The Yellow River Delta(YRD), a critical economic zone along China's eastern coast, also functions as a vital ecological reserve in the lower Yellow River. Amidst rapid industrialization and urbanization, the regio...The Yellow River Delta(YRD), a critical economic zone along China's eastern coast, also functions as a vital ecological reserve in the lower Yellow River. Amidst rapid industrialization and urbanization, the region has witnessed significant land use/cover changes(LUCC), impacting ecosystem services(ES) and ecological security patterns(ESP). Investigating LUCC's effects on ES and ESP in the YRD is crucial for ecological security and sustainable development. This study utilized the PLUS model to simulate 2030 land use scenarios, including natural development(NDS), economic development(EDS), and ecological protection scenarios(EPS). Subsequently, the InVEST model and circuit theory were applied to assess ES and ESP under varying LUCC scenarios from 2010 to 2030. Findings indicate:(1) Notable LUCC from 2010 to 2030, marked by decreasing cropland and increasing construction land and water bodies.(2) From 2010 to 2020, improvements were observed in carbon storage,water yield, soil retention, and habitat quality, whereas 2020–2030 saw increases in water yield and soil retention but declines in habitat quality and carbon storage. Among the scenarios, EPS showed superior performance in all four ES.(3) Between 2010 and 2030, ecological sources, corridors, and pinchpoints expanded, displaying significant spatial heterogeneity. The EPS scenario yielded the most substantial increases in ecological sources,corridors, and pinchpoints, totaling 582.89 km^(2), 645.03 km^(2),and 64.43 km^(2), respectively. This study highlights the importance of EPS, offering insightful scientific guidance for the YRD's sustainable development.展开更多
Soil salinization is one of the major land degradation types and has greatly influenced sustainable agricultural development. Zonation of saline-alkali land is the precondition for effective amelioration. The present ...Soil salinization is one of the major land degradation types and has greatly influenced sustainable agricultural development. Zonation of saline-alkali land is the precondition for effective amelioration. The present situation of saline-alkali land is monitored by remote sensing image processing. Causes for land salinization are analyzed, especially the two key factors, ground water depth and its mineralization degree, are analyzed by using long-term observation data. Previously, zonation of saline-alkali soil was made descriptively and artificially. Based on the present situation of saline-alkali land, ground water depth and ground water mineralization degree, the zonation of saline-alkali land for amelioration in the Yellow River Delta was completed quantitatively. Four different types of saline-alkali land amelioration zones are delineated, namely, easy ameliorated zone, relatively difficult ameliorated zone, difficult ameliorated zone and unfavorable ameliorated zone. Countermeasures for ameliorating saline-alkali soils are put forward according to ecological conditions of different saline-alkali land zones.展开更多
Taking the Yellow River Delta for example, this paper applied remote sensing and GIS to explore land use changes in the local area from 1980 to 2010. The results showed that arable land, and urban and rural constructi...Taking the Yellow River Delta for example, this paper applied remote sensing and GIS to explore land use changes in the local area from 1980 to 2010. The results showed that arable land, and urban and rural construction land were major land use types in the Yellow River Delta, unused land also took a large ratio; land use changes occurred mainly in coastal regions, in terms of change matrix, 25.46% of the grassland was reclaimed as arable land, unused land also witnessed great changes, specifi cally, 11.14% turned to arable land, 23.25% to construction land. This study provided references for the land use planning and development of the local area.展开更多
