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91.
Ryan C. Schwartz Peter J. Deadman Daniel J. Scott Linda D. Mortsch 《Journal of the American Water Resources Association》2004,40(3):647-662
ABSTRACT: Recent research that couples climate change scenarios based on general circulation models (GCM) with Great Lakes hydrologic models has indicated that average water levels are projected to decline in the future. This paper outlines a methodology to assess the potential impact of declining water levels on Great Lakes waterfront communities, using the Lake Huron shoreline at Goderich, Ontario, as an example. The methodology utilizes a geographic information system (GIS) to combine topographic and bathymetric datasets. A digital elevation surface is used to model projected shoreline change for 2050 using water level scenarios. An arbitrary scenario, based on a 1 m decline from February 2001 lake levels, is also modeled. By creating a series of shoreline scenarios, a range of impact and cost scenarios are generated for the Goderich Harbor and adjacent marinas. Additional harbor and marina dredging could cost as much as CDN $7.6 million. Lake freighters may experience a 30 percent loss in vessel capacity. The methodology is used to provide initial estimates of the potential impacts of climate change that can be readily updated as more robust climate change scenarios become available and is adaptable for use in other Great Lakes coastal communities. 相似文献
92.
93.
94.
Chansheng He 《Journal of the American Water Resources Association》1997,33(5):1055-1068
ABSTRACT: Growing interest in agricultural irrigation in the Great Lakes basin presents an increasing competition to other uses of Great Lakes water. This paper, through a case study of the Mud Creek Irrigation District in the Saginaw Bay basin, Michigan, evaluates the potential hydrologic effects of withdrawing water for agricultural irrigation to the Great Lakes. Crop growth simulation models for corn, soybeans, dry beans, and the FAO Penman method were used to estimate the difference in evapotranspiration rates between irrigated and nonirrigated identical crops, based on climate, soil, and management data. The simulated results indicate that an additional 70–120 mm of water would be evapotranspirated during the growing season from irrigated crop fields as compared to nonirrigated identical plantings. Dependent upon the magnitude of irrigation expansion, an equivalent of about 1 to 5 mm of water from Lakes Huron-Michigan could be lost to the atmosphere. If agricultural irrigation further expands in the entire Great Lakes basin, the aggregated potential of water loss to the atmosphere through ET from all five Great Lakes would be even greater. 相似文献
95.
Martin H. David Erhard F. Joeres Eric D. Loucks Kenneth W. Potter Stuart S. Rosenthal 《Journal of the American Water Resources Association》1988,24(1):141-148
ABSTRACT: Water level fluctuations of the Great Lakes often have created regional controversies among the states and Canadian provinces that share this vast resource. Even though the 100-year range of their water levels is only four to five feet, episodes of high and low Great Lakes water levels have been a recurring problem throughout the twentieth century. The possibility of increased diversion and consumptive use has exacerbated the existing conflicts over how to manage this water resource. A research project evaluated the effects of interbasin diversion on the Great Lakes system and on the industries that depend on the maintenance of historical water levels, namely hydropower and commercial navigation. The simulation approach employed in this research and some of the important findings are presented. The approach is similar to that used in recent government studies of Great Lakes water level regulation. Several significant modifications were made specifically addressing the diversion issue. Aggregate annual impacts to hydropower and shipping resulting from a diversion of 10,000 cubic feet per second were found to vary from 60 to 100 million dollars. Increases in impacts as a function of diversion rate are nonlinear for the navigation industry. 相似文献
96.
97.
Model simulations of dissolved oxygen characteristics of Minnesota lakes: Past and future 总被引:1,自引:0,他引:1
A deterministic, one-dimensional, unsteady numerical model has been developed, tested, and applied to simulate mean daily
dissolved oxygen (DO) characteristics in 27 lake classes in the state of Minnesota. Reaeration and photosynthesis are the
oxygen sources, while respiration, sedimentary, and biochemical water column oxygen demand are the sinks of oxygen in the
model. The lake classes are differentiated by surface area (A
s), maximum depth (H
max), and trophic status expressed as Secchi depth (Z
s). Because lake stratification is most important to lake oxygen dynamics, simulated DO characteristics are plotted in terms
of a stratification parameterA
s/H
max
0.25
and Secchi depthZ
s. Simulations provide DO profiles on a daily time scale. Specific DO characteristics of ecological and environmental interest
are epilimnetic DO, hypolimnetic DO, DO gradient from surface to bottom, and DO minima and maxima. Specific results are as
follows: Simulated mean daily and weekly DO values in the epilimnion of all lakes for both past and future climate scenarios
are near saturation over the summer season. Hypolimnetic DO values depend strongly on lake morphometry, trophic status, and
time throughout the summer season. Future climate conditions are specified as the historical records from 1955 to 1979, adjusted
(monthly) by the 2 × CO2 GISS model output to account for doubling of atmospheric CO2. With this climate change, weekly averaged epilimnetic DO is projected to drop by less than 2 mg/liter, and will remain above
7 mg/liter throughout the open water season. The hypolimnetic DO reductions after climate change are on the order of 2–8 mg/liter.
Periods of anoxia are longer by as much as 80 days. Those changes would alter water quality dynamics in lakes and have a profound
effect on lake ecosystems including indigenous fishes. The results presented are useful for evaluating environmental management
options. 相似文献
98.
本文全面分析了珠江三角洲水土资源开发利用的现状,阐明了水土资源开发利用中出现的环境问题及原因。因此,提出了该地区水土资源进一步合理开发利用的对策。 相似文献
99.
三峡工程移民卫生防病现状调查报告 总被引:3,自引:0,他引:3
本文报道了三峡工程四川库区移民安置区的自然疫源性疾病,虫媒传染病,介水传染病和地方病等的目前流行态势和环境卫生状况;预测了移民过程中地潜在危险,针对存在的问题,指出加强移民的卫生防病,对保护移民健康,保障移民工作顺利进行了是十分重要的。 相似文献
100.
Arnold Gurtner-Zimmermann 《Environmental management》1996,20(4):449-459
This article presents a model of remedial action planning, which includes four key variables that determine progress in plan development and implementation and explain the differing level of achievement in individual sites. The model is illustrated by the characteristics and developments of four remedial action plan (RAP) processes (Lower Green Bay and Fox River, Collingwood Harbour, Spanish Harbour, and the Metro Toronto and Region RAPs). Differences in the local context of the plans have, to a significant degree, predisposed individual planning and implementation experiences. Local context includes three variables, namely geographical—technical and sociopolitical aspects and the previous history of water pollution management in the area. RAP precursors are a necessary precondition for progress in planning and substantive achievements. While there is a tendency that most geographically focused RAPs in administratively simple areas accomplish most, the motivation and political clout of RAP participants are strongly intervening factors. Resource input from upper levels of government, in particular financial commitment for plan implementation, is the fourth necessary ingredient for progress due to the RAPs' weak regulatory and institutional framework. Unfortunately, upper levels of government have shown widespread reluctance to lead in remedial action planning. This was only in part offset by local commitment and support for RAP and its cause. 相似文献