assumptions that are made in hydrologic studies. For example, it may be appropriate to assume that regional groundwater flow systems are recharged in uplands and discharged in lowlands. However, a similar assumption commonly does not apply on a local scale, because of the spatial and temporal dynamics of groundwater recharge. Lack of appreciation of such hydrologic factors can lead to misunderstanding of the hydrologic function of wetlands within various parts of the landscape and mismanagement of wetland ecosystems. 相似文献
72.
盐城市湿地园林建设初探 总被引:1,自引:0,他引:1
湿地园林是以湿地为对象的园林形式,为现代园林的一个组成部分,是利用现代园林建设和生态学原理,对湿地生态系统的保护、重建和恢复,艺术地再现自然湿地景现.在此,以湿地园林为研究对象,分析国内外湿地园林的发展概况,论述盐城市湿地园林建设的现状以及存在的问题,运用生态学和现代园林建设理论对盐城市湿地园林的建设进行初步的探索,较为详细的阐述其发展的规划目标以及建设的思路与对策,进一步强调湿地园林在建设城市大园林、改善生态环境方面的作用,并对湿地园林的未来进行展望. 相似文献
73.
74.
鄱阳湖湿地管理对策研究 总被引:8,自引:0,他引:8
本文分析和研究了鄱阳湖湿地损失的原因和管理现状,提出了鄱阳湖湿地可持续发展的管理策略。 相似文献
75.
四川若尔盖湿地退化成因分析与对策研究 总被引:8,自引:0,他引:8
本文以四川若尔盖湿地为研究对象,主要贡献为:(1)应用卫星遥感数据对若尔盖湿地退化趋势进行了科学定量分析;(2)采用博弈论的分析方法对相关利益主体进行解析,在寻求利益均衡点的基础上,提出湿地保护性开发对策;(3)针对湿地退化因素提出了多种对策,其中生态移民的设想对保护四川若尔盖湿地较为适宜;(4)提出了“禁止-限制-发展”的产业结构调整思路,以指导湿地的合理开发利用。 相似文献
76.
随着非点源污染在水环境污染中所占比例越来越重,治理非点源污染问题迫在眉睫。本文在讨论了各种污水治理技术的前提下,提出了自己关于控制非点源污染的治理技术。 相似文献
77.
78.
Inamdar S 《Environmental monitoring and assessment》2007,133(1-3):347-363
Storm event exports of dissolved were explored for multiple events in the Point Peter Brook watershed (PPBW), a glaciated, forested watershed located in Western
New York, USA. Investigations were performed across four catchments (1.6–696 ha) with varying topography and the extent of
surface-saturated areas. While wetland and riparian waters were important sources of during non-storm periods, throughfall and litter leachate were the dominant contributors of during storm events. Ammonium concentrations in catchment discharge displayed a sinusoidal seasonal pattern with a maximum
during early spring (March) and a minimum in late summer (August–September). Storm event concentrations of in streamflow were much greater than baseflow values and showed a consistent temporal pattern with an increase in concentrations
on the hydrograph rising limb, a peak at or before the discharge peak, followed by a decline in concentrations. Storm event
patterns of DON were similar to while the patterns of differed from for the summer and fall events. The storm event expression of was attributed to throughfall and throughfall-mediated leaching of the litter layer. The reactive behavior of precluded its use in an end member mixing model (EMMA) for predicting streamflow concentrations. While concentrations of
in precipitation and streamflow were high for the spring events, exports of in streamflow were highest for the large and intense storm events. Baseflow concentrations increased with the percent wetland/saturated area in the catchment but the same trend did not hold for storm-event
concentrations. 相似文献
79.
应用模糊综合-加权模型,以及温州市3个典型湿地沉积物中7种重金属含量数据,对温瑞塘河重金属污染进行评价。模糊综合评价结果表明,温州市居民区河流三垟湿地沉积物属于Ⅴ级重金属污染水平,主要污染元素为Zn和Cd;山前上游河段卧龙河沉积物为Ⅲ级污染,主要污染物是Cd。工业区河流牛桥底河沉积物虽然也是Ⅴ级,但是Cu、Cr、Ni、Zn和Cd 5种重金属污染分值为1.0,小于前2个典型河段的1.2和3.3。内梅罗指数法和潜在生态危害系数法评价结果显示,沉积物的重金属污染程度为牛桥底河三垟湿地卧龙河,这与模糊综合评价结果相符。 相似文献
80.
Marek MV Janouš D Taufarová K Havránková K Pavelka M Kaplan V Marková I 《Environmental pollution (Barking, Essex : 1987)》2011,159(5):1035-1039
By comparing five ecosystem types in the Czech Republic over several years, we recorded the highest carbon sequestration potential in an evergreen Norway spruce forest (100%) and an agroecosystem (65%), followed by European beech forest (25%) and a wetland ecosystem (20%). Because of a massive ecosystem respiration, the final carbon gain of the grassland was negative. Climate was shown to be an important factor of carbon uptake by ecosystems: by varying the growing season length (a 22-d longer season in 2005 than in 2007 increased carbon sink by 13%) or by the effect of short- term synoptic situations (e.g. summer hot and dry days reduced net carbon storage by 58% relative to hot and wet days). Carbon uptake is strongly affected by the ontogeny and a production strategy which is demonstrated by the comparison of seasonal course of carbon uptake between coniferous (Norway spruce) and deciduous (European beech) stands. 相似文献