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11.
“证据权”法在西南“三江”南段矿产资源评价中的应用 总被引:3,自引:5,他引:3
证据权法本身是一种离散的多元统计方法。阐述了矿物资源潜力区的概念,简述证据权法的基本原理。以西南“三江”南段为例,首先在地质、地球物理、地球化学以及遥感地质等致矿信息提取的基础上,运用证据权法定量分析各类致矿信息(控矿因素)与矿产资源空间分布的关系;进而选择最佳控矿因素作为资源评价变量,据其变量计算每个单元的后验成矿概率;最终根据后验成矿概率定量圈定和评价找矿靶区。实践证明:在GIS环境下“,证据权”与找矿信息结合能够有效区分矿化有利地段和不利地段,从而达到定量快速圈定和评价找矿靶区之目的。整个过程是借助于MOPAS3.0评价系统实现的。 相似文献
12.
李霞宿星张满银任皓晨周自强吴玮江董耀刚王国亚 《冰川冻土》2023,(1):67-79
Analysis and assessment of landslide susceptibility using 3S technology and mathematical statistical model is still the current hot topics. It is very important for selection of unit and factor and model to the landslide susceptibility assessment reasonably. Tianshui City is selected as the study area which is in the typical regions of Longzhong ecologically vulnerable area. Based on the weights-of-evidence approach(WOE)and two kinds of assessment units(grid-unit,GU,slope-unit,SU)and also two resolutions(30 m,10 m),a total of four differ⁃ ent data sets(GU30,SU30,GU10,SU10)is established. Then quantitative analysis and contrast assessment di⁃ vision of the loess landslide susceptibility in the study area though selected four kinds of thirteen factors. The re⁃ sults show that stratum lithology,altitude,relief amplitude,roughness and slope are the key control factors of landslide development in the area. The geological factors and topographic factors control and determine the for⁃ mation and development of the landslides in study area. The susceptibility value of stratum lithology is the high⁃ est value. Statistical analysis of susceptibility division is carried out according to the point and area of landslide respectively. The landslide ratio shows that the division based on the slope-unit is higher than that of the grid-unit. Landslide susceptibility area in highest division based on the slope-unit and 10m high resolution is account⁃ ed for the highest. Therefore,it has higher precision in landslide susceptibility analysis and assessment that us⁃ ing the slope-unit and high resolution data. The landslide susceptibility result is consistent with the actual land⁃ slide development in the study area. The division results can also be used for the landslide prevention and control and national spatial planning in the study area. © 2023 Chinese Journal of General Practitioners. All rights reserved. 相似文献
13.
Weights-of-evidence (WofE) and logistic regression techniques were used in a GIS framework to predict the spatial likelihood
(prospectivity) of crushed-stone aggregate quarry development. The joint conditional probability models, based on geology,
transportation network, and population density variables, were defined using quarry location and time of development data
for the New England States, North Carolina, and South Carolina, USA. The Quarry Operation models describe the distribution of active aggregate quarries, independent of the date of opening. The New Quarry models describe the distribution of aggregate quarries when they open. Because of the small number of new quarries developed
in the study areas during the last decade, independent New Quarry models have low parameter estimate reliability. The performance
of parameter estimates derived for Quarry Operation models, defined by a larger number of active quarries in the study areas,
were tested and evaluated to predict the spatial likelihood of new quarry development. Population density conditions at the
time of new quarry development were used to modify the population density variable in the Quarry Operation models to apply
to new quarry development sites. The Quarry Operation parameters derived for the New England study area, Carolina study area,
and the combined New England and Carolina study areas were all similar in magnitude and relative strength. The Quarry Operation
model parameters, using the modified population density variables, were found to be a good predictor of new quarry locations.
Both the aggregate industry and the land management community can use the model approach to target areas for more detailed
site evaluation for quarry location. The models can be revised easily to reflect actual or anticipated changes in transportation
and population features. 相似文献
14.
基于证据权法的泥石流危险度区划 总被引:1,自引:0,他引:1
针对泥石流危险度区划方法存在不足的问题,根据泥石流形成的要素提取危险度评价因子,运用证据权法客观地筛选出评价因子和确定危险度的权重,进而优选出具有代表性的评价因子,避免了主观赋权和筛选因子的随意性;根据不同评价因子权重值的叠加来确定某一单元泥石流危险度发育程度的概率。以吉林省磐石市泥石流危险度区划为例进行验证,结果表明:中度和低度危险区内有泥石流点163个,囊括了75.81%的泥石流灾害点,符合磐石市泥石流危险度总体不高、局部地区危险度较大的实际情况。 相似文献
15.
