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531.
城市化可能引起的地貌灾害及其防治 总被引:2,自引:0,他引:2
城市化可能导致流水地貌过程系统的变化,加剧水土流失和洪水威胁;还可能导致重力地貌过程系统的变化,造成土滑、滑坡和崩塌等灾害;城区地下水、地下其它液体和固体物质的开采,可能引起地面沉降或坍陷。这一切会影响自然环境与人类环境,故应采取相应的防治措施。 相似文献
532.
533.
We compared the composition of diatom assemblages collected from New Jersey Pinelands blackwater streams draining four different land uses, including forest land, abandoned-cranberry bogs, active-cranberry bogs, and developed and upland-agricultural land. Over a 2-year period (2002-2003), we collected 132 diatom taxa at 14 stream sites. Between-year variability in the composition of stream samples was high. Most diatom species were rarely encountered and were found in low abundance. Specific conductance and pH were higher at developed/agricultural sites compared with all other site types. Neither species richness nor genus richness was significantly different between stream types. However, clear community patterns were evident, and a significant difference in species composition existed between the developed/agricultural sites and both cranberry and forest sites. The primary community gradient, represented by the first axis of a DCA ordination, was associated with variations in pH and specific conductance. Although community patterns revealed by ordinating the data collected in 2002 differed from those obtained using the 2003 data, both ordinations contrasted the developed/agricultural sites and the other sites. Acidobiontic and acidophilous diatoms characterized the dominant species at forest, abandoned-bog, and cranberry sites, whereas indifferent species dominated the developed/agricultural samples. Although our study demonstrated a relationship between the composition of diatom assemblages and watershed conditions, several factors, including taxonomic problems, the large number of diatom species, incomplete pH classifications, and year-to-year variability may limit the utility of diatom species as indicators of watershed conditions in the New Jersey Pinelands. 相似文献
534.
We use an econometrically-based landscape simulation to investigate the effect of conservation on the net change in local development – the amount of land directly protected from development minus the amount of development that may occur on neighboring unprotected private land in response to conservation. First, we use spatial-panel data from Wisconsin to estimate parcel-level subdivision probabilities and density expectations, controlling for the endogenous location of open space. Second, we use these subdivision probabilities and density expectations in a landscape simulation model. Our simulation results indicate that 57% of conserved open space created between 1978 and 2009 generated close to zero net change in local development. This suggests that conserved open space mostly reallocated development in a small neighborhood (in a half-mile radius) rather than altering the total amount of development. We explore the landscape conditions that may lead to conservation having either a positive or negative effect on local development. 相似文献
535.
536.
《环境科学学报(英文版)》2023,35(3):678-690
Antibiotics in soil environment are regarded as emerging pollutants and have introduced increasing risks to soil ecosystem and human health in rapid urbanization areas. Identifying the occurrence and spatial variability of antibiotics in soils is an urgent issue in sustaining soil security. In this study, antibiotics in soils were investigated and analyzed in Beijing-Tianjin-Hebei urban agglomeration. The occurrence, spatial distribution, and related affecting factors of antibiotics in soils were identified and ecological risks of antibiotics in soil environment were assessed. Results showed that (1) The mean concentration of soil antibiotics in Beijing-Tianjin-Hebei urban agglomeration was 21.79 µg/kg. Land use substantially affected the occurrence and concentration of antibiotics in soils. Concentrations of antibiotics in cropland and orchard soils were 2-3 times higher than the other land use types. (2) The concentrations of antibiotics in soils in Beijing-Tianjin-Hebei urban agglomeration presented a spatial pattern of high values in southeast, and low values in northwest. Spatial variability of antibiotics in soils was closely related to the application of organic fertilizer and wastewater irrigation as well as topographical features. Furthermore, soil properties and land management policy had substantial influences on soil antibiotics, and soil heavy metals may aggravate the accumulation of antibiotics in soils. (3) Ecological risks assessment of antibiotics in soils demonstrated that erythromycin (ERY), sulfamethoxazole (SMX), and doxycycline (DOX) may introduce high risks to soil ecosystem health, and more attention should be paid to the areas with intensive human activities that had potential high risk to soil ecosystem health. This study suggests that scientific land and soil management should be considered to prevent soil antibiotic pollution and sustain soil security in urban agglomeration. 相似文献
537.
本章针对固体废物最终处置的两大途径,即陆地处置和海洋处置,着重介绍了卫生土地填埋、安全土地填埋、海洋倾倒、远洋焚烧、深井灌注处置等方法,以及它们的场地开发和利用、场地选择、设计、建造、操作等. 相似文献
538.
The aim of the study was to delineate soil landscape constraints to various land uses for urban and regional planning in the
coastal areas of New South Wales (NSW), Australia. Soil landscape units mapped at 1:100,000 or coarser were sub-divided into
component facets using advanced terrain modelling techniques in a geographic information system (GIS). The output facet grids
were further overlain and linked with relevant GIS layers and soil databases to derive soil landscape constraint ratings for
various land use purposes such as residential development, cropping and grazing. The constraint ratings for a specific land
use were calculated based on objective and rule-based assessments of soil and landscape features such as engineering hazards,
intrinsic fertility, drainage and other parameters. A series of soil landscape constraint maps which portray specific land
use capability have been produced for the NSW coast. The methodology developed in this study has been demonstrated to be efficient
in delineating soil landscape constraints and there is over 90% agreement between the model outputs and the assessment by
soil surveyors with local knowledge. The output maps show levels of unprecedented detail of soil and landscape constraint
for the coast of NSW and can be readily interpreted by land use planners and land managers for sustainable land use decision
making practices. 相似文献
539.
Detailed analysis of the land cover of the Estonian coastal zone is presented based on Estonian laws on coastal zone management,
the CORINE Land Cover (CLC) system, the status of protected areas, and administrative division data of Estonia. By law the
coastal zone is defined as a 200-m wide zone landward from the mean sea level line. The length of the Estonian coastline (including
the islands) is 3794 km. The 200-m zone of the Estonian coast is very diverse. Out of the 34 CORINE land cover types represented
in Estonia 30 are found in the coastal zone. Three dominating land cover types in the coastal zone of Estonia are inland marshes,
coniferous forest and semi-natural grassland. Their total share is 47%; the other 27 land cover types represented here cover
53% of the coastal zone. The Estonian coastal zone is generally in a good natural condition. The proportion of artificial
surfaces throughout the zone is merely 4.7%, while agricultural landscapes cover only ca. 10%. Land cover data for the coastal
zone are also presented by county. Of the 200-m coastal zone 24% is under protection, which is more than twice the value for
Estonia as a whole (11%). Legislative protection of the coastal zone is presently satisfactory. The use of the CORINE Land
Cover system enables comparisons with other European regions since CLC data have been compiled for most of Europe. 相似文献
540.
土地资源是人类生存最基本的资源,对它的利用与开发必须保持协调的可持续的发展规划。本文以无公害农产品土地利用为例,从环境的角度,构建了产地环境条件子系统、自然条件子系统、经济效益分析子系统和环境影响分析子系统以及各自包含的评价指数集。产地环境条件指标集和自然条件指标集是基于现状的,采用结果指标表达;针对布局规划,环境影响分析和经济效益分析是一种预测评价,对其指标集的构建采用了过程指标的设计。 相似文献