Geohazard recognition and inventory mapping are absolutely the keys to the establishment of reliable susceptibility and hazard maps. However, it has been challenging to implement geohazards recognition and inventory m...Geohazard recognition and inventory mapping are absolutely the keys to the establishment of reliable susceptibility and hazard maps. However, it has been challenging to implement geohazards recognition and inventory mapping in mountainous areas with complex topography and vegetation cover. Progress in the light detection and ranging(Li DAR) technology provides a new possibility for geohazard recognition in such areas. Specifically, this study aims to evaluate the performances of the Li DAR technology in recognizing geohazard in the mountainous areas of Southwest China through visually analyzing airborne Li DAR DEM derivatives. Quasi-3 D relief image maps are generated based on the sky-view factor(SVF), which makes it feasible to interpret precisely the features of geohazard. A total of 146 geohazards are remotely mapped in the entire 135 km^(2) study area in Danba County, Southwest China, and classified as landslide, rock fall, debris flow based on morphologic characteristics interpreted from SVF visualization maps. Field validation indicate the success rate of Li DAR-derived DEM in recognition and mapping geohazard with higher precision and accuracy. These mapped geohazards lie along both sides of the river, and their spatial distributions are related highly to human engineering activities, such as road excavation and slope cutting. The minimum geohazard that can be recognized in the 0.5 m resolution DEM is about 900 m^(2). Meanwhile, the SVF visualization method is demonstrated to be a great alternative to the classical hillshaded DEM method when it comes to the determination of geomorphological properties of geohazard. Results of this study highlight the importance of Li DAR data for creating complete and accurate geohazard inventories, which can then be used for the production of reliable susceptibility and hazard maps and thus contribute to a better understanding of the movement processes and reducing related losses.展开更多
To fully exploit the technical advantages of the large-depth and high-precision artificial source electromagnetic method in the complex structure area of southern Sichuan and compensate for the shortcomings of the con...To fully exploit the technical advantages of the large-depth and high-precision artificial source electromagnetic method in the complex structure area of southern Sichuan and compensate for the shortcomings of the conventional electromagnetic method in exploration depth,precision,and accuracy,the large-depth and high-precision wide field electromagnetic method is applied to the complex structure test area of the Luochang syncline and Yuhe nose anticline in the southern Sichuan.The advantages of the wide field electromagnetic method in detecting deep,low-resistivity thin layers are demonstrated.First,on the basis of the analysis of physical property data,a geological–geoelectric model is established in the test area,and the wide field electromagnetic method is numerically simulated to analyze and evaluate the response characteristics of deep thin shale gas layers on wide field electromagnetic curves.Second,a wide field electromagnetic test is conducted in the complex structure area of southern Sichuan.After data processing and inversion imaging,apparent resistivity logging data are used for calibration to develop an apparent resistivity interpretation model suitable for the test area.On the basis of the results,the characteristics of the electrical structure change in the shallow longitudinal formation of 6 km are implemented,and the transverse electrical distribution characteristics of the deep shale gas layer are delineated.In the prediction area near the well,the subsequent data verification shows that the apparent resistivity obtained using the inversion of the wide field electromagnetic method is consistent with the trend of apparent resistivity revealed by logging,which proves that this method can effectively identify the weak response characteristics of deep shale gas formations in complex structural areas.This experiment,it is shown shows that the wide field electromagnetic method with a large depth and high precision can effectively characterize the electrical characteristics of deep,low-resistivity thin layers in complex structural areas,and a new set of low-cost evaluation technologies for shale gas target layers based on the wide field electromagnetic method is explored.展开更多
Marine shale gas in the southern Sichuan Basin is the most successful area of shale gas exploration and development in China.In order to open up new shale gas fields and search for new shale gas reserves and productio...Marine shale gas in the southern Sichuan Basin is the most successful area of shale gas exploration and development in China.In order to open up new shale gas fields and search for new shale gas reserves and production replacement blocks,it is necessary to continuously establish and complete the standards on shale gas reservoir evaluation and area selection under different structural settings.The early exploration practice shows that shale in the mountainous complex structural area along the southwestern margin of the Sichuan Basin varies greatly in the gas bearing property,so systematical analysis and study on the shale gas enrichment mechanisms in