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161.
豫东黄河故道湿地鸟类自然保护区现状调查及生态保护规划 总被引:4,自引:0,他引:4
对豫东黄河故道湿地鸟类自然保护区现状进行了调查,并提出了生态保护规划。 相似文献
162.
163.
164.
Free atmospheric phosphine concentrations and fluxes in different wetland ecosystems, China 总被引:3,自引:0,他引:3
Han C Geng J Hong Y Zhang R Gu X Wang X Gao S Glindemann D 《Environmental pollution (Barking, Essex : 1987)》2011,159(2):630-635
Atmospheric phosphine (PH3) fluxes from typical types of wetlands and PH3 concentrations in adjacent atmospheric air were measured. The seasonal distribution of PH3 in marsh and paddy fields were observed. Positive PH3 fluxes are significantly related to high air temperature (summer season) and increased vegetation. It is concluded that vegetation speeds up the liberation of PH3 from soils, while water coverage might function as a diffusion barrier from soils or sediments to the atmosphere. The concentrations of atmospheric PH3 (ng m−3) above different wetlands decrease in the order of paddy fields (51.8 ± 3.1) > marsh (46.5 ± 20.5) > lake (37.0 ± 22.7) > coastal wetland (1.71 ± 0.73). Highest atmospheric PH3 levels in marsh are found in summer. In paddy fields, atmospheric PH3 concentrations in flourishing stages are higher than those in slowly growing stages. 相似文献
165.
Pérez DJ Lukaszewicz G Menone ML Camadro EL 《Environmental pollution (Barking, Essex : 1987)》2011,159(1):281-286
The wetland macrophyte Bidens laevis possesses suitable cytological characteristics for genotoxicity testing. To test its sensitivity as compared to terrestrial plants species currently in use in standardized assays, Methyl Methanesulfonate (MMS), N-ethyl-N-nitrosourea (ENU) and Maleic Hydrazide (HM) were used. On the other hand, the insecticide Endosulfan (ES) - an environmentally relevant contaminant - was assayed in seeds and two-month old plants. Mitotic Index (MI), frequency of Chromosome Aberrations in Anaphase-Telophase (CAAT) and frequency of Abnormal Metaphases (AM) were analyzed. MH, MMS and ENU caused a significant decrease of the MI. MMS was aneugenic whereas MH and ENU were both aneugenic and clastogenic. ES caused a significant concentration-dependent increase of total- and aneugenic-CAAT in roots and a significant high frequency of AM at high concentrations. Because of its sensitivity to mutagenic substances, B. laevis can be regarded as a reliable and convenient species for genotoxicity assays especially if aquatic contaminants are evaluated. 相似文献
166.
Exploring the capacity of radar remote sensing to estimate wetland marshes water storage 总被引:1,自引:0,他引:1
Grings F Salvia M Karszenbaum H Ferrazzoli P Kandus P Perna P 《Journal of environmental management》2009,90(7):2189-2198
This paper focuses on the use of radar remote sensing for water storage estimation in wetland marshes of the Paraná River Delta in Argentina. The approach followed is based on the analysis of a temporal set of ENVISAT ASAR data which includes images acquired under different polarizations and incidence angles as well as different environmental conditions (water level, precipitation, and vegetation condition). Two marsh species, named junco and cortadera, were monitored. This overall data set gave us the possibility of studying and understanding the basic interactions between the radar, the soil under different flood conditions, and the vegetation structure. The comprehension of the observed features was addressed through electromagnetic models developed for these ecosystems. The procedure used in this work to estimate water level within marshes combines a direct electromagnetic model, field work data specifically obtained to feed the model, the actual ASAR measurements and a well known retrieval scheme based on a cost function. Results are validated with water level evaluations at specific points. A map showing an estimation of the water storage capacity and its error in junco and cortadera areas for the date where the investigation was done is also presented. 相似文献
167.