The biogenic sedimentary structures (i.e., the morphology and trace makers of burrows, tracks, trails and traces made by extant organisms) and their composition and distribution characters in different micro environ...The biogenic sedimentary structures (i.e., the morphology and trace makers of burrows, tracks, trails and traces made by extant organisms) and their composition and distribution characters in different micro environments and sub environments of the Yellow River delta in China are described. Three ichnocoenosis can be recognized: (1) Steinichnus-like ichnocoenosis, includes F, Y-shaped traces, birds' footprints on bedding plane, and Y, U-shaped burrows in intrastratal bedding, produced by Coleoptera (Heteroceridae), Orthoptera (Gryllotalpidae) and birds. It is majorly found at the delta plain point bar deposits, denoting the fresh water-related terrestrial environments. (2) Steinichnus-Psilonichnus-like ichnocoenosis, consitsis of Steinichnus-like traces on the bedding plane and Psilonichnus-like burrow which a vertical, irregularly J-, Y-, or U-shaped burrows, some of them with bulbous basal cells burrows in the intrastratal bedding, created by Coleoptera (Heteroceridae), Orthoptera (Gryllotalpidae) and crabs. It is observed in the delta plain abandoned distributary channels, and the delta front tidal creek and subaquous distributary channels, indicating the brackish water environment. (3) Palaeophycus-like ichnocoenosis, includes the round entrance burrows or with craters-shaped loop-protrusionsand and the parallel forked trails on the bedding plane, and the U, J or vertical shaped feeding burrows are in the intrastratal bedding, majorly produced by the clam (bivalve molluscs), gastropods and Nereis. It is present in the subaqueous interdistributary bay, reflecting the intertidal related environment.展开更多
Point bars are well developed on the Yellow River delta, an~ which theShengli I point bar is the most typical. The point bar, being about 4 km in length and several tensto more than 100 meters in width, is located on ...Point bars are well developed on the Yellow River delta, an~ which theShengli I point bar is the most typical. The point bar, being about 4 km in length and several tensto more than 100 meters in width, is located on the south side of the Shengli Bridge in KenliCounty, Dongying, Shandong. It is a typical fine-grained point bar with silt, which is predominant,some clay and minor plant debris and clay boulders. The Shengli I Point bar has complicated 3-Dstructures. Firstly, in a plane view, it comprises mainly eight sedimentary units, bar edge, baredge, bar platform, bar plain, bar channel, bar gully, bar pond and bar bay, developing side by sideand superimposed one by one m a complex way. Secondly, its vertical structures are very complex dueto the partial superimposition of the 8 sedimentary units. Besides hydatogenesis, very intensivewind erosion, eolian, ice and meltwater actions are also visible on the Shengli I point bar. Thecomplex form is made even more complicated because of the above co-actions.展开更多
We have used the Yellow River Delta (Dongying section) as our study area to address the project of "Three Networks Greening" (TNG). With the use of GIS technology and from an ecological point of view, an optimal...We have used the Yellow River Delta (Dongying section) as our study area to address the project of "Three Networks Greening" (TNG). With the use of GIS technology and from an ecological point of view, an optimal allocation scheme of land resources is constructed and applied to guide the adjustment of land resources. Given this scheme, we have calculated that the area of land suitable for forest and shrubs without greening is 2256 km^2. Simultaneously, acting on the layout of the TNG project, afforestation site types are prepared and improved. Soil types, microrelief, salinity and underwater levels are combined as major classification factors and irrigation conditions as a reference to classify sites into eight types. In this way, land suitable for forest and grass is afforested given particular planting patterns. Finally, by overlaying this forestry site type map with the TNG plan map, some suggestions and strategies are proposed and used to direct the TNG project. An ecological oasis of the Yellow River Delta should be the result.展开更多
Comprehensive study on land-use change of spatial pattern and temporal process is the key component in land use/land cover changes (LUCC) study nowadays. According to the theories and methods of Geo-information Tupu (...Comprehensive study on land-use change of spatial pattern and temporal process is the key component in land use/land cover changes (LUCC) study nowadays. According to the theories and methods of Geo-information Tupu (Carto-methodology in Geo-information, CMGI) for geospatial and temporal analysis and integration models of spatial pattern and temporal processes in GIS, the paper puts forward Tupu methodology of land-use change and names the basic synthetic unit of spatial-temporal information Tupu unit. Tupu unit is the synthetic unit for geospatial-temporal analysis, which is synthesized by “space·attribute·process”features