外文翻譯--以gis為基礎(chǔ)的煤礦開采沉陷危機(jī)分析-文庫吧
2024-12-24 08:43 本頁面
【正文】 ccurrence for a given attribute. In the case of subsidence occurrence, if the subsidence event is denotedB and a given factor’s attribute is denoted D, then the frequency ratio of D is the ratio of the conditional probabilities of B . Therefore, the greater this ratio, the stronger the relationship between subsidence occurrence and the given factor’s attribute. The frequency ratio was calculated for each factor type or range that had been identified as significant with respect to causing ground subsidence. The ratios were used for calculating the ground subsidence hazard index (GSHI) and mapping. There have been a few studies carried out on ground subsidence hazard evaluations using the frequency ratio and a GIS。 for example, Kim et al. ( 2022) introduced the analysis of ground subsidence hazard and summarized many ground subsidence hazard evolution studies. Diagrams presented in show the steps for calculating the frequency ratio: (a) finding locations of groundsubsidence, (b) representing cells of class 1 for factor A and (c) describing the area of spatial overlap for areas of subsidence and areas of class 1 for factor A. In the present example in which the study area prises 64 cells, there are 23 ground subsidence cells and 19 cells that are of class 1 for factor A. There are 12 cells of subsidence that are also cells of class 1 for factor A. The percentages for subsidence area with respect to class 1 for factor A and the entire domain are and %, respectively. Therefore, the frequency ratio of class 1 for factor A is . Sensitivity analysis Sensitivity analyses show how a solution changes when the input factors are changed. If the selection of a factor results in a relatively large change in the oute, then the oute is said to depend on that factor. Sensitivity analysis quantifies the uncertainty of each factor. The factors that have the greatest impact on the calculated subsidence hazard map can therefore be identified. Sensitivity analyses model behavior by determining the rate of change in the model output as parameters or input data are varied, thus giving an understanding of how changes in the inputs influence the output. Such analyses explain how inputs affect the output and quantify the strengths of the inputs from the variations in the output. Sensitivity analysis has been applied in a variety of studies. Arhonditsis and Brett (2022) introduced process formulations and sensitivity analysis for a plex eutrophication model of Lake Washington, USA. Joo et al. ( 1998) represented the sensitivity of the leachate level to reduce the high leachate level in landfill. Sensitivity analysis has been applied to landslide susceptibility hazard mapping (Lee and Talib2022). In the present study, the sensitivity analyses were conducted to determine factors involved in ground subsidence. To extract subsidencerelated factors, the frequency ratio model and sensitivity analysis were employed. The sensitivity analysis pared the effects of all factors except one. Data Many studies have identified important factors that contribute to ground subsidence around coal mines (. Waltham 1989。 Coal Industry Promotion Board 1997), including the depth and height of mine cavities, excavation method, degree of inclination of the excavation, scope of mining, structural geology, flow of groundwater and the mechanical characteristics represented by the rock mass rating (RMR). In this study, locations of ground subsidence and factors governing the occurrence of ground subsidence were collected in a vectortype spatial database and then represented on a grid using the ArcGIS software package. The spatial database is shown in Table 1 . The database included a 1:5,000 ground subsidence map, 1:50,000 geological map, 1:5,000 topographic map, 1:5,000 land use map, 1:1,200 mine tunnel map, borehole data and satellite imagery with 1 m resolution. The site Jeongahm was ch
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