This paper attempts to explore a new avenue of urban small-regional population estimation by remote sensing technology, creatively and comprehensively for the first time using a residence count method, area (density) ...This paper attempts to explore a new avenue of urban small-regional population estimation by remote sensing technology, creatively and comprehensively for the first time using a residence count method, area (density) method and model method, incorporating the application experience of American scholars in the light of the state of our country. Firstly, the author proposes theoretical basis for population estimation by remote sensing, on the basis of analysing and evaluating the history and state quo of application of methods of population estimation by remote sensing. Secondly, two original types of mathematical models of population estimation are developed on the basis of remote sensing data, taking Tianjin City as an example. By both of the mathematical models the regional population may be estimated from remote sensing variable values with high accuracy. The number of the independent variables in the latter model is somewhat smaller and the collection of remote sensing data is somewhat easier, but the deviation is a little larger. Finally, some viewpoints on the principled problems about the practical application of remote sensing to population estimation are put forward.展开更多
The permafrost of Mohe County and its suburbs in the Daxing′an Mountains has been influenced by the urbanization.Remote sensing,GIS technology and numerical simulation was used to study the temperature variations of ...The permafrost of Mohe County and its suburbs in the Daxing′an Mountains has been influenced by the urbanization.Remote sensing,GIS technology and numerical simulation was used to study the temperature variations of permafrost with the changes in surface vegetation that cover Mohe County and suburban areas,and the law of permafrost degradation on the study area was analyzed.The research results show that the urban area of the study area increased 114.42%from 2000 to 2016,and the urbanization process is continuing to accelerate.The Normalized Difference Vegetation Index map of 2017 in Mohe County and its suburbs was studied and the maximum proportion of vegetation coverage was different in the four seasons.The numerical calculation model results show that the permafrost temperature change in the study area cyclically fluctuates in a cosine form.The annual variation curve of permafrost temperature gradually decreased and its accompanying phase lag increased with depth.The annual temperature change value with the different depths of the town was greater than the natural ground.The maximum permafrost thawing depths of the town and natural ground were 4.2 m and 2.82 m in 50 a,and the degradation rates of the two permafrost are,respectively,0.88 cm/a and 0.46 cm/a.These results show that urbanization has accelerated the degradation of permafrost.展开更多
Objective Nowadays, high-resolution remote sensing technology has brought new changes to surveys of earthquakes, and the quantitative study of seismic faults based on this technology has become a trend in the world(Ba...Objective Nowadays, high-resolution remote sensing technology has brought new changes to surveys of earthquakes, and the quantitative study of seismic faults based on this technology has become a trend in the world(Barzegari et al., 2017). An Mw 7.2 earthquake occurred in Yutian of Xinjiang on the western end of the Altyn Tagh fault on March 21 st, 2008. It is difficult to access this depopulated zone because of the high altitude and only 1–2 months of snowmelt. This study utilized high-resolution展开更多
Tibet Plateau is Known as "the Roof of the World" with the area of 1,220,000km^2, which is about 1/8 land area of China. Because of the high elevation, cold climate and it caused difficulties in regional eco...Tibet Plateau is Known as "the Roof of the World" with the area of 1,220,000km^2, which is about 1/8 land area of China. Because of the high elevation, cold climate and it caused difficulties in regional economic planning and land resources management. Since 1985, the land use investigation in Tibet has been carried out, in which the basic data and thematic maps must be obtained and completed at county and township levels, in order to meet the needs of local administrations. In the investigation, remote sensing technology was comprehensively adopted. At present, the investigation in county level had been completed and the compilation is going to be carried out. Due to paying a great attention to studying on a series of key technical problems, the systematic methods of using remote sensing technology in the plateau land use investigation were formed and successfully put into application.展开更多
The society needs to develop. Speeding up urban infrastructure is beneficial to improving people's living standard. The exploration of mineral resources must be put on the agenda. Some material resources are very ...The society needs to develop. Speeding up urban infrastructure is beneficial to improving people's living standard. The exploration of mineral resources must be put on the agenda. Some material resources are very important for strengthening urban construction and are indispensable factors. In recent decades, China's scientific and technological level has been developing very rapidly. The country has provided strong support for the development of geological prospecting work. This has gradually led to the development and full application of new technologies related to geological prospecting. The application of remote sensing technology has also greatly improved the efficiency and accuracy of geological prospecting. This paper focuses on the application of modern remote sensing technology in geological prospecting for reference only.展开更多
In this paper, the connotation and application status of hydraulic environmental geological exploration and remote sensing technology of hydraulic engineering environment are respectively studied, and then the applica...In this paper, the connotation and application status of hydraulic environmental geological exploration and remote sensing technology of hydraulic engineering environment are respectively studied, and then the application methods of relevant technologies are analyzed in the geological work practice. It is hoped that the efficiency and accuracy of geological work can be improved through the research.展开更多
