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71.
为描述草海湿地DOM(dissolved organic matter,溶解性有机物)荧光特征,探究其对PFASs(per-and polyfluoroalkyl substances,全氟及多氟化合物)环境行为造成的影响,利用超高效液相色谱-质谱联用技术和三维荧光光谱技术,结合平行因子分析,开展DOM光谱学特性研究,分析ρ(DOM)与ρ(PFASs)的相关关系.结果表明:①草海湿地中共解析出3类4种荧光组分,分别为类腐殖酸[λEx(360 nm)/λEm(450 nm)]、长波段腐殖质[λEx(400 nm)/λEm(510 nm)]、类富里酸[λEx(330 nm)/λEm(400 nm)]和类色氨酸[λEx(280 nm)/λEm(350 nm)],贡献率分别为48.6%、23.6%、22.9%和4.9%,其中类腐殖质总贡献率高达72.2%.在农业生产和人类活动的影响下,总荧光强度大致呈现从入湖区向出湖区逐渐降低、湖心区略高的趋势.②在草海湿地表层水中共检出了12种PFASs,ρ(PFASs)为233.18 ng/L,每种平均值为19.43 ng/L,PFBA(perfluorobutanoic acid,全氟丁酸)是主要污染物;草海湿地入湖区点源影响特征明显,生活污水和农业生产用水是主要的潜在污染源.③相关性分析结果显示,各荧光组分含量均与ρ(PFBS)(potassium perfluorobutanesulfonate,全氟丁烷磺酸)负相关;类色氨酸含量与ρ(PFHpA)(perfluororoheptanoic acid,全氟庚酸)负相关,与ρ(PFTriDA)(perfluorotrideanoic acid,全氟十三酸)则显著正相关.研究显示,草海湿地水体腐殖化程度高,外源特征明显,共检出12种PFASs,初步揭示了草海湿地水环境中ρ(DOM)与ρ(PFASs)的相关关系,其受水体性质及化合物结构等差异的影响,有待进一步开展深入研究. 相似文献
72.
20世纪后半叶,三江平原进行了大规模的开发,虽然为国家粮食供应做出了贡献,但大片湿地遭到破坏。现在为拯救中国这块唯一保持原始面貌的淡水湿地,当地政府制定了具体的三江平原湿地保护条例。建立了国家级的自然保护区,保护三江平原湿地终于纳入了政府工作的议事日程,为了加深人们对保护三江平原湿地意义的认识,本文从分析三江平原湿地的自然状况、三江湿地开发对当地生态和经济的影响入手,论述了三江平原湿地保护的重要意义和应采取的具体措施。 相似文献
73.
Spartina alterniflora was transplanted into dieback areas of a salt marsh in southeast Louisiana at two elevations (ambient and +30 cm) with and
without macro- (N, P, and K) and micronutrient (Fe, Mn, Cu, and Zn) additions to determine if transplant success is dependent
on increasing elevation or nutrients.Spartina alterniflora transplanted into elevated plots had more than twice the above- and belowground biomass as compared to nonelevated plots
after three months of growth. Additionally, there was significantly more vegetative reproduction (greater culm density and
number of newly produced culms) in elevated plots as compared to plots at ambient elevation. Macronutrient additions increased
culm densities only in elevated plots.Spartina alterniflora transplanted into nonelevated plots had lower survival rates even when transplants received nutrient additions. These results
suggest thatS. alterniflora may be transplanted successfully into degraded salt-marsh areas if elevation is increased. The addition of nutrients without
a concomitant increase in elevation is not sufficient for transplant success. 相似文献
74.
Coal companies are reluctant to include wetland development in reclamation plans partly due to a lack of information on the
resulting characteristics of such sites. It is easier for coal companies to recreate terrestrial habitats than to attempt
experimental methods and possibly face significant regulatory disapproval. Therefore, we studied a young (10 years) wetland
on a reclaimed surface coal mine in southern Illinois so as to ascertain soil and water characteristics such that the site
might serve as a model for wetland development on surface mines. Water pH was not measured because of equipment problems,
but evidence (plant life, fish, herpetofauna) suggests suitable pH levels. Other water parameters (conductivity, salinity,
alkalinity, chloride, copper, total hardness, iron, manganese, nitrate, nitrite, phosphate, and sulfate) were measured, and
only copper was seen in potentially high concentrations (but with no obvious toxic effects). Soil variables measured included
pH, nitrate, nitrite, ammonia, potassium, calcium, magnesium, manganese, aluminum, iron, sulfate, chloride, and percent organic
matter. Soils were slightly alkaline and most parameters fell within levels reported for other studies on both natural and
manmade wetlands. Aluminum was high, but this might be indicative more of large amounts complexed with soils and therefore
unavailable, than amounts actually accessible to plants. Organic matter was moderate, somewhat surprising given the age of
the system. 相似文献
75.