this area is of great significance to searching for new shale gas exploration areas.Based on drilling data of 5 wells in the mountainous complex structural area along the southwestern margin of the Sichuan Basin,the main factors controlling the shale gas bearing property and the shale gas enrichment model were discussed based on the systematical experiments and analysis of the outcrops,cores and cuttings of Longmaxi Formation shale from the aspects of organic geochemistry,physical property,gas content,hydrocarbon generation history and pore evolution history,so as to lay a solid geological basis for the birth of a new shale gas area.And the following research results were obtained.First,the shale of the first submember of first Member of Longmaxi Formation(S1l11)in the mountainous complex structural area along the southwestern margin of the Sichuan Basin has an average TOC of 3.02%–4.97%and Ro of 2.38%–3.37%,and the average total gas content in local enrichment zones is up to 4.62 m^(3)/t,so it is classified as quality shale.Second,the detailed studies on hydrocarbon generation history indicate that the shale has the characteristics of“low thermal evolution rate and low maturity”.It is characterized by late hydrocarbon generation,low thermal evolution rate,low current maturity and short late diffusion time,which are favorable for shale gas enrichment.Third,the pore evolution history reveals that shale pore evolution can be divided into six stages,i.e.,sharp pore reduction,pore reduction,organic pore formation,pore preservation,organic pore dissipation and karstification,and organic pore and TOC are the most direct control factors of shale gas content.Fourth,favorable shelf facies belt is conducive to the formation of large-scale reservoir space and effective pores,and diversities of preservation conditions under different structural styles and at different structural positions control different pore evolution stages.The shale gas in the mountainous complex structural area is characterized by horizontal zoning and differential enrichment.“Low thermal evolution rate and low maturity”and“slow structural uplifting”are beneficial to the long-term enrichment and preservation of shale gas.In conclusion,the mountainous complex structural area along the southwestern margin of the Sichuan Basin has a shale gas enrichment model of“sedimentation controlling source rocks,diagenesis controlling reservoirs and structure controlling preservation”.This research result provides idea and reference for searching for new shale gas areas and fields.展开更多
A number of Triassic (245-195 Ma) alkaline or subalkaline igneous complexes were discovered in theYan-liao area in the northern part of the North China platform. These complexes are all poor in SiO_2; most ofthem are ...A number of Triassic (245-195 Ma) alkaline or subalkaline igneous complexes were discovered in theYan-liao area in the northern part of the North China platform. These complexes are all poor in SiO_2; most ofthem are rich in Fe, Mg, K and P and such incompatible elements as Rb, Ba, U and Sr and REE; theinitial ^(87)Sr / ^(86)Sr ratios range from 0.7055 to 0.7057. They might have originated in the altered upper mantle.On that basis coupled with the distribution of the Triassic System and the tectonic deformation, it is suggestedthat there should have existed a tectono-magmatic belt in the area in Triassic time, which is an important mani-festation of the Indosinian movement in the area.展开更多
In the background of a new round reform and western development strategy, making suitability evaluation of construction land complex topography area in southwest China scientifically and accurately has an important gu...In the background of a new round reform and western development strategy, making suitability evaluation of construction land complex topography area in southwest China scientifically and accurately has an important guiding significance on the construction of local urban and rural development. We selected economic factor of construction, safety factor of construction, factor of the present situation of land use and ecological protection factor in Tongzi county as evaluation indexes, and ascertained the weight of each elastic indicator using the analytic hierarchy process method. By the support of GIS and RS technology, we combined the single-factor qualitative classification with the multi-factor weighted overlay analysis to make comprehensive suitability evaluation of construction land on the whole study area. And five different types of construction land were divided, namely, ‘excellent', ‘very good', ‘good', ‘moderate' and ‘poor'. The result shows that the area of ‘excellent' construction land is 30.47 km^2(0.95%), 101.46 km^2(3.16%) of ‘very good', 550.34 km^2(17.16%) of ‘good', and 664.69 km^2(20.72%) and 1 860.65 km^2(58.01%) of ‘moderate' and ‘poor', respectively. The land space bearing capacity is a population of 791 600, and the remaining population capacity is 170 900 persons.展开更多