In order to meet the needs of land and resources management and social and economic development, the national government departments have carried out overall planning and reasonable deployment for the contents of land...In order to meet the needs of land and resources management and social and economic development, the national government departments have carried out overall planning and reasonable deployment for the contents of land change investigation. Through the annual change survey to grasp the current situation of the national land use change, to provide a good guarantee for the rational allocation and development and utilization of land resources in China. Combined with the current situation of land change investigation, the traditional land change investigation mode has been difficult to apply to the new surveying and mapping development background. Relevant staff should actively use new surveying and mapping technology, especially remote sensing technology, to realize the supervision of the whole process of land change investigation. In this paper, the application of remote sensing technology in land change investigation is studied and analyzed.展开更多
Due to the continuous development of science and technology, the role of UAV remote sensing technology in surveying and mapping is very prominent, and its technology has made rapid progress. UAV can use the correspond...Due to the continuous development of science and technology, the role of UAV remote sensing technology in surveying and mapping is very prominent, and its technology has made rapid progress. UAV can use the corresponding software for effective image processing, and also equipped with a variety of sensor equipment to quickly obtain relevant measurement and mapping information, so as to provide the corresponding accurate measurement results. Short cycle, flexible, fast, reliable information, high efficiency, strong adaptability and reliable quality are the advantages of UAV.展开更多
Disaster warning,disaster estimation and relief depend more and more on the application of space remote sensing technologies,such as those used for optic-camera,hyperspectrum,infrared,SAR,seismo-electromagnet and grav...Disaster warning,disaster estimation and relief depend more and more on the application of space remote sensing technologies,such as those used for optic-camera,hyperspectrum,infrared,SAR,seismo-electromagnet and gravitation measurement.On May 12,2008,a magnitude of 8.展开更多
The environmental conditions in China are still very serious. In the years to come, the mission for environmental treatment and protection, supervision,
Establishing the remote sensing algorithm of retrieving the absorption coefficient of seawater petroleum substances is an efficient way to improve the accuracy of retrieving a seawater petroleum concentration using a ...Establishing the remote sensing algorithm of retrieving the absorption coefficient of seawater petroleum substances is an efficient way to improve the accuracy of retrieving a seawater petroleum concentration using a remote sensing technology. A remote sensing reflectance is a basic physical parameter in water color remote sensing. Apply it to directly retrieve the absorption coefficient of seawater petroleum substances is of potential advantage. The absorption coefficient of waters containing petroleum [ACWCP, a_o（λ）], consists of the absorption coefficient of pure water [ACPW, a_w（λ）], plankton [ACP, a_（ph）（λ）], colored scraps [ACCS, a_（d,g）（λ）], and petroleum substance [ACPS, a_（oil）（λ）]. Among those, ACCS consists of the absorption coefficient of nonalgal particle [ACNP, a_d（λ）] and colored dissolved organic matter [ACCDOM, a_g（λ）]. For waters containing petroleum, the retrieved ACCS using the existing method is a combination absorption coefficient of ACNP,ACCDOM and ACPA [CAC, a_（d,g,oil）（λ）]. Therefore, the principle question is how to extract ACPS from CAC.Through the analysis of the three proportion tests conducted between the year of 2013 and 2015 and the corresponding remote sensing data, an algorithm of retrieving the absorption coefficient of petroleum substances is proposed based on remote sensing reflectance. First of all, ACPS and CAC are retrieved from the reflectance using the quasi-analytical algorithm（QAA）, with some parameter modified. Secondly, given the fact that the backscatter coefficient [BC, b_（bp）（555）] of total particles at 555 nm can be obtained completely from the reflectance, the relation between BC and ACNP in petroleum contaminated water can be established. As a result, ACNP can be calculated. Then, combining the remote sensing retrieving algorithm of a_g（440）, the method of achieving the spectral slope of the absorption coefficient can be established, from which ACCDOM,can be calculated. Finally, ACPS can be computed as the residual. The accuracy of ACPS based on this algorithm is 86% compared with the in situ measurements.展开更多
Seagrass beds are crucial coastal ecosystems,functioning as vital blue carbon sinks and natural ecological barriers.However,these ecosystems are increasingly threatened by global climate events,coastal development,and...Seagrass beds are crucial coastal ecosystems,functioning as vital blue carbon sinks and natural ecological barriers.However,these ecosystems are increasingly threatened by global climate events,coastal development,and water eutrophication,making them some of the most endangered ecosystems worldwide.In the Yellow Sea and Bohai Sea regions,seagrass bed assessment and monitoring have been largely overlooked.Thus,strengthening research efforts is necessary to identify current distribution patterns and long-term changes in seagrass bed resources.This study focused on a seagrass bed in Sanggou Bay,Rongcheng,using remote sensing(RS)and geographic information system technologies to analyze multisource satellite data from the US Landsat and Chinese resource satellite series.By combining RS indexes with historical survey data,large-scale temporal and geographic distribution data for seagrass beds were obtained in the study area from 1985 to 2022.The spatial distribution and evolution trends of the seagrass bed were analyzed using a water depth inversion model,and the factors driving its degradation were identified.Results indicated that the seagrass bed area in Sanggou Bay fluctuated between 100 and 140 km^(2) from 1985 to 2010.During 2010–2013,dynamic changes in the seagrass bed area increased,with a considerable decrease in its overall size.After 2014,changes were minimal,indicating a notably stable state.Seagrass bed degradation in Sanggou Bay is influenced by high-intensity human activities,pollution from coastal land sources,raft cultures,underwater terrain conditions,and sedimentary environmental factors.The findings offer essential insights for developing seagrass restoration and protection strategies in Sanggou Bay and contribute to the broader scientific efforts for coastal ecosystem conservation and rehabilitation.展开更多