and composed of relatively homogeneous geographic unit and temporal unit. Based on the spatial features of 4 stages of land-use change in 1956, 1984, 1991, and 1996, a series of Tupu on land-use change in the Yellow River Delta (YRD) are created and studied in the paper, which includes 3 temporal units of spatial-temporal Tupu, process Tupu of land-use changes during the last 40 years, and reconstructions of a series of “arisen”Tupu, “arisen”process Tupu and pattern Tupu on land-use changes in the last 40 years by remapping tables of a reclassifying system. There are 3 methods of Tupu analysis on land-use change that are used to disclose change processes of land-use spatial conversion in YRD, such as spatial query and statistics, order of Tupu units by area and land-use conversion matrixes. In order to reveal the spatial pattern of land-use change processes, we analyze spatial-temporal changes of each Tupu above in various temporal units and spatial difference of pattern Tupu in the last 40 years by dynamic Tupu units. Tupu analysis on regional land-use is a promising trial on the comprehensive research of “spatial pattern of dynamic process”and “temporal process of spatial pattern”in LUCC research. The geo-information Tupu methodology would be a powerful and efficient tool on integrated studies of spatial pattern and temporal process in geoscience.展开更多
Bioturbation is one of the important processes that affect the structure and function of sedimentary environments.The particle mixing and element migration processes caused by bioturbation can interfere with the circu...Bioturbation is one of the important processes that affect the structure and function of sedimentary environments.The particle mixing and element migration processes caused by bioturbation can interfere with the circulation of matter and the explanation of sedimentary records.Therefore,the quantitative characterization of bioturbation structures in the sedimentary sequence is of great significance in the field of sedimentology.Estuaries,where fresh and saltwater mix,exhibit high ecological heterogeneity and biodiversity,making them ideal places to explore bioturbation.This paper targets the subaqueous Yellow River Delta to quantitatively characterize bioturbation structures and their spatial distribution patterns using computed tomography(CT)scanning and three-dimensional reconstruction technology.By combining sediment characteristics and sedimentary environment analysis,the main factors affecting bioturbation structures are elucidated.The results show that bioturbation structures in the subaqueous Yellow River Delta can be divided into four types based on their morphology:uniaxial type,biaxial type,triaxial type,and multiaxial type.Skolithos,Palaeophycus in the uniaxial type,and Thalassinoides in the multiaxial type are the most developed structures.Different types of bioturbation may be constructed by trace-making organisms belonging to the same category or functional group.The intensity of bioturbation in this area ranges from 0 to 4%,with a decreasing trend from nearshore to offshore.There is a downward decreasing trend in the intensity of bioturbation overall in the sedimentary cores,with three vertical distribution patterns:exponential decay pattern,fluctuating decay pattern,and impulsive pattern.The impulsive pattern of bioturbation in a core may indicate the abrupt change in sedimentary environment induced by the Yellow River channel shift in 1996.These results suggest that factors affecting the development of bioturbation include grain size,porosity,consolidation,organic matter content of sediments,and sedimentation rate that is mainly influenced by local hydrodynamic conditions.The environment with clayey silt(average grain size 10μm)and moderate sedimentation rate(around 0.5 cm yr^(-1))is the most suitable area for the development of bioturbation in the Yellow River subaqueous delta.展开更多
This study analyzed land use and land coverchanges and their impact on land surface temperature usingLandsat 5 Thematic Mapper and Landsat 8 OperationalLand Imager and Thermal Infrared Sensor imagery of theYellow Rive...This study analyzed land use and land coverchanges and their impact on land surface temperature usingLandsat 5 Thematic Mapper and Landsat 8 OperationalLand Imager and Thermal Infrared Sensor imagery of theYellow River Delta. Six Landsat images comprising twotime series were used to calculate the land surfacetemperature and correlated vegetation indices. The YellowRiver Delta area has expanded substantially because of thedeposited sediment carried from upstream reaches of theriver. Between 