6 resultados para land suitability assessment

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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空间生态规划着重于研究城乡土地和空间资源,达到城乡土地和空间资源合理配置。辽宁本溪市南芬区属山地资源型工矿城镇,由于空间用地类型配置不合理,中心城区环境污染严重,而广阔的乡村空间资源未尽其用。为此,有必要对南芬全区城乡空间进行生态规划。本文在理论上补充空间生态规划中生态适宜性评价理论,在方法上提出了基于适宜性评价的空间生态规划方法后,就南芬主要用地类型工业用地、居住用地、作物用地和林业用地分别进行生态适宜性评价和用地配置研究,并综合适宜性评价结果和探讨了南芬空间生态分区及空间生态规划途径。 主要结果为:(1) 工业用地最适宜区、次适宜、勉强适宜和不适宜区面积分别为91.23km2、182.72km2、182.08km2和162.97km2;居住用地分别为208.08km2、169.95km2、149.51km2和91.46km2;作物用地分别为124.23km2、130.65km2、159.02km2和205.1km2;林业用地分别为201.7km2、150.43km2、130.21km2和136.66km2。(2) 工业用地现状位于最适宜区、次适宜区、勉强适宜区、不适宜区的面积分别为9.81km2、10.66km2、6.54km2和11.73km2;居住用地分别为9.05 km2、12.57km2、15.7km2和11.53km2;作物用地分别为16.61km2、7.88km2、22.25km2和24.15km2;林业用地分别为193.91km2、104.88km2、81.74km2和67.27km2。(3)综合评价表明,工业用地、居住用地、作物用地、林业用地适宜区面积分别为46.75km2;71.32km2;94.46km2;406.47km2。南芬生态空间区划为生态保护区、生态居住区(2个)和生态工业区(3个)。(4) 最后详细阐述了南芬城乡空间生态规划途径及其内涵,即:生态优先、整体优化、经济优效和社会持续。

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Urbanization can exert a profound influence on land covers and landscape characteristics. In this study, we characterize the impact of urbanization on land cover and lacustrine landscape and their consequences in a large urban lake watershed, Donghu Lake watershed (the largest urban lake in China), Central China, by using Landsat TM satellite images of three periods of 1987, 1993 and 1999 and ground-based information. We grouped the land covers into six categories: water body, vegetable land, forested land, shrub-grass land, open area and urban land, and calculated patch-related landscape indices to analyze the effects of urbanization on landscape features. We overlaid the land cover maps of the three periods to track the land cover change processes. The results indicated that urban land continuously expanded from 9.1% of the total watershed area in 1987, to 19.4% in 1993, and to 29.6% in 1999. The vegetable land increased from 7.0% in 1987, 11.9% in 1993, to 13.9% in 1999 to sustain the demands of vegetable for increased urban population. Concurrently, continuous reduction of other land cover types occurred between 1987 and 1999: water body decreased from 30.4% to 23.8%, and forested land from 33.6% to 24.3%. We found that the expansion of urban land has at least in part caused a decrease in relatively wild habitats, such as urban forest and lake water area. These alterations had resulted in significant negative environmental consequences, including decline of lakes, deterioration of water and air quality, and loss of biodiversity.

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It has been 10 years since the publication of the relative risk model (RRM) for regional scale ecological risk assessment. The approach has since been used successfully for a variety of freshwater, marine, and terrestrial environments in North America, South America, and Australia. During this period the types of stressors have been expanded to include more than contaminants. Invasive species, habitat loss, stream alteration and blockage, temperature, change in land use, and climate have been incorporated into the assessments. Major developments in the RRM have included the extensive use of geographical information systems, uncertainty analysis using Monte Carlo techniques, and its application to retrospective assessments to determine causation. The future uses of the RRM include assessments for forestry and conservation management, an increasing use in invasive species evaluation, and in sustainability. Developments in risk communication, the use of Bayesian approaches, and in uncertainty analyses are on the horizon.

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In this paper, taking the northern region of Changxing County for example, with ammonia nitrogen as a pollution assessment index, we used an improved export coefficient method for estimate polluting load of non-point source pollution (NSP) and the social pollution survey data in the study area to estimate point source pollution. By comparing the total pollution output and the national surface water environmental quality standards find that the whole study area achieves the second water quality standard. However, Jiapu Township exceeds the water quality standards seriously because of the superfluous point source pollution. The water quality of other Townships is good. Further analysis showed that different types of land use and proportions in the northern region of Changxing County have a significant impact on the non-point source pollution, the general law is farmland contributes the largest share of the non-point source pollution output, followed by residential area and bare land, besides, with the increase in the proportion of forest and the decrease of farmland and residential area, the non-point source pollution reduces gradually. © 2010 IEEE.

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An assessment of metal contamination in surface sediments of the Jiaozhou Bay, Qingdao, one of the rapidly developing coastal economic zones in China, is provided. Sediments were collected from 10 stations and a total of 15 heavy metals were analyzed. Concentrations of metals show significant variability and range from 210 to 620 ppm for Ti, 2.7 to 23 ppm for Ni, 4.2 to 28 ppm for Cu, 5.2 to 18 ppm for Pb, 12 to 58 ppm for Zn, 0.03 to 0.11 ppm for Cd, 5 to 51 ppm for Cr, 1.5 to 9.9 ppm for Co, 5.3 to 19 ppm for As, 12 to 32 ppm for Se, and 19 to 97 ppm for Sr. Based on concentration relationships and enrichment factor (EF) analyses, the results indicate that sediment grain size and organic matter played important roles in controlling the distribution of the heavy metals in surface sediments of the Jiaozhou Bay. The study shows that the sediment of the Jiaozhou Bay has been contaminated by heavy metals to various degrees, with prominent arsenic contributing the most to the contamination. The analysis suggests that the major sources of metal contamination in the Jiaozhou Bay are land-based anthropogenic ones, such as discharge of industrial waste water and municipal sewage and run-off. Notably, the elevated heavy metal concentrations of the Jiaozhou Bay sediments could have a significant impact on the bay's ecosystem. With the rapid economic development and urbanization around the Jiaozhou Bay, coastal management and pollution control should focus on these contaminant sources, as well as provide ongoing monitoring studies of heavy metal contamination within the bay.