基于ASTER影像的近海水产养殖信息自动提取方法   总被引：5，自引：1，他引：5  

周小成  汪小钦  向天梁  江洪 《湿地科学》2006,4(1):64-68

水产养殖地已经成为海洋环境监测的热点目标之一。采用具有高光谱分辨率和较高空间分辨率(15m)的ASTER遥感影像,以九龙江河口地区为研究示范区,进行近海水产养殖信息的自动提取方法研究。结果表明,利用ASTER影像的光谱信息和水产养殖地的纹理结构信息,可以实现近海水产养殖地的自动提取。先利用监督分类方法提取混淆有其他水体的水产养殖信息,采用邻域分析来增强水产养殖地的空间纹理信息。通过综合监督分类和水产养殖地空间纹理增强的结果,在专家决策分类器中建立决策规则,进行水产养殖地的自动提取,提取的精度达93%。  相似文献   

Adsorption of aluminium by a latosol as affected by phosphate and glutamic acid     

Jie Wen Yang  Rong Fa Guo  Sheng Qi Chen 《Environmental Geology》2006,50(6):867-871

The effect of phosphate and glutamic acid on adsorption of aluminium onto a latosol was investigated as a function of pH and ligand concentrations through batch equilibrium experiments. The results showed that adsorption of aluminium by the soil was enhanced after addition of phosphate at low pH, and this promotive effect was gradually eliminated with the increase in pH. The positive effect of phosphate on aluminium adsorption onto latosol was attributed to phosphate-induced surface negative charge and formation of ternary surface complexes involving aluminium and phosphate. While using silica as adsorbent, the inactive surfaces for phosphate, promotion of adsorption of aluminium by phosphate was also found. Then it was proposed that additional aluminium might bind to the phosphate adsorbed onto the silica in the form of surface complexes silica–aluminium–phosphate again, and the mechanism might operate in the soil systems as well. Glutamic acid exhibited no influence on the adsorption of aluminium by the soil at low pH. After increasing the pH, adsorption of aluminium was inhibited especially with the highest addition of glutamic acid, probably owing to weak affinity of complexes between glutamic acid and aluminium to the soil.  相似文献   

青海热水柴达尔井田构造组合型式     

文怀军 《中国煤田地质》2006,18(3):14-16

柴达尔井田构造可分为压缩机制的推覆构造与伸展机制的断块体两类。南北F0为逆冲型的控制性边界断裂，井田内部一系列小型弧形构造为逆掩型浅层断裂；F1、F2、F17，是拉伸作用下的同沉积正断层，切断煤系基底T3地层。其动力机制为印度板块向北推移、西伯利亚板块向南运移发生对挤，脆一韧性剪切变形导致了井用现有的构造组合形式。  相似文献   

Early Estimation of Seismic Hazard for Strong Earthquakes in Taiwan   总被引：1，自引：0，他引：1  

Wen-Yu Jean  Yu-Wen Chang  Kuo-Liang Wen  Chin-Hsiung Loh 《Natural Hazards》2006,37(1-2):39-53

A shakemap system providing rapid estimates of strong ground shaking could be useful for emergency response providers in a damaging earthquake. A hybrid procedure, which combines site-dependent ground motion prediction models and the limited observations of the Real-Time Digital stream output system (RTD system operated by Central Weather Bureau, CWB), was set up to provide a high-resolution shakemap in a near-real-time manner after damaging earthquakes in Taiwan. One of the main factors that affect the result of ground motion prediction analysis is the existence of site effects. The purpose of this paper is to investigate the local site effects and their influence in the ground shaking and then establish an early estimation procedure of potential hazard for damaging earthquakes. Based on the attenuation law, the site effects of each TSMIP station are discussed in terms of a bias function that is site and intensity-level dependent function. The standard deviation of the site-dependent ground motion prediction model can be significantly reduced. The nonlinear behavior of ground soil is automatically taken into account in the intensity-level dependent bias function. Both the PGA and the spectral acceleration are studied in this study. Based on the RTD data, event correctors are calculated and applied to precisely estimate the shakemap of damaging earthquakes for emergency response.  相似文献   

