最新刊期
卷 ， 期 6 ， 2008
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- 摘要：In recent years,there have been many catastrophic disasters occurred in China and other countries,which has caused great losses of lives and assets.Spatial information techniques,including,are playing more and more important roles in disaster mitigation.An earthquake,measured 8.0 on the Richter scale,struck Wenchuan County,Sichuan Province at 14∶28 on May 12,2008,and has resulted in a series of catastrophes.Different departments involved in disaster mitigation have used spatial information techniques to provide decision-making support and contributed a lot to the earthquake relief.Besides the prompt response to the disaster,the amount of spatial information collected in this earthquake and the number of specialists in related fields involved in the disaster mitigation are unprecedented.The rapid response action,as a classic case,can provide a very helpful reference and example for future disaster mitigation with the help of spatial information techniques.Firstly,the requirements of spatial information techniques in rapid response to the earthquake are identified,including airborne/space-borne optical and SAR RS data in high spatio-temporal resolution,geometric positioning in high accuracy without GCPs or few GCPs,real time/near-real time data processing,and well prepared spatial data of infrastructures in earthquake area.Disaster mitigation can be classified into three main phases,which focus respectively on rescue of people buried under the ruins,monitoring of the secondary disasters such as land slides,mud flows and quake lakes,and disaster reconstruction planning.In such different phases,spatial information techniques may play different roles.To acquire sufficient space resources,the International Charter "Space and Major Disasters" is activated by its authorized user NDRCC to obtain foreign satellites data,while the national resource satellites Beijing-1 and CBERS are being operated continuously.More than 130 scenes of satellite images are received through the Charter.On the other hand,the advanced airborne sensors such as Leica ADS40,Z/I Imaging DMC,and SWDC-4 are involved to monitor the detailed information about the earthquake.Leica ADS40 has been most widely used in damage information extraction for its convenient processing method and integrated operation environment.SWDC-4,the best airborne digital mapping camera made in China,has also been running stably during the disaster relief.The airborne SAR sensors have shown their flexibility to the weather condition and achieved most volumes of data in its average 11 hours flight per day.However,its data processing speed is in urgent need of improvement.Secondly,the rapid processing technique for different RS data is the key step in the course of disaster rapid response.The satellite ortho-rectified method based on RPC model showed a good accuracy in the satellite RS image processing only with few GCPs,though the disaster area has extremely diversified terrains and was heavily changed by the earthquake.As for the airborne RS data processing,the rapid image matching and mosaic methods used in DPGrid successfully solved the problem of irregular flight line and great rolling stereo image pairs.The image dodging technique can enhance the visibility and interpretation effect of mosaic results of airborne images.Geododging,a software package of image dodging developed by Wuhan University has presented good performance.Thirdly,the damage information extraction and secondary disaster monitoring are two main applications of spatial information techniques in the earthquake rapid response.Two advanced image change detection techniques have been used.One is change detection with images from different sensors.And the other is mono-images change detection according to the spatial shape information based on the object-oriented segmentation.Both can remedy the deficiency of image source and improve the monitoring speed.The optical image data and airborne LIDAR data are both used in the secondary disaster monitoring.Three procedures as watershed segmentation,runoff prediction by distributed hydrologic models,and storage calculation of Quake Lake are integrated to monitor the dangerous conditions of the Quake Lake dam.Finally some conclusions and suggestions are proposed to direct future disaster rapid response.关键词：geospatial information technology;Wenchuan earthquake;relief works;China