Ozone stands out as a crucial trace gas within the Earth’s atmosphere,exerting a substantial influence on climate change and air pollution.Tropospheric ozone plays an important role in the formation of photochemical ...Ozone stands out as a crucial trace gas within the Earth’s atmosphere,exerting a substantial influence on climate change and air pollution.Tropospheric ozone plays an important role in the formation of photochemical smog,and its variations are associated with human activities.The utilization of satellite remote sensing technology for tropospheric ozone monitoring enables a quantitative analysis of its global and regional spatiotemporal characteristics.It also facilitates the investigation of the mechanisms involved in ozone formation within the troposphere.The significant progress in product accuracy and spatiotemporal resolution of ozone remote sensing products,including total ozone and vertical profiles,can be attributed to the extensive development of satellite remote sensing techniques.Nevertheless,the precision of tropospheric ozone products remains inadequate for contemporary scientific purposes,primarily because of faint signals in the lower atmosphere,the intricate nature of the underlying surface,and the existence of clouds and aerosols.This study places emphasis on the satellite remote sensing of tropospheric ozone,encompassing a comprehensive review of the advancements in satellite sensors and the characteristics and suitability of various retrieval algorithms.Moreover,this research delves into the possible utilization of satellite remote sensing for the provision of reliable tropospheric ozone observation data on a global and regional level.展开更多
Mount Lokon is an active mountain near residential areas such as cities Tomohon, Tondano, and Manado. Along with the increasing population and population development around Mount Lokon, vegetation is decreasing due to...Mount Lokon is an active mountain near residential areas such as cities Tomohon, Tondano, and Manado. Along with the increasing population and population development around Mount Lokon, vegetation is decreasing due to converting land from grassland to land use for human activities. Using Landsat 8 OLI/TIRS images, this study was conducted to analyze the surface temperature and vegetation index dynamics around Mount Lokon, including the residential areas. Found that an increase in mean temperature occurred, and the peak increased dramatically in 2018 with temperatures > 26˚C. This result, of course, correlates with the decreasing vegetation area. However, the decline occurred in 2020 due to decreased human activities and land clearing for new settlements caused by activity restrictions which were the effects of the COVID-19 pandemic. Reforestation efforts must be made to increase the vege<span style="font-family:Verdana;">tation around Mount Lokon, including residential areas. The avera</span><span style="font-family:Verdana;">ge surface temperature can be controlled, and living creatures can be given comfort to living things around them even after the pandemic and human activities return to normal.</span>展开更多
Colin Simpson was born in 1941 and inhis finalyears of High School he wasawardeda“Free Place”scholarship to attend theUniv ersity of Melbourne and in 1962 hegraduated Bachelor of Science in geology.He commenced work...Colin Simpson was born in 1941 and inhis finalyears of High School he wasawardeda“Free Place”scholarship to attend theUniv ersity of Melbourne and in 1962 hegraduated Bachelor of Science in geology.He commenced work w ith CarpentariaExploration Company themineral explorationsubsidiary of Mount Isa Mines Ltd.one ofAustralia's largest mining operators.Duringhis univ ersity studies Colin became veryinterested in aerial photographic interpreta-tion for understanding geology and geo-morphology.As a result,in 1968,he wasaccepted into a position in the PhotogeologyGroup of the Federal government Bureau of Mineral Resources,Geology and Geophysics(BMR)based in Canberra.However,within4 years of Colin joining the BMR the realm of aerial photographic interpretation changeddramatically w ith the dev elopment of newremote sensing technology such as airborneradar imaging,and the launch in 1972 ofthe Earth Resources Technology Satellite(ERTS-1).展开更多
Since ancient times, the mining and excavation of minerals have been highly valued by all countries, which have played an important role in national development and social production and life. As early as 1970s and 19...Since ancient times, the mining and excavation of minerals have been highly valued by all countries, which have played an important role in national development and social production and life. As early as 1970s and 1980s, China began to vigorously develop the mining industry, among which the excavation of Daqing Oilfield is more famous, and it can still provide a steady stream of petroleum minerals today. In the past, some safety accidents often occurred in the process of mineral exploitation projects, resulting in casualties and economic losses, which were a kind of loss to the society and the industry. The emergence of geological exploration technology for mineral exploitation made people hope to reduce the risk coefficient of mineral exploitation and improve the efficiency of mineral exploitation, and had an optimized direction. In this paper, the concept and application of geological exploration technology, as well as a series of problems and obstacles will be discussed, combined with examples of remote sensing exploration technology, hoping to provide some reference for future mineral exploration.展开更多
