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黄土丘陵区地形破碎、沟壑纵横，为遥感影象的土地利用自动分类带来了很大困难。仅依靠传统的光谱统计分类方法，难以达到较高的分类精度。本文拟探讨在黄土丘陵区运用大比例尺地形图数据，建立区域数字地貌模型；并在模糊数学理论的指导下，运用数字地貌模型对影象的分层分类结果进行修正和细化。研究表明，此方法能够有效地提高土地利用分类精度和机助制图比例尺。 相似文献
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Exchange flux of total gaseous mercury between air and natural water surfaces in summer season 总被引：5，自引：0，他引：5
The exchanges of mercury between surface and air are of significance in the biogeochemical cycling of Hg in the environment,
but there are still few reliable data on air/surface exchange in aquatic systems. Field measurement campaigns over seawater
surface at Kristineberg Marine Research Station (KMRS) and over Hovg?rds?n River surface at Knobesholm in southwestern Sweden
were conducted to measure mercury flux using a dynamic flux chamber technique coupled with automatic mercury vapor-phase analyzers.
Both sites show net emissions during summer time. Mercury fluxes measured over both river and seawater surfaces exhibit a
consistently diurnal pattern with maximum fluxes during the daytime period and minimum fluxes during the nighttime period.
At freshwater site, mercury flux is strongly correlated with the intensity of net solar radiation, and negatively correlated
with relative humidity. A typical exponential relationship between mercury flux and water temperature was observed at freshwater
measurement site. At seawater site, a strong correlation between mercury flux and intensity of solar radiation was obtained.
The driving force of mercury emission from water surface to air is the super-saturation of dissolved gaseous mercury in aqueous
phase. 相似文献
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在简要介绍三维体元拓扑数据模型建模原理的基础上,分析了三维体元拓扑数据模型的不足,并从处理含夹层地质体和由非平行剖面构建地质体两个方面,改进了三维体元拓扑数据模型的建模条件和数据结构。实验表明,改进后的数据模型更加适合基于剖面的三维地质建模。 相似文献
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正Three-dimensional geological modeling(3DGM) assists geologists to quantitatively study in three-dimensional(3D) space structures that define temporal and spatial relationships between geological objects.The 3D property model can also be used to infer or deduce causes of geological objects.3DGM technology provides technical support for extraction of diverse geoscience information,3D modeling,and quantitative calculation of mineral resources.Based on metallogenic concepts and an ore deposit model, 3DGM technology is applied to analyze geological characteristics of the Tongshan Cu deposit in order to define a metallogenic model and develop a virtual borehole technology;a BP neural network and a 3D interpolation technique were combined to integrate multiple geoscience information in a 3D environment. The results indicate:(1) on basis of the concept of magmatic-hydrothermal Cu polymetallic mineralization and a porphyry Cu deposit model,a spatial relational database of multiple geoscience information for mineralization in the study area(geology,geophysics,geochemistry,borehole,and cross-section data) was established,and 3D metallogenic geological objects including mineralization stratum,granodiorite, alteration rock,and magnetic anomaly were constructed;(2) on basis of the 3D ore deposit model,23,800 effective surveys from 94 boreholes and 21 sections were applied to establish 3D orebody models with a kriging interpolation method;(3) combined 23,800 surveys involving 21 sections,using VC++ and OpenGL platform,virtual borehole and virtual section with BP network,and an improved inverse distance interpolation(IDW) method were used to predict and delineate mineralization potential targets (Cu-grade of cell not less than 0.1%);(4) comparison of 3D ore bodies,metallogenic geological objects of mineralization,and potential targets of mineralization models in the study area,delineated the 3D spatial and temporal relationship and causal processes among the ore bodies,alteration rock,metallogenic stratum,intrusive rock,and the Tongshan Fault.This study provides important technical support and a scientific basis for assessment of the Tongshan Cu deposit and surrounding exploration and mineral resources. 相似文献
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