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发布时间：2021-06-16 - 摘要：The aerial photogrammetry can provide not only high resolution ortho images,accurate Digital Elevation Models and 3D Landscape Maps,but also all kinds of accurate and visualized measuring tools for the fast response to the disaster rescue.These applications of aerial photogrammetry can help the breakdown gang design effective rescue plans and dispatch salvagers rationally shortly after the disaster.However,in the emergency response,the aerial images can not be taken according to the conventional aerial photography in the limited time.That means the airplane should fly along the main traffic lines,e.g.roads,rivers and bridges,and when the airplane fly above a county it should circle around in the air to acquire the detailed information of the county.At the same time,although there are POS（GPS/IMU）data,the precision of POS is very low,because there are neither reference stations for GPS nor ground control points for calibrating the POS system at emergency time.So for the disaster rescue,it is very important to process the mass unconventional aerial images accurately and quickly in a highly efficient way.DPGrid is a haerial photogrammetry software developed by Wuhan University.It utilizes the blade severs as the computing nodes and applies the robust digital photogrammetry arithmetic and parallel computing to realize quick processing of mass aerial data.In the China Earthquake Rescue DPGrid processed 4393 unconventional aerial photography DMC images in 111 hours and provided many timely and accurate surveying and mapping products for the rescue organization.This paper introduces the applications of aerial photogrammetry in the emergency response through discussing the method of how DPGrid processed the mass aerial images in China Earthquake Rescue.The main content includes: the architecture of DPGrid;the robust stereo image matching for the images with large rotation angle;the bundle adjustment with POS but without ground control points for removing the POS relative error;the DPGrid parallel computing for generating ortho images and its production efficiency.The paper also shows readers some aerial photogrammetry products and applications in the Emergency Response.For example,the operator can measure the length of broken bridges on ortho images,evaluate the area and earth volume of landslide mass on ortho image superposed with DEM,and roam and measure 3D coordinates in the 3D virtual environment,etc.The aerial photogrammetry has provided many visualized,accurate and valuable surveying data for the China Earthquake Rescue,and showed its important role in the emergency response.But how to perfect the emergency response mechanism of aerial photogrammetry and make it an important part of the National Emergency Response Mechanism is the duty and incumbency of all surveying workers.关键词：aerial photogrammetry;China earthquake rescue;fast response;DPGrid
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发布时间：2021-06-16 - 摘要：Wenchuan Earthquake,8.0 Richter Magnitude,is the most destructive,most widely-spread and the one entails the most difficulties in disaster-relief since the founding of People’s Republic of China.Along with the earthquake,many secondary disasters,such as mountain collapses,landslides and debris flows and dammed lakes occurred and enlarged the disaster.After the earthquake,National Disaster Reduction Committee（NDRC）and Ministry of Civil Affairs（MCA）triggered the domestic and international satellite remote sensing data achieving mechanism immediately,including the International CHARTER Space and Major Disasters.The achieved data were used for the continuous disaster monitoring and urgent disaster assessment,and provided effective information in disaster relief.This paper establishes an urgent assessment method for catastrophe,which is based on the interpretating with remote sensing data and the deducting by spatial analysis.Taking the urgent assessment using remote sensing data during the Wenchuan Earthquake as an example,this paper apply the method into the assessment for the 152 counties of Sichuan,Shanxi and Gansu provinces.The results show that buildings are destroyed seriously,and the affected population distribute in a very wide area.In general,the disaster loss is distributed corresponding to the fault zone.The disaster loss in mountain area is larger than that in plain area,and the damage in village area is more serious than that in urban area.Wenchuan,Beichuan,Qingchuan,and Mianzhu and other 8 counties in Sichuan province are the most seriously damaged counties.Wen County in Gansu province and Mian county in Shan’xi province are serious damaged.By validation with field investigation,the efficiency of the assessment was approved.The paper developes a step-by-step collection method of assessment,which takes the advantage of the remote sensing data and meets the efficiency need of urgent disaster assessment.The method is also useful for the coordinative operation and comprehensive assessment.The method is scientific,applicable,and feasible in disaster assessment with remote sensing data during catastrophe.关键词：Wenchuan earthquake;disaster remote sensing;catastrophe urgent assessment;damaged buildings assessment;affected population assessment
