In recent years, global reanalysis weather data has been widely used in hydrological modeling around the world, but the results of simulations vary greatly. To consider the applicability of Climate Forecast System Rea...In recent years, global reanalysis weather data has been widely used in hydrological modeling around the world, but the results of simulations vary greatly. To consider the applicability of Climate Forecast System Reanalysis（CFSR） data in the hydrologic simulation of watersheds, the Bahe River Basin was used as a case study. Two types of weather data（conventional weather data and CFSR weather data） were considered to establish a Soil and Water Assessment Tool（SWAT） model, which was used to simulate runoff from 2001 to 2012 in the basin at annual and monthly scales. The effect of both datasets on the simulation was assessed using regression analysis, Nash-Sutcliffe Efficiency（NSE）, and Percent Bias（PBIAS）. A CFSR weather data correction method was proposed. The main results were as follows.（1） The CFSR climate data was applicable for hydrologic simulation in the Bahe River Basin（R^2 of the simulated results above 0.50, NSE above 0.33, and ｜PBIAS｜ below 14.8. Although the quality of the CFSR weather data is not perfect, it achieved a satisfactory hydrological simulation after rainfall data correction.（2） The simulated streamflow using the CFSR data was higher than the observed streamflow, which was likely because the estimation of daily rainfall data by CFSR weather data resulted in more rainy days and stronger rainfall intensity than was actually observed. Therefore, the data simulated a higher base flow and flood peak discharge in terms of the water balance, except for some individual years.（3） The relation between the CFSR rainfall data（x） and the observed rainfall data（y） could berepresented by a power exponent equation： y=1.4789x0.8875（R2=0.98,P〈0.001）. There was a slight variation between the fitted equations for each station. The equation provides a theoretical basis for the correction of CFSR rainfall data.展开更多
It has been confirmed that the key source rocks of Qiongdongnan Basin are associated with the Yacheng Formation, which was deposited in a transitional marine-continental environment. Because the distribution and evolu...It has been confirmed that the key source rocks of Qiongdongnan Basin are associated with the Yacheng Formation, which was deposited in a transitional marine-continental environment. Because the distribution and evolution patterns of the source rocks in the major depressions are different, it is important to determine the most abundant hydrocarbon-generation depressions in terms of exploration effectiveness. Based on an analysis of organic matter characteristics of the source rocks, in combination with drilling data and seismic data, this paper establishes a model to evaluate the hydrocarbon-generation depressions in the deepwater area of Qiongdongnan Basin. First of all, by using the method of seismic-facies model analysis, the distribution of sedimentary facies was determined. Then, the sedimentary facies were correlated with the organic facies, and the distribution of organic facies was predicted. Meanwhile, the thickness of source rocks for all the depressions was calculated on the basis of a quantitative analysis of seismic velocity and lithology. The relationship between mudstone porosity and vitrinite reflectance（Ro） was used to predict the maturity of source rocks. Second, using the parameters such as thickness and maturity of source rocks, the quantity and intensity of gas generation for Yacheng and Lingshui Formations were calculated. Finally, in combination with the identified hydrocarbon resources, the quantity and intensity of gas generation were used as a guide to establish an evaluation standard for hydrocarbon-generation depressions, which was optimized for the main depressions in the Central Depression Belt. It is proposed that Lingshui, Ledong, Baodao and Changchang Depressions are the most abundant hydrocarbon depressions, whilst Songnan and Beijiao Depressions are rich hydrocarbon depressions. Such an evaluation procedure is beneficial to the next stage of exploration in the deep-water area of Qiongdongnan Basin.展开更多
The endoscopic submucosal dissection(ESD)technique has become the gold standard for submucosal tumors that have negligible risk of lymph node metastasis(LNM),due to its minimal invasiveness and ability to improve qual...The endoscopic submucosal dissection(ESD)technique has become the gold standard for submucosal tumors that have negligible risk of lymph node metastasis(LNM),due to its minimal invasiveness and ability to improve quality of life.However,this technique is limited in stage T1 cancers that have a low risk of LNM.Endoscopic full thickness resection can be achieved with laparoscopic endoscopic cooperative surgery(LECS),which combines laparoscopic gastric wall resection and ESD.In LECS,the surgical margins from the tumor are clearly achieved while performing organ-preserving surgery.To overcome the limitation of classical LECS,namely the opening of the gastric wall during the procedure,which increases the risk of peritoneal tumor seeding,non-exposed endoscopic wall-inversion surgery was developed.With this full-thickness resection technique,contact between the intra-abdominal space and the intragastric space was eliminated.展开更多
