Groundwater is important drinking water source in Longdong area. In recent years,as gradual expanding of industrial and agricultural production scales,seen from change trend of water quality,major impact factors of gr...Groundwater is important drinking water source in Longdong area. In recent years,as gradual expanding of industrial and agricultural production scales,seen from change trend of water quality,major impact factors of groundwater in the zone were ammonia nitrogen,COD,sulfate and total dissolved solid. By using specific thought of parameter system method,vulnerability assessment factor system of groundwater and meter point system calculation model in the zone were established. Via calculation and analysis,vulnerability distribution of groundwater in the zone was obtained. According to vulnerability index（ higher,moderate and lower）,zone dividing was conducted,and the areas were respectively 623. 25,4 005. 00 and 6 621. 75 km2,which respectively accounted for 5.54%,35. 60% and 58. 86%. The evaluation provided research basis for prevention,control and protection of groundwater environment in Longdong area.展开更多
Based on the cores from 47 wells and logging data of 130 wells,the main types of sand bodies in the shallow water delta of the Chang 8_(2) sub-member in the Triassic Yanchang Formation,Longdong Area,Ordos Basin were c...Based on the cores from 47 wells and logging data of 130 wells,the main types of sand bodies in the shallow water delta of the Chang 8_(2) sub-member in the Triassic Yanchang Formation,Longdong Area,Ordos Basin were comprehensively analyzed,the distribution characteristics of sand bodies more than 20 m thick were identified,and the genetic types of the thick sand bodies were sorted out.In this region,thick-bed sand bodies can be divided into two types according to the shape and position:type 1 is the sand body in wide strip and is distributed between the average high water mark and the average low water mark;type 2 is distributed on both sides of the average low water mark and is in irregular lump shape.Based on the principle of the volume distribution of sediments and the change rule of accommodation space,the genetic models of two types of thick-bed sand bodies in the Chang 8_(2) sub-member are superimposed distributary channel sand bodies in high accommodation space and superimposed composite sand bodies in low accommodation space.展开更多
Safeguarding the elderly population in the countryside is an inherent requirement for alleviating social conflicts in rural areas and effectively carrying out China’s Rural Revitalization.The existing spatial mismatc...Safeguarding the elderly population in the countryside is an inherent requirement for alleviating social conflicts in rural areas and effectively carrying out China’s Rural Revitalization.The existing spatial mismatch between rural elderly service facilities and pop-ulation distribution in China aggravates the imbalance of facility resource space,how to improve the accuracy of demand and supply results and better measuring the spatial fairness of elderly service is significant to realize the optimal allocation of rural elderly service.Based on the above,this study pays attention to the refined needs of the elderly population,and focuses on the spatial equity of the rural elderly facilities,to make up for the short boards of the basic public services in the countryside and realize the all-round rural revitalization.This study takes Huanxian County in the hilly loess area of Longdong,China as an example and explores the spatial equity of rural elderly services by using the Urban Spatial Network Analysis(UNA)to measure the accessible quantity and supply capacity of elderly services.The results found that there were 553 rural eldercare service facilities in Huanxian County,including 285 eldercare facilities and 268 medical and health facilities,and the spatial distribution is characterized by a southward shift in the east and uneven regional distribution.Overall,the supply capacity of rural pension services was generally good,with the township center as the gathering point and spreading out in a faceted manner,with nearby townships forming a contiguous area;however,there were strong contrasts and obvious differences in the strength of supply capacity.However,the spatial equity of rural eldercare service was poor.In 42.05%of the eld-erly population grid cells,eldercare service spatial equity was extremely low.The spatial distribution also presented a northern preference over the southern,a western preference over the eastern,and a concentration along the highway.The study explored the realization of spatial equity in the optimal allocation of rural elderly services based on paying attention to the refined needs of the rural elderly pop-ulation,a vulnerable group,to provide a reference for solving the shortcomings of basic public services in rural areas.The fair allocation of rural elderly services demands that the spatial optimization of facility layout be organically coordinated with policy,management,and post-maintenance,and all elements in the rural territorial system be fully mobilized to achieve the basic guarantee of China’s rural elderly problems.展开更多
文摘Groundwater is important drinking water source in Longdong area. In recent years,as gradual expanding of industrial and agricultural production scales,seen from change trend of water quality,major impact factors of groundwater in the zone were ammonia nitrogen,COD,sulfate and total dissolved solid. By using specific thought of parameter system method,vulnerability assessment factor system of groundwater and meter point system calculation model in the zone were established. Via calculation and analysis,vulnerability distribution of groundwater in the zone was obtained. According to vulnerability index（ higher,moderate and lower）,zone dividing was conducted,and the areas were respectively 623. 25,4 005. 00 and 6 621. 75 km2,which respectively accounted for 5.54%,35. 60% and 58. 86%. The evaluation provided research basis for prevention,control and protection of groundwater environment in Longdong area.