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发布时间：2021-06-16 - 摘要：Synthetic Aperture Radar（SAR） has significant advantages in disaster monitoring that are all weather,independent of illumination imaging capabilities and strong stereoscopic sense.SAR technology played irreplaceable role in rapid response to Wenchuan Earthquake monitoring and damage assessment.Wenchuan Earthquake generated numerous of landslides,landslide lakes and dams,as well as debris flows.Their quantity,scale and dimension brake historic records.Landslides buried towns and villages,blocked up river channels which inundated villages and heavily destroyed the road networks and made the rescue work extremely difficult.The hardship of rescue efforts was beyond of human imagination in Wenchuan Earthquake.With high resolution SAR images we detecte a great deal of landslides and landslide lakes.Those giant catastrophic landslides reach very large size and scale.One of the largest landslides we detecte has total area of 7 km2 and fly distance of 4 km.They fly from one side of the river bank to the opposite bank.It is hard to explain their behavior and scale with ordinary concept of landslide.Moving such amount of material needs tremendous energy.Does Wenchuan Earthquake provide such amount of energy? Why does Wenchuan Earthquake generate so many seismic secondary disasters? Certainly geosciences community needs further research to solve this puzzle.The microwave remote sensing division in Institute of Remote Sensing Applications made 7 reports on Tangjiashan landslide and Landslide Lake,Beichuan county with multi-temporal SAR images,7 reports on other landslides and landslide lakes,1 report on building damage assessment for several counties,including Anchang town,Huagai Town,Mianzu City and Luojiang City.All the reports were delivered to central and local government,ministries and rescue teams.This paper summaries the work that has been done for Wenchuan Earthquake.This paper presents the SAR image interpretation on building damage assessment,landslide and landslide lake monitoring,especially their characteristics on SAR images.The damaged building normally has no clear texture or shadow in contrast with buildings in good conditions.Owing to the good stereoscopic sense of SAR images,we can identify the back scar,debris deposit,fly trace and measure the total area and the flying distance of a landslide.With continuously acquired multi-temporal SAR images,including TerraSAR-X and COSMO-SkyMed satellite SAR images,we can track the development of a landslide lake such as Tangjiashan Landslide Lake.As water level rising,the small towns such as Xuan Ping,Zhicheng and village Sheng Kenzi are inundated.The Xuan Ping Town is finally total underwater.Many roads along the Jian River are inundated as well.The tail of Tangjiashan Landslide Lake extends toward upstream gradually,and widens the river channel obviously.All the information extracted and evaluation delivered from SAR images made great contribution to the decision making and rescue action.关键词：Wenchuan earthquake;SAR;building damage;landslide;landslide lake
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发布时间：2021-06-16 - 摘要：Earthquake is one of most serious natural disasters in the world.It has wide geographic coverage,huge damage,and long time influence for recovery.The earthquake happened in Wenchuan on May 12,2008 caused great damage in 42 counties in Sichuan province,23 counties in Gansu province,and 19 counties in Shaanxi province.In addition,it also has much influence on Chongqing,Yunnan,Shanxi,Guizhou,and Hubei provinces.Because of the severely destroyed infrastructures,complicated topography and bad weather condition after the earthquake,the disaster situation assessment from ground investigation is very difficult to undertake.In this situation,feasible approaches should be investigated.In this paper,we take the remote sensing monitoring and assessment of the Wenchuan Earthquake disaster situation as a case study and discuss the technical approaches and methods on application of space and airborne remote sensing technology for earthquake disaster situation monitoring and assessment.Firstly,by integrating multi-platform multi-sensor data,we defined the earthquake disaster situation monitoring indexes according to two different disaster severity levels.For areas with high-level disaster loss,aerial photos and high-resolution satellite images with less than 1 meter resolution are used as the major data sources,where four major categories with detailed subclasses are classified,i.e.,1) urban and rural residential areas;2) urban and rural infrastructures such as industrial and mining lands,highways,railways,bridges,tunnels,electric facilities,telecommunication facilities,channels,dikes,reservoirs,and dams;3) geological and environmental change information such as earthquake lakes,rock slumps,landslides,and turbidities;and 4) destroyed farmlands such as croplands and forest lands.For areas with low-level disaster loss,high and medium resolution optical and SAR satellite images before and after the earthquake are used as the major data sources,where four major categories with less detailed subclasses are classified,i.e.,1) urban and rural residential