Objective Complex geological factors have been constraining the oil and gas exploration in the Paleozoic strata of the Qaidam Basin,although there are high-quality hydrocarbon source rocks.One of the most important re...Objective Complex geological factors have been constraining the oil and gas exploration in the Paleozoic strata of the Qaidam Basin,although there are high-quality hydrocarbon source rocks.One of the most important reasons may be reservoir densification due to the multiple stages of destructive cementation,which has hindered our understanding of the Paleozoic petroleum enrichment rules in the Qaidam basin.In recent years.展开更多
In the Qaidam basin,Northwest China,karstic fissures and caves are developed in many places of the Lower Carboniferous Chengqianggou Fm.and Huaitoutala Fm.and the Upper Carboniferous Keluke Fm.,in which are found typi...In the Qaidam basin,Northwest China,karstic fissures and caves are developed in many places of the Lower Carboniferous Chengqianggou Fm.and Huaitoutala Fm.and the Upper Carboniferous Keluke Fm.,in which are found typical karstic marks.Several suites of transgressive carbonate rocks formed during the Late Paleozoic epoch are preserved as reservoir properties in the Qaidam basin,with paleokarst-related cave-fractured diagenetic structures,which provided the basis for cavefractured development.Carbonate and clastic samples covering or infilling caves and fractures in Carboniferous strata were collected in the eastern Qaidam basin to focus on petrological and geochemical analyses of karst and infilling materials.Based on this study of the Caledonian diagenetic sequence,and bitumen-infilled inclusion temperature and burial history,there existed a continuous atmospheric freshwater leaching process,which played a critical role in the construction of the Carboniferous supergene paleokarsts.Investigation and survey of the tectonic setting,plate paleolatitude and river development intensity also proves that there was abundant rainfall during the Indosinian period,after which the strata undergo a shallow burial process.Because Indosinian period is earlier than the key timing of hydrocarbon-generation of the Carboniferous source rocks,this kind of karst reservoir has potential significance for oil-gas resources in this area.展开更多
Four species of the genus Karstsinnectes,which live in dark,low-energy groundwater ecosystems,are currently recorded,mainly distributed in the upstream of the Pearl River,the Youjiang River and the Hongshui River.Comp...Four species of the genus Karstsinnectes,which live in dark,low-energy groundwater ecosystems,are currently recorded,mainly distributed in the upstream of the Pearl River,the Youjiang River and the Hongshui River.Completing biodiversity surveys is particularly difficult due to the particular cave habitats inhabited by these species.In this work,we describe a new cave fish of the genus Karstsinnectes,namely K.cehengensis Luo,Zhao&Zhou,sp.nov.,collected from the Beipanjiang River,the upstream of the Hongshui River.Genetically,the four individuals of the new species form a phylogenetically separate lineage,as the sister clade of K.acridorsalis,with a 9.4–9.5%genetic difference in mitochondrial Cyt b.Morphologically,the new species can be distinguished from its congeners by a combination of the following morphological characteristics:body naked,without body color;eyes reduced,diameter 1.4–3.8%of head length;anterior and posterior nostrils adjacent,anterior nostril not elongated to a barbel-like tip;lateral line incomplete;caudal fin forked;dorsal-fin rays iii-7,pectoral-fin rays i-11–12,pelvic-fin rays i-7,anal-fin rays iii-5,with 14 branched caudal-fin rays.The discovery of this new species represents the northernmost distribution of species within the genus Karstsinnectes and the first record from Guizhou Province.All currently known species of this genus inhabited in caves,making them ideal organisms for studying historical river connectivity and cave formation process.展开更多
Indulge in some ancestor worship and slurp a bowl of pungent river snail noodles in ancient Huangyao amid a magnificent landscape of karst mountains and waterways.Huangyao might not be as famous as its glitzy neighbor...Indulge in some ancestor worship and slurp a bowl of pungent river snail noodles in ancient Huangyao amid a magnificent landscape of karst mountains and waterways.Huangyao might not be as famous as its glitzy neighbor Guilin,but its ancient culture,historic clan architecture and natural surroundings provide an alternative for a trip to Guangxi.Zhuang Autonomous Region.展开更多
DEAR EDITOR,Bostrychus,a genus in the family Eleotridae of the order Gobiiformes,was first established by Lacepède in 1801(Buffon,1801).Bostrychus currently contains seven recognized species,including two recent ...DEAR EDITOR,Bostrychus,a genus in the family Eleotridae of the order Gobiiformes,was first established by Lacepède in 1801(Buffon,1801).Bostrychus currently contains seven recognized species,including two recent additions(B.microphthalmos and B.scalaris)described in 2005(Hoese&Kottelat,2005)and 2008(Larson,2008),respectively.The natural range of Bostrychus species extends from East Asia to Australia,with the exception of B.africanus,Steindachner,1879,which is distributed in West Africa(Herre,1946).Among the recognized species,B.sinensis,B.zonatus,and B.africanus are relatively widespread,inhabiting diverse areas from estuaries to freshwater streams,while B.scalaris is only found at a single mangrove site in the Selangor State of Malaysia(Larson,2008).The remaining three species exhibit a high degree of habitat specialization and are highly localized(Hoese&Kottelat,2005):B.microphthalmos inhabits a cave stream in the Maros karst of southern Sulawesi,B.aruensis is confined to freshwater environments in the Aru Islands of Indonesia,and B.strigogenys is found only in freshwater areas in southern Papua New Guinea and Irian Jaya.展开更多
Karst sinkholes with natural negative landform provide favorable conditions for the pumped storage reservoir construction for less excavation work.However,the construction of the reservoir would plug the natural karst...Karst sinkholes with natural negative landform provide favorable conditions for the pumped storage reservoir construction for less excavation work.However,the construction of the reservoir would plug the natural karst channels for water and air,which would cause remarkable air pressure in karst channels when the groundwater level fluctuates.A large laboratory simulation test was carried out to study the air pressure variation of a reservoir built on the karst sinkhole.The air pressure in the karst channel and inside the model was monitored during the groundwater rising and falling process.Result showed that the variation of air pressure in the karst channel and the surrounding rock exhibited a high degree of similarity.The air pressure increased rapidly at the initial stage of water level rising,followed by a slight decrease,then the air pressure increased sharply when the water level approached the top of the karst cave.The initial peak of air pressure and the final peak of air pressure were defined,and both air pressure peaks were linearly increasing with the water level rising rate.The negative air pressure was also analyzed during the drainage process,which was linearly correlated with the water level falling rate.The causes of air pressure variation in karst channels of a pumped storage reservoir built on the karst sinkhole were discussed.The initial rapid increase,then slight decrease and final sudden increase of air pressure were controlled by the combined effects of air compression in karst channel and air seepage into the surrounding rock.For the drainage process,the instant negative air pressure and gradual recovering of air pressure were controlled by the combined effects of negative air pressure induced by water level falling and air supply from surrounding rock.This work could provide valuable reference for the reservoir construction in karst area.展开更多