Development and Implementation of a Bayesian-based Aquifer Vulnerability Assessment in Florida 总被引:4,自引:1,他引:4
Jonathan D. Arthur H. Alex R. Wood Alan E. Baker James R. Cichon Gary L. Raines 《Natural Resources Research》2007,16(2):93-107
The Florida Aquifer Vulnerability Assessment (FAVA) was designed to provide a tool for environmental, regulatory, resource
management, and planning professionals to facilitate protection of groundwater resources from surface sources of contamination.
The FAVA project implements weights-of-evidence (WofE), a data-driven, Bayesian-probabilistic model to generate a series of
maps reflecting relative aquifer vulnerability of Florida’s principal aquifer systems. The vulnerability assessment process,
from project design to map implementation is described herein in reference to the Floridan aquifer system (FAS). The WofE
model calculates weighted relationships between hydrogeologic data layers that influence aquifer vulnerability and ambient
groundwater parameters in wells that reflect relative degrees of vulnerability. Statewide model input data layers (evidential
themes) include soil hydraulic conductivity, density of karst features, thickness of aquifer confinement, and hydraulic head
difference between the FAS and the watertable. Wells with median dissolved nitrogen concentrations exceeding statistically
established thresholds serve as training points in the WofE model. The resulting vulnerability map (response theme) reflects
classified posterior probabilities based on spatial relationships between the evidential themes and training points. The response
theme is subjected to extensive sensitivity and validation testing. Among the model validation techniques is calculation of
a response theme based on a different water-quality indicator of relative recharge or vulnerability: dissolved oxygen. Successful
implementation of the FAVA maps was facilitated by the overall project design, which included a needs assessment and iterative
technical advisory committee input and review. Ongoing programs to protect Florida’s springsheds have led to development of
larger-scale WofE-based vulnerability assessments. Additional applications of the maps include land-use planning amendments
and prioritization of land purchases to protect groundwater resources. 相似文献
16.
Gary L. Raines Katherine A. Connors Lesley B. Chorlton 《Natural Resources Research》2007,16(2):191-198
Geologic maps are a fundamental data source used to define mineral-resource potential tracts for the first step of a mineral
resource assessment. Further, it is generally believed that the scale of the geologic map is a critical consideration. Previously
published research has demonstrated that the U.S. Geological Survey porphyry tracts identified for the United States, which
are based on 1:500,000-scale geology and larger scale data and published at 1:1,000,000 scale, can be approximated using a
more generalized 1:2,500,000-scale geologic map. Comparison of the USGS porphyry tracts for the United States with weights-of-evidence
models made using a 1:10,000,000-scale geologic map, which was made for petroleum applications, and a 1:35,000,000-scale geologic
map, which was created as context for the distribution of porphyry deposits, demonstrates that, again, the USGS US porphyry
tracts identified are similar to tracts defined on features from these small scale maps. In fact, the results using the 1:35,000,000-scale
map show a slightly higher correlation with the USGS US tract definition, probably because the conceptual context for this
small-scale map is more appropriate for porphyry tract definition than either of the other maps. This finding demonstrates
that geologic maps are conceptual maps. The map information shown in each map is selected and generalized for the map to display
the concepts deemed important for the map maker’s purpose. Some geologic maps of small scale prove to be useful for regional
mineral-resource tract definition, despite the decrease in spatial accuracy with decreasing scale. The utility of a particular
geologic map for a particular application is critically dependent on the alignment of the intention of the map maker with
the application. 相似文献
17.
Quantitative prediction and evaluation of mineral resources are one of the important topics of mathematical geology. On the basis of GIS technologies and weights of evidence modeling, MapGIS is integrated with GIS and mineral-resource prediction and evaluation. The final product is a predictor map of posterior probabilities of occurrence of the discrete event within a small unit cell. Predictor layers were created on a digital database that includes 1:200,000 scale geological, and geochemical, and geophysical maps, and remote-sensing images in study area. According to metallogenetic factors extractiont and weights of evidence modeling, there are four main metal ore belts in the study area: (1) the Batang belt; (2) the Lei Wuqi belt; (3) the Basu-Chayu belt; and (4) the Ganzi-Litang belt. The predictor map of posterior probabilities show that 29% of study area as zones with potential for porphyry copper, and 81% known mineral occurrences success rate is circled in the metallogenetic posterior probabilities map. The results demonstrate plausibility of weights-of-evidence modeling of mineral potential in large areas with small number of mineral prospects. 相似文献
18.