Five new small theropod teeth and one manual ungual have recently been recovered from the Upper Cretaceous Nenjiang Formation in the Songliao Basin.The specimens were examined for their morphological characteristics,l...Five new small theropod teeth and one manual ungual have recently been recovered from the Upper Cretaceous Nenjiang Formation in the Songliao Basin.The specimens were examined for their morphological characteristics,leading to the identification of four distinct taxa.The first taxon consists of three foliodont teeth characterized by a pronounced basal constriction and large hook-like distal denticles,which can be attributed to Troodontidae.The second taxon is represented by an elongated tooth featuring prominent longitudinal ridges,allowing for its assignment to Paronychodon.The third taxon is a bladelike tooth with notably small distal denticles,corresponding to Richardoestesia.The fourth taxon comprises a manual ungual characterized by a transversely wide and nearly symmetrical proximal articular surface,fully enclosed ventral foramina,a flattened ventral surface,and the absence of a flexor tubercle,resembling Alvarezsauridae.These specimens significantly enhance the known dinosaur diversity of the Nenjiang Formation and provide crucial insights for understanding the terrestrial ecosystem in Northeast Asia during the Late Cretaceous.展开更多
Twelve new dinosaur teeth have recently been recovered from three localities in the Upper Cretaceous Nenjiang Formation of the Songliao Basin.Although fragmentary,the material offers enough evidence to identify the fo...Twelve new dinosaur teeth have recently been recovered from three localities in the Upper Cretaceous Nenjiang Formation of the Songliao Basin.Although fragmentary,the material offers enough evidence to identify the following taxa:tyrannosaurids,dromaeosaurines,velociraptorines,hadrosauroids,and titanosaurs.In addition to the previously known dinosaurs from the basin,several new ones have been identified,extending the paleogeographic range of related taxa.The discovery of these new fossil remains provides valuable insights into dinosaur diversity and sheds light on the terrestrial ecosystem during the Late Cretaceous in the Songliao Basin.展开更多
To investigate the characteristics of water environmental pollution in the Nenjiang River Basin,five monitoring sections,including Zhenxi,Xianghai Reservoir,Baishatan,Yuelianghu Reservoir,and Da an,were selected.Utili...To investigate the characteristics of water environmental pollution in the Nenjiang River Basin,five monitoring sections,including Zhenxi,Xianghai Reservoir,Baishatan,Yuelianghu Reservoir,and Da an,were selected.Utilizing water quality monitoring data collected from 2013 to 2022,the fuzzy comprehensive evaluation method was employed to systematically analyze the spatiotemporal variation patterns of water quality,assess the current pollution status,and identify the influencing factors of non-point source pollution.The results indicated that the concentrations of representative pollutants at five sections in the lower reaches of the Nenjiang River generally exhibited a downward trend,accompanied by an overall improvement in water quality.However,the degree of improvement varied considerably among the different sections.Specifically,the water quality of the main stream of the Nenjiang River(Baishatan and Da an)improved from Class IV to Class III.In contrast,the Xianghai Reservoir consistently remained at Class V or below,primarily due to excessive fluoride levels.The water quality at Yuelianghu Reservoir and Heidimiao Section demonstrated a fluctuating but overall improving trend.Based on the analysis of pollution sources,targeted recommendations are proposed,including regulating the ecological water requirements of rivers,restoring wetland ecosystems,and enhancing the management of non-point source pollution.These measures offer scientific support for water quality management and ecological conservation in the river basins.展开更多
Incorporating private and working lands into protected area networks could mitigate the isolation state of protected areas(PAs) and improve the efficiency of conservation.But how to select patches of land for conserva...Incorporating private and working lands into protected area networks could mitigate the isolation state of protected areas(PAs) and improve the efficiency of conservation.But how to select patches of land for conservation is still a troublesome issue.In this study, the MaxEnt model and irreplaceability index were applied to guide marsh conservation in the Nenjiang River Basin, Northeast China.According to the high accuracy of the MaxEnt model predictions(i.e., the average AUC value = 0.933), the Wuyuer River and Zhalong marshes in the downstream reaches of Wuyuer River are the optimal habitat for the Red-crowned crane and migratory waterfowls.There are 22 marsh patches selected by the patch irreplaceability index for conservation, of which 12 patches had been included in the current network of protected areas.The other 10 patches of marsh(amounting to 1096 km^2) far from human disturbances with high NDVI(up to 0.8) and close distance to water(less than 100 m), which are excluded from the existing network of PAs, should be implemented conservation easement programs to improve the protection efficiency of conservation.Specifically, the marshes at Taha, Tangchi, and Lamadian should be given priority for conservation and restoration to reintroduce migratory waterfowls, as this would lessen the current isolation state of the Zhalong National Nature Reserve.展开更多
Temperature-triaxial pressure permeability testing at the axial pressure of 8 MPa and confining pressure of 10 MPa,closed shale system pyrolysis experiment by electrical heating and scanning electron microscopy analys...Temperature-triaxial pressure permeability testing at the axial pressure of 8 MPa and confining pressure of 10 MPa,closed shale system pyrolysis experiment by electrical heating and scanning electron microscopy analysis are used to study the evolution mechanism of in-situ permeability in the direction parallel to bedding of low-maturity shale from Member 2(K_(2)n_(2))of Cretaceous Nenjiang Formation in northern Songliao Basin with mainly Type I kerogen under the effect of temperature.With the increasing temperature,the in-situ permeability presents a peak-valley-peak tendency.The lowest value of in-situ permeability occurs at 375℃.Under the same temperature,the in-situ permeability decreases with the increase of pore pressure.The in-situ permeability evolution of low-maturity shale can be divided into 5 stages:(1)From 25℃to 300℃,thermal cracking and dehydration of clay minerals improve the permeability.However,the value of permeability is less than 0.01×10^(-3)μm^(2).