EI Salvador is gradually consolidating its position as a strategic destination for foreign direct investment,especially for countries with extensive experience in industrial,technological,and logistics development,suc...EI Salvador is gradually consolidating its position as a strategic destination for foreign direct investment,especially for countries with extensive experience in industrial,technological,and logistics development,such as the People’s Republic of China.Thanks to ambitious economic policies based on sustainability,inclusivity,and global competitiveness,the country has clearly defined a development agenda focused on priority sectors with high potential for international cooperation.展开更多
The geological tectonic zone is closely related to outburst.Taking the outburst coal bodies in tectonic zones as the research object,combined with DIC and AE monitoring technologies and discrete element simulation,the...The geological tectonic zone is closely related to outburst.Taking the outburst coal bodies in tectonic zones as the research object,combined with DIC and AE monitoring technologies and discrete element simulation,the mechanical response,crack evolution and energy characteristics of coal bodies under different loading rates(impact disturbances)were studied.The results show that both the uniaxial compressive strength and elastic modulus are positively correlated with the loading rate,with a maximum increase in compressive strength of 25.15%.The uniaxial compressive strength is more sensitive to impact disturbances.The failure modes of coal bodies can be divided into the“slip-crack synchronization(S&C)type”and the“crack-first-then-slip(C&S)type”.The slip in tectonic zones is more severe at high loading rates.At low loading rates,shear cracks dominate(60.01%),while the proportion of tensile cracks increases significantly(70.52%)at high loading rates.Additionally,the rate of axial crack growth decreases as the loading rate increases.The peak values of total energy and dissipated energy increase significantly with the loading rate,and the peak energy of the C&S type is greater than that of the S&C type.Energy is preferentially released through the slip of tectonic zones and the propagation of radial cracks.展开更多
Subduction zones,linking the surface and deep carbon reservoirs,significantly affect the Earth’s long-term climate change and habitability.The subducting slabs undergo decarbonation with increasing pressure and tempe...Subduction zones,linking the surface and deep carbon reservoirs,significantly affect the Earth’s long-term climate change and habitability.The subducting slabs undergo decarbonation with increasing pressure and temperature,during which partial carbon mobilizes out of the slab and returns to the surface by arc volcanism or degassing,while the residual carbon continues to descend to greater depths in the mantle.The estimated carbon influx at subduction zones depends strongly on the calculation model,with contributions from sediments ranging from 15 to 60 Mt C/yr,altered ocean basalts from 18 to 61 Mt C/yr,and serpentinized perdotites from 1.3 to 36 Mt C/yr.The carbon influx varies in space and time.Carbon removal from subducting slab occurs through metamorphic reactions,carbonate dissolution,diapirism,hydrocarbon formation and melting.Among these decarbonation mechanisms,diapirism and slab meting play a decisive role in dictating the depth at which surface carbonates can subduct.Specifically,diapirism may restrict sedimentary carbonates at shallow depths(<200 km),while slab melting exhausts all carbonates from the altered ocean crust near transition zones(410–660 km).Consequently,a mechanism enabling surface carbonates to reach the lower mantle,i.e.,ultra-deep carbon cycle,is required to be in accordance with observations by natural samples.展开更多
Subduction zones are critical interfaces for lithospheric volatile fluxes,where complex tectonic and geochemical interactions facilitate the release of gases and fluids from deep-seated reservoirs within the Earth’s ...Subduction zones are critical interfaces for lithospheric volatile fluxes,where complex tectonic and geochemical interactions facilitate the release of gases and fluids from deep-seated reservoirs within the Earth’s crust.Mud volcanism,as a dynamic manifestation of these processes,contributes CH_(4)emissions that influence the global methane budget and impact marine ecosystems.Although∼2000 CH_(4)-rich mud extrusions have been documented in subduction zones globally,the geological origins and subduction-related geochemical and tectonic mechanisms driving these emissions remain poorly understood.This research examines the Makran subduction zone which hosts one of the world’s largest accretionary wedge and extensive CH_(4)-rich mud extrusions,as a model system.Integrated geochemical,geophysical,and geological observations reveal that thermogenic CH_(4)and clay-rich fluidized muds originate from deeply buried Himalayan turbidites(underthrusted sediments),driven by organic-rich sediment maturation and high fluid overpressure.Key tectonic features,including thrust faults,overburden pressure of wedge-top sediments,normal faults,brittle fractures,and seismicity,facilitate CH_(4)-rich mud extrusions into the hydrosphere and atmosphere.The extruded gases are predominantly CH_(4),with minor C_(2)H_(6),C_(3)H_(8),i-C_(4)H_(10),and n-C_(4)H_(10)while the mud breccia exhibits a chemical composition dominated by SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3),enriched with trace elements(Rb,Zr,and V)and clay minerals,quartz,and carbonates.Geochemical indicators suggest intense chemical weathering and mature sediments classifying the mud breccia as litharenite and sub-litharenite,indicative of deep burial and compaction.These findings model the evolution of CH_(4)-rich mud extrusions through three geological stages:(i)Eocene to Early Miocene pre-thermogenic formation of the CH_(4)-rich source,(ii)Middle Miocene to Pliocene syn-thermogenic CH_(4)and fluidized mud generation,and(iii)Pleistocene to Recent post-thermogenic CH_(4)-rich fluidized mud migration.These findings underscore the critical yet often overlooked role of subduction-related geochemical and tectonic processes in CH_(4)generation and emission,with significant implications for the global CH_(4)budget and marine ecosystems.展开更多
The self-organization mapping （SOM） neural network algorithm is a new method used to identify the ecosystem service zones at regional extent. According to the ecosystem assessment framework of Millennium Ecosystem A...The self-organization mapping （SOM） neural network algorithm is a new method used to identify the ecosystem service zones at regional extent. According to the ecosystem assessment framework of Millennium Ecosystem Assessment （ MA）, this paper develops an indicator system and conducts a spatial cluster analysis at the 1km by I km grid pixel scale with the SOM neural network algorithm to sort the core ecosystem services over the vertical and horizontal dimensions. A case study was carried out in Xilingol League. The ecosystem services in Xilingol League could be divided to six different ecological zones. The SOM neural network algorithm was capable of identifying the similarities among the input data automatically. The research provides both spatially and temporally valuable information targeted sustainable ecosystem management for decision-makers.展开更多