Karst fracture-cavity carbonate reservoirs,in which natural cavities are connected by natural fractures to form cavity clusters in many circumstances,have become significant fields of oil and gas exploration and explo...Karst fracture-cavity carbonate reservoirs,in which natural cavities are connected by natural fractures to form cavity clusters in many circumstances,have become significant fields of oil and gas exploration and exploitation.Proppant fracturing is considered as the best method for exploiting carbonate reservoirs;however,previous studies primarily focused on the effects of individual types of geological formations,such as natural fractures or cavities,on fracture propagation.In this study,true-triaxial physical simulation experiments were systematically performed under four types of stress difference conditions after the accurate prefabrication of four types of different fracture-cavity distributions in artificial samples.Subsequently,the interaction mechanism between the hydraulic fractures and fracture-cavity structures was systematically analyzed in combination with the stress distribution,cross-sectional morphology of the main propagation path,and three-dimensional visualization of the overall fracture network.It was found that the propagation of hydraulic fractures near the cavity was inhibited by the stress concentration surrounding the cavity.In contrast,a natural fracture with a smaller approach angle(0°and 30°)around the cavity can alleviate the stress concentration and significantly facilitate the connection with the cavity.In addition,the hydraulic fracture crossed the natural fracture at the 45°approach angle and bypassed the cavity under higher stress difference conditions.A new stimulation effectiveness evaluation index was established based on the stimulated reservoir area(SRA),tortuosity of the hydraulic fractures(T),and connectivity index(CI)of the cavities.These findings provide new insights into the fracturing design of carbonate reservoirs.展开更多
Based on high-resolution 3D seismic data acquired in the Pearl(Zhujiang)River Mouth Basin of the northern South China Sea,this study investigated the geometry,spatial extension,and throw distribution of the post-rift ...Based on high-resolution 3D seismic data acquired in the Pearl(Zhujiang)River Mouth Basin of the northern South China Sea,this study investigated the geometry,spatial extension,and throw distribution of the post-rift normal fault through detailed seismic interpretation and fault modeling.A total of 289 post-rift normal faults were identified in the study area and can be classified into four types:(1)isolated normal faults above the carbonate platform;(2)isolated normal faults cutting through the carbonate platform;(3)conjugate normal faults,and(4)connecting normal faults.Throw distribution analysis on the fault planes show that the vertical throw profiles of most normal fault exhibit flat-topped profiles.Isolated normal faults above the carbonate platform exhibit roughly concentric ellipses with maximum throw zones in the central section whereas the normal faults cutting through the carbonate platform miss the lowermost section due to the chaotic seismic reflections in the interior of the carbonate platform.The vertical throws of conjugate normal faults anomalously decrease toward their intersection region on the fault plane whereas the connecting normal faults present two maximum throw zones in the central section of the fault plane.According to the symmetric elliptical distribution model of fault throw,an estimation was made indicating that normal faults cutting through the carbonate platform extended downward between-1308 s and-1780 s(two-way travel time)in depth and may not penetrate the entire Liuhua carbonate platform.Moreover,it is observed that the distribution of karst caves on the top of the carbonate platform disaccord with those of hydrocarbon reservoirs and the post-rift normal faults cutting through the carbonate platform in the study area.We propose that these karst caves formed most probably by corrosive fluids derived from magmatic activities during the Dongsha event,rather than pore waters or hydrocarbons.展开更多
Based on the arable land situation in Gejiu City,upland dry planting of indica hybrid rice is being expanded in Karst mountain areas with a rainfall of over 1400 mm and an altitude of 1100-1600 m to develop grain prod...Based on the arable land situation in Gejiu City,upland dry planting of indica hybrid rice is being expanded in Karst mountain areas with a rainfall of over 1400 mm and an altitude of 1100-1600 m to develop grain production.This paper gives a specific description of hybrid rice upland dry seedling technology,upland transplanting technology,fertilization technology,field management,weed prevention and control technology,and disease and pest control.展开更多
The growth of society and population has led to a range of water pollution issues.Among these,non-point source pollution assessment and treatment pose a particular challenge due to its formation mechanism.This has bec...The growth of society and population has led to a range of water pollution issues.Among these,non-point source pollution assessment and treatment pose a particular challenge due to its formation mechanism.This has become a focal point and challenge in water pollution treatment research.The study area for this research was the Huanghou basin in Guizhou Province,southwest China.The land use type of the basin was analyzed using remote sensing technology,and water quality data was collected by distributing points throughout the basin,based on source-sink landscape theory.The distribution map of the basin’s source-sink landscape and the results of water quality data accurately and efficiently identified the areas with high risk of non-point source pollution in the western and southwestern residential and agricultural areas of the upper basin.Hence,a strategy of“increasing sinks and decreasing sources”was proposed.The strategy was implemented at both macro and micro levels to address non-point source pollution in the basin using ecological remediation techniques.The work to control karst rocky desertification should continue at a macro level.The rocky desertification area in the basin should gradually transform into grassland and forested land,while increasing the overall area of the sink landscape.Ecological restoration techniques,such as slope planting,riparian zone vegetation restoration,increasing plant abundance,and restoring aquatic plants,can effectively control non-point source pollution at the micro level.Compared to traditional control methods,this remediation strategy focuses on source and process control.It is more effective and does not require large-scale water pollution control projects,which can save a lot of environmental control funds and management costs.Therefore,it has greater research significance and application value.展开更多