Using energy analysis,the quantifying evaluation and study method on production, living and ecology functions and their sustainability of rural settlement ecosystem in mountain area is established with these energy in...Using energy analysis,the quantifying evaluation and study method on production, living and ecology functions and their sustainability of rural settlement ecosystem in mountain area is established with these energy index such as export of labor and products, export of water resource, internal energy reserve, energy consumption for human living, net energy of ecosystem function and net internal reserve. Taking rural settlement Raosi Village in Hengduan Mountains as a case study, and on the basis of the synthetic research into the ecological process of the complex ecosystem, the study shows that energy costs of production, human living and ecology functions are separately taking 1.36%, 13.59% and 85. 05% of the gross ecosystem functions, and the exertions of production and human living functions are close to a high-point state on the present using level of energy in the settlement. The study also shows that the most important function of a rural settlement in mountain area is its ecological rather productive function.展开更多
On the basis of previous studies and by means of field geological, remote sensing, petrographical,mineralogical, petrochemical and geochemical investigations, the authors studied the temporal-spatial distribu-tion of ...On the basis of previous studies and by means of field geological, remote sensing, petrographical,mineralogical, petrochemical and geochemical investigations, the authors studied the temporal-spatial distribu-tion of the regional structures, volcanic structures and products of volcanic activity in the coastal area ofsoutheastern Zhejiang. On the basis and through a systematic comparison of the products of magmatism in thearea, it is considered that there exists a compsite volcanic structural belt composed of linear and circular struc-tures and it has been demonstrated that there exist volcanic intrusive complexes--'trinity' composed of vol-canic, subvolcanic and plutonic rocks. It is suggested that the volcanic intrusive complexes in the area belong tothe typical syntexis series and that its materials were derived from a mixed source of crust and mantle.展开更多
Jiyang depression, which is the main oil productive area of Shengli oil field, is located at the southeast part of the Bohai Bay Basin and is a terrestrial lacustrine rift subsidence basin formed in the late Mesozoic ...Jiyang depression, which is the main oil productive area of Shengli oil field, is located at the southeast part of the Bohai Bay Basin and is a terrestrial lacustrine rift subsidence basin formed in the late Mesozoic with fully developed fault system. The main hydrocarbon productive formations of this depression are the terrestrial clastic rocks of the Tertiary, which are of strong lateral variation. The complex fault reservoirs and subtle lithological reservoirs distributed extensively and are becoming the main exploration targets in recent years. The exploration and development practice in these years has formed the exploration technologies, mainly including detailed study and description of low grade faults, delineation of microstructures, facies constrained formation description and prediction and low resistivity oil bearing formation’s identification. These exploration technologies have resulted in remarkable effectiveness on the reserve and oil production increments.展开更多
The Huanggang intrusive complex in northern Tongbai area was formed in Early Paleozoic. It mainly consists of ultra basic, basic, intermediate and acid rocks, dominated by intermediate and basic rocks. The complex be...The Huanggang intrusive complex in northern Tongbai area was formed in Early Paleozoic. It mainly consists of ultra basic, basic, intermediate and acid rocks, dominated by intermediate and basic rocks. The complex belongs to calc alkaline series. Geochemical characteristics of major and trace elements show that the complex was derived from the fractional crystallization of co source magma. It is suggested that the complex was formed in island arc tectonic environment and was closely related to the northward subduction of the Erlangping back arc basin. Thus, the subduction of the back arc basin can induce the island arc type magmatism similar to the one formed in the setting of ocean plate subduction.展开更多
This article discusses the design strategy of complex mountain highway bridges.During the research phase,details were obtained based on prior literature review and analysis of engineering materials from mountainous ar...This article discusses the design strategy of complex mountain highway bridges.During the research phase,details were obtained based on prior literature review and analysis of engineering materials from mountainous area bridges.After analyzing the design characteristics of complex mountainous area road and bridge projects,the principles for the design of bridges on complex mountainous area expressways were proposed.The research on bridge design was carried out from five dimensions:bridge type selection,foundation design,superstructure design,connection part design,and material and technological innovation.Eventually,a relatively complete design system was formed.It is expected that this paper can provide technical references and value for road and bridge projects in China and promote the sustainable development of China’s road traffic system from a macro perspective.展开更多
