Understanding the effects of land cover changes on ecosystem carbon stocks is essential for ecosystem management and envi- ronmental protection, particularly in the transboundary region that has undergone marked chang...Understanding the effects of land cover changes on ecosystem carbon stocks is essential for ecosystem management and envi- ronmental protection, particularly in the transboundary region that has undergone marked changes. This study aimed to examine the impacts of land cover changes on ecosystem carbon stocks in the transboundary Tureen River Basin （TTRB）. We extracted the spatial information from Landsat Thematic Imager （TM） and Operational Land Imager （OLI） images for the years 1990 and 2015 and obtained convincing estimates of terrestrial biomass and soil carbon stocks with the INVEST model. The results showed that forestland, cropland and built-up land increased by 57.5, 429.7 and 128.9 km2, respectively, while grassland, wetland and barren land declined by 24.9, 548.0 and 43.0 km2, respectively in the TTRB from 1990 to 2015. The total carbon stocks encompassing aboveground, belowground, soil and litter layer carbon storage pools have declined from 831.48 Tg C in 1990 to 831.42 Tg C in 2015 due to land cover changes. In detail, the carbon stocks de- creased by 3.13 Tg C and 0.44 Tg C in Democratic People＇s Republic of Korea （North Korea） and Russia, respectively, while increased by 3.51 Tg C in China. Furthermore, economic development, and national policy accounted for most land cover changes in the TTRB. Our results imply that effective wetland and forestland protection policies among China, North Korea, and Russia are much needed for protecting the natural resources, promoting local ecosystem services and regional sustainable development in the transnational area.展开更多
The Tumen River had failed to meet Grade Ⅲ and Ⅳ levels in the environmental quality standard for surface water, and had exceeded Grade Ⅴ level. Surface water pollution is serious. The major excessive standard poll...The Tumen River had failed to meet Grade Ⅲ and Ⅳ levels in the environmental quality standard for surface water, and had exceeded Grade Ⅴ level. Surface water pollution is serious. The major excessive standard pollutants were COD Mn and SS. After taking effective treatment steps, the worsening trend of water pollution will be basically under control. But the change of runoff in the Tumen River is large in a year, especially during as long as five month freezing period, smaller flow and lower temperature of river waters led to weak dilution and self purification capacity. The water quality of the Tumen River will not reach the appoint functional water quality standards, even if sewage meets discharge standard, which will influence water resources utilization in the lower reaches of the Tumen River and regional economic development. Therefore water pollution has become the major restrictive factor of the development of the Tumen River area.展开更多
This paper puts forward a new conceptual idea on constructing an international central city in the Tumen River Economy Development Zone (TREDZ) on the basis of analysis of the superiorities and problems in developing...This paper puts forward a new conceptual idea on constructing an international central city in the Tumen River Economy Development Zone (TREDZ) on the basis of analysis of the superiorities and problems in developing city, and from the view point of present social, economic and natural conditions in this area and the background of Northeast Asia. The united international central city is the best distribution model not only in its polycentric spatial structure but also in organizing form. Its feasibility and practicability are thoroughly proved from various aspects including urban planning principles, comparison of port cities, special characteristics of cooperation in TREDZ, and natural, social, cultural factors etc.展开更多
The water conservation(WC) function of ecosystems is related to regional ecological security and the sustainable development of water resources, and the assessment of WC and its influencing factors is crucial for ecol...The water conservation(WC) function of ecosystems is related to regional ecological security and the sustainable development of water resources, and the assessment of WC and its influencing factors is crucial for ecological and water resource management.The Tumen River Basin(TRB) is located in the core of the Northeast Asian ecological network and has been experiencing severe ecological crises and water shortages in recent years due to climate change and human activities. However, these crises have not been fully revealed