The paper gives an overview of the current status of education in geoinformatics in China.First,the paper provides a brief introduction to the history of geoinformatics education in China and a general review of the s...The paper gives an overview of the current status of education in geoinformatics in China.First,the paper provides a brief introduction to the history of geoinformatics education in China and a general review of the scientific and technological development.It then presents how the development affects the education and training in China.In the paper,universities and institutes in China that can award academic degrees related to geoinformatics are summarized,and undergraduate majors are briefly introduced.Next,the paper reports the work having been done by the national expert group on Surveying and Mapping,including the revision of discipline catalog and guide for graduate education and requirements.A list of typical curricula in geoinformatics education is suggested.Activities on promoting the graduate student exchange platform are presented.Finally,a case study of geoinformatics education in Wuhan University is discussed.展开更多
Leaf blast is a significant global problem,severely affecting rice quality and yield,making swift,non-invasive detection crucial for effective field management.This study used hyperspectral remote sensing technology v...Leaf blast is a significant global problem,severely affecting rice quality and yield,making swift,non-invasive detection crucial for effective field management.This study used hyperspectral remote sensing technology via an unmanned aerial vehicle to gather spectral data from rice crops.ANOVA and the Relief-F algorithm were used to identify spectral bands sensitive to the disease and developed a new vegetation index,the rice blast index(RBI).This RBI was compared with 30 established vegetation indexes,using correlation analysis and visual comparison to further shortlist six superior indexes,including RBI.These were evaluated using the K-nearest neighbor(KNN)and random forests(RF)classification models.RBI demonstrated superior detection accuracy for leaf blast in both the KNN model(95.0% overall accuracy and 93.8% kappa coefficient)and the RF model(95.1%overall accuracy and 92.5% kappa coefficient).This study highlights the significant potential of RBI as an effective tool for precise leaf blast detection,offering a powerful new mechanism and theoretical basis for enhanced disease management in rice cultivation.展开更多
Forest ecosystems have been identified as major carbon stocks in terrestrial ecosystems;therefore,their monitoring is critical.Forests cover large areas,making it difficult to monitor and maintain up-to-date informati...Forest ecosystems have been identified as major carbon stocks in terrestrial ecosystems;therefore,their monitoring is critical.Forests cover large areas,making it difficult to monitor and maintain up-to-date information.Advances in remote sensing technologies provide opportunities for detailed small-scale monitoring to global monitoring of forest resources.Airborne laser scanning(ALS)data can provide precise forest structure measurements,but mainly for small-scale forest monitoring due to its expensive cost and limited spatial and temporal coverage.Spaceborne lidar(light detection and ranging)can cover extensive spatial scales,but its suitability as a replacement for ALS measurements remains uncertain.There are still relatively few studies on the performance of spaceborne lidar to estimate forest attributes with sufficient accuracy and precision.Therefore,this study aimed at assessing the performance of spaceborne lidar ICESat-2 canopy height metrics and understanding their uncertainties and utilities by evaluating their agreements with ALS-derived canopy height metrics in Mississippi,United States.We assessed their agreements for different forest types,physiographic regions,a range of canopy cover,and diverse disturbance histories using equivalence tests.Results suggest that ICESat-2 canopy height metrics collected using strong beam mode at night have higher agreement with ALS-derived ones.ICESat-2 showed great potential for estimating canopy heights in evergreen forests with high canopy cover.This study contributes to the scientific community’s understanding of the capabilities and limitations of ICESat-2 to measure canopy heights at regional to global scales.展开更多
Due to differences in environmental factors,the phenology of the same crop is different every year,causing divergent performances of the classifier built by spectral or time-series features Here,we proposed a random f...Due to differences in environmental factors,the phenology of the same crop is different every year,causing divergent performances of the classifier built by spectral or time-series features Here,we proposed a random forest classifier(RFC)based on an asymmetric double S curve model fitted by accumulated temperature(AT)and Vegetation Index(VI),which can be applied in different years without ground samples.We built AT and VI time series from Moderate Resolution Imaging Spectroradiometer 8-day composites of land surface temperatures and Sentinel-2 and Landsat-8,respectively.The RFC was trained by characteristics from the asymmetric double S curve.We prepared RFC by ground samples of 2018 and 2019 and then mapped crops of the same region in 2017.Results indicated that,compared with diverse VI-AT series,the overall accuracy based on universal normalized vegetation index(UNVI)was the best of all(2017:F1=0.91,2018:F1=0.92,2019:F1=0.91)and better than that based on the UNVI-TIME series(2017:F1=0.84,2018:F1=0.81,2019:F1=0.88).It proved that the classification features from the VI-AT series have smaller intra-class differences in 2017,2018,and 2019.展开更多
文摘This paper attempts to explore a new avenue of urban small-regional population estimation by remote sensing technology, creatively and comprehensively for the first time using a residence count method, area (density) method and model method, incorporating the application experience of American scholars in the light of the state of our country. Firstly, the author proposes theoretical basis for population estimation by remote sensing, on the basis of analysing and evaluating the history and state quo of application of methods of population estimation by remote sensing. Secondly, two original types of mathematical models of population estimation are developed on the basis of remote sensing data, taking Tianjin City as an example. By both of the mathematical models the regional population may be estimated from remote sensing variable values with high accuracy. The number of the independent variables in the latter model is somewhat smaller and the collection of remote sensing data is somewhat easier, but the deviation is a little larger. Finally, some viewpoints on the principled problems about the practical application of remote sensing to population estimation are put forward.