The multifractal characteristics of organic-rich shale developed along the margins of basins are essential for understanding reservoir heterogeneity,gas storage mechanisms,and the identification of favorable explorati...The multifractal characteristics of organic-rich shale developed along the margins of basins are essential for understanding reservoir heterogeneity,gas storage mechanisms,and the identification of favorable exploration targets.This study systematically investigates the pore structure of marine shale in the Zhaotong area of the National Shale Gas Exploration Demonstration Area in China by integrating analytical methods such as X-ray diffraction,low-pressure N_(2) adsorption,and field emission scanning electron microscopy with the Frenkel-HalseyHill fractal model.The results reveal that:(1)four distinct shale lithofacies(SL)types were identified-argillaceous/siliceous mixed SL(Type Ⅰ:M-2),carbonate/siliceous mixed SL(Type Ⅱ:M and M-1),argillaceous-rich siliceous SL(Type Ⅲ:S-3),and carbonate-rich and argillaceous/carbonate siliceous SL(Type Ⅳ:S-1 and S-2);(2)Types Ⅱ and Ⅳ generally exhibit higher fractal dimensions(D_(1),D_(2),and D_(3))than Types Ⅰ and Ⅲ,indicating the former’s more complex pore architectures,rougher pore surfaces,and greater potential for gas adsorption;(3)for Types Ⅰ and Ⅲ,fractal dimensions exhibit positive correlations with organic matter content,pore structural parameters,and gas content,suggesting their effectiveness as indicators of reservoir quality.In contrast,in Types Ⅱ and Ⅳ,the D_(2) dimension is positively correlated with gas content,implying that mesopores play a significant role in gas occurrence,even in tectonically modified settings.These results highlight the utility of fractal analysis as a robust method for evaluating reservoirs in structurally complex geological environments.展开更多
Concentrations of dissolved organic matter (DOM), dissolved humic substances (DHS), and DOM-complexed Fe (DOM-Fe) in Yamakuni and Oita Rivers, Japan, of which headstream is near in location, flow pass length is simila...Concentrations of dissolved organic matter (DOM), dissolved humic substances (DHS), and DOM-complexed Fe (DOM-Fe) in Yamakuni and Oita Rivers, Japan, of which headstream is near in location, flow pass length is similar, but watershed soil type differs, were investigated. Soil organic matter level was higher in black Andosols distributing 67% of the watershed area of the Oita River than in Cambisols covering 90% of the watershed area of Yamakuni River. However, the DOM concentration in the Yamakuni River (0.44 - 1.62 mg·C·L-1) tended to be higher than that in the Oita River (0.13 - 1.37 mg·C·L-1). DHS accounted for 49% - 80% of DOM in both rivers. Fe and DOM-Fe concentrations showed a trend to increase toward downstream but decrease at the estuary in both rivers. DOM-Fe accounted for 26% - 90% and 55% - 93% of dissolved Fe in the Yamakuni and Oita Rivers, respectively. Correlation analysis suggested that the DOM-Fe concentration in the river water was controlled by the capacity for supplying Fe ions rather than that for supplying DOM. Although the ability to form a complex with Fe was suggested to be greater in the DOM in the Oita River than that in the Yamakuni River, the DOM-Fe concentration at the estuary was similar in the two rivers. Thus, the effect of soil organic matter level in the watershed area on the supply of Fe or DOM-Fe to the estuarine ecosystem was not significant.展开更多
The Keta Lagoon and its catchment areas in Ghana are influenced by intensive agriculture and the use of agro-chemicals. It has therefore, become necessary to assess the quality of water in the lagoon and the surroundi...The Keta Lagoon and its catchment areas in Ghana are influenced by intensive agriculture and the use of agro-chemicals. It has therefore, become necessary to assess the quality of water in the lagoon and the surrounding fresh water aquifers. In this study, a water quality index (WQI), indicating the water quality has been adopted. The WQI was determined on a basis of various physico-chemical parameters like pH, conductivity, turbidity, dissolved oxygen, calcium, magnesium, chloride, nitrates, ammonium and sodium. The index was used both for tracking changes at one site over time, and for comparisons among sites. The WQI was also employed to wells used for irrigation on farms along the Keta Sand Spit as well as that of the Keta Lagoon Complex and its surrounding floodplains, in order to ascertain the quality of water for public and livestock consumption, irrigation, recreation and other purposes. The WQI of the wells, Keta lagoon and its floodplains showed various degrees of poor water quality and therefore considered unsuitable for drinking and recreation. By WHO standards, this calls for intensive physical and chemical treatment of the water for human consumption.展开更多
In Mesozoic-Cenozoic faulted basin in the periphery of Daqing exploration area, the clastic reservoirs mainly consist of siltstone and gravel-bearing sandstone. The electrical conductivity of the reservoirs is complic...In Mesozoic-Cenozoic faulted basin in the periphery of Daqing exploration area, the clastic reservoirs mainly consist of siltstone and gravel-bearing sandstone. The electrical conductivity of the reservoirs is complicated due to the complex pore structures, which cannot be accurately interpreted with commonly used model. In order to solve the problem, a three-water model has been applied in this study based on in-depth analysis of the conductive mechanism of rocks in the explored area, and favorable application results are achieved.展开更多