to the extent that corresponding scientific measures are lacking. This study analyzed the spatial and temporal evolution characteristics and drivers of WC in the TRB from 1990 to 2019 based on the water yield module of the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST) model. The results showed that: 1) under the combined effect of nature and socioeconomics, the WC depth of the TRB has slowly increased at a rate of 0.11 mm/yr in the past 30 years, with an average WC depth of 36.14 mm. 2) The main driving factor of the spatial variation in WC is precipitation, there is a significant interaction between precipitation and velocity, the interaction between each factor is higher than the contribution of a single factor, and the interactions between factors all have nonlinear enhancement and two-factor enhancement. 3) Among the seven counties and municipalities in the study area, the southern part of Helong City and the southeastern part of Longjing City are extremely important areas for WC(> 75 mm), and they should be regarded as regional water resources and ecological priority protection areas. It is foreseen that under extreme climate conditions in the future, the WC of the watershed is under great potential threat, and protection measures such as afforestation and forestation should begin immediately. Furthermore, the great interannual fluctuations in WC depth may place more stringent requirements on the choice of time scales in the ecosystem service assessment process.展开更多
Understanding the spatial patterns of land-use and land-cover(LULC)and their driving forces in transnational areas is important for the sustainable development of these regions.However,the spatial patterns of LULC and...Understanding the spatial patterns of land-use and land-cover(LULC)and their driving forces in transnational areas is important for the sustainable development of these regions.However,the spatial patterns of LULC and their driving forces across multiple scales are poorly understood in transnational areas.In this study,we analyzed the spatial patterns of LULC and driving forces in the transnational area of Tumen River(TATR)in 2016 across two scales:the entire region and the sub-regions of China,the Democratic People’s Republic of Korea(DPRK),and Russia.Results showed that the LULC was dominated by broadleaf forest and dry farmland in the TATR in 2016,which accounted for 66.86%and 13.60%of the entire region,respectively.Meanwhile,the LULC in the three sub-regions exhibited noticeable differences.In the Chinese and the DPRK’s sub-regions,the area of broadleaf forest was greater than those for the other LULC types,while the Russian sub-region was dominated by broadleaf forest and grassland.The spatial patterns of LULC were mainly influenced by topography,climate,soil properties,and human activities.In addition,the driving forces of the spatial patterns of LULC in the TATR had an obvious scaling effect.Therefore,we suggest that effective policies and regulations with cooperation among China,the DPRK,and Russia are needed to plan the spatial patterns of LULC and improve the sustainable development of the TATR.展开更多
The trans-boundary scope of the Tume n River Basin(TRB)going through China,Russia and DPRK has been defined,and on the basis of this,status of urbanization and its impacts on water environment in recent 20years in TRB...The trans-boundary scope of the Tume n River Basin(TRB)going through China,Russia and DPRK has been defined,and on the basis of this,status of urbanization and its impacts on water environment in recent 20years in TRB have been analyzed.Urbanizatio n in TRB can be characterized as:1)There is medium level of overall urbanization in TRB.Certain distance still exists compared with developed countries.And it is lower than the average urbanization level of Russia and higher than that o f China.2)There is unbalanced distribution of urbanization development in TRB.Urbanization in China part owns the c haracter of low starting point and hi gh-speed development.In Russia part,charac-ter of urbanization can be described as high starting point and stable development.In DPRK part,urbanizatio n level is low,and motive power lacks.3)Due to large population,in China part there is broader region urbanized,larger radius and higher frequency of human activities,which lead to heavier pressure on environment.Meanwhile,the paper has point-ed that impacts of urbanization on wa ter environment are as follows:1)Urban population growth and industr y develop-ment increase the demand for freshwa ter,and also exacerbate the contrad iction between limited water supply and increas-ing freshwater demand.2)Urban