(2)From 300℃to 350℃,organic matter pyrolysis and hydrocarbon expulsion result in mineral intergranular pores and micron pore-fractures,these pores and fractures form an interconnected pore network at limited scale,improving the permeability.But the liquid hydrocarbon,with high content of viscous asphaltene,is more difficult to move under stress and more likely to retain in pores,causing slow rise of the permeability.(3)From 350℃to 375℃,pores are formed by organic matter pyrolysis,but the adsorption swelling of liquid hydrocarbon and additional expansion thermal stress constrained by surrounding stress compress the pore-fracture space,making liquid hydrocarbon difficult to expel and permeability reduce rapidly.(4)From 375℃to 450℃,the interconnected pore network between different mineral particles after organic matter conversion,enlarged pores and transformation of clay minerals promote the permeability to increase constantly even under stress constraints.(5)From 450℃to 500℃,the stable pore system and crossed fracture system in different bedding directions significantly enhance the permeability.The organic matter pyrolysis,pore-fracture structure and surrounding stress in the different stages are the key factors affecting the evolution of in-situ permeability.展开更多
To illuminate the spatio-temporal variation characteristics and geochemical driving mechanism of soil pH in the Nenjiang River Basin,the National Multi-objective Regional Geochemical Survey data of topsoil,the Second ...To illuminate the spatio-temporal variation characteristics and geochemical driving mechanism of soil pH in the Nenjiang River Basin,the National Multi-objective Regional Geochemical Survey data of topsoil,the Second National Soil Survey data and Normalized Difference Vegetation Index(NDVI)were analyzed.The areas of neutral and alkaline soil decreased by 21100 km^(2)and 30500 km^(2),respectively,while that of strongly alkaline,extremely alkaline,and strongly acidic soil increased by 19600 km^(2),18200 km^(2),and 15500 km^(2),respectively,during the past 30 years.NDVI decreased with the increase of soil pH when soil pH>8.0,and it was reversed when soil pH<5.0.There were significant differences in soil pH with various surface cover types,which showed an ascending order:Arbor<reed<maize<rice<high and medium-covered meadow<low-covered meadow<Puccinellia.The weathering products of minerals rich in K_(2)O,Na_(2)O,CaO,and MgO entered into the low plain and were enriched in different parts by water transportation and lake deposition,while Fe and Al remained in the low hilly areas,which was the geochemical driving mechanism.The results of this study will provide scientific basis for making scientific and rational decisions on soil acidification and salinization.展开更多
Objective The Dayangshu Basin located in eastern Inner Mongolia,is one of the key areas for oil and gas exploration in the periphery of Songliao Basin.So far,this basin has been poorly explored,and the basic geologica...Objective The Dayangshu Basin located in eastern Inner Mongolia,is one of the key areas for oil and gas exploration in the periphery of Songliao Basin.So far,this basin has been poorly explored,and the basic geological research is still weak,due to the lack of high-quality paleontologic and stratigraphic data.The previous oil and gas investigations were mainly focused on the Early Cretaceous strata.However,the Late Cretaceous Nenjiang Formation in the basin also has hydrocarbon potential according to the latest research.In recent oil and gas geological survey,palynological fossils have been discovered from the Nenjiang Formation in the Dayangshu Basin,providing new evidence for biostratigraphic division and correlation.展开更多
Assessment of temporal and spatial variations in surface water quality is important to evaluate the health of a watershed and make necessary management decisions to control current and future pollution of receiving wa...Assessment of temporal and spatial variations in surface water quality is important to evaluate the health of a watershed and make necessary management decisions to control current and future pollution of receiving water bodies. In this work, surface water quality data for 12 physical and chemical parameters collected from 10 sampling sites in the Nenjiang River basin during the years(2012-2013) were analyzed. The results show that river water quality has significant temporal and spatial variations. Hierarchical cluster analysis(HCA) grouped 12 months into three periods(LF, MF and HF) and classified 10 monitoring sites into three regions(LP, MP and HP) based on the similarity of water quality characteristics. The principle component analysis(PCA)/factor analysis(FA) was used to recognize the factors or origins responsible for temporal and spatial water quality variations. Temporal and spatial PCA/FA revealed that the Nenjiang River water chemistry was strongly affected by rock/water interaction, hydrologic processes and anthropogenic activities. This work demonstrates that the application of HCA and PCA/FA has achieved meaningful classification based on temporal and spatial criteria.展开更多
Making a brief analysis of the water and soil loss present situation in Daxing＇anling area which locates to the upstream region of Nenjiang River, and giving the water and soil loss of this area that have been made n...Making a brief analysis of the water and soil loss present situation in Daxing＇anling area which locates to the upstream region of Nenjiang River, and giving the water and soil loss of this area that have been made near 20 years, as well as the factors of the water and soil loss. According to the factors corresponding prevention measure and forecast model have been put forward, make a brief introduction to this model in this article. It is helpful to improve the local soil conservation and sustainable development.展开更多
