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681.
Effects of spatial resolution of remotely sensed data on estimating urban
impervious surfaces 总被引:1,自引:0,他引:1
Impervious surfaces are the result of urbanization that can be explicitly quantified, managed and controlled at each stage of land
development. It is a very useful environmental indicator that can be used to measure the impacts of urbanization on surface runoff,
water quality, air quality, biodiversity and microclimate. Therefore, accurate estimation of impervious surfaces is critical for urban
environmental monitoring, land management, decision-making and urban planning. Many approaches have been developed to estimate
surface imperviousness, using remotely sensed data with various spatial resolutions. However, few studies, have investigated the
effects of spatial resolution on estimating surface imperviousness. We compare medium-resolution Landsat data with high-resolution
SPOT images to quantify the imperviousness in Beijing, China. The results indicated that the overall 91% accuracy of estimates of
imperviousness based on TM data was considerably higher than the 81% accuracy of the SPOT data. The higher resolution SPOT data
did not always predict the imperviousness of the land better than the TM data. At the whole city level, the TM data better predicts
the percentage cover of impervious surfaces. At the sub-city level, however, the ring belts from the central core to the urban-rural
peripheral, the SPOT data may better predict the imperviousness. These results highlighted the need to combine multiple resolution
data to quantify the percentage of imperviousness, as higher resolution data do not necessarily lead to more accurate estimates. The
methodology and results in this study can be utilized to identify the most suitable remote sensing data to quickly and efficiently extract
the pattern of the impervious land, which could provide the base for further study on many related urban environmental problems. 相似文献
682.
长江中游湿地区域的池塘经过连续多年的化肥养鱼导致了大量的氮、磷沉积在鱼塘底泥中。分析了鱼塘植莲对养殖后沉积的氮、磷的重新利用及植莲的经济效益。实验于2004年在位于长江中游的武汉市涨渡湖渔场进行。根据收支平衡计算了实验池氮、磷的转移量,根据投入产出计算了实验池的经济收入。逐月分析了池塘中水质理化指标和底泥中总凯氏氮(TKN)和总磷(TP)的含量。方差分析表明:总凯氏氮、总磷在池塘底泥表层(0~5 cm)、中层(5~10 cm)和底层(10~50 cm)当中的含量都出现显著性降低(〖WTBX〗P〖WTBZ〗<005)。养鱼池塘通过植莲后,每公顷有1 50938±2211 kg氮和188995±282 kg磷被重新利用;鱼塘植莲产生的经济效益平均为每公顷52 031±1 579元。实验表明鱼塘植莲既能够有效地改善池塘养殖的生态条件,又能带来较高的经济收入,是长江流域湿地保护和综合利用的一种高效的农业生态模式。 相似文献
683.
基于污染物平衡分析的污水厂尾水补水城市内湖的优化运行研究——以昆明翠湖为例 总被引:1,自引:0,他引:1
针对污水厂尾水补水的城市内湖污染调控问题,提出了基于水量和污染物收支平衡分析的污染物净积累(NPA)模型,建立了污染物输入和输出量化计算方法.最后,以昆明翠湖为案例,在调查水体污染物输入和输出途径及水体自净量计算的基础上,选择COD、TN和TP为代表性污染物,开展了模型和计算方法的应用.结果表明,尾水补水是污染物输入的最主要途径,排水和渗漏是污染物输出的两个主要途径,COD在水体中的净积累程度较低,TN和TP的净积累比例分别达到42.9%和39.0%.以此为基础,本文提出了以调整补水和用水途径为主要手段的水体优化运行方案,并对方案实施后的预期效果进行了分析验证.本研究可为城市景观水体的污染物积累分析提供新方法和典型案例. 相似文献
684.
湖南某植烟土壤重金属含量及其生态风险评价 总被引:4,自引:0,他引:4
采集了湖南某植烟区表层土壤样品112份,测定了土壤中6种重金属元素的含量,并采用单因子污染指数法、综合污染指数法和潜在生态危害指数法对其污染状况进行评价.结果表明,植烟区土壤重金属平均含量分别为36.25(Cu)、69.78(Zn)、37.66(Pb)、0.36(Cd)、12.71(As)、0.27(Hg)mg·kg-1.6个元素的变异系数在32.57%—59.03%之间,属于中等变异,元素分布不均.污染评价结果表明,植烟区土壤重金属Cu、Zn、Pb、As的单因子污染指数平均值小于1,其污染较轻.而重金属Cd和Hg的超标率为54.46%和58.04%,土壤受到Cd和Hg污染.潜在生态风险指数评价结果显示植烟区土壤重金属属于轻度污染.相关性分析结果表明Cu、Zn、Pb和Cd之间呈显著相关性,As和Hg相关性显著,说明其同源性较高.来源分析表明,研究区Cu、Zn、Pb和Cd污染来源东北部主要为矿区污染,西南部主要是人为源,As主要来源为成土母质和生活源,Hg主要为大气污染源. 相似文献
685.
