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191.
1957—2012年中国参考作物蒸散量时空变化及其影响因子分析 总被引:9,自引:1,他引:8
根据1957—2012年全国608个气象站的逐日气象资料,利用Penman-Monteith公式计算作物潜在蒸散量,对全国及水资源一级分区潜在蒸散量时空分布特征、变化趋势进行分析;基于Arc GIS及SPSS软件,采用主成分分析方法,对潜在作物蒸散量的影响因子及其分布特征进行探讨。结果表明:近56 a来,全国年潜在蒸散量在616~2 128 mm之间,河西走廊、南部岭南地区、海南岛以及华南沿海作物潜在蒸散量较大,而在黑龙江一带、四川盆地及西南地区东部,潜在蒸发量较小。各分区年均潜在蒸发量均呈现减少趋势,西北诸河区倾向率最大,为-12.22 mm/10 a;影响潜在蒸散量的因子中,第1主成分为热力学因子,第2主成分为水分因子和辐射因子,第3主成分为地理因子和空气动力学因子,第4主成分为高程因子。 相似文献
192.
以我国114个城市冬季(2013年12月-2014年2月)公布的PM25数据为基础,结合其他相关数据,运用空间自相关分析、克里格插值法和逐步回归分析法,研究我国冬季PM2.5浓度空间分布差异及其影响因素.结果显示,研究期间PM2.5在空间分布上具有高值集聚、低值集聚和高值邻域的低值集聚的变化特征,全局自相关系数Moran's I为0.27.PM2.5浓度分布由北到南、从内陆到沿海具有先升高后逐渐降低的变化趋势,高浓度区域主要集中在华北平原、长江中下游平原和陕西关中平原等地区,这些区域的冬季PM2.5平均质量浓度都达到150 μg·m-3以上,最高达250 μg·m-3.多因子逐步回归分析结果表明,人为活动对我国高浓度PM25(>150μg·m-3)分布影响显著,对低浓度PM2.5(≤75μg·m-3)分布影响不显著.市辖区人口密度和第二产业GDP是显著影响我国高浓度PM2.5分布的主要人为影响因子.市辖区建成区面积、全市年末总人口和市辖区道路面积等是影响我国城市间PM2.5浓度分布差异的主要人为影响因子. 相似文献
193.
Safety and security are of paramount importance, it is important to optimize and improve the routes of trucks that carry hazardous materials. In this study, we not only ensure the risk in the network, but also consider the transportation cost and the factors such as buildings and emergency facilities around the routes. The Geographic Information System (GIS) is used to quantify the factors on each section in the network. We present an epsilon constrained multi-objective mixed-integer linear programming optimization model to find the robust and stable transportation optimization solutions. At the end, we complete a case analysis of the proposed methodology to determine the motorway segments in Jiangsu province, China and test the above algorithm on the network, which has 144 nodes and 388 sections. The results we get show that the factors of buildings play a very important role in the model, and the multi-objective mixed-integer linear optimization model is reasonable and performs good quality. 相似文献
194.
Developing the interaction matrix technique as a tool assessing the impact of traffic on air quality 总被引:1,自引:0,他引:1
This paper develops a technique which can be used as a preliminary tool for assessing air quality related to urban traffic. It combines a Geographic Information System (GIS) with an interaction matrix-type methodology based on a system analysis approach. The matrix identifies and quantifies interactions between all selected variables involved in a system as well as their interaction with the system as a whole. This matrix is used to determine the weightings to apply to spatial datasets within a GIS to develop a pollution vulnerability map. The focus of the paper is to introduce and assess a more versatile coding of the interaction matrix with respect to previously used coding. A case study is presented in which the modified interaction methodology is applied to data for a busy urban location. The resulting vulnerability map, in terms of pollution vulnerable hot spots, was compared to a pollution map derived from an advanced dispersion model. The interaction matrix technique with GIS can be used as a tool complementary to sophisticated numerical modelling and has potential as an analytical tool to evaluate multidisciplinary systems. 相似文献
195.
Analysis tools that combine large spatial and temporal scales are necessary for efficient management of wildlife species,
such as the burrowing owl (Athene cunicularia). We assessed the ability of Ripley’s K-function analysis integrated into a geographic information system (GIS) to determine changes in burrowing owl nest clustering
over two years at NASA Ames Research Center. Specifically, we used these tools to detect changes in spatial and temporal nest
clustering before, during, and after conducting management by mowing to maintain low vegetation height at nest burrows. We
found that the scale and timing of owl nest clustering matched the scale and timing of our conservation management actions
over a short time frame. While this study could not determine a causal link between mowing and nest clustering, we did find
that Ripley’s K and GIS were effective in detecting owl nest clustering and show promise for future conservation uses. 相似文献
196.
Using GIS to Generate Spatially Balanced Random Survey Designs for Natural Resource Applications 总被引:2,自引:0,他引:2
Theobald DM Stevens DL White D Urquhart NS Olsen AR Norman JB 《Environmental management》2007,40(1):134-146
Sampling of a population is frequently required to understand trends and patterns in natural resource management because financial
and time constraints preclude a complete census. A rigorous probability-based survey design specifies where to sample so that
inferences from the sample apply to the entire population. Probability survey designs should be used in natural resource and
environmental management situations because they provide the mathematical foundation for statistical inference. Development
of long-term monitoring designs demand survey designs that achieve statistical rigor and are efficient but remain flexible
to inevitable logistical or practical constraints during field data collection. Here we describe an approach to probability-based
survey design, called the Reversed Randomized Quadrant-Recursive Raster, based on the concept of spatially balanced sampling
and implemented in a geographic information system. This provides environmental managers a practical tool to generate flexible
and efficient survey designs for natural resource applications. Factors commonly used to modify sampling intensity, such as
categories, gradients, or accessibility, can be readily incorporated into the spatially balanced sample design. 相似文献
197.