In this paper,managed forest(MF)and natural forest(NF)in the Huajiang Demonstration Zone of Guanling,Guizhou were selected as research objects,and cropland(CL)was taken as control.High-throughput sequencing technology...In this paper,managed forest(MF)and natural forest(NF)in the Huajiang Demonstration Zone of Guanling,Guizhou were selected as research objects,and cropland(CL)was taken as control.High-throughput sequencing technology was used to study the characteristics of fungal community composition and species diversity in the surface(0-10 cm)soil of each restoration measure,in order to reveal the dominant soil fungal groups and fungal community composition in karst rocky desertification areas,which was conducive to a more comprehensive understanding of the soil conditions of different vegetation restoration measures.Research has shown that vegetation restoration significantly affected the diversity of soil fungal community,with significant increases in Sob index,Ace index,and Chao index.The vegetation restoration has significantly changed the composition of fungal community.The dominant fungi in the CL topsoil are Sordariomycetes(62.28%),Dothideomycetes(12.34%),and Eurotiomycetes(9.12%);the dominant fungi in the MF soil are Sordariomycetes(45.05%),Dothideomycetes(14.74%),and Mortierellomycetes(10.40%);the dominant fungi in the NF soil are unclassified fungal community(26.38%),Sordariomycetes(19.78%),and Agaricomycetes(13.82%).Vegetation restoration has changed the key fungal groups in the soil.Sordariomycetes,Fusarium,and Setophoma are the key dominant fungal groups in CL soil;Dioszegia is key dominant fungal group in MF soil;c_unclassified_k_Fungi,p_unclassified_k_Fungi,o_unclassified_k_Fungi,f_unclassified_k_Fungi,g_unclassified_k_Fungi,Teichospora,and Diaporthe are key dominant fungal groups in NF soil.展开更多
Fast and effective remote sensing monitoring is an important means for analyzing the spatio-temporal changes in ecological quality in fragile karst regions.This study focuses on Guanling Autonomous County,a national-l...Fast and effective remote sensing monitoring is an important means for analyzing the spatio-temporal changes in ecological quality in fragile karst regions.This study focuses on Guanling Autonomous County,a national-level demonstration county for comprehensive desertification control.Based on Landsat TM/OLI remote sensing image data from 2005,2010,2015,and 2020,remote sensing ecological indices were used to analyze the spatio-temporal changes in ecological quality in Guanling Autonomous County from 2005 to 2020.The results show that:①the variance contribution rates of the first principal component for the four periods were 66.31%,71.59%,63.18%,and 75.24%,indicating that PC1 integrated most of the characteristics of the four indices,making the RSEI suitable for evaluating ecological quality in karst mountain areas;②the remote sensing ecological index grades have been increasing year by year,with an overall trend of improving ecological quality.The area of higher-grade ecological quality has increased spatially,while fragmented patches have gradually decreased,becoming more concentrated in the low-altitude areas in the northwest and east,and there is a trend of expansion towards higher-altitude areas;③the ecological environment quality in most areas has improved,with the improvement in RSEI spatio-temporal variation becoming more noticeable with increasing slope.Areas of higher-grade quality appeared in 2010,and the range of higher-grade quality expanded with increasing slope.展开更多
[Objective]The ecological vulnerability and landscape ecological risk of karst mountainous areas have increased as a result of enhanced disturbance of natural resources by human activities.This paper aimed to explore ...[Objective]The ecological vulnerability and landscape ecological risk of karst mountainous areas have increased as a result of enhanced disturbance of natural resources by human activities.This paper aimed to explore the characteristics of ecological risk evolution under different landscape patterns in the region,with a view to providing reference for land classification protection,sustainable use of resources and regional ecological risk optimization in karst mountainous areas.[Method]Taking Huangping County,a typical karst mountainous area,as an example,eight evaluation factors of natural and landscape patterns were selected to construct a landscape ecological risk evaluation model,to quantitatively explore the spatio-temporal evolution of landscape ecological risk and the trend of risk level transfer in the study area from^(2)010-2018,and to reveal the complex relationship between ecological risk and topography in karst mountainous areas.[Result]①From 2010 to 2018,land use types changed to different degrees,with the most amount of woodland transferred out(1627.37 hm^(2))and the most amount of construction land transferred in(1303.93 hm^(2));a total of 3552.31 hm^(2) of land was transferred,with a change ratio of 2.13%,and there was a significant conversion between construction land,arable land,and woodland.②From 2010 to 2018,the landscape ecological risk in the study area changed significantly,and the landscape ecological risk index decreased from 0.3441 to 0.1733,showing an upward and then downward trend;the landscape ecological risk of the whole region was dominated by low-risk and lower-risk zones,and the ecological risk level generally shifted from a high level to a low level,and the ecological environment was improved.③There was a negative correlation between ecological risk and topographic position,and high-risk zones were mainly distributed among low topographic zones;with the change of time,the advantage of risk level for the selection of topography was gradually weakened,and the influence of anthropogenic factors on the ecological risk of the landscape was becoming more and more prominent.[Conclusion]This paper can provide theoretical basis for land use optimization and ecological protection in karst mountainous areas.展开更多
EXCERPTS FROM MAJOR CHINESE MAGAZINES GREEN MOUNTAINS AND CRYSTAL WATERS Outlook Weekly 3 June Guizhou Province in southwest China was once ecologically fragile,but nowadays its forested areas are increasing and it is...EXCERPTS FROM MAJOR CHINESE MAGAZINES GREEN MOUNTAINS AND CRYSTAL WATERS Outlook Weekly 3 June Guizhou Province in southwest China was once ecologically fragile,but nowadays its forested areas are increasing and it is standing out as a pioneer in pursuing ecological progress.In recent years,the ecology in major river basins and mountainous areas has markedly improved.According to Guizhou’s forestry authorities,the area affected by karst rocky desertification has been cut down to 15,500 square km from 37,600 square km in 2005.展开更多
Giants once roamed the karst plains of southern China,three-metre tall apes weighing in at 250 kilograms.These very distant human ancestors–Gigantopithcus blacki–went extinct before humans arrived in the region,with...Giants once roamed the karst plains of southern China,three-metre tall apes weighing in at 250 kilograms.These very distant human ancestors–Gigantopithcus blacki–went extinct before humans arrived in the region,with few clues to why,and so far leaving around 2,000 fossilised teeth and four jawbones as the only signs of their existence.展开更多
As highways are extended to deep mountains,high altitudes,and special geological conditions,tunnel construction becomes more and more challenging,especially the construction of tunnels in karst areas.Due to the partic...As highways are extended to deep mountains,high altitudes,and special geological conditions,tunnel construction becomes more and more challenging,especially the construction of tunnels in karst areas.Due to the particularity of the regional geological structure,karst is well developed in the southwest of our country,especially at areas where the problem of tunnel water inrush in karst areas is more prominent.To further ensure the safe construction and operation of tunnels,the characteristics of tunnels in karst areas is analyzed in this article.展开更多