The study of natural hybridization facilitates our understanding of potential adaptive mechanisms in evolution and the process involved in speciation.In this study,we used multiple data types,including morphological t...The study of natural hybridization facilitates our understanding of potential adaptive mechanisms in evolution and the process involved in speciation.In this study,we used multiple data types,including morphological traits,ddRAD-seq and ecological niche data,to investigate the differences among Rhododendron×duclouxii hybrid zones and the mechanisms underlying natural hybridization and possible future evolutionary pathways.Our results show that the origins of each hybrid zone are independent,with variations in hybrid formation,structural characteristics,and patterns of genetic components and morphological trait differentiation.There were no significant differences in morphological traits or genetic variation between the F_(1)and F_(2)generations;however,the range of variation of the F_(2)generation was broader than that of the F_(1)generation.The distribution and ecological characteristics of R.×duclouxii did not significantly differ from those of the two parental species,indicating weak ecological niche preferences between the hybrid and parental taxa.These results imply that the hybrid zones of R.×duclouxii are characterized by considerable variability,with the magnitude of hybridization in each case likely influenced by unique combinations of biological and ecological factors specific to each hybrid zone.We predict that R.×duclouxii hybrid zones will persist and give rise to complex hybrid swarms,each potentially leading to different evolutionary outcomes.展开更多
Based on the waterflooding development in carbonate reservoirs in the Middle East,this study analyzes the geological characteristics and waterflooding behaviors/patterns of different types of high permeability zones(H...Based on the waterflooding development in carbonate reservoirs in the Middle East,this study analyzes the geological characteristics and waterflooding behaviors/patterns of different types of high permeability zones(HPZs),and proposes rational waterflooding strategies and modes.Four types of HPZs,i.e.sedimentation-dominated,sedimentation-diagenesis coupling,biogenic and composite,are identified in the carbonate reservoirs in the Middle East.Based on their distribution patterns,flow mechanisms,and waterflooding behaviors/patterns,five waterflooding modes are established:(1)the mode with stepwise-infilled areal vertical well pattern,for composite HFZs in patchy distribution;(2)the mode with regular row vertical well pattern for TypeⅠchannel“network”HFZs(with dominant water flow pathways at the base),and the mode with irregular differentiated vertical well pattern for TypeⅡchannel“network”HFZs(where multi-stage superimposition leads to“layered flooding”),for sedimentation-diagenesis coupling HFZs;(3)the mode with row horizontal wells through bottom injection and top production,for biogenic HFZs characterized by thin,contiguous distribution and rapid advancing of injected water along a工-shaped path;and(4)the mode with progressive waterflooding through edge water injection via vertical well and oil production via horizontal well,for sedimentation-dominated HFZs characterized by thick,contiguous distribution and flood first in upper anti-rhythmic reservoirs.Development practices demonstrate that the proposed waterflooding modes are efficient in the highly heterogeneous carbonate reservoirs in the Middle East,with balanced employment of reserves in the adjacent reservoirs and enhanced oil recovery.展开更多
Micro(nano)plastics,as an emerging environmental pollutant,are gradually discovered in hyporheic zones and groundwaterworldwide.Recent studies have focused on the origin and spatial/temporal distribution of micro(nano...Micro(nano)plastics,as an emerging environmental pollutant,are gradually discovered in hyporheic zones and groundwaterworldwide.Recent studies have focused on the origin and spatial/temporal distribution of micro(nano)plastics in regional groundwater,together with the influence of their properties and effects of environmental factors on their transport.However,the transport of micro(nano)plastics in the whole hyporheic zone-groundwater system and the behavior of co-existing substances still lack a complete theoretical interpretation.To provide systematic theoretical support for that,this review summarizes the current pollution status of micro(nano)plastics in the hyporheic zone-groundwater system,provides a comprehensive introduction of their sources and fate,and classifies the transport mechanisms into mechanical transport,physicochemical transport and biological processes assisted transport fromthe perspectives ofmechanical stress,physicochemical reactions,and bioturbation,respectively.Ultimately,this review proposes to advance the understanding of the multi-dimensional hydrosphere transport of micro(nano)plastics centered on groundwater,themicroorganisms-mediated synergistic transformation and co-transport involving the intertidal circulation.Overall,this review systematically dissects the presence and transport cycles of micro(nano)plastics within the hyporheic zone-groundwater system and proposes prospects for future studies based on the limitations of current studies.展开更多
Over 90%of Earth’s carbon is stored in the mantle and core.The deep carbon cycle plays a critical role in regulating surface carbon fluxes,global climate,and the habitability of Earth.Carbon mainly residing within th...Over 90%of Earth’s carbon is stored in the mantle and core.The deep carbon cycle plays a critical role in regulating surface carbon fluxes,global climate,and the habitability of Earth.Carbon mainly residing within the sediments,altered oceanic crust,and mantle peridotite as carbonate minerals and organic carbon is transported to the deep Earth via plate subduction.A series of reactions(e.g.,metamorphism,dissolution,and melting)occurring in the subducting slab drive the carbon removal.Some of the car-bon is recycled to the surface via arc volcanism,while the rest is carried into the deeper Earth.More than two-thirds of the global subduction carbon input comes from sedimen-tary carbon,whose fate during subduction directly affects the flux in the global carbon cycle.Over the past two dec-ades,the sedimentary carbon cycle in subduction zones has been extensively studied by experiments and computational approaches.Here,we provide a comprehensive review of the sources,species,decarbonation reactions,carbon cycle trac-ing,and fluxes of sedimentary carbon in subduction zones,and the role of sedimentary carbon subduction in climate evolution and mantle chemistry.Further research is required for our understanding of deep carbon cycle processes and their role in Earth’s climate.展开更多
The Anninghe–Zemuhe Fault and the Xiaojiang Fault are critical active faults along the middle-eastern boundary of the South Chuan–Dian Block. Many researchers have identified these faults as potential strong-earthqu...The Anninghe–Zemuhe Fault and the Xiaojiang Fault are critical active faults along the middle-eastern boundary of the South Chuan–Dian Block. Many researchers have identified these faults as potential strong-earthquake risk zones. In this study, we leveraged a dense seismic array to investigate the high-resolution shallow crust shear wave velocity(Vs) structure beneath the junction of the Zemuhe Fault Zone and the Xiaojiang Fault Zone, one of the most complex parts of the eastern boundary of the South Chuan–Dian Block. We analyzed the distribution of microseismic events detected between November 2022 and February 2023 based on the fine-scale Vs model obtained. The microseismicity in the study region was clustered into three groups, all spatially related to major faults in this region. These microseismic events indicate near-vertical fault planes, consistent with the fault geometry revealed by other researchers.Moreover, these microseismic events are influenced by the impoundment of the downstream Baihetan Reservoir and the complex tectonic stress near the junction of the Zemuhe Fault Zone and the Xiaojiang Fault Zone. The depths of these microseismic events are shallower in the junction zone, whereas moving south along the Xiaojiang Fault Zone, the microseismic events become deeper.Additionally, we compared our fine-scale local Vs model with velocity models obtained by other researchers and found that our model offers greater detail in characterizing subsurface heterogeneity while demonstrating improved reliability in delineating fault systems.展开更多