The working area is located in the industrially developed region of Rongshengpu-Qianjin, where a surface water system is developed, surface-layer lithology is complicated, and various kinds of hydrocarbon traps are bu...The working area is located in the industrially developed region of Rongshengpu-Qianjin, where a surface water system is developed, surface-layer lithology is complicated, and various kinds of hydrocarbon traps are buried at depth. The seismic data acquired previously couldn＇t be interpreted due to the complex surface and geological conditions. Taking secondary 3D seismic from the Rongshengpu-Qianjin area as an example, this paper describes a set of techniques designed to overcome these difficulties and improve the quality of seismic data. The applied techniques included flexible acquisition geometry, low-noise receiver conditions, quantitative quality control, and so on.展开更多
基金The research was supported by the National Innovation Research Group Science Fund(No.41521002)the National Key Research and Development Program of China(No.2018YFC1505202)。
文摘Geohazard recognition and inventory mapping are absolutely the keys to the establishment of reliable susceptibility and hazard maps. However, it has been challenging to implement geohazards recognition and inventory mapping in mountainous areas with complex topography and vegetation cover. Progress in the light detection and ranging(Li DAR) technology provides a new possibility for geohazard recognition in such areas. Specifically, this study aims to evaluate the performances of the Li DAR technology in recognizing geohazard in the mountainous areas of Southwest China through visually analyzing airborne Li DAR DEM derivatives. Quasi-3 D relief image maps are generated based on the sky-view factor(SVF), which makes it feasible to interpret precisely the features of geohazard. A total of 146 geohazards are remotely mapped in the entire 135 km^(2) study area in Danba County, Southwest China, and classified as landslide, rock fall, debris flow based on morphologic characteristics interpreted from SVF visualization maps. Field validation indicate the success rate of Li DAR-derived DEM in recognition and mapping geohazard with higher precision and accuracy. These mapped geohazards lie along both sides of the river, and their spatial distributions are related highly to human engineering activities, such as road excavation and slope cutting. The minimum geohazard that can be recognized in the 0.5 m resolution DEM is about 900 m^(2). Meanwhile, the SVF visualization method is demonstrated to be a great alternative to the classical hillshaded DEM method when it comes to the determination of geomorphological properties of geohazard. Results of this study highlight the importance of Li DAR data for creating complete and accurate geohazard inventories, which can then be used for the production of reliable susceptibility and hazard maps and thus contribute to a better understanding of the movement processes and reducing related losses.
文摘To fully exploit the technical advantages of the large-depth and high-precision artificial source electromagnetic method in the complex structure area of southern Sichuan and compensate for the shortcomings of the conventional electromagnetic method in exploration depth,precision,and accuracy,the large-depth and high-precision wide field electromagnetic method is applied to the complex structure test area of the Luochang syncline and Yuhe nose anticline in the southern Sichuan.The advantages of the wide field electromagnetic method in detecting deep,low-resistivity thin layers are demonstrated.First,on the basis of the analysis of physical property data,a geological–geoelectric model is established in the test area,and the wide field electromagnetic method is numerically simulated to analyze and evaluate the response characteristics of deep thin shale gas layers on wide field electromagnetic curves.Second,a wide field electromagnetic test is conducted in the complex structure area of southern Sichuan.After data processing and inversion imaging,apparent resistivity logging data are used for calibration to develop an apparent resistivity interpretation model suitable for the test area.On the basis of the results,the characteristics of the electrical structure change in the shallow longitudinal formation of 6 km are implemented,and the transverse electrical distribution characteristics of the deep shale gas layer are delineated.In the prediction area near the well,the subsequent data verification shows that the apparent resistivity obtained using the inversion of the wide field electromagnetic method is consistent with the trend of apparent resistivity revealed by logging,which proves that this method can effectively identify the weak response characteristics of deep shale gas formations in complex structural areas.This experiment,it is shown shows that the wide field electromagnetic method with a large depth and high precision can effectively characterize the electrical characteristics of deep,low-resistivity thin layers in complex structural areas,and a new set of low-cost evaluation technologies for shale gas target layers based on the wide field electromagnetic method is explored.
基金supported by the National Major Science and Technology Project“Test and application of reconnaissance and evaluation technologies for shale gas”(No.:2016ZX05034004)the Project of China Geological Survey“Basic geologic survey of Lower Paleozoic marine shale gas in Sichuan Basin”(No.:DD20160176)+1 种基金“Survey on strategic zone of shale gas in Longmaxi Formation,Sichuan Basin”(No.:DD20160193)“Survey on shale gas enrichment conditions in Sichuan Basin”(No.:12120114071401).