Kristina Veidemane Olgerts Nikodemus 《Journal of Environmental Planning and Management》2015,58(6):949-975
The aim of this paper is to contribute to coherence in marine, coastal and land use planning and management from the perspective of landscape values. At a time when new sea uses are emerging and marine spatial planning laws and regulations are being adopted, but have not yet been put into practice, research studies are required that provide spatial planners with informed insights concerning public stakeholder attitudes to controversial policies. The undertaken research explored the attitudes of two important social groups (local residents and tourists/recreational users) regarding locating wind parks in the marine and/or terrestrial environment along the Latvian coast of the Baltic Sea. The results of the study indicate that both groups support land-based wind park development versus offshore. Moreover, the visibility of wind turbines influences the willingness of tourists to visit recreation sites and impacts directly on their duration of stay. Research findings indicate that policy makers and spatial planners from both marine and land domains should adopt a broader and more integrated approach when setting priorities and allocating space for development activities where both domains are involved. 相似文献
686.
Lucia Filova Jiri Vojar Kamila Svobodova Petr Sklenicka 《Journal of Environmental Planning and Management》2015,58(11):2037-2055
This study deals with an assessment of the visual quality of landscapes, and specifically with the perception of selected elements in the landscape. The aim of the study was to find out how particular elements are perceived in various landscape types, whether this perception is affected by the landscape type in which the elements are placed, and to what extent the respondents’ characteristics affect the assessment. The study was carried out with a sample of respondents of various ages, educational levels and types of employment. The respondents came from Slovakia and the Czech Republic. The preferences of the respondents were determined using an online questionnaire, in which they rated landscape photographs on a 21 point rating scale with a range from ?10 to +10 points. Using generalised linear mixed effect models, it was found that the perception of an element is most affected by the landscape type, since the same element was assessed differently according to the landscape in which it was situated. The results confirmed that selected elements which do not disturb the harmony of the landscape are generally positively perceived, and the selected elements of a technical character are generally negatively perceived. Among the characteristics of the respondents, only gender and the respondent's current place of residence have an effect on their visual preferences. 相似文献
687.
景观水体浮游藻类变化及与水质因子关系分析 总被引:1,自引:0,他引:1
浮游藻类在不同的水质中有着不同的群落组成结构及分布特点,因此相关研究对于水质监测及水环境保护有着重要的指导意义。该研究以无锡长广溪湿地公园内河段的较清洁景观水体为研究对象,设立了10个样点,调查了2009年9月至2010年5月底秋冬春浮游藻类的时空变化情况,并研究分析了多种水质及岸带因子与浮游藻类相关指数变化的关系。研究结果表明:(1)长广溪湿地公园河段浮游藻类的群落组成结构及丰度具有明显的季节变化。秋季以蓝藻为主要优势种,丰度较高,平均值为4.7×106个/L;冬季的优势种以耐寒的硅藻及甲藻为主,丰度较低,最低值出现在1月,平均值为2.7×106个/L;春季以硅藻门为主,其中丰度最高值出现在5月份,平均值为3.4×106个/L。(2)水中的氮营养盐对浮游藻类的群落特征有重要影响,氮含量为影响浮游藻类群落的主要因子。高锰酸盐指数(OC)、补偿电导率及温度对浮游藻类群落也产生一定的影响。(3)水中不同水生植物的组合及河岸带类型对浮游藻类也有影响,有水生植物的样点水质较好,藻类较少;水中无水生植物的样点水质较差,藻类较多。河岸带植被较多的样点水质较好,浮游藻类较少;人工硬质岸带样点的水质差,浮游藻类较多。总之,长广溪湿地公园河段中浮游藻类的时空变化显著。 相似文献
688.
689.
1961-2010年我国冬小麦可种植区变化特征 总被引:3,自引:0,他引:3
冬小麦是我国的主要粮食作物之一,在我国粮食生产和粮食安全方面占有重要地位。论文以全国553个气象台站1961-2010年的基本气象资料为基础,根据温度垂直递减规律,将气象站点的最低温度数据处理到海平面水平,而后利用ArcGIS软件,对海平面水平的最低温度数据进行空间插值,得到海平面水平的最低温度空间分布图;再利用全国的DEM数据将插值后的温度数据还原到相应的海拔高度,得到当地的最低温度空间分布图。参考崔读昌提出的我国内地冬小麦种植北界条件,并综合北疆有积雪覆盖区冬小麦安全越冬的判定条件,计算得到全国1961-2010年内不同年代际的冬小麦可种植区概率。利用不同年代际冬小麦可种植区概率分布图,从空间的角度分析了这50 a冬小麦可种植区的扩张状况、可种植概率的变化情况等,为我国的冬小麦种植区的选择提供参考。 相似文献
690.
Littoral zone is a special land/ landscape type. As an important kind of land resource in support, the use of littoral zone is vital to eastern coastal areas in China. And the research on littoral zone relates to the key theory of landscape ecology. Based on the theory of landscape ecology, the littoral zone was divided into four types: mud flat, sand beach, bench, and biological flat. The distribution of each type in China is pointed out. As a typical open system, littoral zone has six landscape ecological characteristics: (1) high sensitivity to disturbance; (2) distinct edge effect; (3) spatial aggregation of natural resources; (4) frequently spatial oscillation; (5) obviously spatial heterogeneity; and (6) noticeably spatial differentiation. Some proposals are also put forward on the land use and development of littoral zone for environmental protection and environmental management. 相似文献