1986 and 2015, approximately 35% of theland use area of the Yellow River Delta has beentransformed into salterns and aquaculture ponds. Overall,land use conversion has occurred primarily from poorlyutilized land into highly utilized land. To analyze thevariation of land surface temperature, a mono-windowalgorithm was applied to retrieve the regional land surfacetemperature. The results showed bilinear correlationbetween land surface temperature and the vegetationindices (i.e., Normalized Difference Vegetation Index,Adjusted-Normalized Vegetation Index, Soil-AdjustedVegetation Index, and Modified Soil-Adjusted VegetationIndex). Generally, values of the vegetation indices greaterthan the inflection point mean the land surface temperatureand the vegetation indices are correlated negatively, andvice versa. Land surface temperature in coastal areas isaffected considerably by local seawater temperature andweather conditions.展开更多
China’s Yellow River Delta represents a typical area with moist semi-humid soil salinization,and its salinization has seriously affected the sustainable use of local resources.The use of remote sensing technology to ...China’s Yellow River Delta represents a typical area with moist semi-humid soil salinization,and its salinization has seriously affected the sustainable use of local resources.The use of remote sensing technology to understand changes in the spatial and temporal patterns of salinization is key to combating regional land degradation.In this study,a feature space model was constructed for remote sensing and monitoring land salinization using Landsat 8 OIL multi-spectral images.The feature parameters were paired to construct a feature space model;a total of eight feature space models were obtained.An accuracy analysis was conducted by combining salt-loving vegetation data with measured data,and the model demonstrating the highest accuracy was selected to develop salinization inversion maps for 2015 and 2020.The results showed that:(1)The total salinization area of the Yellow River Delta displayed a slight upward trend,increasing from 4244 km^(2) in 2015 to 4629 km^(2) in 2020.However,the area’s salting degree reduced substantially,and the areas of saline soil and severe salinization were reduced in size;(2)The areas with reduced salinization severity were mainly concentrated in areas surrounding cities,and primarily comprised wetlands and some regions around the Bohai Sea;(3)Numerous factors such as the implementation of the“Bohai Granary”cultivation engagement plan,increase in human activities to greening local residential living environments,and seawater intrusion caused by the reduction of sediment contents have impacted the distribution of salinization areas in the Yellow River Delta;(4)The characteristic space method of salinization monitoring has better applicability and can be promoted in humid-sub humid regions.展开更多
基金financially supported by the National Natural Science Foundation of China (Grant No. 41461011)。
文摘The Yellow River Delta(YRD), a critical economic zone along China's eastern coast, also functions as a vital ecological reserve in the lower Yellow River. Amidst rapid industrialization and urbanization, the region has witnessed significant land use/cover changes(LUCC), impacting ecosystem services(ES) and ecological security patterns(ESP). Investigating LUCC's effects on ES and ESP in the YRD is crucial for ecological security and sustainable development. This study utilized the PLUS model to simulate 2030 land use scenarios, including natural development(NDS), economic development(EDS), and ecological protection scenarios(EPS). Subsequently, the InVEST model and circuit theory were applied to assess ES and ESP under varying LUCC scenarios from 2010 to 2030. Findings indicate:(1) Notable LUCC from 2010 to 2030, marked by decreasing cropland and increasing construction land and water bodies.(2) From 2010 to 2020, improvements were observed in carbon storage,water yield, soil retention, and habitat quality, whereas 2020–2030 saw increases in water yield and soil retention but declines in habitat quality and carbon storage. Among the scenarios, EPS showed superior performance in all four ES.(3) Between 2010 and 2030, ecological sources, corridors, and pinchpoints expanded, displaying significant spatial heterogeneity. The EPS scenario yielded the most substantial increases in ecological sources,corridors, and pinchpoints, totaling 582.89 km^(2), 645.03 km^(2),and 64.43 km^(2), respectively. This study highlights the importance of EPS, offering insightful scientific guidance for the YRD's sustainable development.