This work focuses on the influence of Al content on the precipitation of nanoprecipitates,growth of prior austenite grains(PAGs),and impact toughness in simulated coarse-grained heat-affected zones (CGHAZs) of two exp...This work focuses on the influence of Al content on the precipitation of nanoprecipitates,growth of prior austenite grains(PAGs),and impact toughness in simulated coarse-grained heat-affected zones (CGHAZs) of two experimental shipbuilding steels after being subjected to high-heat input welding at 400 kJ·cm^(-1).The base metals (BMs) of both steels contained three types of precipitates Type Ⅰ:cubic (Ti,Nb)(C,N),Type Ⅱ:precipitate with cubic (Ti,Nb)(C,N) core and Nb-rich cap,and Type Ⅲ:ellipsoidal Nb-rich precipitate.In the BM of 60Al and 160Al steels,the number densities of the precipitates were 11.37×10^(5) and 13.88×10^(5) mm^(-2),respectively The 60Al and 160Al steel contained 38.12% and 6.39% Type Ⅲ precipitates,respectively.The difference in the content of Type Ⅲ precipitates in the 60Al steel reduced the pinning effect at the elevated temperature of the CGHAZ,which facilitated the growth of PAGs The average PAG sizes in the CGHAZ of the 60Al and 160Al steels were 189.73 and 174.7μm,respectively.In the 60Al steel,the low lattice mismatch among Cu_(2)S,TiN,and γ-Al_(2)O_(3)facilitated the precipitation of Cu_(2)S and TiN onto γ-Al_(2)O_(3)during welding,which decreased the number density of independently precipitated (Ti,Nb)(C,N) particles but increased that of γ-Al_(2)O_(3)–Ti N–Cu_(2)S particles.Thus abnormally large PAGs formed in the CGHAZ of the 60Al steel,and they reached a maximum size of 1 mm.These PAGs greatly reduced the microstructural homogeneity and consequently decreased the impact toughness from 134 (0.016wt%Al) to 54 J (0.006wt%Al)at-40℃.展开更多
Cross-border e-commerce has emerged as a new growth point in foreign trade.While the Dalian comprehensive pilot zone has made some progress,its development is constrained by issues such as the global economic slowdown...Cross-border e-commerce has emerged as a new growth point in foreign trade.While the Dalian comprehensive pilot zone has made some progress,its development is constrained by issues such as the global economic slowdown,the relatively small scale of cross-border e-commerce,a high concentration of export commodities,imperfect information mechanisms,and high overall costs.To address these challenges,this paper explores the importance of the construction of the Dalian comprehensive pilot zone for cross-border e-commerce to the transformation and upgrading of exports.Based on my research project,“Research on Path Optimization of Financial Support for the Development of Advanced Manufacturing Clusters in Dalian,”this paper analyzes the current challenges and limiting factors and proposes corresponding countermeasures and suggestions.展开更多
This study reconstructed the paleo-uplift and depression pattern within the sequence stratigraphic framework of the Mid-Permian Maokou Formation,Sichuan Basin,investigated its tectono-sedimentary mechanisms and its co...This study reconstructed the paleo-uplift and depression pattern within the sequence stratigraphic framework of the Mid-Permian Maokou Formation,Sichuan Basin,investigated its tectono-sedimentary mechanisms and its control on paleogeomorphology and large-sale shoals based on analysis of outcrops,loggings and seismic data.The results show that the Maokou Formation comprises two third-order sequences,six fourth-order sequences(SSQ1-SSQ6),and four distinct slope-break zones developing progressively from north to south.Slope-break zones I-III in the northern basin,controlled by synsedimentary extensional faults,exhibited a NE-trending linear distribution with gradual southeastward migration.In contrast,slope-break zone IV in the southern basin displayed an arcuate distribution along the Emeishan Large Igneous Province(ELIP).The evolutions of these multistage slope-break zones governed the Mid-Permian paleogeomorphy in the Sichuan Basin transformations from a giant,north-dipping gentle slope(higher in the southwest than in the northeast)in the early-stage(SSQ1-SSQ2)to a platform(south)-basin(north)pattern in the middle-stage(SSQ3-SSQ5).Ultimately,a further depression zone developed in the southwestern basin during the late-stage(SSQ6),forming a paleo-uplift bounded by two depressions.The developments of the Mid-Permian paleogeomorphic configuration reflected the combined control by the rapid subduction of the Mianlüe Ocean and the episodic eruptions of the Emeishan mantle plume(or hot spots),which jointly facilitated the formation of extensive high-energy shoal facies belts along slope-break zones and around paleo-volcanic uplifts.展开更多
The Triassic Xujiahe Formation in the slope zone of the Sichuan foreland basin is a new field of continental tight gas exploration in recent years.The fourth member of the Xujiahe Formation(Xu4 Member),the major inter...The Triassic Xujiahe Formation in the slope zone of the Sichuan foreland basin is a new field of continental tight gas exploration in recent years.The fourth member of the Xujiahe Formation(Xu4 Member),the major interval in the Jianyang Block of the Tianfu gas field in the basin,is characterized by considerable buried depth,tight reservoirs,and strong heterogeneity.By using cast thin section,X-ray diffraction(XRD),scanning electron microscopy(SEM),fluid inclusion thermometry,and core analysis,the reservoir rock types,dominant diageneses,diagenetic history,and controls on high-graded reservoirs were investigated.It is found that the Xu4 Member in Jianyang mainly consists of lithic feldspar sandstones and feldspar lithic sandstones,followed by lithic quartz sandstones.High-energy hydrodynamic conditions in the microfacies of underwater distributary channels and mouth bars are beneficial to the preservation of primary pores and the occurrence of secondary pores,and there are no significant differences in petrophysical properties between these two microfacies.Compaction and calcareous cementation are the dominant controls on reservoir porosity decrease in the Xujiahe Formation;corrosion is the major contributor to porosity increase by generating secondary dissolved pores,e.g.intragranular dissolved pores and intergranular dissolved pores,as major reservoir space in the study area.Fracture zones around the faults inside the Xujiahe Formation(fourth‒order faults)are favorable for proximal tight gas accumulation,preservation,and production.The research findings have been successfully applied to explore the Xujiahe Formation in the slope zone of the Sichuan foreland basin.They can be referential for other similar tight sandstone gas accumulations.展开更多