基金Nation Natural Science Foundation of China under Grant No.41071049Project of the State Key Laboratory Frozen Soil Engineering of CAS under Grant No.SKLFSE201802Project of 2017 Harbin Applied Technology Research and Development under Grant No.2017RAXXJ031。
文摘The permafrost of Mohe County and its suburbs in the Daxing′an Mountains has been influenced by the urbanization.Remote sensing,GIS technology and numerical simulation was used to study the temperature variations of permafrost with the changes in surface vegetation that cover Mohe County and suburban areas,and the law of permafrost degradation on the study area was analyzed.The research results show that the urban area of the study area increased 114.42%from 2000 to 2016,and the urbanization process is continuing to accelerate.The Normalized Difference Vegetation Index map of 2017 in Mohe County and its suburbs was studied and the maximum proportion of vegetation coverage was different in the four seasons.The numerical calculation model results show that the permafrost temperature change in the study area cyclically fluctuates in a cosine form.The annual variation curve of permafrost temperature gradually decreased and its accompanying phase lag increased with depth.The annual temperature change value with the different depths of the town was greater than the natural ground.The maximum permafrost thawing depths of the town and natural ground were 4.2 m and 2.82 m in 50 a,and the degradation rates of the two permafrost are,respectively,0.88 cm/a and 0.46 cm/a.These results show that urbanization has accelerated the degradation of permafrost.
基金supported by the National Natural Science Foundation of China (grants No. 41461164002 and 41631073)
文摘Objective Nowadays, high-resolution remote sensing technology has brought new changes to surveys of earthquakes, and the quantitative study of seismic faults based on this technology has become a trend in the world(Barzegari et al., 2017). An Mw 7.2 earthquake occurred in Yutian of Xinjiang on the western end of the Altyn Tagh fault on March 21 st, 2008. It is difficult to access this depopulated zone because of the high altitude and only 1–2 months of snowmelt. This study utilized high-resolution
文摘Tibet Plateau is Known as "the Roof of the World" with the area of 1,220,000km^2, which is about 1/8 land area of China. Because of the high elevation, cold climate and it caused difficulties in regional economic planning and land resources management. Since 1985, the land use investigation in Tibet has been carried out, in which the basic data and thematic maps must be obtained and completed at county and township levels, in order to meet the needs of local administrations. In the investigation, remote sensing technology was comprehensively adopted. At present, the investigation in county level had been completed and the compilation is going to be carried out. Due to paying a great attention to studying on a series of key technical problems, the systematic methods of using remote sensing technology in the plateau land use investigation were formed and successfully put into application.
文摘The society needs to develop. Speeding up urban infrastructure is beneficial to improving people's living standard. The exploration of mineral resources must be put on the agenda. Some material resources are very important for strengthening urban construction and are indispensable factors. In recent decades, China's scientific and technological level has been developing very rapidly. The country has provided strong support for the development of geological prospecting work. This has gradually led to the development and full application of new technologies related to geological prospecting. The application of remote sensing technology has also greatly improved the efficiency and accuracy of geological prospecting. This paper focuses on the application of modern remote sensing technology in geological prospecting for reference only.
文摘In this paper, the connotation and application status of hydraulic environmental geological exploration and remote sensing technology of hydraulic engineering environment are respectively studied, and then the application methods of relevant technologies are analyzed in the geological work practice. It is hoped that the efficiency and accuracy of geological work can be improved through the research.