基金Study of Sustainable Development Information Tupu in the Yellow River Delta Knowledge Innovation Project of CAS, No.CXIOG-D00-0
文摘Soil salinization is one of the major land degradation types and has greatly influenced sustainable agricultural development. Zonation of saline-alkali land is the precondition for effective amelioration. The present situation of saline-alkali land is monitored by remote sensing image processing. Causes for land salinization are analyzed, especially the two key factors, ground water depth and its mineralization degree, are analyzed by using long-term observation data. Previously, zonation of saline-alkali soil was made descriptively and artificially. Based on the present situation of saline-alkali land, ground water depth and ground water mineralization degree, the zonation of saline-alkali land for amelioration in the Yellow River Delta was completed quantitatively. Four different types of saline-alkali land amelioration zones are delineated, namely, easy ameliorated zone, relatively difficult ameliorated zone, difficult ameliorated zone and unfavorable ameliorated zone. Countermeasures for ameliorating saline-alkali soils are put forward according to ecological conditions of different saline-alkali land zones.
基金Sponsored by Shandong Provincial Natural Science Fund(ZR2011DQ018)Scientific Research Fund of "Young Talents Innovation Project" of Binzhou University(BZXYQNLG200717)
文摘Taking the Yellow River Delta for example, this paper applied remote sensing and GIS to explore land use changes in the local area from 1980 to 2010. The results showed that arable land, and urban and rural construction land were major land use types in the Yellow River Delta, unused land also took a large ratio; land use changes occurred mainly in coastal regions, in terms of change matrix, 25.46% of the grassland was reclaimed as arable land, unused land also witnessed great changes, specifi cally, 11.14% turned to arable land, 23.25% to construction land. This study provided references for the land use planning and development of the local area.
基金supported by the National Science Foundation of China (No. 41272117)the Specialized Research Fund for the Doctoral Program of Higher Education of China (NO. 20094116110002)Developing Projects of Science and Technology of Henan Province (NO.124300510039, 092300410167)
文摘The biogenic sedimentary structures (i.e., the morphology and trace makers of burrows, tracks, trails and traces made by extant organisms) and their composition and distribution characters in different micro environments and sub environments of the Yellow River delta in China are described. Three ichnocoenosis can be recognized: (1) Steinichnus-like ichnocoenosis, includes F, Y-shaped traces, birds' footprints on bedding plane, and Y, U-shaped burrows in intrastratal bedding, produced by Coleoptera (Heteroceridae), Orthoptera (Gryllotalpidae) and birds. It is majorly found at the delta plain point bar deposits, denoting the fresh water-related terrestrial environments. (2) Steinichnus-Psilonichnus-like ichnocoenosis, consitsis of Steinichnus-like traces on the bedding plane and Psilonichnus-like burrow which a vertical, irregularly J-, Y-, or U-shaped burrows, some of them with bulbous basal cells burrows in the intrastratal bedding, created by Coleoptera (Heteroceridae), Orthoptera (Gryllotalpidae) and crabs. It is observed in the delta plain abandoned distributary channels, and the delta front tidal creek and subaquous distributary channels, indicating the brackish water environment. (3) Palaeophycus-like ichnocoenosis, includes the round entrance burrows or with craters-shaped loop-protrusionsand and the parallel forked trails on the bedding plane, and the U, J or vertical shaped feeding burrows are in the intrastratal bedding, majorly produced by the clam (bivalve molluscs), gastropods and Nereis. It is present in the subaqueous interdistributary bay, reflecting the intertidal related environment.
文摘Point bars are well developed on the Yellow River delta, an~ which theShengli I point bar is the most typical. The point bar, being about 4 km in length and several tensto more than 100 meters in width, is located on the south side of the Shengli Bridge in KenliCounty, Dongying, Shandong. It is a typical fine-grained point bar with silt, which is predominant,some clay and minor plant debris and clay boulders. The Shengli I Point bar has complicated 3-Dstructures. Firstly, in a plane view, it comprises mainly eight sedimentary units, bar edge, baredge, bar platform, bar plain, bar channel, bar gully, bar pond and bar bay, developing side by sideand superimposed one by one m a complex way. Secondly, its vertical structures are very complex dueto the partial superimposition of the 8 sedimentary units. Besides hydatogenesis, very intensivewind erosion, eolian, ice and meltwater actions are also visible on the Shengli I point bar. Thecomplex form is made even more complicated because of the above co-actions.
