Sequential indicator simulation is a commonly used method for discrete variable simulation in 3D geological modeling and a widely used stochastic simulation method, which can be used not only for continuous variable s...Sequential indicator simulation is a commonly used method for discrete variable simulation in 3D geological modeling and a widely used stochastic simulation method, which can be used not only for continuous variable simulation but also for discrete variable simulation. In this paper, the X Oilfield in the western South China Sea is taken as an example to compare the sequential indicator simulation method and the Indicator Kriging interpolation method. The results of the final comparison show that the results of the lithofacies model established by the Indicator Kriging deterministic interpolation method are overly smooth, and its coincidence rate with the geological statistical results is not high, thus cannot well reflect the heterogeneity of the underground reservoir, while the simulation results of the lithofacies model established by the sequential indicator stochastic simulation method can fit well with the statistical law of the well, which has eliminated the smoothing effect of Kriging interpolation, thus can better reflect the heterogeneity of the underground reservoir. Therefore, the sequential indicator simulation is more suitable for the characterization of sand bodies and the study of reservoir heterogeneity.展开更多
Arsenic poses a danger to public health and drinking arsenic-rich groundwater is the main route for human exposure to this element.The focus of this study is to assess the risk magnitude and likelihood for arsenic-ric...Arsenic poses a danger to public health and drinking arsenic-rich groundwater is the main route for human exposure to this element.The focus of this study is to assess the risk magnitude and likelihood for arsenic-rich groundwater in Huaihe River Plain,China using Risk Magnitude and Indicator Kriging methods.It has been found that 481 in 5515 investigated samples exceed the drinking water standards of the World Health Organization,which present a high exposure risk for public health.Arsenic concentrations range from 0.001 to 356.00 mg/L,with a median of 2.10 mg/L.The proportion of contaminated shallow groundwater samples is 9.77%,and the counterpart from deep layer is 2.85%,respectively.Arsenic concentrations are obviously higher in plain areas than those in hilly areas.High Risk Magnitude and Very High Risk Magnitude samples are sporadically positioned in inland and coastal plain.According to the prediction of Risk Probability maps over shallow and deep groundwater,high arsenic Risk Probability areas is scattered in the inland and coastal portion,and both Risk Probability peaks are similar.Some high arsenic hazard areas have been found to possess high cancer rates,and high Risk Probability peaks are correlated with cancer cluster.The potential high arsenic hazard areas over shallow groundwater encompass more than 4709 km^(2),while the counterpart over deep groundwater is 1446 km2.2.88 million people are estimated to be potentially exposed to High Risk Probability of arsenic.This paper carried out research on exposure risk of arsenic contamination from Huaihe River Plain,China,which may provide guidance for regionalization of drinking groundwater safety.展开更多
文摘Sequential indicator simulation is a commonly used method for discrete variable simulation in 3D geological modeling and a widely used stochastic simulation method, which can be used not only for continuous variable simulation but also for discrete variable simulation. In this paper, the X Oilfield in the western South China Sea is taken as an example to compare the sequential indicator simulation method and the Indicator Kriging interpolation method. The results of the final comparison show that the results of the lithofacies model established by the Indicator Kriging deterministic interpolation method are overly smooth, and its coincidence rate with the geological statistical results is not high, thus cannot well reflect the heterogeneity of the underground reservoir, while the simulation results of the lithofacies model established by the sequential indicator stochastic simulation method can fit well with the statistical law of the well, which has eliminated the smoothing effect of Kriging interpolation, thus can better reflect the heterogeneity of the underground reservoir. Therefore, the sequential indicator simulation is more suitable for the characterization of sand bodies and the study of reservoir heterogeneity.
基金the Science and Technology Programme of the Jiangsu Province(BK20151093)the Chinese Project of the National Geological Survey(DD20221756).
文摘Arsenic poses a danger to public health and drinking arsenic-rich groundwater is the main route for human exposure to this element.The focus of this study is to assess the risk magnitude and likelihood for arsenic-rich groundwater in Huaihe River Plain,China using Risk Magnitude and Indicator Kriging methods.It has been found that 481 in 5515 investigated samples exceed the drinking water standards of the World Health Organization,which present a high exposure risk for public health.Arsenic concentrations range from 0.001 to 356.00 mg/L,with a median of 2.10 mg/L.The proportion of contaminated shallow groundwater samples is 9.77%,and the counterpart from deep layer is 2.85%,respectively.Arsenic concentrations are obviously higher in plain areas than those in hilly areas.High Risk Magnitude and Very High Risk Magnitude samples are sporadically positioned in inland and coastal plain.According to the prediction of Risk Probability maps over shallow and deep groundwater,high arsenic Risk Probability areas is scattered in the inland and coastal portion,and both Risk Probability peaks are similar.Some high arsenic hazard areas have been found to possess high cancer rates,and high Risk Probability peaks are correlated with cancer cluster.The potential high arsenic hazard areas over shallow groundwater encompass more than 4709 km^(2),while the counterpart over deep groundwater is 1446 km2.2.88 million people are estimated to be potentially exposed to High Risk Probability of arsenic.This paper carried out research on exposure risk of arsenic contamination from Huaihe River Plain,China,which may provide guidance for regionalization of drinking groundwater safety.