F. Douglas Shields 《Journal of the American Water Resources Association》1991,27(3):527-536
ABSTRACT: Stability of vegetated and bare riprap revetments along a Sacramento River reach during the flood of record was assessed. Revetment damages resulting from the flood were identified using records provided by the U.S. Army Corps of Engineers and verified by contacts with local interests. Vegetation on revetments along a 35.6-mile reach was mapped using inspection records and stereo interpretation of aerial phoths taken shortly before and after the flood. A follow-up field inspection was conducted in September 1989. Revetment age, material, bank curvature, vegetation, and damage were mapped from a boat. Mapping results from both 1986 and 1989 were placed in a data base. About 70 percent of the bank line of the study reach was revetted. About two-thirds of the revetment was cobble; one-third was quarry stone. Revetment vegetation varied from none to large (> 50-inch diameter) cotton-woods. About 10 percent of the revetted bank line supported some type of woody vegetation. Damage rates for revetments supporting woody vegetation tended to be lower than for unvegetated revetments of the same age located on banks of similar curvature. Chisquared tests indicated damage rates were greater for older (pre-1950 construction) revetments, but were unable to detect differences based on vegetation or bank curvature. Research is needed to generate design criteria and construction techniques to allow routine use of woody plants in bank protection structures. 相似文献
76.
Louis H. Motz 《Journal of the American Water Resources Association》1990,26(2):233-239
ABSTRACT: A drain function and set of type curves were defined for the mathematical solution that represents one-dimensional flow under nonsteady conditions in a leaky aquifer for the constant drawdown boundary condition. A match point procedure was developed for determining the aquifer parameters transmissivity, storage coefficient, and leakance based on the drain function and type curves. Use of the procedure is illustrated by an example that utilizes simulated aquifer drawdowns and flowrate data. The drain function and type curves developed in this investigation include the effects of leakage for the constant drawdown boundary condition, which is not included in the existing drain function and type curve found in the literature. Thus, a new set of type curves was developed that can be used to analyze drawdowns for one-dimensional flow in a leaky aquifer with constant drawdown at a line sink. Applications would include flow to a canal or river, drainage of agricultural lands, and dewatering associated with strip mining operations. 相似文献
77.
We inventoried wetland impoundments in the Louisiana, USA, coastal zone from the late 1900s to 1985. Historically, impoundment
of wetlands for reclamation resulted in direct wetland loss after levees (dikes) failed and the impounded area was permanently
flooded, reverting not to wetland, but to open-water habitat. A current management approach is to surround wetlands by levees
and water control structures, a practice termed semi-impoundment marsh management. The purpose of this semi-impoundment is
to retard saltwater intrusion and reduce water level fluctuations in an attempt to reduce wetland loss, which is a serious
problem in coastal Louisiana. In order to quantify the total impounded area, we used historic data and high-altitude infrared
photography to map coastal impoundments. Our goal was to produce a documented inventory of wetlands intentionally impounded
by levees in the coastal zone of Louisiana in order to provide a benchmark for further research.
We inventoried 370,658 ha within the coastal zone that had been intentionally impounded before 1985. This area is equal to
about 30% of the total wetland area in the coastal zone. Of that total area, approximately 12% (43,000 ha) is no longer impounded
(i.e., failed impoundments; levees no longer exist or only remnants remain). Of the 328,000 ha still impounded, about 65%
(214,000 ha) is developed (agriculture, aquaculture, urban and industrial development, and contained spoil). The remaining
35% (114,000 ha) of impoundments are in an undeveloped state (wetland or openwater habitat). In December 1985, approximately
50% (78,000 ha) of the undeveloped and failed impoundments were open-water habitat. This inventory will allow researchers
to monitor future change in land-water ratios that occur within impounded wetlands and thus to assess the utility of coastal
wetland management using impoundments. 相似文献
78.
闽江河口湿地资源和保护对策 总被引:7,自引:0,他引:7
该文介绍了闽江河口湿地的基本状况,分析了湿地保护中存在的主要问题,提出了保护闽江河口湿地的建议。 相似文献
79.
鸭绿江口滨海湿地环境保护及其资源持续利用对策 总被引:6,自引:0,他引:6
阐述了鸭绿江滨海湿地生态环境主要类型及其动植物资源现状、主要生态环境问题及其产生原因 ;提出了鸭绿江口滨海湿地环境保护及其资源持续利用对策 相似文献
80.