Humin(HM) is the main organic matter component to af fect the migration and transformation of polycyclic aromatic hydrocarbons(PAHs) in soil. The study on infl uence of the morphology change of inorganic ions on the a...Humin(HM) is the main organic matter component to af fect the migration and transformation of polycyclic aromatic hydrocarbons(PAHs) in soil. The study on infl uence of the morphology change of inorganic ions on the adsorption of PAHs in soil and its organic matter is still rare at microscopic scale. In this paper, yellow soil humin(YS-HM) and lime soil humin(LS-HM) were chosen as samples, then Fe^(3+) and Ca^(2+) were added into samples to facilitate the precipitation by changing the existing conditions of ions, and the mechanism by which inorganic precipitation changed adsorption capacity of karst soil was analyzed from the microscopic scale. The results showed that the adsorption capacity of HM reduced with the inorganic precipitation increasing. The precipitation of Ca^(2+)and Fe^(3+) both reduced the adsorption capacity of YS-HM and LS-HM by 61.71% and 71.83% on average, respectively. The results of scanning electron microscope-energy dispersive spectrometry(SEM-EDS) and pore analysis showed that the HM porosity decreased after formation of Ca^(2+) and Fe^(3+) precipitation. According to the value of Freundlich parameter n, it may be because the precipitation or colloid of Ca^(2+) and Fe^(3+) fi lled micropores and covers high-energy adsorption sites of the HM. This research provides theoretical support for studying the PAHs migration and bioavailability of Calcium-rich in karst soil.展开更多
Karst groundwater is highly vulnerable to contamination,which urges better land use zoning.This paper proposes a new approach,called COCKPIT-PLUS,to minimize groundwater contamination within cockpit karst regions.The ...Karst groundwater is highly vulnerable to contamination,which urges better land use zoning.This paper proposes a new approach,called COCKPIT-PLUS,to minimize groundwater contamination within cockpit karst regions.The method employed four parameters:P(the existence of ponor/swallow hole),L(lineament density),U(sinking stream to an underground river),and S(distance to spring/pumping site).These parameters are essential for identifying contaminant pathways and transport from the surface to the karst groundwater/springs.COCKPIT-PLUS has been developed and validated in the Gunungsewu karst in Java,Indonesia.This research considers a cockpit as a single hydrological unit that uniquely recharges karst groundwater.We analyzed 2,811 cockpits and 81 other closed depressions to develop a land use planning map.The research used the time to first arrival(Ta),time to peak(Tp),and Q_(max/min)ratio parameters of two karst springs and two underground pumping sites for validation.Cockpits with ponors/swallow holes,sinking streams,high lineament density,and short distances to springs are vulnerable to groundwater and thus must be restricted areas for any land uses.The findings show that though the COCKPIT-PLUS uses a limited karst dataset,the proposed method seems reliable enough for a rapid land-use zoning approach in cockpit karst areas.展开更多
Brandisia is a shrubby genus of about eight species distributed basically in East Asian evergreen broadleaved forests(EBLFs),with distribution centers in the karst regions of Yunnan,Guizhou,and Guangxi in southwestern...Brandisia is a shrubby genus of about eight species distributed basically in East Asian evergreen broadleaved forests(EBLFs),with distribution centers in the karst regions of Yunnan,Guizhou,and Guangxi in southwestern China.Based on the hemiparasitic and more or less liana habits of this genus,we hypothesized that its evolution and distribution were shaped by the development of EBLFs there.To test our hypothesis,the most comprehensive phylogenies of Brandisia hitherto were constructed based on plastome and nuclear loci(nrDNA,PHYA and PHYB);then divergence time and ancestral areas were inferred using the combined nuclear loci dataset.Phylogenetic analyses reconfirmed that Brandisia is a member of Orobanchaceae,with unstable placements caused by nuclear-plastid incongruences.Within Brandisia,three major clades were well supported,corresponding to the three subgenera based on morphology.Brandisia was inferred to have originated in the early Oligocene(32.69 Mya)in the Eastern Himalayas-SW China,followed by diversification in the early Miocene(19.45 Mya)in karst EBLFs.The differentiation dates of Brandisia were consistent with the origin of keystone species of EBLFs in this region(e.g.,Fagaceae,Lauraceae,Theaceae,and Magnoliaceae)and the colonization of other characteristic groups(e.g.,Gesneriaceae and Mahonia).These findings indicate that the distribution and evolution of Brandisia were facilitated by the rise of the karst EBLFs in East Asia.In addition,the woody and parasitic habits,and pollination characteristics of Brandisia may also be the important factors affecting its speciation and dispersal.展开更多
Soil erosion is a prominent environmental problem in karst regions.Exploring the spatiotemporal variability of soil erosion and the factors that influence soil erosion is of great significance for regional soil erosio...Soil erosion is a prominent environmental problem in karst regions.Exploring the spatiotemporal variability of soil erosion and the factors that influence soil erosion is of great significance for regional soil erosion prevention and control.However,the mechanisms influencing the characteristic features of the karst basins,such as bedrock exposure and lithology,still need to be further explored.This study used GIS technology,the Revised Universal Soil Loss Equation model,Getis–Ord Gi*,and partial least squares regression(PLSR)to identify the dominant factors influencing soil erosion and the spatiotemporal variability of soil erosion in 31 sub-basins of the Dabang River Basin(DRB),a typical karst area of Southwest China,from 2010 to 2020.The results indicated that soil erosion in the DRB from 2010 to 2020 was generally decreasing,the mean soil erosion in the DRB in 2010,2015 and 2020 was 18.46,16.51 and 15.29 t ha^(-1)a^(-1),respectively.During the study period,the area of slight erosion increased by 26.39%(706.54 km^(2)),while severe erosion enlarged by 26.36 km^(2).Spatially,the DRB was primarily affected by medium and slight soil erosion.The hot spot areas of soil erosion(key control areas)were mainly concentrated in the central and southern parts of the basin,decreasing each year,and the area of soil erosion hot pots has decreased from 43.22%to 20.60%.PLSR decoupling results show that elevation,bedrock exposure,land use type,interbedded limestone and clastic rock,and vegetation coverage were identified as the key variables affecting soil erosion,explaining 52.8%of soil erosion variability,with a high value of the Variable Importance on Projection(VIP)more than 1.These results can be used as a reference for comprehensive control of soil erosion and water loss in the basin.展开更多
基金supported by the National Natural Science Fund(grants No.41272159 and 41572099)Geological Survey Project of China Geological Survey (grant No.1212011120964)
文摘Objective Complex geological factors have been constraining the oil and gas exploration in the Paleozoic strata of the Qaidam Basin,although there are high-quality hydrocarbon source rocks.One of the most important reasons may be reservoir densification due to the multiple stages of destructive cementation,which has hindered our understanding of the Paleozoic petroleum enrichment rules in the Qaidam basin.In recent years.