[Objective]The research aimed to analyze and contrast flood cause in Nenjiang Basin between 2013 and 1998.[Method]Based on meteorological and hydrological data in and around Nenjiang Basin,geographic information syste...[Objective]The research aimed to analyze and contrast flood cause in Nenjiang Basin between 2013 and 1998.[Method]Based on meteorological and hydrological data in and around Nenjiang Basin,geographic information system as data processing platform,statistical methods such as synthesis analysis and correlation analysis were combined to contrast and analyze the flood cause in the Nenjiang Basin between 2013 and1998.[Result]The similarities of two floods in Nenjiang Basin were that rainstorm frequency and summer precipitation were more,and many large and medium-sized reservoirs which undertook the flood control task were running above flood level.In order to protect the safety of reservoir dam,flood discharge volume increased.And the difference was external forcing factor which caused atmospheric circulation abnormality,thus the impact factors of summer more rainfall were not the same.The main reason for more precipitation in Nenjiang Basin in summer of 2013：The northeast cold vortex activity was frequent,and the path was by north;water vapor transport was sufficient at 850 hPa;at 500 hPa,the Eurasian zonal circulation was weak,the West Pacific subtropical high pressure abnormally moved northward,blocking high of the Sea of Okhotsk was obvious,and Heilongjiang region was controlled by negative anomaly in midsummer;East Asian westerly jet location was abnormal at 200 hPa,and East Asian summer monsoon was strong.[Conclusion]The research had very important significance for understanding occurrence rule of flood and improving disaster prevention and mitigation capabilities in Nenjiang Basin.展开更多
In a region where lizard fossils are rare,this study explores a groundbreaking discovery of squamate lizard materials from the upper part of Nenjiang Formation(early Campanian)in Jilin Province,Northeast China.Despite...In a region where lizard fossils are rare,this study explores a groundbreaking discovery of squamate lizard materials from the upper part of Nenjiang Formation(early Campanian)in Jilin Province,Northeast China.Despite the fragmentary nature of the dentaries,they exhibit distinct tooth morphological characteristics of squamate lizards,suggesting insectivorous and omnivorous diets for these small reptiles.This finding not only represents a significant addition to the squamate lizard fossil records from the Late Cre-taceous in Northeast China but also contributes to our understanding of the paleogeographic distribution of squamate lizards.Furthermore,it sheds new light on the terrestrial vertebrate fauna of the Cretaceous Songliao Basin.展开更多
This paper studied seismic imaging of the sedimentary system of the Nenjiang Formation in the Northern Songliao Basin based on seismic sedimentology. An accurate and detailed depiction and explanation is provided for ...This paper studied seismic imaging of the sedimentary system of the Nenjiang Formation in the Northern Songliao Basin based on seismic sedimentology. An accurate and detailed depiction and explanation is provided for underground geological bodies within a relative geological period using the stratal slice technology,based on three-order sequence correlations of well logging and seismic data for the purpose of obtaining high-resolution pictures of the sedimentary system. Research results have revealed that the sedimentary system of the Upper Cretaceous Nenjiang Formation in the Northern Songliao Basin includes meandering streams,anastomosing streams,lake deltas,and sediment gravity flow channels. Based on seismic imaging analysis,the genesis and seismic geomorphology of the sedimentary system of the Nenjiang Formation are explored in order to understand the spatial distribution of typical sedimentary bodies and the evolution of streams in the Nenjiang Formation. According to the research results,the sedimentation of the Nenjiang Formation was subject to the delta system in the east and northeast of the formation. The provenance in the northeastern part played a dominant role during the deposition of the Nenjiang Formation for some time;after the earlier maximum flooding in the second and third members of the Nenjiang Formation,the northeastern system began to decline and was gradually replaced by the eastern system. Stratal slices have revealed that a well-developed gravity flow channel system was developed in the first member of the Nenjiang Formation,and massive slip blocks occurred in the second and third members of the formation. The research results indicated that the large gravity flow channel system in the first member of the Nenjiang Formation was formed by streams that emptied directly into the lake;and the slip blocks in the second and third members were the results of gravity sliding of sediments along steep slopes at the delta front.展开更多
In the summer of 1998, an exceptionally serious flood, with the characteristics of high water level, large volume of flow, long duration and serious losses caused by the disaster, occurred in the Nenjiang River basin ...In the summer of 1998, an exceptionally serious flood, with the characteristics of high water level, large volume of flow, long duration and serious losses caused by the disaster, occurred in the Nenjiang River basin and the Songhua River basin. Greater flood peak occurred three times in the trunk stream of the Nenjiang River for the floods occurred in its tributaries one after another. At Jiangqiao Hydrometric Station, the water level was 141.90 m and the rate of flow was 12?000 m 3/s. The flood is ranged to a catastrophic one, which occurs once in 50 years. Ranged to a catastrophic flood at Qiqihar Hydrometric Station that occurs once in 400 years, its water level, 0.89 m higher than the former all time highest, was 149.30?m and the corresponding rate of flow was 14?800?m 3/s. The water level that exceeded the all time highest lasted for 7 days. At Harbin Hydrometric Station, the water level, 0.59?m higher than the former all time highest, was 120.89?m and the corresponding rate of flow was 17?400?m 3/s. The water level that exceeded the all time highest lasted for 9 to 10 days. The flood here is ranged to a catastrophic one, which occurs once in 150 years. The flood of the Nenjiang River damaged 456×10 4?ha of crops and 115×10 4 rooms and the direct loss of economy exceeded 40 billion yuan(RMB). The main reasons of the flood are great rainfall, long flood season, unreasonable land use, regional ecological environment degradation and lack of water control projects. It is obvious that the following measures are greatly needed: the comprehensive management of the river basins; the formulation of development planning of the river basins, especially the water control projects; the development of agriculture based on ecological security.展开更多
