GIS在斜坡稳定性空间评价预测中应用初探   总被引：3，自引：0，他引：3  

沈芳  程东  向喜琼 《矿物岩石》1998,(Z1)

本文通过对ＧＩＳ的剖析,对ＧＩＳ应用于斜坡稳定性空间评价预测进行了初步探讨,提出了研究与应用的思路,并在贵州某流域作了应用尝试。  相似文献   

黑土区土壤有机质和全氮含量遥感反演研究   总被引：1，自引：0，他引：1  

郑淼  王翔  李思佳  张丽  宋开山 《地理科学》2022,42(8):1336-1347

以东北典型黑土区耕地为研究区,以Sentinel-2A（全球环境与安全监测计划的第二颗卫星,于2015年6月23日发射）影像作为数据源,构建光谱指数,分别采用多元逐步线性回归（Multiple Stepwise Linear Regression, MSLR）和随机森林（Random Forest, RF）算法建立土壤有机质（SOM）和土壤全氮（STN）预测模型,并采用十折交叉验证方法评估模型的性能。研究对比分析了不同气候、土壤类型和地形下土壤有机质和全氮的空间分布差异。研究表明：① 海伦示范区的SOM和STN含量最高,其年均温最低,高程最高,年降水量多,SOM含量升高,其年均温最低,年降水量多,STN含量升高;② 与基于多元逐步线性回归算法建立的SOM和STN预测模型相比,随机森林算法建立的SOM和STN预测模型,有着更高的精度和稳定性;③ 运用RF算法建立的SOM反演模型的R²为0.96,均方根误差为5.49 g/kg,STN反演模型的R²为0.95,均方根误差为0.27 g/kg; ④ 不同示范区统一建立SOM和STN预测模型,有助于提高预测精度,实现跨区域建模与制图。  相似文献   

锡矿自然重砂矿物组合规律及其找矿意义     

张翔  董国臣  申俊峰  代友旭  景国庆  罗微  王松阳 《地质通报》2014,33(12):1869-1877

为探究不同类型锡矿床所反映出的自然重砂矿物组合特征,统计了云南、福建、江西、浙江、湖南、青海和广西7省共35个典型锡矿床的自然重砂情况,通过计算和分析各自然重砂矿物在所对应类型矿床中的报出频率,得出矽卡岩型、热液脉型和斑岩型3种锡矿所对应的自然重砂矿物组合。所反映出的重砂矿物组合既有相似之处,如均出现锡石+白钨矿(或黑钨矿)的矿物组合,亦反映出不相同的地方,如矽卡岩型锡矿石榴子石报出率高,斑岩型锡矿锆石报出率高等。因此,按照矿床类型建立的自然重砂矿物组合对于建立自然重砂找矿模型具有重要意义。  相似文献   

韩城区块构造煤类型及其产出煤粉特征分析     

张晓玉  王安民  张傲翔  姚征  李翔  邸潇菲 《中国煤炭地质》2014,(8):91-94

构造煤的发育是产生煤粉的关键,破碎后煤岩会产生固有煤粉,而疏松的结构会使得煤岩更容易受钻井、压裂和排采等工程扰动影响,进而产生更多的煤粉。韩城区块经历多期构造,断裂构造造成的煤岩脆性变形、褶皱拉伸与挤压造成的煤岩韧性变形导致构造煤发育。以采集煤样宏观特征差异划分煤体结构类型,运用测井解释识别不同煤体结构类型煤,从纵向和横向上总结区块煤体结构分布规律,并揭示不同煤体结构类型对产出煤粉形态、浓度、粒度特征的影响。  相似文献   

Research on eco-environmental vulnerability evaluation of the Anning River Basin in the upper reaches of the Yangtze River     

Huaiyong Shao  Meng Liu  Qiufang Shao  Xiaofei Sun  Jinhui Wu  Zhiying Xiang  Wunian Yang 《Environmental Earth Sciences》2014,72(5):1555-1568

The Anning River Basin is located in the transitional zone of the Qinghai-Tibet Plateau, Yunnan-Kweichow Plateau and Sichuan Basin. This transitional zone is an important ecological barrier of the upper reaches of the Yangtze River and plays a significant role in the ecological security and ecological construction of Sichuan Province. However, the innate vulnerability of the eco-environment combined with the unreasonable development and use of minerals, hydropower, agriculture and animal husbandry resources contribute to prominent eco-environmental problems. In support of remote sensing and geographical information system, this study uses the spatial principal component analysis (SPCA) method to build the evaluation model for the vulnerability evaluation and analysis of the eco-environment in the Anning River Basin. The following indicators are selected for the SPCA: elevation, slope, vegetation index, land use, soil type, soil erosion, precipitation, temperature, and population density. Thereafter, the first four principal components are selected and their corresponding weights are determined. The eco-environmental vulnerability comprehensive index of the Anning River Basin is calculated by using these data. According to the calculated results, the eco-environmental vulnerability of the Anning River Basin is divided into five levels, namely, potential vulnerability, slight vulnerability, light vulnerability, moderate vulnerability, and high vulnerability. Eco-environmental changes for the past 20 years (from 1990 to 2010) are discussed and analyzed as well as the driving forces. The analysis shows that the eco-environmental vulnerability of the Anning River Basin is at the moderate level, and exhibits obvious vertical distribution characteristics. The main reasons that cause eco-environmental changes are mainly human factors, socioeconomic factors, and environmental protection policies like “Natural Forests Protection” and “Grain-for-Green”. Based on the vulnerability classification results, the Anning River Basin is divided into three partitions for different degrees of eco-environmental reconstruction and protection, which provides foundation for the local eco-environmental reconstruction so as to reconstruct in order of the importance and urgency.  相似文献   

