Based on the transmitting theory of "smoke ring effect", the transient electromagnetism technique was used in coal mines to detect abnormal areas of aquiferous structures in both roofs and floors of coal sea...Based on the transmitting theory of "smoke ring effect", the transient electromagnetism technique was used in coal mines to detect abnormal areas of aquiferous structures in both roofs and floors of coal seams and in front of excavated roadways. Survey devices, working methods and techniques as well as data processing and interpretation are discussed systematically. In addition, the direction of mini-wireframe emission electromagnetic wave of the full space transient electromagnetism technique was verified by an underground borehole for water detection and drainage. The result indicates that this technique can detect both horizontal and vertical development rules of abnormal water bodies to a certain depth below the floor of coal seams and can also detect the abnormal, low resistance water bodies within a certain distance of roofs. Furthermore, it can detect such abnormal bodies in ahead of the excavated roadway front. Limited by the underground environment, the full space transient electromagnetism technique can detect to a depth of only 120 m or so.展开更多
During the rapid industrialization and urbanization of China,urban agglomeration in river basin areas raises the problems of over-use of water resources and pollution of the water environment.Related research in China...During the rapid industrialization and urbanization of China,urban agglomeration in river basin areas raises the problems of over-use of water resources and pollution of the water environment.Related research in China has mainly focused on the conflicts among economic growth,urban expansion and water resource shortages within admin-istrative boundaries.However,water environments are much more dependent on their physical boundaries than their administrative boundaries.Consistent with the nature of water environment,this study aims at analyzing coordination relationships between urban development and water environment changes within physical river basin boundaries.We chose the Shayinghe River Basin,China,as our case study area which is facing serious challenges related to water en-vironment protection.Then we classified 35 county-level administrative units into upstream,midstream and down-stream regions based on their physical characteristics;analyzed the coordination degree of urban agglomeration using the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method;and constructed cooperative models using the Linear Programming (LP function) to simulate four scenarios of the coordination relationship be-tween urban population increase and water environment protection based on existing water resources and water pollu-tion data.The results show that the present coordinative situation in Shayinghe River Basin is not sustainable.In gen-eral,more than 50% administrative units are in the bad coordinative situation.In particular,the downstream region is under worse condition than the upstream and midstream regions.Cooperative models in scenario analyses indicate that the population scale set in existing urban master plannings is not coordinated with the water environment protection.To reach the goal of regional sustainable development,the total population needs to be controlled such that it will re-main at 4.5×10 7 or below by 2020 given the capacity of water environment.展开更多
Abrupt changes in freshwater inputs from large rivers usually imply regime shifts in coastal water environments. The influence of a water regulation event on the age of the Yellow River water in the Bohai was modeled ...Abrupt changes in freshwater inputs from large rivers usually imply regime shifts in coastal water environments. The influence of a water regulation event on the age of the Yellow River water in the Bohai was modeled using constituent-oriented age and residence time theory to better understand the change in the environmental function of the hydrodynamic field owing to human activities. The water ages in Laizhou Bay, the central basin, and the Bohai strait are sensitive to water regulation. The surface ages in those areas can decrease by about 300 days, particularly in July, and the age stratification is also strengthened. A water regulation event can result in declines in the water age in early July ahead of declines in the water age under climatological conditions(without the regulation event) by about 1 and 5 months in the central basin and Laizhou Bay, respectively. The change in the coastal circulation due to the water regulation event is the primary reason for the change in the Yellow River water age. The high Yellow River flow rate can enhance the density flow and, therefore, reduce the age of the Yellow River water. The subsequent impact of a single water regulation event can last about 1.0 to 4.0 years in different subregions.展开更多
文摘Based on the transmitting theory of "smoke ring effect", the transient electromagnetism technique was used in coal mines to detect abnormal areas of aquiferous structures in both roofs and floors of coal seams and in front of excavated roadways. Survey devices, working methods and techniques as well as data processing and interpretation are discussed systematically. In addition, the direction of mini-wireframe emission electromagnetic wave of the full space transient electromagnetism technique was verified by an underground borehole for water detection and drainage. The result indicates that this technique can detect both horizontal and vertical development rules of abnormal water bodies to a certain depth below the floor of coal seams and can also detect the abnormal, low resistance water bodies within a certain distance of roofs. Furthermore, it can detect such abnormal bodies in ahead of the excavated roadway front. Limited by the underground environment, the full space transient electromagnetism technique can detect to a depth of only 120 m or so.
基金Under the auspices of National Science and Technology Major Project (No.2009ZX07210)National Natural Science Foundation of China (No.40871261)
文摘During the rapid industrialization and urbanization of China,urban agglomeration in river basin areas raises the problems of over-use of water resources and pollution of the water environment.Related research in China has mainly focused on the conflicts among economic growth,urban expansion and water resource shortages within admin-istrative boundaries.However,water environments are much more dependent on their physical boundaries than their administrative boundaries.Consistent with the nature of water environment,this study aims at analyzing coordination relationships between urban development and water environment changes within physical river basin boundaries.We chose the Shayinghe River Basin,China,as our case study area which is facing serious challenges related to water en-vironment protection.Then we classified 35 county-level administrative units into upstream,midstream and down-stream regions based on their physical characteristics;analyzed the coordination degree of urban agglomeration using the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method;and constructed cooperative models using the Linear Programming (LP function) to simulate four scenarios of the coordination relationship be-tween urban population increase and water environment protection based on existing water resources and water pollu-tion data.The results show that the present coordinative situation in Shayinghe River Basin is not sustainable.In gen-eral,more than 50% administrative units are in the bad coordinative situation.In particular,the downstream region is under worse condition than the upstream and midstream regions.Cooperative models in scenario analyses indicate that the population scale set in existing urban master plannings is not coordinated with the water environment protection.To reach the goal of regional sustainable development,the total population needs to be controlled such that it will re-main at 4.5×10 7 or below by 2020 given the capacity of water environment.
基金the National Natural Science Foundation of China (Nos. 41176007 and 40706007)
文摘Abrupt changes in freshwater inputs from large rivers usually imply regime shifts in coastal water environments. The influence of a water regulation event on the age of the Yellow River water in the Bohai was modeled using constituent-oriented age and residence time theory to better understand the change in the environmental function of the hydrodynamic field owing to human activities. The water ages in Laizhou Bay, the central basin, and the Bohai strait are sensitive to water regulation. The surface ages in those areas can decrease by about 300 days, particularly in July, and the age stratification is also strengthened. A water regulation event can result in declines in the water age in early July ahead of declines in the water age under climatological conditions(without the regulation event) by about 1 and 5 months in the central basin and Laizhou Bay, respectively. The change in the coastal circulation due to the water regulation event is the primary reason for the change in the Yellow River water age. The high Yellow River flow rate can enhance the density flow and, therefore, reduce the age of the Yellow River water. The subsequent impact of a single water regulation event can last about 1.0 to 4.0 years in different subregions.