ABSTRACT: Based on the Landsat 5 and Landsat 7 TM images, the land use/cover change was detected in the upstream area of the Nenjiang River between 1995 and 2000. With the spatial analysis techniques of GIS, the maps ...ABSTRACT: Based on the Landsat 5 and Landsat 7 TM images, the land use/cover change was detected in the upstream area of the Nenjiang River between 1995 and 2000. With the spatial analysis techniques of GIS, the maps of land use degree and its change within this period were produced. To identify the causes of changes, elevation and slope were regarded as the main natural influencing factors and were transformed from coverage format to grid format within GIS. The Thiesson polygon method was used to the spatial allocation of socio-economic factors including human population, livestock numbers, mechanizing power of farming and the nearest distance from the changed pixel to the trunk stream and to main settlements, thereby the spatial relationship between land use degree change and socio-economic factor variation was analyzed. According to results of the spatial correlation, the determinants of changes in land use/cover, i. e. elevation, slope, population density change, livestock increase were extracted quantitatively in this area. At last, the spatial multi-linear regression model of land use degree change was developed as follows: △ La = 11. 037-4. 512 * eleva-tion-0. 298 * slope + 0. 292 *△ population + 2. 596 *△ livestock.展开更多
Songliao Basin is a large-scale Cretaceouscontinental sedimentary basin in northeastern China.In the northern Songliao Basin Nenjiang FormationUnit 1 are mainly dark mudstones with dolostoneinterbeds.Understanding the...Songliao Basin is a large-scale Cretaceouscontinental sedimentary basin in northeastern China.In the northern Songliao Basin Nenjiang FormationUnit 1 are mainly dark mudstones with dolostoneinterbeds.Understanding the sedimentary characte-ristics and dolomitization of the dolostones is of greatsignificance to the paleoenvironment and paleoc-limate reconstruction and oil reservoirs studies.Basedon the drill core description of the Nenjiang FormationUnit 1 from Sk I in Songliao Basin,we calculated 44dolostone layers with two different shapes of beds andlens.Microscopic and Scanning Electron Microscopic(SEM)observation indicate that dolomite minerals areeuhedral rhombic crystals or subhedral to anhedralirregular-shaped crystals,and dolostone is named asargilaceous micritic dolostone.展开更多
Fossil lizards are scarce in Jinlin Province,with only two jaws of Middle Eocene Acrodonta.Here the authors report the first scincomorph lizard materials from the early Campanian Nenjiang Formation in Nong’an,Changch...Fossil lizards are scarce in Jinlin Province,with only two jaws of Middle Eocene Acrodonta.Here the authors report the first scincomorph lizard materials from the early Campanian Nenjiang Formation in Nong’an,Changchun,Jilin Province.Three tooth morphologies of scincomorph lizards represented by fragmentary dentaries are tentatively identified as Scincomorpha.The morphology of the crowns indicates probably the insectivorous and omnivorous diets of these small lizards.It is the first lizard fossils discovered in the Late Cretaceous of Northeast China,extends the known paleogeographic distribution of scincomorph lizards,and provides new information about the terrestrial vertebrate fauna of the Cretaceous Songliao Basin.展开更多
As an important river in the western part of Jilin Province,the lower reach of the Nenjiang River is an important wetland water source conservation area in Jilin Province.Within the watershed,it governs the Momoge Wet...As an important river in the western part of Jilin Province,the lower reach of the Nenjiang River is an important wetland water source conservation area in Jilin Province.Within the watershed,it governs the Momoge Wetland,the Xianghai Wetland,and the Danjiang Wetland in Jilin Province.The main problem in the lower reaches of the Nenjiang River is the uneven distribution of water resources in time and space,and the intensification of land salinization.Zhenlai County and Da an City in the Nenjiang River Basin have sufficient surface water resources,with surface water as the drinking water source.Baicheng City and Tongyu County have scarce surface water resources,and both use groundwater as their domestic water source.The main polluted section in the basin is the Xianghai Reservoir,and the annual water quality evaluation is Class V.However,the water quality of the Tao er River,the main stream of the Nenjiang River,is significantly better than that of the Xianghai Reservoir.In order to better study the water environmental pollution situation in the Nenjiang River basin,monitoring data from five sections of non seasonal rivers in the basin from 2012 to 2021 were selected for studying water quality.This in-depth exploration of the water pollution status and river water quality change trends in the Nenjiang River basin is of great significance for future rural development,agricultural pattern transformation,and the promotion of water ecological civilization construction.展开更多
The Nenjiang Formation in the Songliao Basin is a symmetrical sequence of progradation-retrogradation,and is formed in the transgression cycle and regression cycle(T-R cycles)of the base level of deposition.We analyze...The Nenjiang Formation in the Songliao Basin is a symmetrical sequence of progradation-retrogradation,and is formed in the transgression cycle and regression cycle(T-R cycles)of the base level of deposition.We analyzed the drilling,well logging,core data,and seismic profiles of basin level,and by using the sequence stratigraphy,identified one secondary sequence boundary,two third-order sequence boundaries,and eight fourth-order sequence boundaries in the Nenjiang Formation.These eleven sequence boundaries can be divided into structural unconformity,depositional unconformity,flooding surface,and forced regression surface.Therefore the Nenjiang Formation can be subdivided into one secondary sequence,three third-order sequences,and ten fourth-order sequences.We have restored the sedimentary filling evolution within the stratigraphic framework of fourth-order sequences in the Nenjiang Formation.The sedimentary period of the first member of the Nenjiang Formation was corresponded to the global transgression period,which is also the development period of transgression cycle(T cycle),when the lake basin had the largest scope and deepest sedimentary water,the SB07(the maximum flooding surface)was formed on the top of strata during this period;covering above the SB07,there developed a set of condensation layer-oil shale,which is distributed in the whole basin and is the important source bed and regional cover.Therefore,a retrogradation sequence was formed in the T cycle of the first member of