基金financially supported by the China Geological Survey(Grant No.DD20190107,DD20190094)。
文摘In the Qaidam basin,Northwest China,karstic fissures and caves are developed in many places of the Lower Carboniferous Chengqianggou Fm.and Huaitoutala Fm.and the Upper Carboniferous Keluke Fm.,in which are found typical karstic marks.Several suites of transgressive carbonate rocks formed during the Late Paleozoic epoch are preserved as reservoir properties in the Qaidam basin,with paleokarst-related cave-fractured diagenetic structures,which provided the basis for cavefractured development.Carbonate and clastic samples covering or infilling caves and fractures in Carboniferous strata were collected in the eastern Qaidam basin to focus on petrological and geochemical analyses of karst and infilling materials.Based on this study of the Caledonian diagenetic sequence,and bitumen-infilled inclusion temperature and burial history,there existed a continuous atmospheric freshwater leaching process,which played a critical role in the construction of the Carboniferous supergene paleokarsts.Investigation and survey of the tectonic setting,plate paleolatitude and river development intensity also proves that there was abundant rainfall during the Indosinian period,after which the strata undergo a shallow burial process.Because Indosinian period is earlier than the key timing of hydrocarbon-generation of the Carboniferous source rocks,this kind of karst reservoir has potential significance for oil-gas resources in this area.
基金supported by the Guizhou Province Top Discipline Construction Program Project(QianjiaoKeyan Fa[2019]125)the Guizhou Normal University Academic Emerging Talent Fund Project(Qianshi Xin Miao[2021]20)the Postgraduate Education Innovation Programme of Guizhou Province(Qianjiaohe YJSKYJJ[2021]091)。
文摘Four species of the genus Karstsinnectes,which live in dark,low-energy groundwater ecosystems,are currently recorded,mainly distributed in the upstream of the Pearl River,the Youjiang River and the Hongshui River.Completing biodiversity surveys is particularly difficult due to the particular cave habitats inhabited by these species.In this work,we describe a new cave fish of the genus Karstsinnectes,namely K.cehengensis Luo,Zhao&Zhou,sp.nov.,collected from the Beipanjiang River,the upstream of the Hongshui River.Genetically,the four individuals of the new species form a phylogenetically separate lineage,as the sister clade of K.acridorsalis,with a 9.4–9.5%genetic difference in mitochondrial Cyt b.Morphologically,the new species can be distinguished from its congeners by a combination of the following morphological characteristics:body naked,without body color;eyes reduced,diameter 1.4–3.8%of head length;anterior and posterior nostrils adjacent,anterior nostril not elongated to a barbel-like tip;lateral line incomplete;caudal fin forked;dorsal-fin rays iii-7,pectoral-fin rays i-11–12,pelvic-fin rays i-7,anal-fin rays iii-5,with 14 branched caudal-fin rays.The discovery of this new species represents the northernmost distribution of species within the genus Karstsinnectes and the first record from Guizhou Province.All currently known species of this genus inhabited in caves,making them ideal organisms for studying historical river connectivity and cave formation process.
文摘Indulge in some ancestor worship and slurp a bowl of pungent river snail noodles in ancient Huangyao amid a magnificent landscape of karst mountains and waterways.Huangyao might not be as famous as its glitzy neighbor Guilin,but its ancient culture,historic clan architecture and natural surroundings provide an alternative for a trip to Guangxi.Zhuang Autonomous Region.
基金supported by the National Natural Science Foundation of China(41776143)。
文摘DEAR EDITOR,Bostrychus,a genus in the family Eleotridae of the order Gobiiformes,was first established by Lacepède in 1801(Buffon,1801).Bostrychus currently contains seven recognized species,including two recent additions(B.microphthalmos and B.scalaris)described in 2005(Hoese&Kottelat,2005)and 2008(Larson,2008),respectively.The natural range of Bostrychus species extends from East Asia to Australia,with the exception of B.africanus,Steindachner,1879,which is distributed in West Africa(Herre,1946).Among the recognized species,B.sinensis,B.zonatus,and B.africanus are relatively widespread,inhabiting diverse areas from estuaries to freshwater streams,while B.scalaris is only found at a single mangrove site in the Selangor State of Malaysia(Larson,2008).The remaining three species exhibit a high degree of habitat specialization and are highly localized(Hoese&Kottelat,2005):B.microphthalmos inhabits a cave stream in the Maros karst of southern Sulawesi,B.aruensis is confined to freshwater environments in the Aru Islands of Indonesia,and B.strigogenys is found only in freshwater areas in southern Papua New Guinea and Irian Jaya.
基金support from the National Natural Science Foundation of China(Grant.No.42162027)the Science and technology foundation of Guizhou Province(Grant.No.2022-212,2023-006)are greatly appreciated.