基于虚拟SAN的网格GIS数据存储技术研究     

高劲松  张文  关泽群  邓世军 《武汉大学学报(信息科学版)》2005,30(3):214-217

针对空间数据存储的特点，结合网格和虚拟SAN技术的优势，提出了基于虚拟SAN的网格GIS数据存储解决方案．旨在解决网格GIS环境下的数据存储问题。  相似文献   

陕西金矿床类型及其找矿方向     

齐文  侯满堂 《陕西地质》2005,23(1):1-10

通过对陕西金矿资源的分析、总结,将陕西金矿成因类型划分为7类14亚类;与金矿有关的成矿系列划分为3个矿床成矿系列组合,7个成矿系列类型,10个成矿系列和4个亚系列;金矿床空间分布严格受隐伏基底和出露基底,隐伏岩体、重磁吻合构造,构造和成矿时代的控制;与金成矿有关的Ⅲ级成矿区(带)有4条,有关的Ⅳ级成矿区(带)有10条,有关的Ⅴ级主要金成矿区(带)有16条;提出了金矿新的找矿方向,为今后本区金矿地质找矿的新突破提供信息.  相似文献   

镇旬矿田泥盆系和志留系铅锌矿的成矿地质条件分析   总被引：9，自引：3，他引：9       下载免费PDF全文

齐文  侯满堂 《中国地质》2005,32(3):452-462

对镇（安）旬（阳）矿田泥盆系、志留系铅锌矿的成矿地质条件分析表明，本区泥盆系、志留系铅锌矿总体属层控矿床类型。铅锌矿赋存于下志留统悔子垭组、中志留统双河镇组及中泥盆统大枫沟组、上泥盆统南羊山组；控矿构造为断裂、褶皱，容矿构造为顺层断裂带、剪切带，含矿岩石为含碳砂岩、千枚岩及灰岩、生物灰岩、白云岩；沉积环境为浅水陆棚相、台地边缘及泻湖、潮坪、台地浅海。以旬阳泗人沟为代表的志留系铅锌矿属细碎屑岩沉积强改造型铅锌矿床；以旬阳大岭、赵家庄为代表的泥盆系铅锌矿属碳酸盐岩沉积弱改造型铅锌矿床；以镇安锡铜沟、月西为代表的泥盆系铅锌矿属碳酸盐岩沉积强改造型铅锌矿床。  相似文献   

WAFS产品中GRIB资料中国区产品评估   总被引：1，自引：0，他引：1  

苏丽蓉  温志军 《气象科技》2005,33(4):373-377

为了给使用WAFS产品的用户提供量化参考依据，选取WAFS产品中常用区域和层次的GRIB数据，利用由国家气象中心提供的风、温客观分析网格点资料，与WAFS中同时刻的预报场产品（风、温网格点资料），用均方根误差进行数字化形式分析比较。结果表明：WAFS提供的风、温预报，通常是短时效的风、温预报比长时效的风、温预报更接近客观分析场；低层的预报比高层的预报更接近客观分析场；风的预报以v矢量的预报优于u矢量的预报；风的误差主要来源于u矢量的误差。  相似文献   

一种基于InSAR相干系数的SAR阴影提取方法   总被引：1，自引：0，他引：1  

王健  向茂生  李绍恩 《武汉大学学报(信息科学版)》2005,30(12):1063-1066

给出了一种新的阴影提取方法,根据阴影区域在InSAR相干系数图上的特性,利用Sigma滤波和最优阈值分割算法实现阴影的自动提取。实验结果表明,本方法是一种高效的阴影提取方法。  相似文献   

基于地表定量参数的沙漠化遥感监测方法     

曾永年  冯兆东  向南平 《国土资源遥感》2005,16(2):40-44

利用野外沙漠化调查的定位数据和ETM+ 遥感数据，在实验分析的基础上，探讨了沙漠化程度与地表参数之间的定量关系，即沙漠化与植被指数（NDVI）、地表辐射温度（LST）之间的关系，提出了综合反映沙漠化土地生物物理特征的遥感监测指数——沙漠化遥感监测差值指数（DDI），为沙漠化遥感监测提供有效的定量化方法。  相似文献