the Nenjiang Formation,characterized by the retrograding delta at a low angle.The delta has a giant front,a small plain,and many underwater distributary channels.Meanwhile,large gravity flow channels and sublacustrine fans are developed in the front of the delta.During the depositional period of the second member of the Nenjiang Formation,the R cycle began to develop due to the compression of the pacific tectonic domain;the source direction rotated 90°along with the eastern uplifting of the basin,and formed a series of east-west prograded and forced retrogradations.The prograding delta at high angel was developed in the interior of the sequence;the delta had a small front,a giant plain,and fewer underwater distributary channels,with the collapse at the foreslope,forming a series of slump fans.The slump fans can be divided into three types:discrete type,superimposed type,and fluid type.We built a whole"triad model"of the slump fan.Pointed out that the sequence of forced retrogradation formed by R cycle is a good structural mark of basin optimization,and rejected the viewpoint of"transgression"in the Nenjiang Formation of the Songliao Basin.展开更多
基金Supported by National Nature Science Foundation of China(No.41202012)Ministry of Science and Higher Education of the Russian Federation(No.123120600034-2)。
文摘Five new small theropod teeth and one manual ungual have recently been recovered from the Upper Cretaceous Nenjiang Formation in the Songliao Basin.The specimens were examined for their morphological characteristics,leading to the identification of four distinct taxa.The first taxon consists of three foliodont teeth characterized by a pronounced basal constriction and large hook-like distal denticles,which can be attributed to Troodontidae.The second taxon is represented by an elongated tooth featuring prominent longitudinal ridges,allowing for its assignment to Paronychodon.The third taxon is a bladelike tooth with notably small distal denticles,corresponding to Richardoestesia.The fourth taxon comprises a manual ungual characterized by a transversely wide and nearly symmetrical proximal articular surface,fully enclosed ventral foramina,a flattened ventral surface,and the absence of a flexor tubercle,resembling Alvarezsauridae.These specimens significantly enhance the known dinosaur diversity of the Nenjiang Formation and provide crucial insights for understanding the terrestrial ecosystem in Northeast Asia during the Late Cretaceous.
基金supported financially by China Geological Survey(Grant No.DD20230221)the Key Laboratory of Stratigraphy and Palaeontology,Ministry of Natural Resources(Grant No.KLSP SP202301)National Nature Science Foundation of China(Grant No.41202012).
文摘Twelve new dinosaur teeth have recently been recovered from three localities in the Upper Cretaceous Nenjiang Formation of the Songliao Basin.Although fragmentary,the material offers enough evidence to identify the following taxa:tyrannosaurids,dromaeosaurines,velociraptorines,hadrosauroids,and titanosaurs.In addition to the previously known dinosaurs from the basin,several new ones have been identified,extending the paleogeographic range of related taxa.The discovery of these new fossil remains provides valuable insights into dinosaur diversity and sheds light on the terrestrial ecosystem during the Late Cretaceous in the Songliao Basin.
文摘To investigate the characteristics of water environmental pollution in the Nenjiang River Basin,five monitoring sections,including Zhenxi,Xianghai Reservoir,Baishatan,Yuelianghu Reservoir,and Da an,were selected.Utilizing water quality monitoring data collected from 2013 to 2022,the fuzzy comprehensive evaluation method was employed to systematically analyze the spatiotemporal variation patterns of water quality,assess the current pollution status,and identify the influencing factors of non-point source pollution.The results indicated that the concentrations of representative pollutants at five sections in the lower reaches of the Nenjiang River generally exhibited a downward trend,accompanied by an overall improvement in water quality.However,the degree of improvement varied considerably among the different sections.Specifically,the water quality of the main stream of the Nenjiang River(Baishatan and Da an)improved from Class IV to Class III.In contrast,the Xianghai Reservoir consistently remained at Class V or below,primarily due to excessive fluoride levels.The water quality at Yuelianghu Reservoir and Heidimiao Section demonstrated a fluctuating but overall improving trend.Based on the analysis of pollution sources,targeted recommendations are proposed,including regulating the ecological water requirements of rivers,restoring wetland ecosystems,and enhancing the management of non-point source pollution.These measures offer scientific support for water quality management and ecological conservation in the river basins.
基金Under the auspices of National Key Research and Development Program of China(No.2016YFA0600401)the Key Research Program of Frontier Sciences from Chinese Academy of Sciences+1 种基金Fundamental Research Funds in Heilongjiang Provincial Universities(No.135209252,135309359)the Philosophy and Social Sciences Research Plan of Heilongjiang Province(No.16JLC01)
文摘Incorporating private and working lands into protected area networks could mitigate the isolation state of protected areas(PAs) and improve the efficiency of conservation.But how to select patches of land for conservation is still a troublesome issue.In this study, the MaxEnt model and irreplaceability index were applied to guide marsh conservation in the Nenjiang River Basin, Northeast China.According to the high accuracy of the MaxEnt model predictions(i.e., the average AUC value = 0.933), the Wuyuer River and Zhalong marshes in the downstream reaches of Wuyuer River are the optimal habitat for the Red-crowned crane and migratory waterfowls.There are 22 marsh patches selected by the patch irreplaceability index for conservation, of which 12 patches had been included in the current network of protected areas.The other 10 patches of marsh(amounting to 1096 km^2) far from human disturbances with high NDVI(up to 0.8) and close distance to water(less than 100 m), which are excluded from the existing network of PAs, should be implemented conservation easement programs to improve the protection efficiency of conservation.Specifically, the marshes at Taha, Tangchi, and Lamadian should be given priority for conservation and restoration to reintroduce migratory waterfowls, as this would lessen the current isolation state of the Zhalong National Nature Reserve.