This study utilizes panel data from 293 Chinese cities at the prefecture level or above,spanning from 2013 to 2022,to empirically examine the net effects and underlying mechanisms of establishing pilot free trade zone...This study utilizes panel data from 293 Chinese cities at the prefecture level or above,spanning from 2013 to 2022,to empirically examine the net effects and underlying mechanisms of establishing pilot free trade zones(FTZs)on integration into the digital global value chain(DGVC).The results demonstrate that the establishment of pilot FTZs positively promotes integration into the DGVC and generates a spatial spillover effect.Compared to coastal areas and small-and medium-sized cities,pilot FTZs have a more significant impact on the integration of inland regions and large cities into the DGVC.Mechanism tests reveal that pilot FTZs drive integration into the DGVC primarily by promoting digital industry agglomeration and enhancing the technological content of exports.Furthermore,bilateral foreign direct investment and digital trade rules positively amplify the impact of pilot FTZs on integration into the DGVC.Therefore,this study recommends comprehensively deepening the development of pilot FTZs,consistently enhancing the technological content of exports,and proactively establishing a sound digital trade regulatory framework.These recommendations offer valuable insights for DGVC integration and the construction of a high-standard free trade network.展开更多
With ongoing global climate change,drought has become the primary threat constraining food security in China.Traditional assessment frameworks based on administrative boundaries or macro-climatic zoning overlook varia...With ongoing global climate change,drought has become the primary threat constraining food security in China.Traditional assessment frameworks based on administrative boundaries or macro-climatic zoning overlook variation in vulnerability affected by key agronomic practices,such as crop phenology and cropping systems,thereby limiting their accuracy.To address this research gap,this study developed and validated a novel drought risk assessment framework based on agricultural cropping zones(single-,double-,and triple-cropping zones).The framework coupled a Geographical and Temporal Neural Network Weighted Regression(GTNNWR)model for forecasting future crop vegetation dynamics with the Standardized Precipitation Evapotranspiration Index(SPEI)to assess drought risk under historical(2001-2020)and projected future(2021-2100)scenarios.The GTNNWR model achieved R^(2) values ranging from 0.72 to 0.82 and RMSE values between 0.11 and 0.14 for NDVI prediction,significantly outperforming conventional models.Historical drought risk assessment revealed that drought events were most frequent during summer and concentrated in single-cropping and double-cropping zones.Future projections indicate a substantial intensification of drought risk.Under the Shared Socioeconomic Pathway(SSP)126 scenario,drought risk is projected to increase in the triple-cropping zones of the middle and lower reaches of the Yangtze River Plain.Under the SSP245 scenario,the frequency of spring and winter droughts is anticipated to rise markedly.Under the SSP585 scenario,drought intensity is projected to intensify in central–eastern single-cropping zones and southwestern double-cropping zones.This assessment framework based on agricultural cropping zones can precisely identify drought risks and facilitate adaptation in agricultural management,such as optimizing irrigation systems and adjusting crop structures.展开更多
In order to avoid brittle fracture failure, a ductile engineered cementitious composite （ECC） was attempted in steel/concrete connection zones to replace normal concrete. The influence of the ECC material ductility ...In order to avoid brittle fracture failure, a ductile engineered cementitious composite （ECC） was attempted in steel/concrete connection zones to replace normal concrete. The influence of the ECC material ductility on connection failure modes and structural performance was investigated via the pushout test of stud/ECC connection, the pullout test of two-dimensional anchor bolt/ECC connection and the finite element modeling （FEM）. The experimental results suggest that the micromechanically designed ECC with a tensile ductility 300 times that of normal concrete switches the brittle fracture failure mode to a ductile one in steel connection zones. This modification in material behavior leads to higher load carrying capacity and structural ductility, which is also confirmed in FEM investigation. The enhancement in structural response through material ductility engineering is expected to be applicable to a wide range of engineering structures where steel and concrete come into contact.展开更多
Since the mid-late Eocene, North China has been subjected to extensional stress, resulting in the formation and development of basins. The dynamic origin of this crustal extension has long been an issue of debate. Thi...Since the mid-late Eocene, North China has been subjected to extensional stress, resulting in the formation and development of basins. The dynamic origin of this crustal extension has long been an issue of debate. This paper presents the results of kinematic analyses of faults obtained from two seperated areas in North China. In the Weihe graben situated on the southernmost margin of the Ordos block, analyses of fault kinematics were coupled with an analysis of the basin's subsidence history. Three successive extensional tectonic phases accompaning the basin's formation and development have been distinguished. The Palaeogene extension was oriented in a WNW-ESE direction; the Neogene extension in a NE-SW direction and the Pliocene-Quaternary extension in a NW-SE direction. Such changes have also been recorded by fault kinematics along the southern Tanlu fault zone. This has been demonstrated by three successive sets of fault striations indicating normal dip slip resulting from NW-SE extension, then left-lateral slip with a normal component resulting from NE-SW extension, and right-lateral slip with a minor normal component, respectively. The kinematic history of faults and their chronological evolution indicate changes in continental dynamics acting in North China over Cenozoic time.展开更多
Integration of remote sensing data and the geographical information system （GIS） for the exploration of groundwater resources has become a breakthrough in the field of groundwater research, which assists in assessin...Integration of remote sensing data and the geographical information system （GIS） for the exploration of groundwater resources has become a breakthrough in the field of groundwater research, which assists in assessing, monitoring, and conserving groundwater resources. In the present paper, various groundwater potential zones for the assessment of groundwater availability in Theni district have been delineated using remote sensing and GIS techniques. Survey of India toposheets and IRS-IC satel- lite imageries are used to prepare various thematic layers viz. lithology, slope, land-use, lineament, drainage, soil, and rainfall were transformed to raster data using feature to raster converter tool in ArcGIS. The raster maps of these factors are allocated a fixed score and weight computed from multi influencing factor （MIF） technique. Moreover, each weighted thematic layer is statistically computed to get the groundwater potential zones. The groundwater potential zones thus obtained were divided into four categories, viz., very poor, poor, good, and very good zones. The result depicts the groundwater potential zones in the study area and found to be helpful in better planning and management of ground- water resonrces.展开更多
文摘EI Salvador is gradually consolidating its position as a strategic destination for foreign direct investment,especially for countries with extensive experience in industrial,technological,and logistics development,such as the People’s Republic of China.Thanks to ambitious economic policies based on sustainability,inclusivity,and global competitiveness,the country has clearly defined a development agenda focused on priority sectors with high potential for international cooperation.