基金Supported by the National Basic Research Program of China (973 Program)(2014CB239000)China Petroleum Scientific Research and Technology Development Project (YJXK2019-16)。
文摘Based on the cores from 47 wells and logging data of 130 wells,the main types of sand bodies in the shallow water delta of the Chang 8_(2) sub-member in the Triassic Yanchang Formation,Longdong Area,Ordos Basin were comprehensively analyzed,the distribution characteristics of sand bodies more than 20 m thick were identified,and the genetic types of the thick sand bodies were sorted out.In this region,thick-bed sand bodies can be divided into two types according to the shape and position:type 1 is the sand body in wide strip and is distributed between the average high water mark and the average low water mark;type 2 is distributed on both sides of the average low water mark and is in irregular lump shape.Based on the principle of the volume distribution of sediments and the change rule of accommodation space,the genetic models of two types of thick-bed sand bodies in the Chang 8_(2) sub-member are superimposed distributary channel sand bodies in high accommodation space and superimposed composite sand bodies in low accommodation space.
基金Under the auspices of the National Natural Science Foundation of China(No.42271222)Natural Science Foundation of Gansu Province(No.22JR5RA130,22JR5RA143)。
文摘Safeguarding the elderly population in the countryside is an inherent requirement for alleviating social conflicts in rural areas and effectively carrying out China’s Rural Revitalization.The existing spatial mismatch between rural elderly service facilities and pop-ulation distribution in China aggravates the imbalance of facility resource space,how to improve the accuracy of demand and supply results and better measuring the spatial fairness of elderly service is significant to realize the optimal allocation of rural elderly service.Based on the above,this study pays attention to the refined needs of the elderly population,and focuses on the spatial equity of the rural elderly facilities,to make up for the short boards of the basic public services in the countryside and realize the all-round rural revitalization.This study takes Huanxian County in the hilly loess area of Longdong,China as an example and explores the spatial equity of rural elderly services by using the Urban Spatial Network Analysis(UNA)to measure the accessible quantity and supply capacity of elderly services.The results found that there were 553 rural eldercare service facilities in Huanxian County,including 285 eldercare facilities and 268 medical and health facilities,and the spatial distribution is characterized by a southward shift in the east and uneven regional distribution.Overall,the supply capacity of rural pension services was generally good,with the township center as the gathering point and spreading out in a faceted manner,with nearby townships forming a contiguous area;however,there were strong contrasts and obvious differences in the strength of supply capacity.However,the spatial equity of rural eldercare service was poor.In 42.05%of the eld-erly population grid cells,eldercare service spatial equity was extremely low.The spatial distribution also presented a northern preference over the southern,a western preference over the eastern,and a concentration along the highway.The study explored the realization of spatial equity in the optimal allocation of rural elderly services based on paying attention to the refined needs of the rural elderly pop-ulation,a vulnerable group,to provide a reference for solving the shortcomings of basic public services in rural areas.The fair allocation of rural elderly services demands that the spatial optimization of facility layout be organically coordinated with policy,management,and post-maintenance,and all elements in the rural territorial system be fully mobilized to achieve the basic guarantee of China’s rural elderly problems.