基金supported by the National Science Foundation of China (Grant No.40771172)the Main Direction Program of Knowledge In-novation of the Chinese Academy of Sciences (kzcx2-yw-308)
文摘We have used the Yellow River Delta (Dongying section) as our study area to address the project of "Three Networks Greening" (TNG). With the use of GIS technology and from an ecological point of view, an optimal allocation scheme of land resources is constructed and applied to guide the adjustment of land resources. Given this scheme, we have calculated that the area of land suitable for forest and shrubs without greening is 2256 km^2. Simultaneously, acting on the layout of the TNG project, afforestation site types are prepared and improved. Soil types, microrelief, salinity and underwater levels are combined as major classification factors and irrigation conditions as a reference to classify sites into eight types. In this way, land suitable for forest and grass is afforested given particular planting patterns. Finally, by overlaying this forestry site type map with the TNG plan map, some suggestions and strategies are proposed and used to direct the TNG project. An ecological oasis of the Yellow River Delta should be the result.
基金supported by the National Natural Science Foundation of China(40371093)the Special Funds for Major State Basic Research Project(G20000779,2002CB412408)+2 种基金Opening Fund projects of State Key Laboratory of Remote Sensing Science in the Institute of Remote Sensing Applications(SK040006)Opening Fund projects of State Key Laboratory of Estuarine and Coastal Research of East China Normal University,China Postdoctoral Science Foundationthe Project from'863'Marine Monitor of Hi-Tech Research and Development Program of China(2001AA633010).
文摘Comprehensive study on land-use change of spatial pattern and temporal process is the key component in land use/land cover changes (LUCC) study nowadays. According to the theories and methods of Geo-information Tupu (Carto-methodology in Geo-information, CMGI) for geospatial and temporal analysis and integration models of spatial pattern and temporal processes in GIS, the paper puts forward Tupu methodology of land-use change and names the basic synthetic unit of spatial-temporal information Tupu unit. Tupu unit is the synthetic unit for geospatial-temporal analysis, which is synthesized by “space·attribute·process”features and composed of relatively homogeneous geographic unit and temporal unit. Based on the spatial features of 4 stages of land-use change in 1956, 1984, 1991, and 1996, a series of Tupu on land-use change in the Yellow River Delta (YRD) are created and studied in the paper, which includes 3 temporal units of spatial-temporal Tupu, process Tupu of land-use changes during the last 40 years, and reconstructions of a series of “arisen”Tupu, “arisen”process Tupu and pattern Tupu on land-use changes in the last 40 years by remapping tables of a reclassifying system. There are 3 methods of Tupu analysis on land-use change that are used to disclose change processes of land-use spatial conversion in YRD, such as spatial query and statistics, order of Tupu units by area and land-use conversion matrixes. In order to reveal the spatial pattern of land-use change processes, we analyze spatial-temporal changes of each Tupu above in various temporal units and spatial difference of pattern Tupu in the last 40 years by dynamic Tupu units. Tupu analysis on regional land-use is a promising trial on the comprehensive research of “spatial pattern of dynamic process”and “temporal process of spatial pattern”in LUCC research. The geo-information Tupu methodology would be a powerful and efficient tool on integrated studies of spatial pattern and temporal process in geoscience.