areas;2) urban and rural infrastructures such as industrial and mining lands,highways,railways,and large reservoirs;3) geological and environmental change information such as earthquake lakes,rock slumps,landslides,and turbidities;and 4) destroyed farmlands such as croplands and forest lands.By combining the multi-temporal,multi-source data before and after the earthquake,we establish the technical flows for quick geometric processing,quick data quality analysis and assessment,quick change detection,quick target interpretation,quick spatial risk assessment for landslides induced by earthquake,and the synthesis of these methods for disaster monitoring.For geometric processing,the ImageInfo software module PixelGrid is used.For image fusion,the data fusion module of ImageInfo is used.For interpretation of different area of images,the ArcGIS software is used.Additionally,the SINMAP module under ArcGIS software is also used for the validation of the extracted geological risk areas.The approach has been successfully applied in monitoring,mapping,and statistical assessment of the earthquake disaster situation.In addition,we also develope an application system which could provide functionalities for disaster information management,visualization,and statistical analysis.It utilize 2D WebGIS user interface and 3D virtual simulation environment to manage the disaster database and visualize the monitored results as 2D maps,statistic tables,graphs,and 3D models,and provide functionalities for measure and analysis.Finally,we also addressed and discussed some practical problems when applying this approach that should be well justified in the future,including the development of new geometric correction algorithm without control points,and the standardization of the workflow described in this paper for better accuracy.关键词：Wenchuan Earthquake;remote sensing;monitoring and assessment
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发布时间：2021-06-16 - 摘要：The aerial remote sensing（RS） by unmanned aerial vehicles（UAV）,which is flexible and quick,showed great benefits in data collection for the area impacted by 5·12 Wenchuan earthquake.A framework of 3D visualization management system for UAV remote sensing image has been developed.There are four parts in this 3D visualization system: flight tracking design system,remote sensing image acquiring system,image processing system,and 3D visualization management system.The flight tracking system provides the tools to design flight path for UAV in a 3-D visualization environments.The flight path design can be loaded into the UAV flight path control system to control the UAV direction,speed,and so on.The remote sensing image acquiring system is to acquire remote sensing images by controlling the attitudes and camera actions of the aerial vehicles.The image processing system includes the functions of image distortion correction and registration.The 3D management system handles the management and 3D visualization of UAV images.The key technologies regarding the system are discussed.The high-resolution remote sensing images are used as base images,and the geometric correction and Gray-Scale transform methods are employed to change original UAV remote sensing images to new ones in geographic coordinate system.UAV remote sensing images are managed by spatial index in 3D visualization environment which has multi-scale remote sensing images from different satellites.The paper establishes the quadtree pyramid and LOD model for managing large volume remote sensing data,which can provide more fluent visualization when users navigate in the 3D virtual environment.A 3D visualization management system for UAV remote sensing images has been implemented based on the VGE-3DGlobeEarth platform.From the experimental results,the system works well when it manages and visualizes the UAV remote sensing images in the areas impacted by 5·12 Wenchuan earthquake.With regard to the roles of UAV remote sensing in the 5·12 Wenchuan earthquake rescue,it is argued that UAV remote sensing images acquiring and visualization management system can be a very important supporting tool for quick response of emergent events such as floods,earthquakes,forest fires,and environmental pollution earthquakes.关键词：UAV（unmanned aviation vehicle）;remote sensing image;image rectification;3D visualization;5·12 Wenchuan Earthquake