文摘Karst sinkholes with natural negative landform provide favorable conditions for the pumped storage reservoir construction for less excavation work.However,the construction of the reservoir would plug the natural karst channels for water and air,which would cause remarkable air pressure in karst channels when the groundwater level fluctuates.A large laboratory simulation test was carried out to study the air pressure variation of a reservoir built on the karst sinkhole.The air pressure in the karst channel and inside the model was monitored during the groundwater rising and falling process.Result showed that the variation of air pressure in the karst channel and the surrounding rock exhibited a high degree of similarity.The air pressure increased rapidly at the initial stage of water level rising,followed by a slight decrease,then the air pressure increased sharply when the water level approached the top of the karst cave.The initial peak of air pressure and the final peak of air pressure were defined,and both air pressure peaks were linearly increasing with the water level rising rate.The negative air pressure was also analyzed during the drainage process,which was linearly correlated with the water level falling rate.The causes of air pressure variation in karst channels of a pumped storage reservoir built on the karst sinkhole were discussed.The initial rapid increase,then slight decrease and final sudden increase of air pressure were controlled by the combined effects of air compression in karst channel and air seepage into the surrounding rock.For the drainage process,the instant negative air pressure and gradual recovering of air pressure were controlled by the combined effects of negative air pressure induced by water level falling and air supply from surrounding rock.This work could provide valuable reference for the reservoir construction in karst area.
基金sponsored by the National Natural Science Foundation of China(Grants Nos.52104046 and 52104010).
文摘Karst fracture-cavity carbonate reservoirs,in which natural cavities are connected by natural fractures to form cavity clusters in many circumstances,have become significant fields of oil and gas exploration and exploitation.Proppant fracturing is considered as the best method for exploiting carbonate reservoirs;however,previous studies primarily focused on the effects of individual types of geological formations,such as natural fractures or cavities,on fracture propagation.In this study,true-triaxial physical simulation experiments were systematically performed under four types of stress difference conditions after the accurate prefabrication of four types of different fracture-cavity distributions in artificial samples.Subsequently,the interaction mechanism between the hydraulic fractures and fracture-cavity structures was systematically analyzed in combination with the stress distribution,cross-sectional morphology of the main propagation path,and three-dimensional visualization of the overall fracture network.It was found that the propagation of hydraulic fractures near the cavity was inhibited by the stress concentration surrounding the cavity.In contrast,a natural fracture with a smaller approach angle(0°and 30°)around the cavity can alleviate the stress concentration and significantly facilitate the connection with the cavity.In addition,the hydraulic fracture crossed the natural fracture at the 45°approach angle and bypassed the cavity under higher stress difference conditions.A new stimulation effectiveness evaluation index was established based on the stimulated reservoir area(SRA),tortuosity of the hydraulic fractures(T),and connectivity index(CI)of the cavities.These findings provide new insights into the fracturing design of carbonate reservoirs.
基金The National Natural Science Foundation of China under contract No.42276066the Key Research and Development Program(International Science and Technology Cooperation Development Program)of Hainan Province under contract No.GHYF2022009the Youth Innovation Promotion Association of CAS under contract No.2018401.
文摘Based on high-resolution 3D seismic data acquired in the Pearl(Zhujiang)River Mouth Basin of the northern South China Sea,this study investigated the geometry,spatial extension,and throw distribution of the post-rift normal fault through detailed seismic interpretation and fault modeling.A total of 289 post-rift normal faults were identified in the study area and can be classified into four types:(1)isolated normal faults above the carbonate platform;(2)isolated normal faults cutting through the carbonate platform;(3)conjugate normal faults,and(4)connecting normal faults.Throw distribution analysis on the fault planes show that the vertical throw profiles of most normal fault exhibit flat-topped profiles.Isolated normal faults above the carbonate platform exhibit roughly concentric ellipses with maximum throw zones in the central section whereas the normal faults cutting through the carbonate platform miss the lowermost section due to the chaotic seismic reflections in the interior of the carbonate platform.The vertical throws of conjugate normal faults anomalously decrease toward their intersection region on the fault plane whereas the connecting normal faults present two maximum throw zones in the central section of the fault plane.According to the symmetric elliptical distribution model of fault throw,an estimation was made indicating that normal faults cutting through the carbonate platform extended downward between-1308 s and-1780 s(two-way travel time)in depth and may not penetrate the entire Liuhua carbonate platform.Moreover,it is observed that the distribution of karst caves on the top of the carbonate platform disaccord with those of hydrocarbon reservoirs and the post-rift normal faults cutting through the carbonate platform in the study area.We propose that these karst caves formed most probably by corrosive fluids derived from magmatic activities during the Dongsha event,rather than pore waters or hydrocarbons.
文摘Based on the arable land situation in Gejiu City,upland dry planting of indica hybrid rice is being expanded in Karst mountain areas with a rainfall of over 1400 mm and an altitude of 1100-1600 m to develop grain production.This paper gives a specific description of hybrid rice upland dry seedling technology,upland transplanting technology,fertilization technology,field management,weed prevention and control technology,and disease and pest control.
文摘The growth of society and population has led to a range of water pollution issues.Among these,non-point source pollution assessment and treatment pose a particular challenge due to its formation mechanism.This has become a focal point and challenge in water pollution treatment research.The study area for this research was the Huanghou basin in Guizhou Province,southwest China.The land use type of the basin was analyzed using remote sensing technology,and water quality data was collected by distributing points throughout the basin,based on source-sink landscape theory.The distribution map of the basin’s source-sink landscape and the results of water quality data accurately and efficiently identified the areas with high risk of non-point source pollution in the western and southwestern residential and agricultural areas of the upper basin.Hence,a strategy of“increasing sinks and decreasing sources”was proposed.The strategy was implemented at both macro and micro levels to address non-point source pollution in the basin using ecological remediation techniques.The work to control karst rocky desertification should continue at a macro level.The rocky desertification area in the basin should gradually transform into grassland and forested land,while increasing the overall area of the sink landscape.Ecological restoration techniques,such as slope planting,riparian zone vegetation restoration,increasing plant abundance,and restoring aquatic plants,can effectively control non-point source pollution at the micro level.Compared to traditional control methods,this remediation strategy focuses on source and process control.It is more effective and does not require large-scale water pollution control projects,which can save a lot of environmental control funds and management costs.Therefore,it has greater research significance and application value.
基金Supported by National Natural Science Foundation of China (42177446,41601584)Guizhou Provincial Science and Technology Fund (Qiankehe[2017]1417)Guizhou Normal University (Qianshixinmiao[2022]28).