基金supported by the National Natural Science Foundation of China(No.42176077)。
文摘Bioturbation is one of the important processes that affect the structure and function of sedimentary environments.The particle mixing and element migration processes caused by bioturbation can interfere with the circulation of matter and the explanation of sedimentary records.Therefore,the quantitative characterization of bioturbation structures in the sedimentary sequence is of great significance in the field of sedimentology.Estuaries,where fresh and saltwater mix,exhibit high ecological heterogeneity and biodiversity,making them ideal places to explore bioturbation.This paper targets the subaqueous Yellow River Delta to quantitatively characterize bioturbation structures and their spatial distribution patterns using computed tomography(CT)scanning and three-dimensional reconstruction technology.By combining sediment characteristics and sedimentary environment analysis,the main factors affecting bioturbation structures are elucidated.The results show that bioturbation structures in the subaqueous Yellow River Delta can be divided into four types based on their morphology:uniaxial type,biaxial type,triaxial type,and multiaxial type.Skolithos,Palaeophycus in the uniaxial type,and Thalassinoides in the multiaxial type are the most developed structures.Different types of bioturbation may be constructed by trace-making organisms belonging to the same category or functional group.The intensity of bioturbation in this area ranges from 0 to 4%,with a decreasing trend from nearshore to offshore.There is a downward decreasing trend in the intensity of bioturbation overall in the sedimentary cores,with three vertical distribution patterns:exponential decay pattern,fluctuating decay pattern,and impulsive pattern.The impulsive pattern of bioturbation in a core may indicate the abrupt change in sedimentary environment induced by the Yellow River channel shift in 1996.These results suggest that factors affecting the development of bioturbation include grain size,porosity,consolidation,organic matter content of sediments,and sedimentation rate that is mainly influenced by local hydrodynamic conditions.The environment with clayey silt(average grain size 10μm)and moderate sedimentation rate(around 0.5 cm yr^(-1))is the most suitable area for the development of bioturbation in the Yellow River subaqueous delta.
文摘This study analyzed land use and land coverchanges and their impact on land surface temperature usingLandsat 5 Thematic Mapper and Landsat 8 OperationalLand Imager and Thermal Infrared Sensor imagery of theYellow River Delta. Six Landsat images comprising twotime series were used to calculate the land surfacetemperature and correlated vegetation indices. The YellowRiver Delta area has expanded substantially because of thedeposited sediment carried from upstream reaches of theriver. Between 1986 and 2015, approximately 35% of theland use area of the Yellow River Delta has beentransformed into salterns and aquaculture ponds. Overall,land use conversion has occurred primarily from poorlyutilized land into highly utilized land. To analyze thevariation of land surface temperature, a mono-windowalgorithm was applied to retrieve the regional land surfacetemperature. The results showed bilinear correlationbetween land surface temperature and the vegetationindices (i.e., Normalized Difference Vegetation Index,Adjusted-Normalized Vegetation Index, Soil-AdjustedVegetation Index, and Modified Soil-Adjusted VegetationIndex). Generally, values of the vegetation indices greaterthan the inflection point mean the land surface temperatureand the vegetation indices are correlated negatively, andvice versa. Land surface temperature in coastal areas isaffected considerably by local seawater temperature andweather conditions.
基金The Strategic Priority Research Program of Chinese Academy of Sciences(XDA19040501)The Construction Project of the China Knowledge Center for Engineering Sciences and Technology(CKCEST-2021-2-18)。
文摘China’s Yellow River Delta represents a typical area with moist semi-humid soil salinization,and its salinization has seriously affected the sustainable use of local resources.The use of remote sensing technology to understand changes in the spatial and temporal patterns of salinization is key to combating regional land degradation.In this study,a feature space model was constructed for remote sensing and monitoring land salinization using Landsat 8 OIL multi-spectral images.The feature parameters were paired to construct a feature space model;a total of eight feature space models were obtained.An accuracy analysis was conducted by combining salt-loving vegetation data with measured data,and the model demonstrating the highest accuracy was selected to develop salinization inversion maps for 2015 and 2020.The results showed that:(1)The total salinization area of the Yellow River Delta displayed a slight upward trend,increasing from 4244 km^(2) in 2015 to 4629 km^(2) in 2020.However,the area’s salting degree reduced substantially,and the areas of saline soil and severe salinization were reduced in size;(2)The areas with reduced salinization severity were mainly concentrated in areas surrounding cities,and primarily comprised wetlands and some regions around the Bohai Sea;(3)Numerous factors such as the implementation of the“Bohai Granary”cultivation engagement plan,increase in human activities to greening local residential living environments,and seawater intrusion caused by the reduction of sediment contents have impacted the distribution of salinization areas in the Yellow River Delta;(4)The characteristic space method of salinization monitoring has better applicability and can be promoted in humid-sub humid regions.