黄河流域生态环境脆弱性评价、空间分析及预测 总被引:1,自引:0,他引:1
生态环境脆弱性是制约经济可持续、高质量发展的重要因素。以2005—2018年黄河流域73个城市为研究对象,构建了黄河流域生态环境脆弱性的评价指标体系,采用主成分分析计算了黄河流域生态环境脆弱指数,并依据自然断点法将评价结果分为极度脆弱、重度脆弱、中度脆弱、轻度脆弱、微度脆弱五类。进一步通过空间相关分析揭示了黄河流域生态环境脆弱性的时空演变特征,并利用CA-Markov模型对黄河流域2025年生态环境脆弱性进行了预测。结果表明:(1)黄河上、中、下游生态环境脆弱性分别表现“低—中—高”的分布特征,且生态环境脆弱性变化趋势存在区别:上游虽差异较大但波动相似,中游波动方向相反,下游在2016年之后整体呈下降趋势。(2)黄河流域生态环境脆弱性存在空间相关性,上游呈现低—低聚集,下游呈现高—高聚集,中游空间相关性不显著。(3)预测2025年黄河流域中游地区重度脆弱有所扩张,下游地区极度脆弱向中心区域明显收缩。黄河流域生态环境的治理与保护并非一朝一夕之事,也并非某一流域单独能够完成的,黄河上、中、下游要根据不同的自然条件制定与之相适宜、符合整体发展需要的治理与保护措施。 相似文献
198.
Minggang Cai Aklima Nargis Ahsan Habi Md Nazrul Islam Kai Chen Md Shafiqul Islam Sarker A N M Al-Razee Wenbin Liu Guorui Liu 《环境科学学报(英文版)》2022,34(11):159-174
In this study, concentrations of Cr, Mn, Ni, Cu, Zn, Cd and Pb were determined in road dusts collected from different locations in Dhaka to assess source, contamination status and health risk. Energy-dispersive X-ray fluorescence spectroscopy and energy-dispersive X-ray spectroscopy were used to determine Cr, Mn, Ni, Cu, Zn, Cd and Pb and their mean concentrations were 162.27 ± 29.46, 721.18 ± 180.14, 35.65 ± 12.55, 104.56 ± 128.33, 515.32 ± 321.90, BDL, and 342.82 ± 591.20 mg/kg, respectively. Among the heavy metals, highest concentrations of Cu, Zn and Pb were found at urban sites-7 (municipal waste dumping) and 8 (medical waste incineration). Highest concentration of Cr followed by Cu and Zn was found at site-5 (Tejgaon, urban). Principal component analysis revealed that anthropogenic activities are the potential sources for Cr, Ni, Cu, Zn and Pb while earth crust for Mn. Pollution index and pollution load index results suggested that all the sites were contaminated and/or degraded by Cr, Cu, Zn and Pb except sites-9 (urban), 10 (sub-urban), 11 (rural) while sites-7 and 8 (urban) were extremely degraded. For noncarcinogenic health risk, hazard quotient values for dermal were higher compared to that of inhalation/ingestion. Though hazard index values were less than 1 at all the sites, these were at least one order of magnitude higher for children group than that of adult group, thus the children group may face more noncarcinogenic health risk at sites-7 and 8. Values of incremental lifetime cancer risk were from 10−9 to 10−11 showed no carcinogenic health risk by road dusts contaminated with the heavy metals. 相似文献
199.
Groundwater management can be effectively conducted by using groundwater contamination map assessment. In this study, a modified DRASTIC approach using geographic information system (GIS) was applied to evaluate groundwater vulnerability in Kerman plain (Iran). The Wilcoxon rank-sum nonparametric statistical test was applied to modify the rates of DRASTIC. In addition, the analytic hierarchy process (AHP) method was employed to evaluate the validity of the criteria and sub criteria of all the parameters of the DRASTIC model, which proposed as an alternative treatment of the imprecision demands. The GIS offers spatial analysis in which the multi index evaluation can be effectively conducted through the AHP. The non-point source pollution was effectively determined by the modified DRASTIC method compared with the traditional method. The regression coefficient revealed the relationship between the vulnerability index and the nitrate concentration. The best result was obtained by using AHP–AHP, followed by DRASTIC–AHP, modified DRASTIC–AHP, and AHP–DRASTIC models. In this study, the DRASTIC method failed to provide satisfactory result. Additionally, by using both the original DRASTIC and the modified DRASTIC methods in the study area, AHP–AHP performed highly in the Kerman plain, suggesting that the southern and south east parts of the area considerably calls for conservation against contamination. 相似文献
200.
The expectations on protected areas to deliver not only biodiversity conservation but also to provide an array of different ecosystem services rise. Sequestration and storage of carbon are promising services that protected areas may provide. This study integrates spatially explicit data on terrestrial Natura 2000 sites, soil organic carbon, and agricultural land values to estimate the potential for climate-smart conservation planning in the European Union. The objectives of this study are to analyse spatial relations between protected areas soil carbon content, and land values on the European Union's land area as well as to locate and quantify the proportion of land with high carbon and low economic value within and outside protected areas. We apply a unique interdisciplinary framework with methods ranging from analyses based on geographical information systems, agricultural economics to statistics. Findings indicate that there is a significant overlap between Natura 2000 sites and regions with high carbon content across Europe. Statistical analyses show that carbon-rich regions have significantly lower land values than other areas. Our results suggest that biodiversity protection and mitigation of climate change through conservation of soil carbon could be simultaneously achieved in Europe's protected areas and beyond. We conclude that there is a notable potential for climate-smart conservation in Europe that needs further investigation. 相似文献