Extracting urban areas in China using DMSP/OLS nighttime light data integrated with biophysical composition information

DMSP/OLS nighttime light (NTL) image is a widely used data source for urbanization studies. Although OLS NTL data are able to map nighttime luminosity, the identification accuracy of distribution of urban areas (UAD) is limited by the overestimation of the lit areas resulting from the coarse spatial resolution. In view of geographical condition, we integrate NTL with Biophysical Composition Index (BCI) and propose a new spectral index, the BCI Assisted NTL Index (BANI) to capture UAD. Comparisons between BANI approach and NDVI-assisted SVM classification are carried out using UAD extracted from Landsat TM/ETM+ data as reference. Results show that BANI is capable of improving the accuracy of UAD extraction using NTL data. The average overall accuracy (OA) and Kappa coefficient of sample cities increased from 88.53% to 95.10% and from 0.56 to 0.84, respectively. Moreover, with regard to cities with more mixed land covers, the accuracy of extraction results is high and the improvement is obvious. For other cities, the accuracy also increased to varying degrees. Hence, BANI approach could achieve better UAD extraction results compared with NDVI-assisted SVM method, suggesting that the proposed method is a reliable alternative method for a large-scale urbanization study in China’s mainland.     

福建省制造业内部产业结构评价与演变趋势

采用Gibbs-Mirtin 多样化指数和区位熵、产值贡献率,对福建省2005―2013 年20 个制造业行业面板数据进行了测算,并从产业部门多样化和优势产业专业化2 个角度对福建省制造业产业结构特点及演变规律进行了分析。研究表明：福建省制造业产业多样化水平逐年提升,全省产业朝多部门均衡发展;各个制造业专业化发展水平存在差异,化学纤维制造业、通信设备、计算机及其他电子设备制造业等行业专业化水平高,行业优势明显;全省20 个制造业总体产业优势不明显,研究时段内区位熵始终≥1 的行业仅占35%,对全省20 个制造业产值贡献达46.71%;非金属矿物制品业及农副食品加工业等新的优势产业及潜力产业涌现,关联产业优势程度成对上升,产业专业化发展形势良好。     

煤田火区环境影响综合评价指标体系与评价方法

在研究煤田火区对自然-社会经济系统影响的基础上,提出了煤田火区环境影响综合评价指标体系的构建思路,建立了煤田火区环境影响评价的一般性指标体系,包括5级32个指标。以内蒙古乌达煤田火区为实例,论述了煤火环境影响综合评价的实施过程。根据煤田火区特征,在一般指标体系框架内确定了23个评价指标,采用层次分析法与综合指数法相结合,建立了火区环境影响综合评价公式。评价结果表明,乌达煤田火区对环境的影响为较严重水平,与定性分析结果相符。     

贵州区域地质灾害发育程度初探

根据全省完成的县（市）地质灾害调查与区划成果,结合各地行政区面积及山地丘陵比例,采用地质灾害综合发育程度指数法,对9个地区级行政区域进行地质灾害发育程度分析,划分出的地质灾害高、中、低发育区比较符合省情实际,对地方政府的地质灾害防治工作具一定的指导意义。     

产气率:油页岩工业品质评价值得重视的指标——以鄂尔多斯盆地何1井三叠系延长组油页岩为例

通过对鄂尔多斯盆地何1井三叠系延长组油页岩工业指标分析,发现油页岩产油率与产气率具有良好的线性关系,随着产油率的增加,产气率呈线性增加.据70件油页岩样品分析结果,平均产油率为5.9%,平均产气率为3.7%,平均油气产率为9.6%,产气率占油气产率的38.5%.说明产气率在油气产率中占有较大比重,是油页岩工业品质评价的重要指标.     