基金supported by the National Natural Science Foundation of China(Nos.52374122 and 51874165)the Liaoning Revitalization Talents Program(No.XLYC1902106).
文摘The geological tectonic zone is closely related to outburst.Taking the outburst coal bodies in tectonic zones as the research object,combined with DIC and AE monitoring technologies and discrete element simulation,the mechanical response,crack evolution and energy characteristics of coal bodies under different loading rates(impact disturbances)were studied.The results show that both the uniaxial compressive strength and elastic modulus are positively correlated with the loading rate,with a maximum increase in compressive strength of 25.15%.The uniaxial compressive strength is more sensitive to impact disturbances.The failure modes of coal bodies can be divided into the“slip-crack synchronization(S&C)type”and the“crack-first-then-slip(C&S)type”.The slip in tectonic zones is more severe at high loading rates.At low loading rates,shear cracks dominate(60.01%),while the proportion of tensile cracks increases significantly(70.52%)at high loading rates.Additionally,the rate of axial crack growth decreases as the loading rate increases.The peak values of total energy and dissipated energy increase significantly with the loading rate,and the peak energy of the C&S type is greater than that of the S&C type.Energy is preferentially released through the slip of tectonic zones and the propagation of radial cracks.
基金supported by the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2022QNLM050201-3)the National Key R&D Program of China(No.2022YFF0801000)the National Natural Science Foundation of China(Nos.92158206,42003049).
文摘Subduction zones,linking the surface and deep carbon reservoirs,significantly affect the Earth’s long-term climate change and habitability.The subducting slabs undergo decarbonation with increasing pressure and temperature,during which partial carbon mobilizes out of the slab and returns to the surface by arc volcanism or degassing,while the residual carbon continues to descend to greater depths in the mantle.The estimated carbon influx at subduction zones depends strongly on the calculation model,with contributions from sediments ranging from 15 to 60 Mt C/yr,altered ocean basalts from 18 to 61 Mt C/yr,and serpentinized perdotites from 1.3 to 36 Mt C/yr.The carbon influx varies in space and time.Carbon removal from subducting slab occurs through metamorphic reactions,carbonate dissolution,diapirism,hydrocarbon formation and melting.Among these decarbonation mechanisms,diapirism and slab meting play a decisive role in dictating the depth at which surface carbonates can subduct.Specifically,diapirism may restrict sedimentary carbonates at shallow depths(<200 km),while slab melting exhausts all carbonates from the altered ocean crust near transition zones(410–660 km).Consequently,a mechanism enabling surface carbonates to reach the lower mantle,i.e.,ultra-deep carbon cycle,is required to be in accordance with observations by natural samples.
基金funded by the National Natural Science Foundation of China(Grants No.92058213 and No.U22A20581)the Specific Research Fund of the Innovation Platform for Academicians of Hainan Province(Grant No.YSPTZX202204)key R&D projects of Hainan Province(ZDYF2024GXJS022).
文摘Subduction zones are critical interfaces for lithospheric volatile fluxes,where complex tectonic and geochemical interactions facilitate the release of gases and fluids from deep-seated reservoirs within the Earth’s crust.Mud volcanism,as a dynamic manifestation of these processes,contributes CH_(4)emissions that influence the global methane budget and impact marine ecosystems.Although∼2000 CH_(4)-rich mud extrusions have been documented in subduction zones globally,the geological origins and subduction-related geochemical and tectonic mechanisms driving these emissions remain poorly understood.This research examines the Makran subduction zone which hosts one of the world’s largest accretionary wedge and extensive CH_(4)-rich mud extrusions,as a model system.Integrated geochemical,geophysical,and geological observations reveal that thermogenic CH_(4)and clay-rich fluidized muds originate from deeply buried Himalayan turbidites(underthrusted sediments),driven by organic-rich sediment maturation and high fluid overpressure.Key tectonic features,including thrust faults,overburden pressure of wedge-top sediments,normal faults,brittle fractures,and seismicity,facilitate CH_(4)-rich mud extrusions into the hydrosphere and atmosphere.The extruded gases are predominantly CH_(4),with minor C_(2)H_(6),C_(3)H_(8),i-C_(4)H_(10),and n-C_(4)H_(10)while the mud breccia exhibits a chemical composition dominated by SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3),enriched with trace elements(Rb,Zr,and V)and clay minerals,quartz,and carbonates.Geochemical indicators suggest intense chemical weathering and mature sediments classifying the mud breccia as litharenite and sub-litharenite,indicative of deep burial and compaction.These findings model the evolution of CH_(4)-rich mud extrusions through three geological stages:(i)Eocene to Early Miocene pre-thermogenic formation of the CH_(4)-rich source,(ii)Middle Miocene to Pliocene syn-thermogenic CH_(4)and fluidized mud generation,and(iii)Pleistocene to Recent post-thermogenic CH_(4)-rich fluidized mud migration.These findings underscore the critical yet often overlooked role of subduction-related geochemical and tectonic processes in CH_(4)generation and emission,with significant implications for the global CH_(4)budget and marine ecosystems.
基金Supported by the National Scientific Foundation of China(4080123170873118)+6 种基金the Chinese Academy of Sciences(KZCX2-YW-305-2KSCX2-YW-N-039KZCX2-YW-326-1)the Ministry of Science and Technology of China(2006DFB91912012006BAC08B032006BAC08B062008BAK47B02)~~
文摘The self-organization mapping （SOM） neural network algorithm is a new method used to identify the ecosystem service zones at regional extent. According to the ecosystem assessment framework of Millennium Ecosystem Assessment （ MA）, this paper develops an indicator system and conducts a spatial cluster analysis at the 1km by I km grid pixel scale with the SOM neural network algorithm to sort the core ecosystem services over the vertical and horizontal dimensions. A case study was carried out in Xilingol League. The ecosystem services in Xilingol League could be divided to six different ecological zones. The SOM neural network algorithm was capable of identifying the similarities among the input data automatically. The research provides both spatially and temporally valuable information targeted sustainable ecosystem management for decision-makers.
基金supported by the National Natural Science Foundation of China,China(32300200,31670213,32160240)Postdoctoral Directional Training Foundation of Yunnan Province,China(E33O31C261)+2 种基金the Key Basic Research Program of Yunnan Province,China(202101BC070003)the CAS President’s International Fellowship Initiative,China(2024PVA0087)supported by the Rural and Environment Science and Analytical Services Division of the Scottish Government,United Kingdom.