Landslide susceptibility analysis based on ArcGIS and Artificial Neural Network for a large catchment in Three Gorges region,China   总被引：1，自引：0，他引：1  

Renneng Bi  Markus Schleier  Joachim Rohn  Dominik Ehret  Wei Xiang 《Environmental Earth Sciences》2014,72(6):1925-1938

A landslide susceptibility map is very important and necessary to efficiently prevent and mitigate the losses brought by natural hazard for a large area. For the purpose of landslide susceptibility analysis for the whole Xiangxi catchment (3,209 km²), Artificial Neural Network (ANN) analysis was applied as the main method. The whole catchment was divided into two parts: the training area and the implementation area. The backwater area (559 km²) of Xiangxi catchment was used as the training area for the ANN method. In the training area the correlations between the landslide distribution and its causative factors, which includes lithology, slope angle, slope curvature and river network, have been analyzed based on the geological map and digital elevation model (DEM). The back-propagation training algorithm in ANN was selected to train the sample data from the training area, which were composed of input data (causative factors) and target output data (landslide occurrence), in order to find the correlations between them. Based on these correlations and input data in the implementation area (causative factors), the network output data were obtained for the implementation area. In the end, a map of landslide susceptibility, which was established by network output data, was presented for Xiangxi catchment. ArcGIS was applied to extract and quantify input information from a DEM for susceptibility analysis and also to present the result visually. As a result, a landslide susceptibility map, in which 70 % of all landslides are rightly classified in the training area (backwater area), was created for Xiangxi catchment.  相似文献   

准噶尔盆地南部四棵树河地区新近系龟壳状结构石膏脉的发现及成因     

赵晓东  杨少春  向奎  刘金华  张世奇  魏晓晴 《新疆地质》2014,(1):96-101

原生的石膏脉通常呈层、片状分布,在准噶尔盆地南部四棵树河地区野外地质考察中发现有龟壳状结构的石膏脉晶体。通过对周边地区露头实测、探勘、取样及盆地腹部钻井取心资料分析,结合前人研究成果,对龟壳状结构石膏脉形成的古环境背景、盆内沉积证据、龟裂成因和充填石膏成因进行系统研究。准噶尔盆地在三叠—新近纪为内陆浅水湖盆沉积,南部山前地区新近系沙湾组发育辫状河三角洲相和湖泊相,岩相古地理特征受湖平面升降及构造综合控制。研究区发育大量红层沉积,盆地岩石的"先成岩、后胶结"为龟壳状结构石膏脉形成提供了必要条件。综合认为,龟壳状结构石膏脉的形成可能是经"两期盐湖、四个阶段"的作用而成,主要分为一期盐湖作用的原始状态阶段和龟裂状态阶段、二期盐湖作用的龟裂注溶盐水状态和龟裂充填石膏状态。龟壳状结构石膏脉的发现可推测盆地腹部存在天然储层裂缝改造区,为预测有利区带提供地质依据,并对中国西北地区新近纪干旱沉积环境指示具一定参考意义。  相似文献   

An Overview of Ocean Predictability and Ocean Ensemble Forecast     

Wang Hui  Liu Na  Li Benxia  Li Xiang 《地球科学进展》2014,29(11):1212-1225

Ocean is a highly complex and nonlinear dynamical system. The inevitable errors in both data and numerical models lead to uncertainties in ocean numerical prediction. By understanding features and properties in the ocean on multiple scales, it is important to quantify and estimate the predictability of the ocean, and analyze the reasons and mechanism of error growth. The efforts focus on investigating the method to reduce the uncertainties and errors in forecasting and increase the time limit of ocean predictability. The advances will result in improved marine forecasting models and forecasting skill. Understanding limitations and identifying the research needed to increase accuracy will lead to fundamental progress in ocean forecast, which is of great significance. The present study described and illustrated the mechanics and computations involved in modeling and predicting uncertainties for ocean prediction and its modern applications. Firstly, it discussed the fundamental concept and classification of the ocean predictability. The research status of ocean predictability is introduced including the dynamics methodologies and the ocean ensemble prediction. Three of the dynamical computational methodologies including the singular vector, Lyapunov exponent and bred vector method were introduced. Three ocean ensemble prediction methods including initial condition ensemble, multi-model ensemble and atmospheric forcing ensemble were described and illustrated. Finally, this paper gave a future prospective of ocean predictability and its application.  相似文献   

甘肃金塔县晚古生代拐把头花岗岩地球化学特征及构造意义     

赵玮  王启航  杨春霞  王晓伟  高翔 《甘肃地质》2014,23(3):15-20

拐把头花岗岩具有高硅低铝、富钾贫钠、准铝质或I型花岗岩,明显富集Rb、Th、K等大离子不相容元素,亏损Ba、Sr、P、Ti等元素,并具有弱Nb亏损,稀土元素分布曲线呈明显的＂海鸥＂型,形成于挤压的构造背景下,代表了北山晚古生代晚期重要的构造—岩浆事件。  相似文献   

甘肃金塔县老虎山晚古生代华北型富镁埃达克岩的发现及构造动力学意义     

王启航  王晓伟  杨春霞  高翔  赵玮 《甘肃地质》2014,23(1):28-34

甘肃省金塔县老虎山一带首次发现的华北型富镁埃达克岩,地球化学特征表明具有典型C型埃达克岩特征,表现为高Sr低Y、高钾低钠,富集LREE,亏损HREE,无Eu异常或轻微异常,Mg#值(0.56)等特征显示出具有加厚下地壳部分熔融并和玄武岩浆发生混合作用的产物,暗示志留纪晚期北山古大洋已消亡,明水—公婆泉地体和马鬃山中间地块发生碰撞拼接,为北山构造演化提供了依据。  相似文献