文摘Marine shale gas in the southern Sichuan Basin is the most successful area of shale gas exploration and development in China.In order to open up new shale gas fields and search for new shale gas reserves and production replacement blocks,it is necessary to continuously establish and complete the standards on shale gas reservoir evaluation and area selection under different structural settings.The early exploration practice shows that shale in the mountainous complex structural area along the southwestern margin of the Sichuan Basin varies greatly in the gas bearing property,so systematical analysis and study on the shale gas enrichment mechanisms in this area is of great significance to searching for new shale gas exploration areas.Based on drilling data of 5 wells in the mountainous complex structural area along the southwestern margin of the Sichuan Basin,the main factors controlling the shale gas bearing property and the shale gas enrichment model were discussed based on the systematical experiments and analysis of the outcrops,cores and cuttings of Longmaxi Formation shale from the aspects of organic geochemistry,physical property,gas content,hydrocarbon generation history and pore evolution history,so as to lay a solid geological basis for the birth of a new shale gas area.And the following research results were obtained.First,the shale of the first submember of first Member of Longmaxi Formation(S1l11)in the mountainous complex structural area along the southwestern margin of the Sichuan Basin has an average TOC of 3.02%–4.97%and Ro of 2.38%–3.37%,and the average total gas content in local enrichment zones is up to 4.62 m^(3)/t,so it is classified as quality shale.Second,the detailed studies on hydrocarbon generation history indicate that the shale has the characteristics of“low thermal evolution rate and low maturity”.It is characterized by late hydrocarbon generation,low thermal evolution rate,low current maturity and short late diffusion time,which are favorable for shale gas enrichment.Third,the pore evolution history reveals that shale pore evolution can be divided into six stages,i.e.,sharp pore reduction,pore reduction,organic pore formation,pore preservation,organic pore dissipation and karstification,and organic pore and TOC are the most direct control factors of shale gas content.Fourth,favorable shelf facies belt is conducive to the formation of large-scale reservoir space and effective pores,and diversities of preservation conditions under different structural styles and at different structural positions control different pore evolution stages.The shale gas in the mountainous complex structural area is characterized by horizontal zoning and differential enrichment.“Low thermal evolution rate and low maturity”and“slow structural uplifting”are beneficial to the long-term enrichment and preservation of shale gas.In conclusion,the mountainous complex structural area along the southwestern margin of the Sichuan Basin has a shale gas enrichment model of“sedimentation controlling source rocks,diagenesis controlling reservoirs and structure controlling preservation”.This research result provides idea and reference for searching for new shale gas areas and fields.
文摘A number of Triassic (245-195 Ma) alkaline or subalkaline igneous complexes were discovered in theYan-liao area in the northern part of the North China platform. These complexes are all poor in SiO_2; most ofthem are rich in Fe, Mg, K and P and such incompatible elements as Rb, Ba, U and Sr and REE; theinitial ^(87)Sr / ^(86)Sr ratios range from 0.7055 to 0.7057. They might have originated in the altered upper mantle.On that basis coupled with the distribution of the Triassic System and the tectonic deformation, it is suggestedthat there should have existed a tectono-magmatic belt in the area in Triassic time, which is an important mani-festation of the Indosinian movement in the area.
基金Funded by National Natural Science Foundation of China(No.40771135No.41201546+6 种基金and No 41261038)Special Project for Technological Basic Work of China(No.2011FY110400)Basic and Frontier Research Project in Chongqing of China(No.cstc2014jcyj A1557)Science and Technology Project of Chongqing Municipal Education Commission(No.KJ130625)Science and Technology Planning of Guizhou Province in China(Qiankehe JZ code[2014]200206)Natural Science Foundation of Chongqing in China(No.cstc2012jj A20010)Chongqing Normal University Graduate Student Research Innovation Project(No.YKC14010)
文摘In the background of a new round reform and western development strategy, making suitability evaluation of construction land complex topography area in southwest China scientifically and accurately has an important guiding significance on the construction of local urban and rural development. We selected economic factor of construction, safety factor of construction, factor of the present situation of land use and ecological protection factor in Tongzi county as evaluation indexes, and ascertained the weight of each elastic indicator using the analytic hierarchy process method. By the support of GIS and RS technology, we combined the single-factor qualitative classification with the multi-factor weighted overlay analysis to make comprehensive suitability evaluation of construction land on the whole study area. And five different types of construction land were divided, namely, ‘excellent', ‘very good', ‘good', ‘moderate' and ‘poor'. The result shows that the area of ‘excellent' construction land is 30.47 km^2(0.95%), 101.46 km^2(3.16%) of ‘very good', 550.34 km^2(17.16%) of ‘good', and 664.69 km^2(20.72%) and 1 860.65 km^2(58.01%) of ‘moderate' and ‘poor', respectively. The land space bearing capacity is a population of 791 600, and the remaining population capacity is 170 900 persons.