基流分割法在黄河流域地下水研究中的应用

为研究黄河流域地下水可再生能力变化规律和制定黄河流域水资源管理方案,应用基流指数法(BFI)和直线平割法的原理与方法,计算了黄河流域干流13个水文断面与20条主要支流31个水文断面的基流量,并分析了基流量的形成机理、地下水对黄河水的贡献、基流变化过程、流域地下水资源的构成及地下水资源总量.研究结果表明:花园口断面的基流量占多年平均径流量的44%,流域内河水与地下水存在极其密切的转化关系,地下水对黄河水的贡献很大.黄河的径流量与基流量主要来自兰州以上的源区,兰州断面的年径流量与基流量分别占花园口断面径流量的59%和60%;而兰州以下到花园口之间的上、中游地区,地下水对黄河水的贡献很小.1990年前后,黄河干流与支流河段的基流量发生了很大变化.除玛多以上的源头段基流量衰减率较大外(衰减率为0.38),兰州以上的干流河段基流量衰减率较小(0.08～0.20),而兰州以下的黄河干流基流量衰减率都很大(0.22～0.31).基流量的剧烈衰减是天然和人类活动(如地下水开采)共同作用下地下水资源量减少的结果.从流域水循环的观点考虑,黄河流域的区域地下水资源由参与黄河水循环的地下水资源、未参与黄河水循环的地下水资源和流域地下水的开采等3大部分构成.1990年6月-2000年6月近10年黄河流域地下水天然资源量平均值为353.9 亿m~3/a,比多年地下水资源量平均值减少了15 % .     

Application of Fractal Models to Distinguish between Different Mineral Phases

Fractal modeling is demonstrated to be an effective and rapid tool to distinguish between mineral phases in rock samples. It supplements work that previously could be performed only by observing the interpenetrational or metasomatic phenomena between different minerals with the aid of mineralographic microscope. The Gejiu tin district in southwestern China was chosen as a study area for the recognition and characterization of the spatial distribution of two phases (Types I and II) of cassiterite. Vector patterns used for this study were extracted from digital photomicrographs and analyzed with the aid of MapGIS. Perimeter–area fractal dimension, cumulative number–area exponent, and shape index were determined in order to quantify geometrical irregularities and spatial cassiterite phase distribution characteristics. The results show that fractal dimensions based on area and perimeter are larger for crystals of Type I than for those of Type II. The mean shape index (SI) increases from 0.54 (Type I) to 0.64 (Type II), indicating an increase in regularity. The number–area exponent also increases from 0.88 to 1.15, indicating the smaller crystals of Type II. The cumulative number–shape index log–log plot shows two separate straight-line segments. One of these probably represents a background shape realized during the original process of natural crystallization, whereas the other likely represents anomalous shapes because of weathering or other superimposed processes. Two parallel lines can be constructed on the perimeter–area log–log plots. The upper line, with a larger intercept, represents crystals with lower SI. The lower line represents crystals with higher SI, indicating that the intercept provides a measure of the irregularity of grains. By combining the perimeter–area model with cumulative number–area plot and shape index, the two phases of cassiterite can be distinguished and characterized. One phase has fewer crystals of large size, and the other has smaller crystals. This difference can be explained by assuming that under higher-temperature conditions, the large cassiterite crystals formed earlier than the smaller crystals. Consequently, the large cassiterites underwent longer, high-intensive weathering than the small crystals so that their shapes became more irregular. The younger, more abundant small cassiterites retained their original regular shapes.     

地质环境容量与评价研究

本文系统总结了当今地质环境容量研究存在的主要问题及发展趋势,应用地质环境容量评价指标体系,初步建立了地质环境容量评价理论框架.在此基础上结合上海市主要环境地质问题,分析其主要影响因素,分层次选取合适的评价指标,对上海市地质环境容量进行实证分析.     

灰色关联度法在地下水脆弱性评价与分区中的应用

提出采用灰色系统理论中的灰色关联度分析方法对地下水脆弱性进行研究,选取地下水位埋深、包气带岩性、含水层砂层厚度等6个因子建立脆弱性评价指标体系,采用离差最大化方法确定评价指标的权重,使得权重的分配有了一定的理论依据。并以MATLAB为平台编制了常用计算程序,将其应用于抚州市地下水脆弱性评价与分区,取得良好结果。     

Darkness on the Edge of Town: Mapping Urban and Peri-Urban Australia Using Nighttime Satellite Imagery

This article explores the use of nighttime satellite imagery for mapping urban and peri-urban areas of Australia. A population-weighted measure of urban sprawl is used to characterize relative levels of sprawl for Australia's urban areas. In addition, the expansive areas of low light surrounding most major metropolitan areas are used to map the urban–bush interface of exurban land use. Our findings suggest that 82 percent of the Australian population lives in urban areas, 15 percent live in peri-urban or exurban areas, and 3 percent live in rural areas. This represents a significantly more concentrated human settlement pattern than presently exists in the United States.