文摘In this paper,managed forest(MF)and natural forest(NF)in the Huajiang Demonstration Zone of Guanling,Guizhou were selected as research objects,and cropland(CL)was taken as control.High-throughput sequencing technology was used to study the characteristics of fungal community composition and species diversity in the surface(0-10 cm)soil of each restoration measure,in order to reveal the dominant soil fungal groups and fungal community composition in karst rocky desertification areas,which was conducive to a more comprehensive understanding of the soil conditions of different vegetation restoration measures.Research has shown that vegetation restoration significantly affected the diversity of soil fungal community,with significant increases in Sob index,Ace index,and Chao index.The vegetation restoration has significantly changed the composition of fungal community.The dominant fungi in the CL topsoil are Sordariomycetes(62.28%),Dothideomycetes(12.34%),and Eurotiomycetes(9.12%);the dominant fungi in the MF soil are Sordariomycetes(45.05%),Dothideomycetes(14.74%),and Mortierellomycetes(10.40%);the dominant fungi in the NF soil are unclassified fungal community(26.38%),Sordariomycetes(19.78%),and Agaricomycetes(13.82%).Vegetation restoration has changed the key fungal groups in the soil.Sordariomycetes,Fusarium,and Setophoma are the key dominant fungal groups in CL soil;Dioszegia is key dominant fungal group in MF soil;c_unclassified_k_Fungi,p_unclassified_k_Fungi,o_unclassified_k_Fungi,f_unclassified_k_Fungi,g_unclassified_k_Fungi,Teichospora,and Diaporthe are key dominant fungal groups in NF soil.
基金Supported by Guizhou Provincial Key Technology R&D Program ([2023]General 211)Guizhou Science and Technology Innovation Base Construction Project (Qian Ke He Zhong Yin Di[2023]005).
文摘Fast and effective remote sensing monitoring is an important means for analyzing the spatio-temporal changes in ecological quality in fragile karst regions.This study focuses on Guanling Autonomous County,a national-level demonstration county for comprehensive desertification control.Based on Landsat TM/OLI remote sensing image data from 2005,2010,2015,and 2020,remote sensing ecological indices were used to analyze the spatio-temporal changes in ecological quality in Guanling Autonomous County from 2005 to 2020.The results show that:①the variance contribution rates of the first principal component for the four periods were 66.31%,71.59%,63.18%,and 75.24%,indicating that PC1 integrated most of the characteristics of the four indices,making the RSEI suitable for evaluating ecological quality in karst mountain areas;②the remote sensing ecological index grades have been increasing year by year,with an overall trend of improving ecological quality.The area of higher-grade ecological quality has increased spatially,while fragmented patches have gradually decreased,becoming more concentrated in the low-altitude areas in the northwest and east,and there is a trend of expansion towards higher-altitude areas;③the ecological environment quality in most areas has improved,with the improvement in RSEI spatio-temporal variation becoming more noticeable with increasing slope.Areas of higher-grade quality appeared in 2010,and the range of higher-grade quality expanded with increasing slope.
基金the National Natural Science Foundation of China(41661088)Project for Guizhou Province"High-level Innovative Talent Training Program‘Hundred’Level Talents"(QKHPTRC[2016]5674)Guizhou Science and Technology Plan Project(QKHZC[2023]GENERAL211).
文摘[Objective]The ecological vulnerability and landscape ecological risk of karst mountainous areas have increased as a result of enhanced disturbance of natural resources by human activities.This paper aimed to explore the characteristics of ecological risk evolution under different landscape patterns in the region,with a view to providing reference for land classification protection,sustainable use of resources and regional ecological risk optimization in karst mountainous areas.[Method]Taking Huangping County,a typical karst mountainous area,as an example,eight evaluation factors of natural and landscape patterns were selected to construct a landscape ecological risk evaluation model,to quantitatively explore the spatio-temporal evolution of landscape ecological risk and the trend of risk level transfer in the study area from^(2)010-2018,and to reveal the complex relationship between ecological risk and topography in karst mountainous areas.[Result]①From 2010 to 2018,land use types changed to different degrees,with the most amount of woodland transferred out(1627.37 hm^(2))and the most amount of construction land transferred in(1303.93 hm^(2));a total of 3552.31 hm^(2) of land was transferred,with a change ratio of 2.13%,and there was a significant conversion between construction land,arable land,and woodland.②From 2010 to 2018,the landscape ecological risk in the study area changed significantly,and the landscape ecological risk index decreased from 0.3441 to 0.1733,showing an upward and then downward trend;the landscape ecological risk of the whole region was dominated by low-risk and lower-risk zones,and the ecological risk level generally shifted from a high level to a low level,and the ecological environment was improved.③There was a negative correlation between ecological risk and topographic position,and high-risk zones were mainly distributed among low topographic zones;with the change of time,the advantage of risk level for the selection of topography was gradually weakened,and the influence of anthropogenic factors on the ecological risk of the landscape was becoming more and more prominent.[Conclusion]This paper can provide theoretical basis for land use optimization and ecological protection in karst mountainous areas.
文摘EXCERPTS FROM MAJOR CHINESE MAGAZINES GREEN MOUNTAINS AND CRYSTAL WATERS Outlook Weekly 3 June Guizhou Province in southwest China was once ecologically fragile,but nowadays its forested areas are increasing and it is standing out as a pioneer in pursuing ecological progress.In recent years,the ecology in major river basins and mountainous areas has markedly improved.According to Guizhou’s forestry authorities,the area affected by karst rocky desertification has been cut down to 15,500 square km from 37,600 square km in 2005.
文摘Giants once roamed the karst plains of southern China,three-metre tall apes weighing in at 250 kilograms.These very distant human ancestors–Gigantopithcus blacki–went extinct before humans arrived in the region,with few clues to why,and so far leaving around 2,000 fossilised teeth and four jawbones as the only signs of their existence.
文摘As highways are extended to deep mountains,high altitudes,and special geological conditions,tunnel construction becomes more and more challenging,especially the construction of tunnels in karst areas.Due to the particularity of the regional geological structure,karst is well developed in the southwest of our country,especially at areas where the problem of tunnel water inrush in karst areas is more prominent.To further ensure the safe construction and operation of tunnels,the characteristics of tunnels in karst areas is analyzed in this article.