infrastructure doesn’t match with urban productive function especially treatment facili-ties,which results in the pollution of the Tumen River.3)The pollution situation in the Tumen River got peak point in1995,and presently,such situation has been improved in great scale,due to effective interventions adopted.However,there still exist 2enterprises that are urgent to be harnessed.Moreover,pollution of municipal sewage will become more and more apparent.4)The influence of urbanization on soil is mainly caused by industrial effl uent and slag,and pollut-ed water irrigation.Soil and water l oss has also been a serious problem caused by urbanization.5)Urbanization results in the decrease of wetlands area.Fur thermore,the paper has given a brief account of the perspective and recom menda-tions on urbanization and environme ntal impacts.展开更多
The average size of the sand of dune in the vicinity of Tumen River is 0.12～0.30 mm, its standard deviation is 0.45～0.99 φ and the frequency cumulative distribution curve is divided into the single peak and the dou...The average size of the sand of dune in the vicinity of Tumen River is 0.12～0.30 mm, its standard deviation is 0.45～0.99 φ and the frequency cumulative distribution curve is divided into the single peak and the double peak. The Ski of the single peak is negative and the double peak is positive. There are two different areas in the plot of the Ski versus σi* It is shown that the sedimentary environment of the dunes is neritic deposit by the expressions of the grain-size parameters. All of the characters show that the sand dunes in Estuary of Tumen River may be the dunes of sea facies which were changed again by weathering and fluvialaction.展开更多
The influence of land based source pollutants to marine ecological environment is principally in coastal or enclosed sea waters. Flux of land based source pollutants into the sea will be effected due to social and ...The influence of land based source pollutants to marine ecological environment is principally in coastal or enclosed sea waters. Flux of land based source pollutants into the sea will be effected due to social and economic development in the Tumen River basin. Pollutant type and primary pollution factor of the Tumen River in Northeast China is described by weighted coefficient method in this paper. The results indicate that the river is organic pollution type and primary pollution factor is COD. Fresh water fraction proves that the estuary is not affected by tide cycle. COD annual flux entering the Sea of Japan calculated by zero dimension model in 1993 was 90.50 ×10 3 tons. It is estimated with emission coefficient method that the COD will be 176.4 ×10 3 and 458.6 ×10 3 tons for the years of 2000 and 2010 respectively.展开更多
The development of world economy has been heading for globalization and regionalization. In recent years, this tendency has born great impact on the rapid economic development of the Asian and Pacific countries, which...The development of world economy has been heading for globalization and regionalization. In recent years, this tendency has born great impact on the rapid economic development of the Asian and Pacific countries, which assumes the form of economic growth triangle as their major way for regional cooperation involving multiple nations. Among these, the Tumen River Triangle consisting of six countries' cooperation may have attracted great attention. Since 1991 when UNDP began to draw up plans for such a mammoth project which is called the Tumen River Area Development Project (or TRADP), the international economic cooperation in this area has been developing energetically. It is now necessary to assess the characteristics of geographical conditions and various economic resources from the viewpoints of economic geography and expound the mammoth benefits both in economy and to society. The demonstration would undoubtedly absorb more international capital to this area and enhance its economic and social development.展开更多
