基于序列参数的水库地震类型综合判定研究     

宋金  杨马陵  吴时平  蒋海昆 《中国地震》2013,29(4):462-471

收集整理了我国大陆东部地区44 组水库地震序列,其中震群型32 组,主余型和孤立型12 组。分别计算了44 组序列的h 值、b 值、归一化熵值K、能量均匀度U、地震发生方式参数ρ 等5 个序列参数。在95% 的置信水平下,对每一参数分震群型、主余型加孤立型两大类进行差异性检验。结果表明,h、U、ρ 值对水库地震序列类型的分类能力不强;b 值平均值虽存在一定差异,但数值分布范围有部分重叠;K 值差异性显著,K = 0. 35 可作为区分震群型与主余型加孤立型两类水库地震序列的判别指标。在此基础上,建立以上述5 个参数为自变量的Fisher 判别函数,用于序列类型的综合判定。结果显示,所有数据全部参与建立判别函数并进行回溯性内符判别检验,识别正确率为97. 6% ;利用32 组序列参数参与判别函数建立,另外10 组进行外推检验,识别正确率为100% ,表明上述综合判别方法具有较高的水库地震序列分类能力。  相似文献   

K油田开发中的砂体成像及油藏描述     

王红梅  杨建锋  李永新  孟凡娓 《CT理论与应用研究》2013,(4):633-642

K油田位于哈萨克斯坦南图尔盖盆地阿克赛隆起带上,主要产层为白垩系底砂岩及侏罗系河道砂。油田区南北跨度较大,油藏类型多样,砂体边界识别困难。该油田在2000年之后逐步投入开发,但在开发过程中发现相邻井的出油情况差异较大,油水关系复杂,油田需要提高对油藏的识别精度来应对新一轮增储上产及井网调整问题。利用敏感属性分析、3D可视化模块、地质统计反演等技术,重新认识和评价了K区油藏特征,识别区内多个独立油藏,厘清油藏间的油水关系,总结该区不同油藏类型的含油气规律,就目前困扰K油田勘探开发工作的问题给出解答。  相似文献   

Prediction of the consumption rates for juvenile Atlantic salmon (Salmo salar L.) on the scale of habitat patches: Development of empirical models based on stomach contents     

Frédéric Burton  Daniel Boisclair 《Limnologica》2013,43(5):332-338

Rivers and streams are unstable environments in which estimation of energetic costs and benefits of habitat utilization are the daunting exercise. Empirical models of food consumption may be used to estimate energetic benefits based on abiotic and biotic conditions in patches of habitat. We performed thirty daily surveys of fish stomach contents to estimate the consumption rates for juvenile Atlantic salmon (Salmo salar) in a river. The data were used to assess whether variations of daily consumption rates existed within the river, and to develop empirical models that could predict fish consumption rates using abiotic and biotic conditions as independent variables. Daily consumption rates based on stomach content surveys in the field (range: 0.15–1.49 g dry/(100 g wet day)) varied significantly depending on habitat patch (500–1000 m²), summer period, and sampling year. Variables such as water temperature, numerical density of salmon, water depth and moon phase explained 83–93% of the variations in daily food consumption rates. Daily consumption rates tended to increase with water temperature and depth, and were also higher near a full moon. However, they tended to decrease with the numerical density of salmon. Our work suggests that empirical models based on independent variables that are relatively simple to estimate in the field may be developed to predict fish consumption rates in different habitat patches in a river.  相似文献   

北京翠湖湿地生境恢复及效果评估   总被引：1，自引：0，他引：1  

李伟  崔丽娟  赵欣胜  张曼胤  王义飞  商晓静 《湿地科学与管理》2013,(3):17-21

湿地恢复是指通过生态技术或生态工程对退化或消失的湿地进行修复或重建,再现退化前的结构和功能以及相关的物理、化学和生物学特性,使其发挥应有的作用。自2010年,翠湖湿地综合运用了微地形重塑、基质恢复、植被种植和岸带护坡等湿地生境恢复技术,累计应用面积约13.33 hm2。翠湖湿地应用生境恢复技术之后,有效改善了水环境质量,血红裸藻"水华"现象爆发频率显著降低,水华覆盖面积得到有效控制。同时,湿地基质质量得到了有效提升。湿地植被覆盖度由恢复之前的51%增加到恢复后的71%;植物物种由221种增加为236种;水鸟种类和偶见种有所增加。本研究可为城市湿地恢复提供技术支撑。  相似文献   

Horizontal rough fracture type curves for groundwater movement     

《水文科学杂志》2013,58(6):1125-1138

Abstract

Type curves are derived analytically for radial flow in rough horizontal fractures toward a well. The basic assumptions are that there is no turbulent flow near the borehole and the well storage is ignored. The basis of the methodology is to write explicit expressions for the continuity and cubic law flow equations, which are combined using a Boltzmann transformation leading to a simple ordinary differential equation for groundwater movement. Solutions are presented as a set of type curves for different fracture apertures. It is observed that the solutions provide a method of uniquely identifying fracture hydraulic parameters when the fracture is smooth, but pose ambiguity for rough fracture parameter estimations. However, large time portions of these type curves appear as straight lines on semi-logarithmic paper, which provides a unique way for rough fracture parameter determination. Identification of the fracture parameters, namely, the aperture and relative roughness, is possible in a unique manner with the use of these lines and the dimensionless time drawdown concept. The cubic law is the asymptotic behaviour, either for large times or large fracture apertures. Prior to this asymptotic part, there is a non-cubic portion which gives rise to systematic deviations from the cubic law. The technique presented is useful, especially for evaluating pumping tests from a single major fracture isolated by packers.  相似文献   