基金The national natural science Foundations of China under Grant (41761091)The first-class discipline group of geography of Guizhou Province under Grant (N0.[2019]125)+3 种基金Youth Science and Technology Talents Growth Fund of Education Department of Guizhou Province,China (No.KY[2022] 001)Scientific Research Funds of Guiyang University,China (No.GYU-KY-[2022])The Joint Foundation of Guizhou Province under Grant (LH [2017]7348)The Doctor Foundation of Guizhou Normal University under Grant (GZNUD [2017]10)。
文摘Humin(HM) is the main organic matter component to af fect the migration and transformation of polycyclic aromatic hydrocarbons(PAHs) in soil. The study on infl uence of the morphology change of inorganic ions on the adsorption of PAHs in soil and its organic matter is still rare at microscopic scale. In this paper, yellow soil humin(YS-HM) and lime soil humin(LS-HM) were chosen as samples, then Fe^(3+) and Ca^(2+) were added into samples to facilitate the precipitation by changing the existing conditions of ions, and the mechanism by which inorganic precipitation changed adsorption capacity of karst soil was analyzed from the microscopic scale. The results showed that the adsorption capacity of HM reduced with the inorganic precipitation increasing. The precipitation of Ca^(2+)and Fe^(3+) both reduced the adsorption capacity of YS-HM and LS-HM by 61.71% and 71.83% on average, respectively. The results of scanning electron microscope-energy dispersive spectrometry(SEM-EDS) and pore analysis showed that the HM porosity decreased after formation of Ca^(2+) and Fe^(3+) precipitation. According to the value of Freundlich parameter n, it may be because the precipitation or colloid of Ca^(2+) and Fe^(3+) fi lled micropores and covers high-energy adsorption sites of the HM. This research provides theoretical support for studying the PAHs migration and bioavailability of Calcium-rich in karst soil.
文摘Karst groundwater is highly vulnerable to contamination,which urges better land use zoning.This paper proposes a new approach,called COCKPIT-PLUS,to minimize groundwater contamination within cockpit karst regions.The method employed four parameters:P(the existence of ponor/swallow hole),L(lineament density),U(sinking stream to an underground river),and S(distance to spring/pumping site).These parameters are essential for identifying contaminant pathways and transport from the surface to the karst groundwater/springs.COCKPIT-PLUS has been developed and validated in the Gunungsewu karst in Java,Indonesia.This research considers a cockpit as a single hydrological unit that uniquely recharges karst groundwater.We analyzed 2,811 cockpits and 81 other closed depressions to develop a land use planning map.The research used the time to first arrival(Ta),time to peak(Tp),and Q_(max/min)ratio parameters of two karst springs and two underground pumping sites for validation.Cockpits with ponors/swallow holes,sinking streams,high lineament density,and short distances to springs are vulnerable to groundwater and thus must be restricted areas for any land uses.The findings show that though the COCKPIT-PLUS uses a limited karst dataset,the proposed method seems reliable enough for a rapid land-use zoning approach in cockpit karst areas.
基金funded by the Key Projects of the Joint Fund of the National Natural Science Foundation of China(U1802232)the national youth talent support program+2 种基金CAS"Light of West China"ProgramYunnan youth talent support program(YNWR-QNBJ-2018-183 to Y.N.)Vietnam Academy of Science and Technology(UQDTCB.06/22-23)。
文摘Brandisia is a shrubby genus of about eight species distributed basically in East Asian evergreen broadleaved forests(EBLFs),with distribution centers in the karst regions of Yunnan,Guizhou,and Guangxi in southwestern China.Based on the hemiparasitic and more or less liana habits of this genus,we hypothesized that its evolution and distribution were shaped by the development of EBLFs there.To test our hypothesis,the most comprehensive phylogenies of Brandisia hitherto were constructed based on plastome and nuclear loci(nrDNA,PHYA and PHYB);then divergence time and ancestral areas were inferred using the combined nuclear loci dataset.Phylogenetic analyses reconfirmed that Brandisia is a member of Orobanchaceae,with unstable placements caused by nuclear-plastid incongruences.Within Brandisia,three major clades were well supported,corresponding to the three subgenera based on morphology.Brandisia was inferred to have originated in the early Oligocene(32.69 Mya)in the Eastern Himalayas-SW China,followed by diversification in the early Miocene(19.45 Mya)in karst EBLFs.The differentiation dates of Brandisia were consistent with the origin of keystone species of EBLFs in this region(e.g.,Fagaceae,Lauraceae,Theaceae,and Magnoliaceae)and the colonization of other characteristic groups(e.g.,Gesneriaceae and Mahonia).These findings indicate that the distribution and evolution of Brandisia were facilitated by the rise of the karst EBLFs in East Asia.In addition,the woody and parasitic habits,and pollination characteristics of Brandisia may also be the important factors affecting its speciation and dispersal.
基金supported by National Natural Science Foundation of China(32060372,32360421)Guizhou Science and Technology Department(Qian Ke He Ji Chu ZK-[2023]Key 029Qiankehe Zhicheng[2021]Yiban462)。
文摘Soil erosion is a prominent environmental problem in karst regions.Exploring the spatiotemporal variability of soil erosion and the factors that influence soil erosion is of great significance for regional soil erosion prevention and control.However,the mechanisms influencing the characteristic features of the karst basins,such as bedrock exposure and lithology,still need to be further explored.This study used GIS technology,the Revised Universal Soil Loss Equation model,Getis–Ord Gi*,and partial least squares regression(PLSR)to identify the dominant factors influencing soil erosion and the spatiotemporal variability of soil erosion in 31 sub-basins of the Dabang River Basin(DRB),a typical karst area of Southwest China,from 2010 to 2020.The results indicated that soil erosion in the DRB from 2010 to 2020 was generally decreasing,the mean soil erosion in the DRB in 2010,2015 and 2020 was 18.46,16.51 and 15.29 t ha^(-1)a^(-1),respectively.During the study period,the area of slight erosion increased by 26.39%(706.54 km^(2)),while severe erosion enlarged by 26.36 km^(2).Spatially,the DRB was primarily affected by medium and slight soil erosion.The hot spot areas of soil erosion(key control areas)were mainly concentrated in the central and southern parts of the basin,decreasing each year,and the area of soil erosion hot pots has decreased from 43.22%to 20.60%.PLSR decoupling results show that elevation,bedrock exposure,land use type,interbedded limestone and clastic rock,and vegetation coverage were identified as the key variables affecting soil erosion,explaining 52.8%of soil erosion variability,with a high value of the Variable Importance on Projection(VIP)more than 1.These results can be used as a reference for comprehensive control of soil erosion and water loss in the basin.