文摘The study of natural hybridization facilitates our understanding of potential adaptive mechanisms in evolution and the process involved in speciation.In this study,we used multiple data types,including morphological traits,ddRAD-seq and ecological niche data,to investigate the differences among Rhododendron×duclouxii hybrid zones and the mechanisms underlying natural hybridization and possible future evolutionary pathways.Our results show that the origins of each hybrid zone are independent,with variations in hybrid formation,structural characteristics,and patterns of genetic components and morphological trait differentiation.There were no significant differences in morphological traits or genetic variation between the F_(1)and F_(2)generations;however,the range of variation of the F_(2)generation was broader than that of the F_(1)generation.The distribution and ecological characteristics of R.×duclouxii did not significantly differ from those of the two parental species,indicating weak ecological niche preferences between the hybrid and parental taxa.These results imply that the hybrid zones of R.×duclouxii are characterized by considerable variability,with the magnitude of hybridization in each case likely influenced by unique combinations of biological and ecological factors specific to each hybrid zone.We predict that R.×duclouxii hybrid zones will persist and give rise to complex hybrid swarms,each potentially leading to different evolutionary outcomes.
基金Supported by the China National Petroleum Corporation Major Science and Technology Project(2023ZZ19-01,2023ZZ19-07).
文摘Based on the waterflooding development in carbonate reservoirs in the Middle East,this study analyzes the geological characteristics and waterflooding behaviors/patterns of different types of high permeability zones(HPZs),and proposes rational waterflooding strategies and modes.Four types of HPZs,i.e.sedimentation-dominated,sedimentation-diagenesis coupling,biogenic and composite,are identified in the carbonate reservoirs in the Middle East.Based on their distribution patterns,flow mechanisms,and waterflooding behaviors/patterns,five waterflooding modes are established:(1)the mode with stepwise-infilled areal vertical well pattern,for composite HFZs in patchy distribution;(2)the mode with regular row vertical well pattern for TypeⅠchannel“network”HFZs(with dominant water flow pathways at the base),and the mode with irregular differentiated vertical well pattern for TypeⅡchannel“network”HFZs(where multi-stage superimposition leads to“layered flooding”),for sedimentation-diagenesis coupling HFZs;(3)the mode with row horizontal wells through bottom injection and top production,for biogenic HFZs characterized by thin,contiguous distribution and rapid advancing of injected water along a工-shaped path;and(4)the mode with progressive waterflooding through edge water injection via vertical well and oil production via horizontal well,for sedimentation-dominated HFZs characterized by thick,contiguous distribution and flood first in upper anti-rhythmic reservoirs.Development practices demonstrate that the proposed waterflooding modes are efficient in the highly heterogeneous carbonate reservoirs in the Middle East,with balanced employment of reserves in the adjacent reservoirs and enhanced oil recovery.
基金supported by the National Natural Science Foundation of China(Nos.22036001,42342057,and 22236006).
文摘Micro(nano)plastics,as an emerging environmental pollutant,are gradually discovered in hyporheic zones and groundwaterworldwide.Recent studies have focused on the origin and spatial/temporal distribution of micro(nano)plastics in regional groundwater,together with the influence of their properties and effects of environmental factors on their transport.However,the transport of micro(nano)plastics in the whole hyporheic zone-groundwater system and the behavior of co-existing substances still lack a complete theoretical interpretation.To provide systematic theoretical support for that,this review summarizes the current pollution status of micro(nano)plastics in the hyporheic zone-groundwater system,provides a comprehensive introduction of their sources and fate,and classifies the transport mechanisms into mechanical transport,physicochemical transport and biological processes assisted transport fromthe perspectives ofmechanical stress,physicochemical reactions,and bioturbation,respectively.Ultimately,this review proposes to advance the understanding of the multi-dimensional hydrosphere transport of micro(nano)plastics centered on groundwater,themicroorganisms-mediated synergistic transformation and co-transport involving the intertidal circulation.Overall,this review systematically dissects the presence and transport cycles of micro(nano)plastics within the hyporheic zone-groundwater system and proposes prospects for future studies based on the limitations of current studies.
基金supported by the National Natural Science Foundation of China(No.42274137).
文摘Over 90%of Earth’s carbon is stored in the mantle and core.The deep carbon cycle plays a critical role in regulating surface carbon fluxes,global climate,and the habitability of Earth.Carbon mainly residing within the sediments,altered oceanic crust,and mantle peridotite as carbonate minerals and organic carbon is transported to the deep Earth via plate subduction.A series of reactions(e.g.,metamorphism,dissolution,and melting)occurring in the subducting slab drive the carbon removal.Some of the car-bon is recycled to the surface via arc volcanism,while the rest is carried into the deeper Earth.More than two-thirds of the global subduction carbon input comes from sedimen-tary carbon,whose fate during subduction directly affects the flux in the global carbon cycle.Over the past two dec-ades,the sedimentary carbon cycle in subduction zones has been extensively studied by experiments and computational approaches.Here,we provide a comprehensive review of the sources,species,decarbonation reactions,carbon cycle trac-ing,and fluxes of sedimentary carbon in subduction zones,and the role of sedimentary carbon subduction in climate evolution and mantle chemistry.Further research is required for our understanding of deep carbon cycle processes and their role in Earth’s climate.
基金funded by the National Key R&D Program of China (Grant No. 2021YFC3000704)the National Natural Science Foundation of China (Grant No. 42125401)the Central Public-interest Scientific Institution Basal Research Fund (Grant No. CEAIEF20240401)。
文摘The Anninghe–Zemuhe Fault and the Xiaojiang Fault are critical active faults along the middle-eastern boundary of the South Chuan–Dian Block. Many researchers have identified these faults as potential strong-earthquake risk zones. In this study, we leveraged a dense seismic array to investigate the high-resolution shallow crust shear wave velocity(Vs) structure beneath the junction of the Zemuhe Fault Zone and the Xiaojiang Fault Zone, one of the most complex parts of the eastern boundary of the South Chuan–Dian Block. We analyzed the distribution of microseismic events detected between November 2022 and February 2023 based on the fine-scale Vs model obtained. The microseismicity in the study region was clustered into three groups, all spatially related to major faults in this region. These microseismic events indicate near-vertical fault planes, consistent with the fault geometry revealed by other researchers.Moreover, these microseismic events are influenced by the impoundment of the downstream Baihetan Reservoir and the complex tectonic stress near the junction of the Zemuhe Fault Zone and the Xiaojiang Fault Zone. The depths of these microseismic events are shallower in the junction zone, whereas moving south along the Xiaojiang Fault Zone, the microseismic events become deeper.Additionally, we compared our fine-scale local Vs model with velocity models obtained by other researchers and found that our model offers greater detail in characterizing subsurface heterogeneity while demonstrating improved reliability in delineating fault systems.