文摘Using energy analysis,the quantifying evaluation and study method on production, living and ecology functions and their sustainability of rural settlement ecosystem in mountain area is established with these energy index such as export of labor and products, export of water resource, internal energy reserve, energy consumption for human living, net energy of ecosystem function and net internal reserve. Taking rural settlement Raosi Village in Hengduan Mountains as a case study, and on the basis of the synthetic research into the ecological process of the complex ecosystem, the study shows that energy costs of production, human living and ecology functions are separately taking 1.36%, 13.59% and 85. 05% of the gross ecosystem functions, and the exertions of production and human living functions are close to a high-point state on the present using level of energy in the settlement. The study also shows that the most important function of a rural settlement in mountain area is its ecological rather productive function.
文摘On the basis of previous studies and by means of field geological, remote sensing, petrographical,mineralogical, petrochemical and geochemical investigations, the authors studied the temporal-spatial distribu-tion of the regional structures, volcanic structures and products of volcanic activity in the coastal area ofsoutheastern Zhejiang. On the basis and through a systematic comparison of the products of magmatism in thearea, it is considered that there exists a compsite volcanic structural belt composed of linear and circular struc-tures and it has been demonstrated that there exist volcanic intrusive complexes--'trinity' composed of vol-canic, subvolcanic and plutonic rocks. It is suggested that the volcanic intrusive complexes in the area belong tothe typical syntexis series and that its materials were derived from a mixed source of crust and mantle.
文摘Jiyang depression, which is the main oil productive area of Shengli oil field, is located at the southeast part of the Bohai Bay Basin and is a terrestrial lacustrine rift subsidence basin formed in the late Mesozoic with fully developed fault system. The main hydrocarbon productive formations of this depression are the terrestrial clastic rocks of the Tertiary, which are of strong lateral variation. The complex fault reservoirs and subtle lithological reservoirs distributed extensively and are becoming the main exploration targets in recent years. The exploration and development practice in these years has formed the exploration technologies, mainly including detailed study and description of low grade faults, delineation of microstructures, facies constrained formation description and prediction and low resistivity oil bearing formation’s identification. These exploration technologies have resulted in remarkable effectiveness on the reserve and oil production increments.
文摘The Huanggang intrusive complex in northern Tongbai area was formed in Early Paleozoic. It mainly consists of ultra basic, basic, intermediate and acid rocks, dominated by intermediate and basic rocks. The complex belongs to calc alkaline series. Geochemical characteristics of major and trace elements show that the complex was derived from the fractional crystallization of co source magma. It is suggested that the complex was formed in island arc tectonic environment and was closely related to the northward subduction of the Erlangping back arc basin. Thus, the subduction of the back arc basin can induce the island arc type magmatism similar to the one formed in the setting of ocean plate subduction.
文摘This article discusses the design strategy of complex mountain highway bridges.During the research phase,details were obtained based on prior literature review and analysis of engineering materials from mountainous area bridges.After analyzing the design characteristics of complex mountainous area road and bridge projects,the principles for the design of bridges on complex mountainous area expressways were proposed.The research on bridge design was carried out from five dimensions:bridge type selection,foundation design,superstructure design,connection part design,and material and technological innovation.Eventually,a relatively complete design system was formed.It is expected that this paper can provide technical references and value for road and bridge projects in China and promote the sustainable development of China’s road traffic system from a macro perspective.
基金supported by the National Natural Science Foundation of China(Grant No.42272163)the Fund of State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China)(Grant No.SKLDOG2024-ZYTS-01).