基金Supported by the Special Major Scientific Research Project of PetroChina(2021ZZ10-01)。
文摘Temperature-triaxial pressure permeability testing at the axial pressure of 8 MPa and confining pressure of 10 MPa,closed shale system pyrolysis experiment by electrical heating and scanning electron microscopy analysis are used to study the evolution mechanism of in-situ permeability in the direction parallel to bedding of low-maturity shale from Member 2(K_(2)n_(2))of Cretaceous Nenjiang Formation in northern Songliao Basin with mainly Type I kerogen under the effect of temperature.With the increasing temperature,the in-situ permeability presents a peak-valley-peak tendency.The lowest value of in-situ permeability occurs at 375℃.Under the same temperature,the in-situ permeability decreases with the increase of pore pressure.The in-situ permeability evolution of low-maturity shale can be divided into 5 stages:(1)From 25℃to 300℃,thermal cracking and dehydration of clay minerals improve the permeability.However,the value of permeability is less than 0.01×10^(-3)μm^(2).(2)From 300℃to 350℃,organic matter pyrolysis and hydrocarbon expulsion result in mineral intergranular pores and micron pore-fractures,these pores and fractures form an interconnected pore network at limited scale,improving the permeability.But the liquid hydrocarbon,with high content of viscous asphaltene,is more difficult to move under stress and more likely to retain in pores,causing slow rise of the permeability.(3)From 350℃to 375℃,pores are formed by organic matter pyrolysis,but the adsorption swelling of liquid hydrocarbon and additional expansion thermal stress constrained by surrounding stress compress the pore-fracture space,making liquid hydrocarbon difficult to expel and permeability reduce rapidly.(4)From 375℃to 450℃,the interconnected pore network between different mineral particles after organic matter conversion,enlarged pores and transformation of clay minerals promote the permeability to increase constantly even under stress constraints.(5)From 450℃to 500℃,the stable pore system and crossed fracture system in different bedding directions significantly enhance the permeability.The organic matter pyrolysis,pore-fracture structure and surrounding stress in the different stages are the key factors affecting the evolution of in-situ permeability.
基金supported by China Geological Survey(DD20230554,DD20230089)the Strategic Priority Research Program of the Chinese Academy of Science(XDA28020302)the funding project of Northeast Geological S&T Innovation Center of China Geological Survey(QCJJ2022-40).
文摘To illuminate the spatio-temporal variation characteristics and geochemical driving mechanism of soil pH in the Nenjiang River Basin,the National Multi-objective Regional Geochemical Survey data of topsoil,the Second National Soil Survey data and Normalized Difference Vegetation Index(NDVI)were analyzed.The areas of neutral and alkaline soil decreased by 21100 km^(2)and 30500 km^(2),respectively,while that of strongly alkaline,extremely alkaline,and strongly acidic soil increased by 19600 km^(2),18200 km^(2),and 15500 km^(2),respectively,during the past 30 years.NDVI decreased with the increase of soil pH when soil pH>8.0,and it was reversed when soil pH<5.0.There were significant differences in soil pH with various surface cover types,which showed an ascending order:Arbor<reed<maize<rice<high and medium-covered meadow<low-covered meadow<Puccinellia.The weathering products of minerals rich in K_(2)O,Na_(2)O,CaO,and MgO entered into the low plain and were enriched in different parts by water transportation and lake deposition,while Fe and Al remained in the low hilly areas,which was the geochemical driving mechanism.The results of this study will provide scientific basis for making scientific and rational decisions on soil acidification and salinization.
基金supported by the China Geological Survey(Grant No.DD20160163 and DD20190097).
文摘Objective The Dayangshu Basin located in eastern Inner Mongolia,is one of the key areas for oil and gas exploration in the periphery of Songliao Basin.So far,this basin has been poorly explored,and the basic geological research is still weak,due to the lack of high-quality paleontologic and stratigraphic data.The previous oil and gas investigations were mainly focused on the Early Cretaceous strata.However,the Late Cretaceous Nenjiang Formation in the basin also has hydrocarbon potential according to the latest research.In recent oil and gas geological survey,palynological fossils have been discovered from the Nenjiang Formation in the Dayangshu Basin,providing new evidence for biostratigraphic division and correlation.
基金Project(2012ZX07501002-001)supported by Major Science and Technology Program for Water Pollution Control and Treatment of the Ministry of Science and Technology,China
文摘Assessment of temporal and spatial variations in surface water quality is important to evaluate the health of a watershed and make necessary management decisions to control current and future pollution of receiving water bodies. In this work, surface water quality data for 12 physical and chemical parameters collected from 10 sampling sites in the Nenjiang River basin during the years(2012-2013) were analyzed. The results show that river water quality has significant temporal and spatial variations. Hierarchical cluster analysis(HCA) grouped 12 months into three periods(LF, MF and HF) and classified 10 monitoring sites into three regions(LP, MP and HP) based on the similarity of water quality characteristics. The principle component analysis(PCA)/factor analysis(FA) was used to recognize the factors or origins responsible for temporal and spatial water quality variations. Temporal and spatial PCA/FA revealed that the Nenjiang River water chemistry was strongly affected by rock/water interaction, hydrologic processes and anthropogenic activities. This work demonstrates that the application of HCA and PCA/FA has achieved meaningful classification based on temporal and spatial criteria.
基金Supportde by The Natual Science Fund of Heilongjiang Province(E0335)
文摘Making a brief analysis of the water and soil loss present situation in Daxing＇anling area which locates to the upstream region of Nenjiang River, and giving the water and soil loss of this area that have been made near 20 years, as well as the factors of the water and soil loss. According to the factors corresponding prevention measure and forecast model have been put forward, make a brief introduction to this model in this article. It is helpful to improve the local soil conservation and sustainable development.