基金support from the National Natural Science Foundation of China (No. U1960202)the Opening Foundation from Shanghai Engineering Research Center of Hot Manufacturing, China (No. 18DZ2253400)。
文摘This work focuses on the influence of Al content on the precipitation of nanoprecipitates,growth of prior austenite grains(PAGs),and impact toughness in simulated coarse-grained heat-affected zones (CGHAZs) of two experimental shipbuilding steels after being subjected to high-heat input welding at 400 kJ·cm^(-1).The base metals (BMs) of both steels contained three types of precipitates Type Ⅰ:cubic (Ti,Nb)(C,N),Type Ⅱ:precipitate with cubic (Ti,Nb)(C,N) core and Nb-rich cap,and Type Ⅲ:ellipsoidal Nb-rich precipitate.In the BM of 60Al and 160Al steels,the number densities of the precipitates were 11.37×10^(5) and 13.88×10^(5) mm^(-2),respectively The 60Al and 160Al steel contained 38.12% and 6.39% Type Ⅲ precipitates,respectively.The difference in the content of Type Ⅲ precipitates in the 60Al steel reduced the pinning effect at the elevated temperature of the CGHAZ,which facilitated the growth of PAGs The average PAG sizes in the CGHAZ of the 60Al and 160Al steels were 189.73 and 174.7μm,respectively.In the 60Al steel,the low lattice mismatch among Cu_(2)S,TiN,and γ-Al_(2)O_(3)facilitated the precipitation of Cu_(2)S and TiN onto γ-Al_(2)O_(3)during welding,which decreased the number density of independently precipitated (Ti,Nb)(C,N) particles but increased that of γ-Al_(2)O_(3)–Ti N–Cu_(2)S particles.Thus abnormally large PAGs formed in the CGHAZ of the 60Al steel,and they reached a maximum size of 1 mm.These PAGs greatly reduced the microstructural homogeneity and consequently decreased the impact toughness from 134 (0.016wt%Al) to 54 J (0.006wt%Al)at-40℃.
文摘Cross-border e-commerce has emerged as a new growth point in foreign trade.While the Dalian comprehensive pilot zone has made some progress,its development is constrained by issues such as the global economic slowdown,the relatively small scale of cross-border e-commerce,a high concentration of export commodities,imperfect information mechanisms,and high overall costs.To address these challenges,this paper explores the importance of the construction of the Dalian comprehensive pilot zone for cross-border e-commerce to the transformation and upgrading of exports.Based on my research project,“Research on Path Optimization of Financial Support for the Development of Advanced Manufacturing Clusters in Dalian,”this paper analyzes the current challenges and limiting factors and proposes corresponding countermeasures and suggestions.
基金Supported by the Key projects of the PetroChina Joint Fund Under the National Natural Science Foundation of China(U23B20154,92255302)Science and Technology Cooperation Project of the Innovation Consortium between PetroChina and Southwest Petroleum University(2020CX010000)Open Fund of the Key Laboratory of Carbonate Reservoirs,China National Petroleum Corporation(RIPED-2024-JS-1804).
文摘This study reconstructed the paleo-uplift and depression pattern within the sequence stratigraphic framework of the Mid-Permian Maokou Formation,Sichuan Basin,investigated its tectono-sedimentary mechanisms and its control on paleogeomorphology and large-sale shoals based on analysis of outcrops,loggings and seismic data.The results show that the Maokou Formation comprises two third-order sequences,six fourth-order sequences(SSQ1-SSQ6),and four distinct slope-break zones developing progressively from north to south.Slope-break zones I-III in the northern basin,controlled by synsedimentary extensional faults,exhibited a NE-trending linear distribution with gradual southeastward migration.In contrast,slope-break zone IV in the southern basin displayed an arcuate distribution along the Emeishan Large Igneous Province(ELIP).The evolutions of these multistage slope-break zones governed the Mid-Permian paleogeomorphy in the Sichuan Basin transformations from a giant,north-dipping gentle slope(higher in the southwest than in the northeast)in the early-stage(SSQ1-SSQ2)to a platform(south)-basin(north)pattern in the middle-stage(SSQ3-SSQ5).Ultimately,a further depression zone developed in the southwestern basin during the late-stage(SSQ6),forming a paleo-uplift bounded by two depressions.The developments of the Mid-Permian paleogeomorphic configuration reflected the combined control by the rapid subduction of the Mianlüe Ocean and the episodic eruptions of the Emeishan mantle plume(or hot spots),which jointly facilitated the formation of extensive high-energy shoal facies belts along slope-break zones and around paleo-volcanic uplifts.
基金supported by the China National Petroleum Corporation Science and Technology Project(Study on genesis mechanism and distribution law of high quality reservoir of the fourth Member of Xujiahe Formation in middle and west Sichuan area,20230301-23)。
文摘The Triassic Xujiahe Formation in the slope zone of the Sichuan foreland basin is a new field of continental tight gas exploration in recent years.The fourth member of the Xujiahe Formation(Xu4 Member),the major interval in the Jianyang Block of the Tianfu gas field in the basin,is characterized by considerable buried depth,tight reservoirs,and strong heterogeneity.By using cast thin section,X-ray diffraction(XRD),scanning electron microscopy(SEM),fluid inclusion thermometry,and core analysis,the reservoir rock types,dominant diageneses,diagenetic history,and controls on high-graded reservoirs were investigated.It is found that the Xu4 Member in Jianyang mainly consists of lithic feldspar sandstones and feldspar lithic sandstones,followed by lithic quartz sandstones.High-energy hydrodynamic conditions in the microfacies of underwater distributary channels and mouth bars are beneficial to the preservation of primary pores and the occurrence of secondary pores,and there are no significant differences in petrophysical properties between these two microfacies.Compaction and calcareous cementation are the dominant controls on reservoir porosity decrease in the Xujiahe Formation;corrosion is the major contributor to porosity increase by generating secondary dissolved pores,e.g.intragranular dissolved pores and intergranular dissolved pores,as major reservoir space in the study area.Fracture zones around the faults inside the Xujiahe Formation(fourth‒order faults)are favorable for proximal tight gas accumulation,preservation,and production.The research findings have been successfully applied to explore the Xujiahe Formation in the slope zone of the Sichuan foreland basin.They can be referential for other similar tight sandstone gas accumulations.