The status of aquatic ecosystems refers to the overall condition of water bodies and the surrounding environmental com-partments.Preserving the integrity of aquatic ecosystems is crucial for water resource conservatio...The status of aquatic ecosystems refers to the overall condition of water bodies and the surrounding environmental com-partments.Preserving the integrity of aquatic ecosystems is crucial for water resource conservation and the restoration of aquatic habitats.However,it remains challenges for researchers and policymakers worldwide to assess and monitor the health of aquatic ecosystems.The present work summarized the evolution of water ecological assessments,focusing on their role in water governance,the development of indicator systems,and the challenges and perspective of research and implementation worldwide.To do so,we reviewed the cases from several representative countries and regions worldwide such as the United States,the European Union,China,Brazil,and India,representing different stages of socio-economic development.These cases demonstrate that water ecological assessments have evolved from broad scientific evaluations to more targeted,refined approaches,reflecting continuous improvements in both ecological assessment techniques and management strategies.To date,the implementation of water ecological assessments remains challenging,including in-consistencies in indicator selection,limitations in ecological monitoring,and the growing uncertainty induced by climate change.Therefore,it is essential to establish a harmonized set of core indicators and develop a methodological framework that is both accurate and practical for routine applications.Such improvements will enhance the effectiveness of water eco-logical assessments,supporting science-informed decision-making in aquatic ecosystem management.展开更多
Hydropower,an immaculate carbon-neutral source of renewable energy,ranks as China's third largest energy sector.The hydropower development presents both positive and negative environmental externalities.The exploi...Hydropower,an immaculate carbon-neutral source of renewable energy,ranks as China's third largest energy sector.The hydropower development presents both positive and negative environmental externalities.The exploitation of water resources yields adverse implications on the hydrological environment,aquatic ecology,terrestrial ecology,and local climate fluctuations.The transformation of the river basin water environment reflects not merely the direct impact and environmental degradation ensuing from hydropower exploitation,but also the environmental precipitators and triggers of aquatic ecological imbalance,terrestrial ecological destruction,and local climate alterations.China's prevailing constitution and fundamental laws anchor a legal bedrock for China's economic progression and ecological preservation,culminating in a nascent water legal standard system underpinned by the“four water laws”.Guided by the legislative rationale of comprehensive watershed management,watershed laws such as the Yangtze River Protection Law and the Yellow River Protection Law orchestrate the design and cooperative governance of paramount rivers like the Yellow River and the Yangtze River,infusing the essence of judicious laws and chartering pathways for prudent governance geared towards watershed conservation.The formulation of critical legislation to protect the environmental integrity of key river basins that are undergoing hydropower development,the enhancement of the environmental impact assessment infrastructure for hydropower development,and the scientific orchestration of river basin ecological flow arrangements and river basin ecological environment partition control systems all serve to circumvent and respond to the impacts on the ecological environment in river basins,thereby offering robust legal fortification for the ecological environment in river basins.展开更多
基金International Partnership Program of Chinese Academy of Sciences,No.131551KYSB20160002 National Natural Science Foundation of China,No.41401602+2 种基金 Natural Science Basic Research Plan in Shaanxi Province of China,No.2014JQ2-4021 Key Scientific and Technological Innovation Team Plan of Shaanxi Province,No.2014KCT-27 Graduate Student Innovation Project of Northwest University,No.YZZ15011
文摘In recent years, global reanalysis weather data has been widely used in hydrological modeling around the world, but the results of simulations vary greatly. To consider the applicability of Climate Forecast System Reanalysis（CFSR） data in the hydrologic simulation of watersheds, the Bahe River Basin was used as a case study. Two types of weather data（conventional weather data and CFSR weather data） were considered to establish a Soil and Water Assessment Tool（SWAT） model, which was used to simulate runoff from 2001 to 2012 in the basin at annual and monthly scales. The effect of both datasets on the simulation was assessed using regression analysis, Nash-Sutcliffe Efficiency（NSE）, and Percent Bias（PBIAS）. A CFSR weather data correction method was proposed. The main results were as follows.（1） The CFSR climate data was applicable for hydrologic simulation in the Bahe River Basin（R^2 of the simulated results above 0.50, NSE above 0.33, and ｜PBIAS｜ below 14.8. Although the quality of the CFSR weather data is not perfect, it achieved a satisfactory hydrological simulation after rainfall data correction.（2） The simulated streamflow using the CFSR data was higher than the observed streamflow, which was likely because the estimation of daily rainfall data by CFSR weather data resulted in more rainy days and stronger rainfall intensity than was actually observed. Therefore, the data simulated a higher base flow and flood peak discharge in terms of the water balance, except for some individual years.（3） The relation between the CFSR rainfall data（x） and the observed rainfall data（y） could berepresented by a power exponent equation： y=1.4789x0.8875（R2=0.98,P〈0.001）. There was a slight variation between the fitted equations for each station. The equation provides a theoretical basis for the correction of CFSR rainfall data.