文摘In order to meet the needs of land and resources management and social and economic development, the national government departments have carried out overall planning and reasonable deployment for the contents of land change investigation. Through the annual change survey to grasp the current situation of the national land use change, to provide a good guarantee for the rational allocation and development and utilization of land resources in China. Combined with the current situation of land change investigation, the traditional land change investigation mode has been difficult to apply to the new surveying and mapping development background. Relevant staff should actively use new surveying and mapping technology, especially remote sensing technology, to realize the supervision of the whole process of land change investigation. In this paper, the application of remote sensing technology in land change investigation is studied and analyzed.
文摘Due to the continuous development of science and technology, the role of UAV remote sensing technology in surveying and mapping is very prominent, and its technology has made rapid progress. UAV can use the corresponding software for effective image processing, and also equipped with a variety of sensor equipment to quickly obtain relevant measurement and mapping information, so as to provide the corresponding accurate measurement results. Short cycle, flexible, fast, reliable information, high efficiency, strong adaptability and reliable quality are the advantages of UAV.
文摘Disaster warning,disaster estimation and relief depend more and more on the application of space remote sensing technologies,such as those used for optic-camera,hyperspectrum,infrared,SAR,seismo-electromagnet and gravitation measurement.On May 12,2008,a magnitude of 8.
文摘The environmental conditions in China are still very serious. In the years to come, the mission for environmental treatment and protection, supervision,
基金The National Natural Science Foundation of China under contract No.41271364the Key Projects in the National Science and Technology Pillar Program of China under contract No.2012BAH32B01-4the Program for Scientific Research Start-up Funds of Guangdong Ocean University under contract No.E16187
文摘Establishing the remote sensing algorithm of retrieving the absorption coefficient of seawater petroleum substances is an efficient way to improve the accuracy of retrieving a seawater petroleum concentration using a remote sensing technology. A remote sensing reflectance is a basic physical parameter in water color remote sensing. Apply it to directly retrieve the absorption coefficient of seawater petroleum substances is of potential advantage. The absorption coefficient of waters containing petroleum [ACWCP, a_o（λ）], consists of the absorption coefficient of pure water [ACPW, a_w（λ）], plankton [ACP, a_（ph）（λ）], colored scraps [ACCS, a_（d,g）（λ）], and petroleum substance [ACPS, a_（oil）（λ）]. Among those, ACCS consists of the absorption coefficient of nonalgal particle [ACNP, a_d（λ）] and colored dissolved organic matter [ACCDOM, a_g（λ）]. For waters containing petroleum, the retrieved ACCS using the existing method is a combination absorption coefficient of ACNP,ACCDOM and ACPA [CAC, a_（d,g,oil）（λ）]. Therefore, the principle question is how to extract ACPS from CAC.Through the analysis of the three proportion tests conducted between the year of 2013 and 2015 and the corresponding remote sensing data, an algorithm of retrieving the absorption coefficient of petroleum substances is proposed based on remote sensing reflectance. First of all, ACPS and CAC are retrieved from the reflectance using the quasi-analytical algorithm（QAA）, with some parameter modified. Secondly, given the fact that the backscatter coefficient [BC, b_（bp）（555）] of total particles at 555 nm can be obtained completely from the reflectance, the relation between BC and ACNP in petroleum contaminated water can be established. As a result, ACNP can be calculated. Then, combining the remote sensing retrieving algorithm of a_g（440）, the method of achieving the spectral slope of the absorption coefficient can be established, from which ACCDOM,can be calculated. Finally, ACPS can be computed as the residual. The accuracy of ACPS based on this algorithm is 86% compared with the in situ measurements.
基金supported by the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2022QNLM 050302-4)the Geological Survey Project of the China Geological Survey(No.DD20230071)+1 种基金the China Geological Survey Project‘Investigation and Monitoring of the Coastal Geological Environment of the Yangtze River Estuary’(No.DD20242714)the cooperation fund of Collaborative Research on Marine Geological Environment and Hazards in the Yangtze River Delta and Red River Delta.
文摘Seagrass beds are crucial coastal ecosystems,functioning as vital blue carbon sinks and natural ecological barriers.However,these ecosystems are increasingly threatened by global climate events,coastal development,and water eutrophication,making them some of the most endangered ecosystems worldwide.In the Yellow Sea and Bohai Sea regions,seagrass bed assessment and monitoring have been largely overlooked.Thus,strengthening research efforts is necessary to identify current distribution patterns and long-term changes in seagrass bed resources.This study focused on a seagrass bed in Sanggou Bay,Rongcheng,using remote sensing(RS)and geographic information system technologies to analyze multisource satellite data from the US Landsat and Chinese resource satellite series.By combining RS indexes with historical survey data,large-scale temporal and geographic distribution data for seagrass beds were obtained in the study area from 1985 to 2022.The spatial distribution and evolution trends of the seagrass bed were analyzed using a water depth inversion model,and the factors driving its degradation were identified.Results indicated that the seagrass bed area in Sanggou Bay fluctuated between 100 and 140 km^(2) from 1985 to 2010.During 2010–2013,dynamic changes in the seagrass bed area increased,with a considerable decrease in its overall size.After 2014,changes were minimal,indicating a notably stable state.Seagrass bed degradation in Sanggou Bay is influenced by high-intensity human activities,pollution from coastal land sources,raft cultures,underwater terrain conditions,and sedimentary environmental factors.The findings offer essential insights for developing seagrass restoration and protection strategies in Sanggou Bay and contribute to the broader scientific efforts for coastal ecosystem conservation and rehabilitation.