基金Supported by Science and Technology Research Item of Heilongjiang Meteorological Bureau in 2014,China(HQ2014018)
文摘[Objective]The research aimed to analyze and contrast flood cause in Nenjiang Basin between 2013 and 1998.[Method]Based on meteorological and hydrological data in and around Nenjiang Basin,geographic information system as data processing platform,statistical methods such as synthesis analysis and correlation analysis were combined to contrast and analyze the flood cause in the Nenjiang Basin between 2013 and1998.[Result]The similarities of two floods in Nenjiang Basin were that rainstorm frequency and summer precipitation were more,and many large and medium-sized reservoirs which undertook the flood control task were running above flood level.In order to protect the safety of reservoir dam,flood discharge volume increased.And the difference was external forcing factor which caused atmospheric circulation abnormality,thus the impact factors of summer more rainfall were not the same.The main reason for more precipitation in Nenjiang Basin in summer of 2013：The northeast cold vortex activity was frequent,and the path was by north;water vapor transport was sufficient at 850 hPa;at 500 hPa,the Eurasian zonal circulation was weak,the West Pacific subtropical high pressure abnormally moved northward,blocking high of the Sea of Okhotsk was obvious,and Heilongjiang region was controlled by negative anomaly in midsummer;East Asian westerly jet location was abnormal at 200 hPa,and East Asian summer monsoon was strong.[Conclusion]The research had very important significance for understanding occurrence rule of flood and improving disaster prevention and mitigation capabilities in Nenjiang Basin.
基金Supported by Fund from the Key Laboratory of Stratigraphy and P alaeontology,Ministry of Natural Resources(No.KLSP SP202301).
文摘In a region where lizard fossils are rare,this study explores a groundbreaking discovery of squamate lizard materials from the upper part of Nenjiang Formation(early Campanian)in Jilin Province,Northeast China.Despite the fragmentary nature of the dentaries,they exhibit distinct tooth morphological characteristics of squamate lizards,suggesting insectivorous and omnivorous diets for these small reptiles.This finding not only represents a significant addition to the squamate lizard fossil records from the Late Cre-taceous in Northeast China but also contributes to our understanding of the paleogeographic distribution of squamate lizards.Furthermore,it sheds new light on the terrestrial vertebrate fauna of the Cretaceous Songliao Basin.
基金supported by the Major State Basic Research Development Program of China (No. 2006CB202302)the China National Science and Technology Major Project (No. 2016ZX05007-002)
文摘This paper studied seismic imaging of the sedimentary system of the Nenjiang Formation in the Northern Songliao Basin based on seismic sedimentology. An accurate and detailed depiction and explanation is provided for underground geological bodies within a relative geological period using the stratal slice technology,based on three-order sequence correlations of well logging and seismic data for the purpose of obtaining high-resolution pictures of the sedimentary system. Research results have revealed that the sedimentary system of the Upper Cretaceous Nenjiang Formation in the Northern Songliao Basin includes meandering streams,anastomosing streams,lake deltas,and sediment gravity flow channels. Based on seismic imaging analysis,the genesis and seismic geomorphology of the sedimentary system of the Nenjiang Formation are explored in order to understand the spatial distribution of typical sedimentary bodies and the evolution of streams in the Nenjiang Formation. According to the research results,the sedimentation of the Nenjiang Formation was subject to the delta system in the east and northeast of the formation. The provenance in the northeastern part played a dominant role during the deposition of the Nenjiang Formation for some time;after the earlier maximum flooding in the second and third members of the Nenjiang Formation,the northeastern system began to decline and was gradually replaced by the eastern system. Stratal slices have revealed that a well-developed gravity flow channel system was developed in the first member of the Nenjiang Formation,and massive slip blocks occurred in the second and third members of the formation. The research results indicated that the large gravity flow channel system in the first member of the Nenjiang Formation was formed by streams that emptied directly into the lake;and the slip blocks in the second and third members were the results of gravity sliding of sediments along steep slopes at the delta front.
文摘In the summer of 1998, an exceptionally serious flood, with the characteristics of high water level, large volume of flow, long duration and serious losses caused by the disaster, occurred in the Nenjiang River basin and the Songhua River basin. Greater flood peak occurred three times in the trunk stream of the Nenjiang River for the floods occurred in its tributaries one after another. At Jiangqiao Hydrometric Station, the water level was 141.90 m and the rate of flow was 12?000 m 3/s. The flood is ranged to a catastrophic one, which occurs once in 50 years. Ranged to a catastrophic flood at Qiqihar Hydrometric Station that occurs once in 400 years, its water level, 0.89 m higher than the former all time highest, was 149.30?m and the corresponding rate of flow was 14?800?m 3/s. The water level that exceeded the all time highest lasted for 7 days. At Harbin Hydrometric Station, the water level, 0.59?m higher than the former all time highest, was 120.89?m and the corresponding rate of flow was 17?400?m 3/s. The water level that exceeded the all time highest lasted for 9 to 10 days. The flood here is ranged to a catastrophic one, which occurs once in 150 years. The flood of the Nenjiang River damaged 456×10 4?ha of crops and 115×10 4 rooms and the direct loss of economy exceeded 40 billion yuan(RMB). The main reasons of the flood are great rainfall, long flood season, unreasonable land use, regional ecological environment degradation and lack of water control projects. It is obvious that the following measures are greatly needed: the comprehensive management of the river basins; the formulation of development planning of the river basins, especially the water control projects; the development of agriculture based on ecological security.
基金Under the auspices of the Key Knowledge-Innovation Project of the Chinese Academy of the Science(KZCX1-Y-02)andthe project of National Ninth Five-year Plan(96-B02-01).