基金The National Science and Technology Major Project of the Ministry of Science and Technology of China under contract No.2011ZX05025
文摘It has been confirmed that the key source rocks of Qiongdongnan Basin are associated with the Yacheng Formation, which was deposited in a transitional marine-continental environment. Because the distribution and evolution patterns of the source rocks in the major depressions are different, it is important to determine the most abundant hydrocarbon-generation depressions in terms of exploration effectiveness. Based on an analysis of organic matter characteristics of the source rocks, in combination with drilling data and seismic data, this paper establishes a model to evaluate the hydrocarbon-generation depressions in the deepwater area of Qiongdongnan Basin. First of all, by using the method of seismic-facies model analysis, the distribution of sedimentary facies was determined. Then, the sedimentary facies were correlated with the organic facies, and the distribution of organic facies was predicted. Meanwhile, the thickness of source rocks for all the depressions was calculated on the basis of a quantitative analysis of seismic velocity and lithology. The relationship between mudstone porosity and vitrinite reflectance（Ro） was used to predict the maturity of source rocks. Second, using the parameters such as thickness and maturity of source rocks, the quantity and intensity of gas generation for Yacheng and Lingshui Formations were calculated. Finally, in combination with the identified hydrocarbon resources, the quantity and intensity of gas generation were used as a guide to establish an evaluation standard for hydrocarbon-generation depressions, which was optimized for the main depressions in the Central Depression Belt. It is proposed that Lingshui, Ledong, Baodao and Changchang Depressions are the most abundant hydrocarbon depressions, whilst Songnan and Beijiao Depressions are rich hydrocarbon depressions. Such an evaluation procedure is beneficial to the next stage of exploration in the deep-water area of Qiongdongnan Basin.
文摘The endoscopic submucosal dissection(ESD)technique has become the gold standard for submucosal tumors that have negligible risk of lymph node metastasis(LNM),due to its minimal invasiveness and ability to improve quality of life.However,this technique is limited in stage T1 cancers that have a low risk of LNM.Endoscopic full thickness resection can be achieved with laparoscopic endoscopic cooperative surgery(LECS),which combines laparoscopic gastric wall resection and ESD.In LECS,the surgical margins from the tumor are clearly achieved while performing organ-preserving surgery.To overcome the limitation of classical LECS,namely the opening of the gastric wall during the procedure,which increases the risk of peritoneal tumor seeding,non-exposed endoscopic wall-inversion surgery was developed.With this full-thickness resection technique,contact between the intra-abdominal space and the intragastric space was eliminated.
基金supported by the National Key R&D Program of China(2022YFC3203500)the Joint Research Project for the Yangtze River Conservation(Phase II),China(2022-LHYJ-02-0603)China Three Gorges Group of the Yangtze River limited project(202003140)。
文摘The status of aquatic ecosystems refers to the overall condition of water bodies and the surrounding environmental com-partments.Preserving the integrity of aquatic ecosystems is crucial for water resource conservation and the restoration of aquatic habitats.However,it remains challenges for researchers and policymakers worldwide to assess and monitor the health of aquatic ecosystems.The present work summarized the evolution of water ecological assessments,focusing on their role in water governance,the development of indicator systems,and the challenges and perspective of research and implementation worldwide.To do so,we reviewed the cases from several representative countries and regions worldwide such as the United States,the European Union,China,Brazil,and India,representing different stages of socio-economic development.These cases demonstrate that water ecological assessments have evolved from broad scientific evaluations to more targeted,refined approaches,reflecting continuous improvements in both ecological assessment techniques and management strategies.To date,the implementation of water ecological assessments remains challenging,including in-consistencies in indicator selection,limitations in ecological monitoring,and the growing uncertainty induced by climate change.Therefore,it is essential to establish a harmonized set of core indicators and develop a methodological framework that is both accurate and practical for routine applications.Such improvements will enhance the effectiveness of water eco-logical assessments,supporting science-informed decision-making in aquatic ecosystem management.
文摘Hydropower,an immaculate carbon-neutral source of renewable energy,ranks as China's third largest energy sector.The hydropower development presents both positive and negative environmental externalities.The exploitation of water resources yields adverse implications on the hydrological environment,aquatic ecology,terrestrial ecology,and local climate fluctuations.The transformation of the river basin water environment reflects not merely the direct impact and environmental degradation ensuing from hydropower exploitation,but also the environmental precipitators and triggers of aquatic ecological imbalance,terrestrial ecological destruction,and local climate alterations.China's prevailing constitution and fundamental laws anchor a legal bedrock for China's economic progression and ecological preservation,culminating in a nascent water legal standard system underpinned by the“four water laws”.Guided by the legislative rationale of comprehensive watershed management,watershed laws such as the Yangtze River Protection Law and the Yellow River Protection Law orchestrate the design and cooperative governance of paramount rivers like the Yellow River and the Yangtze River,infusing the essence of judicious laws and chartering pathways for prudent governance geared towards watershed conservation.The formulation of critical legislation to protect the environmental integrity of key river basins that are undergoing hydropower development,the enhancement of the environmental impact assessment infrastructure for hydropower development,and the scientific orchestration of river basin ecological flow arrangements and river basin ecological environment partition control systems all serve to circumvent and respond to the impacts on the ecological environment in river basins,thereby offering robust legal fortification for the ecological environment in river basins.