基金supported by the National Natural Science Foundation of China(grant nos.42375142 and 42305154)the Open Fund of Innovation Center for FengYun Meteorological Satellite(FYSIC)and“FengYun Application Pioneering Project”(grant no.FY-APP-ZX-2022.0214)the National Civilian Space Infrastructure Project(grant no.Y5BZ31AC60).
文摘Ozone stands out as a crucial trace gas within the Earth’s atmosphere,exerting a substantial influence on climate change and air pollution.Tropospheric ozone plays an important role in the formation of photochemical smog,and its variations are associated with human activities.The utilization of satellite remote sensing technology for tropospheric ozone monitoring enables a quantitative analysis of its global and regional spatiotemporal characteristics.It also facilitates the investigation of the mechanisms involved in ozone formation within the troposphere.The significant progress in product accuracy and spatiotemporal resolution of ozone remote sensing products,including total ozone and vertical profiles,can be attributed to the extensive development of satellite remote sensing techniques.Nevertheless,the precision of tropospheric ozone products remains inadequate for contemporary scientific purposes,primarily because of faint signals in the lower atmosphere,the intricate nature of the underlying surface,and the existence of clouds and aerosols.This study places emphasis on the satellite remote sensing of tropospheric ozone,encompassing a comprehensive review of the advancements in satellite sensors and the characteristics and suitability of various retrieval algorithms.Moreover,this research delves into the possible utilization of satellite remote sensing for the provision of reliable tropospheric ozone observation data on a global and regional level.
文摘Mount Lokon is an active mountain near residential areas such as cities Tomohon, Tondano, and Manado. Along with the increasing population and population development around Mount Lokon, vegetation is decreasing due to converting land from grassland to land use for human activities. Using Landsat 8 OLI/TIRS images, this study was conducted to analyze the surface temperature and vegetation index dynamics around Mount Lokon, including the residential areas. Found that an increase in mean temperature occurred, and the peak increased dramatically in 2018 with temperatures > 26˚C. This result, of course, correlates with the decreasing vegetation area. However, the decline occurred in 2020 due to decreased human activities and land clearing for new settlements caused by activity restrictions which were the effects of the COVID-19 pandemic. Reforestation efforts must be made to increase the vege<span style="font-family:Verdana;">tation around Mount Lokon, including residential areas. The avera</span><span style="font-family:Verdana;">ge surface temperature can be controlled, and living creatures can be given comfort to living things around them even after the pandemic and human activities return to normal.</span>
文摘Colin Simpson was born in 1941 and inhis finalyears of High School he wasawardeda“Free Place”scholarship to attend theUniv ersity of Melbourne and in 1962 hegraduated Bachelor of Science in geology.He commenced work w ith CarpentariaExploration Company themineral explorationsubsidiary of Mount Isa Mines Ltd.one ofAustralia's largest mining operators.Duringhis univ ersity studies Colin became veryinterested in aerial photographic interpreta-tion for understanding geology and geo-morphology.As a result,in 1968,he wasaccepted into a position in the PhotogeologyGroup of the Federal government Bureau of Mineral Resources,Geology and Geophysics(BMR)based in Canberra.However,within4 years of Colin joining the BMR the realm of aerial photographic interpretation changeddramatically w ith the dev elopment of newremote sensing technology such as airborneradar imaging,and the launch in 1972 ofthe Earth Resources Technology Satellite(ERTS-1).
文摘Since ancient times, the mining and excavation of minerals have been highly valued by all countries, which have played an important role in national development and social production and life. As early as 1970s and 1980s, China began to vigorously develop the mining industry, among which the excavation of Daqing Oilfield is more famous, and it can still provide a steady stream of petroleum minerals today. In the past, some safety accidents often occurred in the process of mineral exploitation projects, resulting in casualties and economic losses, which were a kind of loss to the society and the industry. The emergence of geological exploration technology for mineral exploitation made people hope to reduce the risk coefficient of mineral exploitation and improve the efficiency of mineral exploitation, and had an optimized direction. In this paper, the concept and application of geological exploration technology, as well as a series of problems and obstacles will be discussed, combined with examples of remote sensing exploration technology, hoping to provide some reference for future mineral exploration.
基金The work is supported by the National Basic Research Program of China(973 Program)(grant number 2011CB707105)the National Natural Science Foundation of China(grant number 41271397)the Program for New Century Excellent Talents in University(grant number NCET-13-0435).