安徽省东至地区金矿类型及找矿方向   总被引：4，自引：0，他引：4  

聂张星  李敏  沈欢喜  熊明强  钱祥 《安徽地质》2013,(2):81-85

安徽省东至地区位于扬子陆块北缘,跨下扬子前陆带和江南隆起带两个次级构造单元,独特的大地构造环境造就了本区有利的金矿成矿地质条件,形成多种类型的金矿床,其成因类型主要包括岩浆热液型和风化壳型,工业类型主要有破碎带蚀变岩型、含金石英脉型、微细粒浸染型及红土型。各类型金矿分类聚集,形成两个主要的金矿成矿带。沿赵家岭断层带以破碎带蚀变岩型为主,伴有含金石英脉型,中畈—戴家一带,赵家岭—杨家山一带均具较大找矿潜力,是本区金矿勘查重点地区,九华庄等地也具一定的找矿潜力;沿高坦断裂以微细粒浸染型为主,伴有破碎带蚀变岩型及红土型,查册桥地区是其重点勘查区,铜锣尖、小河等地找矿潜力也较大。  相似文献   

Heavy Metal Pollution in Sediments from Aquatic Ecosystems in China     

Liwen Zhang  Hongbo Shao 《洁净——土壤、空气、水》2013,41(9):878-882

We conducted an analysis of heavy metals content, including As, Cd, Cr, Cu, Hg, Pb, and Zn in sediments from aquatic ecosystems in China measured in recent publications. Then, we evaluated the extent of heavy metal pollution in these ecosystems in seven different industrial districts in China (Dongbei, Huabei, Huazhong, Huanan, Huaxik, Xibei, and Huadong) with the potential ecological risk index. We found that Cd was the most concentrated pollutant, followed by Hg and As, while Cr, Cu, Pb, Zn were found in low concentrations in sediments from all types of aquatic ecosystem in China. Sediments collected from all seven industrial districts were heavily polluted, and the sequence, from most to least polluted was Dongbei>Huabei>Huazhong>Huanan>Huaxi>Xibei>Huadong. All four types of aquatic ecosystem were found to be seriously polluted and the sequence, from most to least polluted was: river>sea>lake>wetland. Specifically, Cd and Hg were the most serious pollutants in all four aquatic ecosystems, and As was also a serious pollutant in rivers. For the seven industrial districts studied the sea was the most polluted ecosystem in Dongbei, the river was the most polluted ecosystem in Huabei, Huanan, Huazhong, and the lake was the most polluted in Huadong, Huaxi, and Xibei.  相似文献   

基于语义类型本体的地名组配查询     

陈健  张斌  梁汝鹏 《地理空间信息》2013,(3):126-127

地名查询方式多种多样,但它们都没有考虑地名语义类型因素,而语义类型恰恰是地名信息中相当重要的一部分。以地名语义分类为基础,构建了地名语义类型本体模型,并以郑州市为例进行了地名组配查询实验。结果表明,该方式对于检索地名的相关信息具有较好的辅助作用,为地名查询与检索作了有益的补充。  相似文献   

基于MSAVI-WI特征空间的新疆渭干河-库车河流域绿洲土壤盐渍化研究   总被引：5，自引：0，他引：5  

丁建丽  瞿娟  孙永猛  张永福 《地理研究》2013,32(2):223-232

土壤盐渍化是造成干旱区土地荒漠化及生态恶化的重要原因,及时获取大尺度高精度土壤盐渍信息是防治工作的基础。选取新疆塔里木盆地北缘渭干河—库车河流域三角洲绿洲为研究区,利用Lansat-TM数据与野外实测数据分析盐渍化土壤与修改型土壤调整植被指数(MSAVI)、湿度指数(WI)之间的关系,在此基础上提出了MSAVI-WI特征空间概念,构建了土壤盐渍化遥感监测指数模型(MWI)。结果表明:MWI与土壤表层含盐量相关性较高,其相关性为0.844,精度高于土壤盐渍监测常用的盐分指数与实测数据的相关性。MWI能较好的反映盐渍化土壤地表植被及土壤水分的组合变化,具有明确的生物物理意义,并且特征参量简单,理论上易于理解,实践上易于实现,MWI模型的构建有利于干旱区大尺度土壤盐渍化定量监测与评价工作的开展。  相似文献   

Stochastic gradient boosting classification trees for forest fuel types mapping through airborne laser scanning and IRS LISS-III imagery     

《International Journal of Applied Earth Observation and Geoinformation》2013

This paper presents an application of Airborne Laser Scanning (ALS) data in conjunction with an IRS LISS-III image for mapping forest fuel types. For two study areas of 165 km² and 487 km² in Sicily (Italy), 16,761 plots of size 30-m × 30-m were distributed using a tessellation-based stratified sampling scheme. ALS metrics and spectral signatures from IRS extracted for each plot were used as predictors to classify forest fuel types observed and identified by photointerpretation and fieldwork. Following use of traditional parametric methods that produced unsatisfactory results, three non-parametric classification approaches were tested: (i) classification and regression tree (CART), (ii) the CART bagging method called Random Forests, and (iii) the CART bagging/boosting stochastic gradient boosting (SGB) approach. This contribution summarizes previous experiences using ALS data for estimating forest variables useful for fire management in general and for fuel type mapping, in particular. It summarizes characteristics of classification and regression trees, presents the pre-processing operation, the classification algorithms, and the achieved results. The results demonstrated superiority of the SGB method with overall accuracy of 84%. The most relevant ALS metric was canopy cover, defined as the percent of non-ground returns. Other relevant metrics included the spectral information from IRS and several other ALS metrics such as percentiles of the height distribution, the mean height of all returns, and the number of returns.  相似文献