A multiple purpose wetland inventory is being developed and promoted through partnerships and specific analyses at different scales in response to past uncertainties and gaps in inventory coverage. A partnership approach is being promoted through the Ramsar Convention on Wetlands to enable a global inventory database to be compiled from individual projects and analyses using remote sensing and GIS. Individual projects that are currently part of this global effort are described. They include an analysis of the Ramsar sites' database to map the distribution of Ramsar sites across global ecoregions and to identify regions and wetland types that are under-represented in the database. Given the extent of wetland degradation globally, largely due to agricultural activities, specific attention is directed towards the usefulness of Earth Observation in providing information that can be used to more effectively manage wetlands. As an example, a further project using satellite data and GIS to quantify the condition of wetlands along the western coastline of Sri Lanka is described and trends in land use due to changes in agriculture, sedimentation and settlement patterns are outlined. At a regional scale, a project to map and assess, using remote sensing, individual wetlands used for agriculture in eight countries in southern Africa is also described. Land cover and the extent of inundation at each site is being determined from a multi-temporal data set of images as a base for further assessment of land use change. Integrated fully within these analyses is the development of local capacity to plan and undertake such analyses and in particular to relate the outcomes to wetland management and to compile data on the distribution, extent and condition of wetlands globally. 相似文献
168.
Polycyclic aromatic hydrocarbons (PAHs) concentrations were determined in sediments and three types of wetland plants collected from the intertidal flats in the Chongming wetland. The concentration of total PAHs in sediments ranged from 38.7 to 136.2 ng g−1. Surface sediment concentrations were higher in regions with plant cover than in bare regions. Rhizome-layer sediments (56.8-102.4 ng g−1) contained less PAHs than surface sediments (0-5 cm). Concentrations of PAHs in plant tissues ranged from 51.9 to 181.2 ng g−1, with highest concentrations in the leaves of Scirpus. Most of the PAHs in the leaves and other plant tissues were low molecular weight compounds (LMW, 2-4 rings), and a similar distribution pattern of PAHs in different types of plants was also observed. Source analysis indicated that plants and sediments both came from pyrogenic sources, but plants had additional petroleum contamination. The low ratio of benzo[a]anthracene over chrysene suggests that the wetland PAHs came mainly from long-distance atmospheric transportation. Significant bioaccumulation of PAHs from the sediments into plants was not observed for high molecular weight PAHs (HMW, 5-6 rings) in Chongming wetland. The small RCFs (root concentration factor from sediments) for HMW PAHs and large RCFs for LMW PAHs suggested that roots accumulated LMW PAHs selectively from sediments in Chongming wetland. 相似文献
169.
Wise Use of Wetlands: Current State of Protection and Utilization of Chinese Wetlands and Recommendations for Improvement 总被引:2,自引:0,他引:2
Wetland protection and utilization sometimes appear to be in conflict, but promoting the wise use of wetlands can solve this
problem. All countries face the challenge of sustainable development of wetlands to a greater or lesser extent, but the problem
is especially urgent in developing countries, such as China, that want to accelerate their economic development without excessive
environmental cost. Chinese wetlands contribute greatly to economic development, but improper use of these natural resources
has endangered their existence. It is thus necessary to provide scientific guidance to managers and users of wetlands. In
this paper, we analyze the present status of Chinese wetland protection and utilization, and discuss problems in six categories:
a lack of public awareness of the need for wetland protection; insufficient funding for wetland protection and management;
an imperfect legal system to protect wetlands; insufficient wetland research; lack of coordination among agencies and unclear
responsibilities; and undeveloped technologies related to wetland use and protection. The wise use of Chinese wetlands will
require improvements in four main areas: increased wetland utilization research, scientific management of wetland utilization,
improved laws and regulations to protect wetlands, and wider dissemination of wetland knowledge. Based on these categories,
we propose a framework for the optimization of wetland use by industry to provide guidance for China and other countries that
cannot sacrifice economic benefits to protect their wetlands. 相似文献
170.
In this work, the potential for natural attenuation (NA) of Cr(VI) is evaluated for sub-wetland ground water at a chromium-contaminated site in Connecticut, incorporating the experimental findings of previous work at the site. Experimental data is assessed through long-term attenuation capacity calculations and modeling, which incorporates statistical uncertainty of parametric values. The NA evaluation yielded the following results: (1) Significant increases in Cr(VI) concentration and extremely long chromium source dissolution timeframes are required to exceed the attenuation capacity of the sub-wetland region soils studied in this work; and (2) Based on the 1-D transport modeling and incorporating input parameter uncertainty, there is an approximately 92% and 98% probability that the applicable regulatory criteria will not be exceeded at Point C, near a river which serves as the receptor, for the cases of (1) sorption of Cr(VI) only and (2) pseudo first order disappearance of Cr(VI) from the aqueous phase only, respectively. 相似文献