文摘The paper gives an overview of the current status of education in geoinformatics in China.First,the paper provides a brief introduction to the history of geoinformatics education in China and a general review of the scientific and technological development.It then presents how the development affects the education and training in China.In the paper,universities and institutes in China that can award academic degrees related to geoinformatics are summarized,and undergraduate majors are briefly introduced.Next,the paper reports the work having been done by the national expert group on Surveying and Mapping,including the revision of discipline catalog and guide for graduate education and requirements.A list of typical curricula in geoinformatics education is suggested.Activities on promoting the graduate student exchange platform are presented.Finally,a case study of geoinformatics education in Wuhan University is discussed.
文摘Leaf blast is a significant global problem,severely affecting rice quality and yield,making swift,non-invasive detection crucial for effective field management.This study used hyperspectral remote sensing technology via an unmanned aerial vehicle to gather spectral data from rice crops.ANOVA and the Relief-F algorithm were used to identify spectral bands sensitive to the disease and developed a new vegetation index,the rice blast index(RBI).This RBI was compared with 30 established vegetation indexes,using correlation analysis and visual comparison to further shortlist six superior indexes,including RBI.These were evaluated using the K-nearest neighbor(KNN)and random forests(RF)classification models.RBI demonstrated superior detection accuracy for leaf blast in both the KNN model(95.0% overall accuracy and 93.8% kappa coefficient)and the RF model(95.1%overall accuracy and 92.5% kappa coefficient).This study highlights the significant potential of RBI as an effective tool for precise leaf blast detection,offering a powerful new mechanism and theoretical basis for enhanced disease management in rice cultivation.
基金Funding for this project was provided in part by the McIntire-Stennis project accession number MISZ-700001support from the National Key Research and Development Program of China(2023YFB3907401)+1 种基金National Natural Science Foundation of China(grant no.42201366)Nanjing Normal University(grant no.184080H202B349).
文摘Forest ecosystems have been identified as major carbon stocks in terrestrial ecosystems;therefore,their monitoring is critical.Forests cover large areas,making it difficult to monitor and maintain up-to-date information.Advances in remote sensing technologies provide opportunities for detailed small-scale monitoring to global monitoring of forest resources.Airborne laser scanning(ALS)data can provide precise forest structure measurements,but mainly for small-scale forest monitoring due to its expensive cost and limited spatial and temporal coverage.Spaceborne lidar(light detection and ranging)can cover extensive spatial scales,but its suitability as a replacement for ALS measurements remains uncertain.There are still relatively few studies on the performance of spaceborne lidar to estimate forest attributes with sufficient accuracy and precision.Therefore,this study aimed at assessing the performance of spaceborne lidar ICESat-2 canopy height metrics and understanding their uncertainties and utilities by evaluating their agreements with ALS-derived canopy height metrics in Mississippi,United States.We assessed their agreements for different forest types,physiographic regions,a range of canopy cover,and diverse disturbance histories using equivalence tests.Results suggest that ICESat-2 canopy height metrics collected using strong beam mode at night have higher agreement with ALS-derived ones.ICESat-2 showed great potential for estimating canopy heights in evergreen forests with high canopy cover.This study contributes to the scientific community’s understanding of the capabilities and limitations of ICESat-2 to measure canopy heights at regional to global scales.
基金partially supported by the National Natural Science Foundation of China[gran numbers 41830108 and 41971321)Key Research Program of Frontier Sciences,CAS[grant number ZDBS-LY-DQC012]+2 种基金Major Science and Technology Projects of XPCC[grant number 2018AA00402]Innovation Team of XPCC’s Key Area[grant number 2018CB004]Changping Huang was supported by Youth Innovation Promotion Association,CAS(grant number Y2021047).
文摘Due to differences in environmental factors,the phenology of the same crop is different every year,causing divergent performances of the classifier built by spectral or time-series features Here,we proposed a random forest classifier(RFC)based on an asymmetric double S curve model fitted by accumulated temperature(AT)and Vegetation Index(VI),which can be applied in different years without ground samples.We built AT and VI time series from Moderate Resolution Imaging Spectroradiometer 8-day composites of land surface temperatures and Sentinel-2 and Landsat-8,respectively.The RFC was trained by characteristics from the asymmetric double S curve.We prepared RFC by ground samples of 2018 and 2019 and then mapped crops of the same region in 2017.Results indicated that,compared with diverse VI-AT series,the overall accuracy based on universal normalized vegetation index(UNVI)was the best of all(2017:F1=0.91,2018:F1=0.92,2019:F1=0.91)and better than that based on the UNVI-TIME series(2017:F1=0.84,2018:F1=0.81,2019:F1=0.88).It proved that the classification features from the VI-AT series have smaller intra-class differences in 2017,2018,and 2019.