Analyzing the spatial patterns of net primary productivity(NPP)and its driving forces in transnational areas provides a solid basis for understanding regional ecological processes and ecosystem services.However,the sp...Analyzing the spatial patterns of net primary productivity(NPP)and its driving forces in transnational areas provides a solid basis for understanding regional ecological processes and ecosystem services.However,the spatial patterns of NPP and its driving forces have been poorly understood on multiple scales in transnational areas.In this study,the spatial patterns of NPP in the transnational area of the Tumen River(TATR)in 2016 were simulated using the Carnegie Ames Stanford Approach(CASA)model,and its driving forces were analyzed using a stepwise multiple linear regression model.We found that the total amount of NPP in the TATR in 2016 was approximately 14.53 TgC.The amount of NPP on the Chinese side(6.23 TgC)was larger than those on the other two sides,accounting for 42.88%of the total volume of the entire region.Among different land-use and land-cover(LULC)types,the amount of NPP of the broadleaf forest was the largest(11.22 TgC),while the amount of NPP of the bare land was the smallest.The NPP per unit area was about 603.21 gC/(m2 yr)across the entire region,while the NPP per unit area on the Chinese side was the largest,followed by the Russian side and the DPRK's side.The spatial patterns of NPP were influenced by climate,topography,soil texture,and human activities.In addition,the driving forces of the spatial patterns of NPP in the TATR had an obvious scaling effect,which was mainly caused by the spatial heterogeneity of climate,topography,soil texture,and human activities.We suggest that effective land management policies with cooperation among China,the DPRK,and Russia are needed to maintain NPP and improve environmental sustainability in the TATR.展开更多
基金Under the auspices of the National Key Research and Development Project(No.2016YFA0602301)National Natural Science Foundation of China(No.41730643,41671219,41771109,31500400)
文摘Understanding the effects of land cover changes on ecosystem carbon stocks is essential for ecosystem management and envi- ronmental protection, particularly in the transboundary region that has undergone marked changes. This study aimed to examine the impacts of land cover changes on ecosystem carbon stocks in the transboundary Tureen River Basin （TTRB）. We extracted the spatial information from Landsat Thematic Imager （TM） and Operational Land Imager （OLI） images for the years 1990 and 2015 and obtained convincing estimates of terrestrial biomass and soil carbon stocks with the INVEST model. The results showed that forestland, cropland and built-up land increased by 57.5, 429.7 and 128.9 km2, respectively, while grassland, wetland and barren land declined by 24.9, 548.0 and 43.0 km2, respectively in the TTRB from 1990 to 2015. The total carbon stocks encompassing aboveground, belowground, soil and litter layer carbon storage pools have declined from 831.48 Tg C in 1990 to 831.42 Tg C in 2015 due to land cover changes. In detail, the carbon stocks de- creased by 3.13 Tg C and 0.44 Tg C in Democratic People＇s Republic of Korea （North Korea） and Russia, respectively, while increased by 3.51 Tg C in China. Furthermore, economic development, and national policy accounted for most land cover changes in the TTRB. Our results imply that effective wetland and forestland protection policies among China, North Korea, and Russia are much needed for protecting the natural resources, promoting local ecosystem services and regional sustainable development in the transnational area.
文摘The Tumen River had failed to meet Grade Ⅲ and Ⅳ levels in the environmental quality standard for surface water, and had exceeded Grade Ⅴ level. Surface water pollution is serious. The major excessive standard pollutants were COD Mn and SS. After taking effective treatment steps, the worsening trend of water pollution will be basically under control. But the change of runoff in the Tumen River is large in a year, especially during as long as five month freezing period, smaller flow and lower temperature of river waters led to weak dilution and self purification capacity. The water quality of the Tumen River will not reach the appoint functional water quality standards, even if sewage meets discharge standard, which will influence water resources utilization in the lower reaches of the Tumen River and regional economic development. Therefore water pollution has become the major restrictive factor of the development of the Tumen River area.
文摘This paper puts forward a new conceptual idea on constructing an international central city in the Tumen River Economy Development Zone (TREDZ) on the basis of analysis of the superiorities and problems in developing city, and from the view point of present social, economic and natural conditions in this area and the background of Northeast Asia. The united international central city is the best distribution model not only in its polycentric spatial structure but also in organizing form. Its feasibility and practicability are thoroughly proved from various aspects including urban planning principles, comparison of port cities, special characteristics of cooperation in TREDZ, and natural, social, cultural factors etc.
