顾及特征水深点距离重分配的反距离加权插值算法          下载免费PDF全文

王怀计  祝俊慧  胡莹  王瑞富 《海洋通报》2022,(1):9-18

水深是反映海底地形地貌的最基础要素,对缺失的水深点进行准确的插值能帮助有效地表达海底地形地貌起伏形态。针对海底地形变化复杂的区域,传统的反距离加权插值法存在只考虑样本水深点与待插值水深点之间的距离,而忽略了样本水深点之间的空间相关性的问题。本文提出了一种顾及特征水深点距离重分配的反距离加权插值算法。该算法首先对离散的水深点构建特征水深线,在特征水深线的基础上,提取特征水深线上的特征点作为特征水深点;然后在所有样本水深点到待插值水深点距离之和不变的约束下,提出距离重分配的量化指标;最后构造出一个顾及特征水深点距离重分配的IDW插值算法模型。实验结果表明,在海底地形变化复杂的区域,顾及特征水深点距离重分配的反距离加权插值算法与传统的IDW、自然邻域插值、样条函数插值算法等相比,能有效提高水深点的插值精准度。  相似文献   

松辽盆地砂岩层铀成矿地质条件初步探讨     

田兆成 《吉林地质》2014,(2):50-55

本文通过对松辽盆地地质条件下铀源条件、矿化异常与后期改造的数据分析与研究,得出以下结论:第一、松辽盆地边缘地区可作为今后地浸砂岩型铀矿找矿和研究工作重点,其中双辽地区和缘庆安地区为重点找矿区。第二、松辽盆地白垩系中泉头组和登娄库组为重点矿化异常层位,白垩系各组段地层中盆地边缘的河流相地层为找寻铀矿的重点对象。  相似文献   

雷暴微物理过程对电活动影响的数值模拟研究   总被引：2，自引：0，他引：2  

赵鹏国  周筠珺  邓德文  刘畅 《高原气象》2013,32(3)

在一维时变雷暴云起电放电模式的基础上,分别利用对流降水试验合作计划(CCOPE)和夏季雷暴放电与降水研究(STEPS)一次雷暴的实测探空资料进行了初步模拟,并通过敏感性试验研究了软雹垂直通量、地面温度和反转温度对雷暴云起电放电过程的影响.模式考虑的冰晶生成机制为Fletcher 和H-M冰晶生成机制.对比CCOPE和STEPS雷暴个例的模拟与观测结果,发现垂直电场正负极大值出现的位置与实测结果较接近,但电场极值差异较大,模拟结果明显大于实测结果.敏感性试验表明,当软雹垂直通量增加时,雷暴云首次放电时间降低,而单位时间内发生闪电的次数(闪频)随之增大.当地面温度较高时,雷暴云中负电荷的垂直厚度较小,雷暴云的正、负电荷最大密度较大.当反转温度较低时,冰晶所带负电荷的垂直范围较大.在敏感性试验中,当模式中地面温度为32℃,反转温度＜-26℃时,雷暴云出现反极性电荷结构.该模式能较直观地模拟雷暴发展过程中的电荷结构和电场时空分布等.  相似文献   

某地下厂房围岩特征及其稳定性分析     

郝永华  张咸恭 《地球科学》1992,17(2):212-217

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Textural re-equilibration,hydrothermal alteration and element redistribution in Fe-Ti oxide pods,Singhbhum Shear Zone,eastern India     