文摘The multifractal characteristics of organic-rich shale developed along the margins of basins are essential for understanding reservoir heterogeneity,gas storage mechanisms,and the identification of favorable exploration targets.This study systematically investigates the pore structure of marine shale in the Zhaotong area of the National Shale Gas Exploration Demonstration Area in China by integrating analytical methods such as X-ray diffraction,low-pressure N_(2) adsorption,and field emission scanning electron microscopy with the Frenkel-HalseyHill fractal model.The results reveal that:(1)four distinct shale lithofacies(SL)types were identified-argillaceous/siliceous mixed SL(Type Ⅰ:M-2),carbonate/siliceous mixed SL(Type Ⅱ:M and M-1),argillaceous-rich siliceous SL(Type Ⅲ:S-3),and carbonate-rich and argillaceous/carbonate siliceous SL(Type Ⅳ:S-1 and S-2);(2)Types Ⅱ and Ⅳ generally exhibit higher fractal dimensions(D_(1),D_(2),and D_(3))than Types Ⅰ and Ⅲ,indicating the former’s more complex pore architectures,rougher pore surfaces,and greater potential for gas adsorption;(3)for Types Ⅰ and Ⅲ,fractal dimensions exhibit positive correlations with organic matter content,pore structural parameters,and gas content,suggesting their effectiveness as indicators of reservoir quality.In contrast,in Types Ⅱ and Ⅳ,the D_(2) dimension is positively correlated with gas content,implying that mesopores play a significant role in gas occurrence,even in tectonically modified settings.These results highlight the utility of fractal analysis as a robust method for evaluating reservoirs in structurally complex geological environments.
文摘Concentrations of dissolved organic matter (DOM), dissolved humic substances (DHS), and DOM-complexed Fe (DOM-Fe) in Yamakuni and Oita Rivers, Japan, of which headstream is near in location, flow pass length is similar, but watershed soil type differs, were investigated. Soil organic matter level was higher in black Andosols distributing 67% of the watershed area of the Oita River than in Cambisols covering 90% of the watershed area of Yamakuni River. However, the DOM concentration in the Yamakuni River (0.44 - 1.62 mg·C·L-1) tended to be higher than that in the Oita River (0.13 - 1.37 mg·C·L-1). DHS accounted for 49% - 80% of DOM in both rivers. Fe and DOM-Fe concentrations showed a trend to increase toward downstream but decrease at the estuary in both rivers. DOM-Fe accounted for 26% - 90% and 55% - 93% of dissolved Fe in the Yamakuni and Oita Rivers, respectively. Correlation analysis suggested that the DOM-Fe concentration in the river water was controlled by the capacity for supplying Fe ions rather than that for supplying DOM. Although the ability to form a complex with Fe was suggested to be greater in the DOM in the Oita River than that in the Yamakuni River, the DOM-Fe concentration at the estuary was similar in the two rivers. Thus, the effect of soil organic matter level in the watershed area on the supply of Fe or DOM-Fe to the estuarine ecosystem was not significant.
文摘The Keta Lagoon and its catchment areas in Ghana are influenced by intensive agriculture and the use of agro-chemicals. It has therefore, become necessary to assess the quality of water in the lagoon and the surrounding fresh water aquifers. In this study, a water quality index (WQI), indicating the water quality has been adopted. The WQI was determined on a basis of various physico-chemical parameters like pH, conductivity, turbidity, dissolved oxygen, calcium, magnesium, chloride, nitrates, ammonium and sodium. The index was used both for tracking changes at one site over time, and for comparisons among sites. The WQI was also employed to wells used for irrigation on farms along the Keta Sand Spit as well as that of the Keta Lagoon Complex and its surrounding floodplains, in order to ascertain the quality of water for public and livestock consumption, irrigation, recreation and other purposes. The WQI of the wells, Keta lagoon and its floodplains showed various degrees of poor water quality and therefore considered unsuitable for drinking and recreation. By WHO standards, this calls for intensive physical and chemical treatment of the water for human consumption.
文摘In Mesozoic-Cenozoic faulted basin in the periphery of Daqing exploration area, the clastic reservoirs mainly consist of siltstone and gravel-bearing sandstone. The electrical conductivity of the reservoirs is complicated due to the complex pore structures, which cannot be accurately interpreted with commonly used model. In order to solve the problem, a three-water model has been applied in this study based on in-depth analysis of the conductive mechanism of rocks in the explored area, and favorable application results are achieved.
文摘The working area is located in the industrially developed region of Rongshengpu-Qianjin, where a surface water system is developed, surface-layer lithology is complicated, and various kinds of hydrocarbon traps are buried at depth. The seismic data acquired previously couldn＇t be interpreted due to the complex surface and geological conditions. Taking secondary 3D seismic from the Rongshengpu-Qianjin area as an example, this paper describes a set of techniques designed to overcome these difficulties and improve the quality of seismic data. The applied techniques included flexible acquisition geometry, low-noise receiver conditions, quantitative quality control, and so on.