文摘ABSTRACT: Based on the Landsat 5 and Landsat 7 TM images, the land use/cover change was detected in the upstream area of the Nenjiang River between 1995 and 2000. With the spatial analysis techniques of GIS, the maps of land use degree and its change within this period were produced. To identify the causes of changes, elevation and slope were regarded as the main natural influencing factors and were transformed from coverage format to grid format within GIS. The Thiesson polygon method was used to the spatial allocation of socio-economic factors including human population, livestock numbers, mechanizing power of farming and the nearest distance from the changed pixel to the trunk stream and to main settlements, thereby the spatial relationship between land use degree change and socio-economic factor variation was analyzed. According to results of the spatial correlation, the determinants of changes in land use/cover, i. e. elevation, slope, population density change, livestock increase were extracted quantitatively in this area. At last, the spatial multi-linear regression model of land use degree change was developed as follows: △ La = 11. 037-4. 512 * eleva-tion-0. 298 * slope + 0. 292 *△ population + 2. 596 *△ livestock.
文摘Songliao Basin is a large-scale Cretaceouscontinental sedimentary basin in northeastern China.In the northern Songliao Basin Nenjiang FormationUnit 1 are mainly dark mudstones with dolostoneinterbeds.Understanding the sedimentary characte-ristics and dolomitization of the dolostones is of greatsignificance to the paleoenvironment and paleoc-limate reconstruction and oil reservoirs studies.Basedon the drill core description of the Nenjiang FormationUnit 1 from Sk I in Songliao Basin,we calculated 44dolostone layers with two different shapes of beds andlens.Microscopic and Scanning Electron Microscopic(SEM)observation indicate that dolomite minerals areeuhedral rhombic crystals or subhedral to anhedralirregular-shaped crystals,and dolostone is named asargilaceous micritic dolostone.
文摘Fossil lizards are scarce in Jinlin Province,with only two jaws of Middle Eocene Acrodonta.Here the authors report the first scincomorph lizard materials from the early Campanian Nenjiang Formation in Nong’an,Changchun,Jilin Province.Three tooth morphologies of scincomorph lizards represented by fragmentary dentaries are tentatively identified as Scincomorpha.The morphology of the crowns indicates probably the insectivorous and omnivorous diets of these small lizards.It is the first lizard fossils discovered in the Late Cretaceous of Northeast China,extends the known paleogeographic distribution of scincomorph lizards,and provides new information about the terrestrial vertebrate fauna of the Cretaceous Songliao Basin.
文摘As an important river in the western part of Jilin Province,the lower reach of the Nenjiang River is an important wetland water source conservation area in Jilin Province.Within the watershed,it governs the Momoge Wetland,the Xianghai Wetland,and the Danjiang Wetland in Jilin Province.The main problem in the lower reaches of the Nenjiang River is the uneven distribution of water resources in time and space,and the intensification of land salinization.Zhenlai County and Da an City in the Nenjiang River Basin have sufficient surface water resources,with surface water as the drinking water source.Baicheng City and Tongyu County have scarce surface water resources,and both use groundwater as their domestic water source.The main polluted section in the basin is the Xianghai Reservoir,and the annual water quality evaluation is Class V.However,the water quality of the Tao er River,the main stream of the Nenjiang River,is significantly better than that of the Xianghai Reservoir.In order to better study the water environmental pollution situation in the Nenjiang River basin,monitoring data from five sections of non seasonal rivers in the basin from 2012 to 2021 were selected for studying water quality.This in-depth exploration of the water pollution status and river water quality change trends in the Nenjiang River basin is of great significance for future rural development,agricultural pattern transformation,and the promotion of water ecological civilization construction.
基金supported by National Basic Research Program of China(Grant Nos.2006CB701404,2009CB219308)
文摘The Nenjiang Formation in the Songliao Basin is a symmetrical sequence of progradation-retrogradation,and is formed in the transgression cycle and regression cycle(T-R cycles)of the base level of deposition.We analyzed the drilling,well logging,core data,and seismic profiles of basin level,and by using the sequence stratigraphy,identified one secondary sequence boundary,two third-order sequence boundaries,and eight fourth-order sequence boundaries in the Nenjiang Formation.These eleven sequence boundaries can be divided into structural unconformity,depositional unconformity,flooding surface,and forced regression surface.Therefore the Nenjiang Formation can be subdivided into one secondary sequence,three third-order sequences,and ten fourth-order sequences.We have restored the sedimentary filling evolution within the stratigraphic framework of fourth-order sequences in the Nenjiang Formation.The sedimentary period of the first member of the Nenjiang Formation was corresponded to the global transgression period,which is also the development period of transgression cycle(T cycle),when the lake basin had the largest scope and deepest sedimentary water,the SB07(the maximum flooding surface)was formed on the top of strata during this period;covering above the SB07,there developed a set of condensation layer-oil shale,which is distributed in the whole basin and is the important source bed and regional cover.Therefore,a retrogradation sequence was formed in the T cycle of the first member of the Nenjiang Formation,characterized by the retrograding delta at a low angle.The delta has a giant front,a small plain,and many underwater distributary channels.Meanwhile,large gravity flow channels and sublacustrine fans are developed in the front of the delta.During the depositional period of the second member of the Nenjiang Formation,the R cycle began to develop due to the compression of the pacific tectonic domain;the source direction rotated 90°along with the eastern uplifting of the basin,and formed a series of east-west prograded and forced retrogradations.The prograding delta at high angel was developed in the interior of the sequence;the delta had a small front,a giant plain,and fewer underwater distributary channels,with the collapse at the foreslope,forming a series of slump fans.The slump fans can be divided into three types:discrete type,superimposed type,and fluid type.We built a whole"triad model"of the slump fan.Pointed out that the sequence of forced retrogradation formed by R cycle is a good structural mark of basin optimization,and rejected the viewpoint of"transgression"in the Nenjiang Formation of the Songliao Basin.