基金supported by the Key Project of the Hainan Province Marxist Theory Research and Development Program,titled“Research on the Opportunities and Challenges of the Digital Economy Partnership Agreement(DEPA)for the Construction of the Hainan Free Trade Port”(Grant Number:2023HNMGC02).
文摘This study utilizes panel data from 293 Chinese cities at the prefecture level or above,spanning from 2013 to 2022,to empirically examine the net effects and underlying mechanisms of establishing pilot free trade zones(FTZs)on integration into the digital global value chain(DGVC).The results demonstrate that the establishment of pilot FTZs positively promotes integration into the DGVC and generates a spatial spillover effect.Compared to coastal areas and small-and medium-sized cities,pilot FTZs have a more significant impact on the integration of inland regions and large cities into the DGVC.Mechanism tests reveal that pilot FTZs drive integration into the DGVC primarily by promoting digital industry agglomeration and enhancing the technological content of exports.Furthermore,bilateral foreign direct investment and digital trade rules positively amplify the impact of pilot FTZs on integration into the DGVC.Therefore,this study recommends comprehensively deepening the development of pilot FTZs,consistently enhancing the technological content of exports,and proactively establishing a sound digital trade regulatory framework.These recommendations offer valuable insights for DGVC integration and the construction of a high-standard free trade network.
文摘With ongoing global climate change,drought has become the primary threat constraining food security in China.Traditional assessment frameworks based on administrative boundaries or macro-climatic zoning overlook variation in vulnerability affected by key agronomic practices,such as crop phenology and cropping systems,thereby limiting their accuracy.To address this research gap,this study developed and validated a novel drought risk assessment framework based on agricultural cropping zones(single-,double-,and triple-cropping zones).The framework coupled a Geographical and Temporal Neural Network Weighted Regression(GTNNWR)model for forecasting future crop vegetation dynamics with the Standardized Precipitation Evapotranspiration Index(SPEI)to assess drought risk under historical(2001-2020)and projected future(2021-2100)scenarios.The GTNNWR model achieved R^(2) values ranging from 0.72 to 0.82 and RMSE values between 0.11 and 0.14 for NDVI prediction,significantly outperforming conventional models.Historical drought risk assessment revealed that drought events were most frequent during summer and concentrated in single-cropping and double-cropping zones.Future projections indicate a substantial intensification of drought risk.Under the Shared Socioeconomic Pathway(SSP)126 scenario,drought risk is projected to increase in the triple-cropping zones of the middle and lower reaches of the Yangtze River Plain.Under the SSP245 scenario,the frequency of spring and winter droughts is anticipated to rise markedly.Under the SSP585 scenario,drought intensity is projected to intensify in central–eastern single-cropping zones and southwestern double-cropping zones.This assessment framework based on agricultural cropping zones can precisely identify drought risks and facilitate adaptation in agricultural management,such as optimizing irrigation systems and adjusting crop structures.
基金The National Natural Science Foundation of China(No. 51008071)the Natural Science Foundation fo Jiangsu Province(No. BK2010413)Teaching & Research Excellence Grant for Young Faculty Members at Southeast University,the US National Science Foundation (No. CMS-0223971,CMS-0329416)
文摘In order to avoid brittle fracture failure, a ductile engineered cementitious composite （ECC） was attempted in steel/concrete connection zones to replace normal concrete. The influence of the ECC material ductility on connection failure modes and structural performance was investigated via the pushout test of stud/ECC connection, the pullout test of two-dimensional anchor bolt/ECC connection and the finite element modeling （FEM）. The experimental results suggest that the micromechanically designed ECC with a tensile ductility 300 times that of normal concrete switches the brittle fracture failure mode to a ductile one in steel connection zones. This modification in material behavior leads to higher load carrying capacity and structural ductility, which is also confirmed in FEM investigation. The enhancement in structural response through material ductility engineering is expected to be applicable to a wide range of engineering structures where steel and concrete come into contact.
基金supported by the programmes"Dynamique et Billan de la Terre","Imageric et Structure de la Terre"(Tectoscope)of In-stitut National des Sciences de l'Univers(INSU)and Centre National de la Recherche Scientifiquc(Paris,France).
文摘Since the mid-late Eocene, North China has been subjected to extensional stress, resulting in the formation and development of basins. The dynamic origin of this crustal extension has long been an issue of debate. This paper presents the results of kinematic analyses of faults obtained from two seperated areas in North China. In the Weihe graben situated on the southernmost margin of the Ordos block, analyses of fault kinematics were coupled with an analysis of the basin's subsidence history. Three successive extensional tectonic phases accompaning the basin's formation and development have been distinguished. The Palaeogene extension was oriented in a WNW-ESE direction; the Neogene extension in a NE-SW direction and the Pliocene-Quaternary extension in a NW-SE direction. Such changes have also been recorded by fault kinematics along the southern Tanlu fault zone. This has been demonstrated by three successive sets of fault striations indicating normal dip slip resulting from NW-SE extension, then left-lateral slip with a normal component resulting from NE-SW extension, and right-lateral slip with a minor normal component, respectively. The kinematic history of faults and their chronological evolution indicate changes in continental dynamics acting in North China over Cenozoic time.
基金sponsored jointly by the Department of Science and Technology(DST,India)Tamil Nadu State Planning Commission(SPC-SLUB)(Project No:NRDMS/11/1027/05)
文摘Integration of remote sensing data and the geographical information system （GIS） for the exploration of groundwater resources has become a breakthrough in the field of groundwater research, which assists in assessing, monitoring, and conserving groundwater resources. In the present paper, various groundwater potential zones for the assessment of groundwater availability in Theni district have been delineated using remote sensing and GIS techniques. Survey of India toposheets and IRS-IC satel- lite imageries are used to prepare various thematic layers viz. lithology, slope, land-use, lineament, drainage, soil, and rainfall were transformed to raster data using feature to raster converter tool in ArcGIS. The raster maps of these factors are allocated a fixed score and weight computed from multi influencing factor （MIF） technique. Moreover, each weighted thematic layer is statistically computed to get the groundwater potential zones. The groundwater potential zones thus obtained were divided into four categories, viz., very poor, poor, good, and very good zones. The result depicts the groundwater potential zones in the study area and found to be helpful in better planning and management of ground- water resonrces.