基金Under the auspices of National Natural Science Foundation of China (No. 41830643)the Scientific Research Project of the Education Department of Jilin Province (No. JJKH20210567KJ)+1 种基金the Doctoral Research Start-up Fund (No.[2020]35)Scientific Development Project (No.[2019]2) of Yanbian University。
文摘The water conservation(WC) function of ecosystems is related to regional ecological security and the sustainable development of water resources, and the assessment of WC and its influencing factors is crucial for ecological and water resource management.The Tumen River Basin(TRB) is located in the core of the Northeast Asian ecological network and has been experiencing severe ecological crises and water shortages in recent years due to climate change and human activities. However, these crises have not been fully revealed to the extent that corresponding scientific measures are lacking. This study analyzed the spatial and temporal evolution characteristics and drivers of WC in the TRB from 1990 to 2019 based on the water yield module of the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST) model. The results showed that: 1) under the combined effect of nature and socioeconomics, the WC depth of the TRB has slowly increased at a rate of 0.11 mm/yr in the past 30 years, with an average WC depth of 36.14 mm. 2) The main driving factor of the spatial variation in WC is precipitation, there is a significant interaction between precipitation and velocity, the interaction between each factor is higher than the contribution of a single factor, and the interactions between factors all have nonlinear enhancement and two-factor enhancement. 3) Among the seven counties and municipalities in the study area, the southern part of Helong City and the southeastern part of Longjing City are extremely important areas for WC(> 75 mm), and they should be regarded as regional water resources and ecological priority protection areas. It is foreseen that under extreme climate conditions in the future, the WC of the watershed is under great potential threat, and protection measures such as afforestation and forestation should begin immediately. Furthermore, the great interannual fluctuations in WC depth may place more stringent requirements on the choice of time scales in the ecosystem service assessment process.
基金Under the auspices of National Natural Science Foundation of China(No.41771094,41871185,41801184)。
文摘Understanding the spatial patterns of land-use and land-cover(LULC)and their driving forces in transnational areas is important for the sustainable development of these regions.However,the spatial patterns of LULC and their driving forces across multiple scales are poorly understood in transnational areas.In this study,we analyzed the spatial patterns of LULC and driving forces in the transnational area of Tumen River(TATR)in 2016 across two scales:the entire region and the sub-regions of China,the Democratic People’s Republic of Korea(DPRK),and Russia.Results showed that the LULC was dominated by broadleaf forest and dry farmland in the TATR in 2016,which accounted for 66.86%and 13.60%of the entire region,respectively.Meanwhile,the LULC in the three sub-regions exhibited noticeable differences.In the Chinese and the DPRK’s sub-regions,the area of broadleaf forest was greater than those for the other LULC types,while the Russian sub-region was dominated by broadleaf forest and grassland.The spatial patterns of LULC were mainly influenced by topography,climate,soil properties,and human activities.In addition,the driving forces of the spatial patterns of LULC in the TATR had an obvious scaling effect.Therefore,we suggest that effective policies and regulations with cooperation among China,the DPRK,and Russia are needed to plan the spatial patterns of LULC and improve the sustainable development of the TATR.
文摘The trans-boundary scope of the Tume n River Basin(TRB)going through China,Russia and DPRK has been defined,and on the basis of this,status of urbanization and its impacts on water environment in recent 20years in TRB have been analyzed.Urbanizatio n in TRB can be characterized as:1)There is medium level of overall urbanization in TRB.Certain distance still exists compared with developed countries.And it is lower than the average urbanization level of Russia and higher than that o f China.2)There is unbalanced distribution of urbanization development in TRB.Urbanization in China part owns the c haracter of low starting point and hi gh-speed development.In Russia part,charac-ter of urbanization can be described as high starting point and stable development.In DPRK part,urbanizatio n level is low,and motive power lacks.3)Due to large population,in China part there is broader region urbanized,larger radius and higher frequency of human activities,which lead to heavier pressure on environment.Meanwhile,the paper has point-ed that impacts of urbanization on wa ter environment are as follows:1)Urban population growth and industr y develop-ment increase the demand for freshwa ter,and also exacerbate the contrad iction between limited water supply and increas-ing freshwater demand.2)Urban infrastructure doesn’t match with urban productive function especially treatment facili-ties,which results in the pollution of the Tumen River.3)The pollution situation in the Tumen River got peak point in1995,and presently,such situation has been improved in great scale,due to effective interventions adopted.However,there still exist 2enterprises that are urgent to be harnessed.Moreover,pollution of municipal sewage will become more and more apparent.4)The influence of urbanization on soil is mainly caused by industrial effl uent and slag,and pollut-ed water irrigation.Soil and water l oss has also been a serious problem caused by urbanization.5)Urbanization results in the decrease of wetlands area.Fur thermore,the paper has given a brief account of the perspective and recom menda-tions on urbanization and environme ntal impacts.