《Chemie der Erde / Geochemistry》2021,81(1):125679

This study describes textures and mineral chemistry of magnetite-ilmenite-bearing pods/pockets in mineralogically diverse feldspathic schist near Pathargora in the Singhbhum Shear Zone, eastern India. The textural and geochemical characteristics of the magnetite-ilmenite assemblage are the results of a protracted geological history involving magmatic crystallization and oxidation-exsolution of titanomagnetite, deformation-induced recrystallization and textural re-equilibration and hydrothermal fluid-induced hematitization of magmatic magnetite. The magnetite grains contain characteristic trellis and sandwich ilmenite lamella, which are interpreted to be the products of oxidation-exsolution of ulvöspinel component of magnetite-ulvöspinel solid solution. The exsolution process was accompanied by preferential partitioning of spinel elements such as Cr, Al and V in magnetite and Ti, Mn, Mg, HFS elements (Nb, Ta), transition elements (Sc, Co, Cu and Zn) and granitophile elements (Mo, Sn and W) in ilmenite. The deformed sandwich lamella is locally recrystallized and transformed into granular ilmenite close to fractures, micro-shear planes and magnetite grain boundaries. Coarse granules of ilmenite, within or associated with magnetite, are of two textural types: one invariably contains Fe-rich exsolved phase and may be of magmatic origin, while the other mostly formed by strain-induced, fluid-mediated expulsion (from the interior of magnetite to its boundary) and dynamic recrystallization of existing ilmenite lamella in magnetite, and dynamic recrystallization of primary ilmenite containing Fe-rich exsolved phases. Magnetite is variably hematitized. The highly porous nature and trace element geochemistry of hematite and mass-balance calculations suggest the hematitization was mostly redox-independent and was caused by infiltration of metal-rich, reduced and acidic fluid. The hematitization process was associated with significant enrichment and immobilization of U, Th, Pb, REEs, Cu, Mo and W and depletion of Ni, Cr, V in hematite.  相似文献   

Modelling dynamic water redistribution patterns in arid catchments in the Negev Desert of Israel     

E. Buis  A. Veldkamp 《地球表面变化过程与地形》2008,33(1):107-122

In arid climate regions, redistribution of runoff water is highly relevant for vegetation development. The process of water redistribution at catchment scale is studied with the landscape process model LAPSUS, mainly used for erosion and sedimentation modelling. LAPSUS, formerly applied in Mediterranean climates, is modified to deal with the arid climate of the Negev Desert of Israel. Daily event based model runs were used instead of yearly model runs, and the infiltration module was modified to better represent the spatial diversity in water availability in an arid catchment. The model is calibrated for two small catchments in the Negev Desert of Israel, Halluqim and Avdat. First, a sensitivity analysis of the modified LAPSUS is performed. Pore volume appears to have an especially strong influence on the modelling results. Second, the capability of LAPSUS to deal with varying surface characteristics is assessed by comparing the water redistribution patterns in the two catchments with field data. Simulation results demonstrate that the catchments respond very differently to precipitation. Water redistribution is larger in the dominantly bedrock covered Halluqim compared to the dominantly loess covered catchment of Avdat. Consequently, Halluqim has more positions with water accumulation than Avdat, and can sustain a larger vegetation cover, including Mediterranean species. Finally, the modelled infiltration patterns are compared with vegetation cover in the catchments. The results indicate that there is a broad agreement between infiltration and vegetation patterns, but locally there is a strong mismatch, indicating that some of the involved processes are still missing from the model. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

荒漠化草原植被斑块分布对地表径流、侵蚀及养分流失的影响   总被引：5，自引：2，他引：3  

李小军  汪君  高永平 《中国沙漠》2011,31(5):1112-1118

地表径流是干旱区水、养分和土壤物质迁移和再分配的主要途径之一,它在很大程度上受植被格局的影响。研究了腾格里沙漠东南缘生物土壤结皮斑块和灌丛斑块镶嵌分布的植被格局对地表径流、侵蚀及其驱动下的资源再分配的影响。结果表明,植被斑块对地表径流和侵蚀产物起着拦截作用,能显著减少资源的流失。生物土壤结皮斑块和植被斑块之间存在资源(径流、侵蚀产物及养分等)再分配的源-汇关系。模拟降雨条件下,含有灌丛斑块和生物土壤结皮斑块的样方出现表面积水和径流需要的时间均显著大于只含生物土壤结皮斑块的样方;含两类斑块的样方出现径流需要的降雨量显著大于只含生物土壤结皮斑块的样方。在模拟降水和自然降水条件下,生物土壤结皮斑块产生的径流、侵蚀产物、有机质、氮及溶解养分中均大量被位于下坡向的灌丛斑块截获;灌丛斑块土壤水分入渗深度显著大于结皮斑块。灌丛斑块对生物土壤结皮斑块产生的地表径流、侵蚀产物及其携带的资源的捕获能显著减少资源流失,有效地防止荒漠化的进一步发生发展。  相似文献   

郜城煤矿构造岩井壁破坏机制研究     

王志荣  陈玲霞 《煤田地质与勘探》1994,22(5):38-40

在详细研究构造岩软弱夹层工程地质特性的基础上,对构造岩井壁的应力应变进行了细致分析。并根据岩石强度理论计算出井壁塑性变形区半径,可供建井部门在锚喷支护及设计注浆孔深时参考。   相似文献