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11.
将模糊数学应用于上海指数法 ,在评价函数中引入半梯形隶属函数和倍斜率隶属函数 ,提出模糊上海指数法 ;将此法应用于延安市的大气质量评价工作 ,与欧几里德贴近度法和上海指数法的评价结果进行比较表明 ,模糊上海指数法的评价结果是科学合理的。  相似文献   
12.
Hot Spots of Perforated Forest in the Eastern United States   总被引:1,自引:0,他引:1  
National assessments of forest fragmentation satisfy international biodiversity conventions, but they do not identify specific places where ecological impacts are likely. In this article, we identify geographic concentrations (hot spots) of forest located near holes in otherwise intact forest canopies (perforated forest) in the eastern United States, and we describe the proximate causes in terms of the nonforest land-cover types contained in those hot spots. Perforated forest, defined as a 0.09-ha unit of forest that is located at the center of a 7.29-ha neighborhood containing 60–99% forest with relatively low connectivity, was mapped over the eastern United States by using land-cover maps with roads superimposed. Statistically significant (P < 0.001) hot spots of high perforation rate (perforated area per unit area of forest) were then located by using a spatial scan statistic. Hot spots were widely distributed and covered 20.4% of the total area of the 10 ecological provinces examined, but 50.1% of the total hot-spot area was concentrated in only two provinces. In the central part of the study area, more than 90% of the forest edge in hot spots was attributed to anthropogenic land-cover types, whereas in the northern and southern parts it was more often associated with seminatural land cover such as herbaceous wetlands.  相似文献   
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14.
以我国最大的内陆淡水湖——博斯腾湖为研究对象,利用Terra/MODIS L1B空间分辨率为250 m和500 m的遥感反射率数据及湖水矿化度实测数据建立线性回归模型,分析湖表面矿化度的空间分布特征。结果表明:空间分辨率为500 m的1~7个波段组合建立的多元线性回归模型相关性最高(R~2=0.70),模型验证结果显示,实测值和反演值的相关系数(R~2)为0.82,均方根误差(RMSE)为0.12。利用最优模型对博斯腾湖湖面矿化度进行反演,其分布存在明显的空间梯度,西北、东北和东南湖区矿化度较高,而西南湖区和湖区南部矿化度较低。  相似文献   
15.

Background

The association between metals in water and soil and adverse child neurologic outcomes has focused on the singular effect of lead (Pb), mercury (Hg), and arsenic (As). This study describes the complex association between soil concentrations of As combined with Pb and the probability of intellectual disability (ID) in children.

Methods

We used a retrospective cohort design with 3988 mother child pairs who were insured by Medicaid and lived during pregnancy and early childhood in South Carolina between 1/1/97 and 12/31/02. The children were followed until 6/1/08, using computerized service files, to identify the diagnosis of ID in medical records and verified by either school placement or disability service records. The soil was sampled using a uniform grid and analyzed for eight metals. The metal concentrations were interpolated using Bayesian Kriging to estimate concentration at individual residences.

Results

The probability of ID increased for increasing concentrations of As and Pb in the soil. The Odds Ratio for ID, for one unit change in As was 1.130 (95% confidence interval 1.048-1.218) for Pb was 1.002 (95% confidence interval 1.000-1.004). We identified effect modification for the infants based on their birth weight for gestational age status and only infants who were normal size for their gestational age had increased probability of ID based on the As and Pb soil concentrations (OR for As at normal weight for gestational age = 1.151 (95% CI: 1.061-1.249) and OR for Pb at normal for gestational age = 1.002 (95% CI: 1.002-1.004)). For normal weight for gestational age children when As = 22 mg kg−1 and Pb = 200 mg kg−1 the risk for ID was 11% and when As = 22 mg kg−1and Pb = 400 mg kg−1 the probability of ID was 65%.

Conclusion

The probability of ID is significantly associated with the interaction between Pb and As for normal weight for gestational age infants.  相似文献   
16.
Nature-based solutions (NBS) find increasing attention as actions to address societal challenges through harnessing ecological processes, yet knowledge gaps exist regarding approaches to landscape planning with NBS. This paper aims to provide suggestions of how planning NBS can be conceptualized and applied in practice. We develop a framework for planning NBS by merging insights from literature and a case study in the Lahn river landscape, Germany. Our framework relates to three key criteria that define NBS, and consists of six steps of planning: Co-define setting, Understand challenges, Create visions and scenarios, Assess potential impacts, Develop solution strategies, and Realize and monitor. Its implementation is guided by five principles, namely Place-specificity, Evidence base, Integration, Equity, and Transdisciplinarity. Drawing on the empirical insights from the case study, we suggest suitable methods and a checklist of supportive procedures for applying the framework in practice. Taken together, our framework can facilitate planning NBS and provides further steps towards mainstreaming.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01365-1) contains supplementary material, which is available to authorized users.  相似文献   
17.
文章利用基于微波遥感的土壤水分产品评价辽宁省近40年(1979~2015)来干旱事件的时空变化特征。研究结果表明:辽宁省地表土壤水分呈现东高西低的空间分布;采用了一种具有时-频多分辨功能的小波分析(Wavelet Analysis)来更好地研究土壤水分时间序列变化规律,发现辽宁省年平均土壤水分随着时间具有波动降低趋势,并伴随有10年和20年左右的两个主要周期;从季节上看,四个季节的土壤水分时间序列变化十分剧烈,春夏两季土壤水分呈现出增加趋势,秋冬两季的土壤水分呈现出降低趋势。  相似文献   
18.
文章通过判别分析法,尝试构建一套针对不同主体功能定位县通用的指标体系,以反映社会经济发展状况、生态环境保护重要性、国土空间开发支撑条件。通过在广西10个不同主体功能定位县的实践应用,将县域空间划分为城镇空间、农业空间和生态空间,重点开发区、农产品主产区、重点生态功能区的城镇空间分别小于30%、20%和10%,农产品主产区的农业空间和重点生态功能区的生态空间均大于50%。研究成果为全省范围推广县域空间功能区划提供了科学依据。  相似文献   
19.
空间规划体系下,环境规划在空间落地性以及精细化程度上存在短板。建议环境规划进一步完善生态保护红线制度,探索环境质量底线、环保负面清单的划定技术思路与技术路线,推动环境保护系统化参与空间规划。  相似文献   
20.
采用主成分分析法在2010年平水期对五大连池药泉湖6个采样点的8个水质指标进行分析,同时研究药泉湖水体污染的空间分布特征。结果表明:高锰酸盐指数是影响药泉湖水质的首要因子,即有机污染对水体污染的贡献最大;瀑布出水口采样点污染最严重,该出水口为药泉湖观光景区入口,因此要密切关注药泉湖人为点源污染,加大景区环境管制力度。  相似文献   
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