文摘The average size of the sand of dune in the vicinity of Tumen River is 0.12～0.30 mm, its standard deviation is 0.45～0.99 φ and the frequency cumulative distribution curve is divided into the single peak and the double peak. The Ski of the single peak is negative and the double peak is positive. There are two different areas in the plot of the Ski versus σi* It is shown that the sedimentary environment of the dunes is neritic deposit by the expressions of the grain-size parameters. All of the characters show that the sand dunes in Estuary of Tumen River may be the dunes of sea facies which were changed again by weathering and fluvialaction.
文摘The influence of land based source pollutants to marine ecological environment is principally in coastal or enclosed sea waters. Flux of land based source pollutants into the sea will be effected due to social and economic development in the Tumen River basin. Pollutant type and primary pollution factor of the Tumen River in Northeast China is described by weighted coefficient method in this paper. The results indicate that the river is organic pollution type and primary pollution factor is COD. Fresh water fraction proves that the estuary is not affected by tide cycle. COD annual flux entering the Sea of Japan calculated by zero dimension model in 1993 was 90.50 ×10 3 tons. It is estimated with emission coefficient method that the COD will be 176.4 ×10 3 and 458.6 ×10 3 tons for the years of 2000 and 2010 respectively.
文摘The development of world economy has been heading for globalization and regionalization. In recent years, this tendency has born great impact on the rapid economic development of the Asian and Pacific countries, which assumes the form of economic growth triangle as their major way for regional cooperation involving multiple nations. Among these, the Tumen River Triangle consisting of six countries' cooperation may have attracted great attention. Since 1991 when UNDP began to draw up plans for such a mammoth project which is called the Tumen River Area Development Project (or TRADP), the international economic cooperation in this area has been developing energetically. It is now necessary to assess the characteristics of geographical conditions and various economic resources from the viewpoints of economic geography and expound the mammoth benefits both in economy and to society. The demonstration would undoubtedly absorb more international capital to this area and enhance its economic and social development.
文摘Analyzing the spatial patterns of net primary productivity(NPP)and its driving forces in transnational areas provides a solid basis for understanding regional ecological processes and ecosystem services.However,the spatial patterns of NPP and its driving forces have been poorly understood on multiple scales in transnational areas.In this study,the spatial patterns of NPP in the transnational area of the Tumen River(TATR)in 2016 were simulated using the Carnegie Ames Stanford Approach(CASA)model,and its driving forces were analyzed using a stepwise multiple linear regression model.We found that the total amount of NPP in the TATR in 2016 was approximately 14.53 TgC.The amount of NPP on the Chinese side(6.23 TgC)was larger than those on the other two sides,accounting for 42.88%of the total volume of the entire region.Among different land-use and land-cover(LULC)types,the amount of NPP of the broadleaf forest was the largest(11.22 TgC),while the amount of NPP of the bare land was the smallest.The NPP per unit area was about 603.21 gC/(m2 yr)across the entire region,while the NPP per unit area on the Chinese side was the largest,followed by the Russian side and the DPRK's side.The spatial patterns of NPP were influenced by climate,topography,soil texture,and human activities.In addition,the driving forces of the spatial patterns of NPP in the TATR had an obvious scaling effect,which was mainly caused by the spatial heterogeneity of climate,topography,soil texture,and human activities.We suggest that effective land management policies with cooperation among China,the DPRK,and Russia are needed to maintain NPP and improve environmental sustainability in the TATR.