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发布时间：2021-06-16 - 摘要：On May 12th,2008,a magnitude of Richter 8.0 earthquake attacked Wenchuan in Sichuan Province,China,which caused fatal death and millions of people homeless.The landslides caused by earthquake damed some riverways in the mountainous areas,forming tens of quake lakes,among which the Tangjiashan Quake Lake was the largest one and the most dangerous to threaten the downriver residents.Therefore,it is urgent to find solutions to solve the problem of the quake lake for government.Fast and precisely calculation of quake lake water capacity is a key issue for solving the threat of it.Traditional capacity calculation methods,taking the water surface as a plane with a given water level,just consider the static capacity in which the water level is required to be monitored for a long time.Complex hydrodynamic model and complicated model inputs,which highly demand the computing resource and are compute-intensive,must be taken into consideration when calculating dynamic capacity.It cannot satisfy a fast process dealing with the emergence.In this paper,a pixel-based curved water surface method is proposed to calculate the total capacity including dynamic capacity with a natural curved water surface,and the technologies of Geographic Information System（GIS） and remote sensing are integrated in this method.The backwater area is extracted from a corrected geometrically SPOT-5 image,and then the riverway DEM is intersected to obtain the boundary of water body consisting of a set of points.A 3D curved water surface,which depicts the large ratio of slope for water surface in mountainous areas,can be draw out by interpolating these concrete points.Finally,capacity calculation is carried out based on a calculation model after interpolating the point boundary to a curved water surface.The model takes the space between the pixels on water surface and the riverway DEM as an underside-squared prism.The volume composed of riverway DEM and water surface are divided into many small prisms to calculate the capacity respectively.The total water capacity of the quake lake is obtained by summing up these volumes.Considering the calculation efficiency of this method,an improved,pixel-based river segmentation algorithm is proposed in this study.It is fully considered the rationality of pixel-based curved water surface method and the efficiency of the traditional static capacity calculation method.An experiment is carried out to implement these algorithms.At last,a comparison,among the ArcGIS method,the proposed methods including the pixel based curved water surface method and the improved pixel-based river segmentation method,is conducted to prove that the improved method is more acceptable for its calculation speed and accuracy.And it can be used for daily operation for monitoring the capacity of a lake or reservoir.关键词：quake lake;dynamic capacity;river segmentation;geomatics
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发布时间：2021-06-16 - 摘要：This paper has presentsed the development and applications of 3D Geographic Information System on Wenchuan Earthquake,focusesed on the organizing technology of massive spatial data based on virtual quadtree for the application of 3D Geographic Information System,at the same time gave some proctical effects of the using,The paper has indicated that 3D Geographic Information System technology is useful to the earthquake relief and it is a powerful assisting tool for remote sensing image interpretation.关键词：Wenchuan Earthquake;3D;GIS;VQT
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发布时间：2021-06-16 - 摘要：Wenchuan Earthquake has seriously caused many huge landslides in the rivers in Si Chuan Province.As a result,huge water volume was blocked in the rivers and numerous dammed lakes appeared in the following days,which may result in inundation on the lake area and flooding disaster in the lower reaches.Therefore,it is urgent to reconnoitre the exsited dammed lakes and its spatial distribution,to monitor the stability of these dams and to evaluate the potential inundation area when the dam-break events occur.Incorporating the basic information of dammed lakes provided by other ministries,high resolution remote sensing imageries（including Spaceborne,Airborne and Unmanned Aerial Vehicle） from May,12 to June,12 2008,were used to confine the spatial distribution and to reconnoitre these dammed lakes.Based on the ’Atlas of Sichuan Province in 2001’,combining with ’Sichuan Electronic Map in 2008’ and ’1∶50000 topographic map’as well,most of the dammed lakes were named from the nearest village at the same riverside,while other dammed lakes located deeply in the mountains with scarce villages were named from a nearer village,with serial numbers.Up to June 12,2008,we have identified total 52 dammed lakes in the heavily-affected area of’Wenchuan Earthquake’.The spatial distribution with high precision longitude and latitude of the dammed lakes,indicates a significant linear feature,which is consistent with earthquake faults.The risk evaluation of the dammed lakes in the heavily-affected area of ’Wenchuan Earthquake’,was carried out mainly by using the monitoring results of high resolution remote sensing datasets and the authoritatively published results.According to the scale,the composition of the dams,the size and water storage capacity of these lakes,the distribution of the downstream cities and towns,population status and economic development levels,the possible affected area and the potential impact,the risk of the dammed lakes were divided into three levels: Extremely Dangerous,High Dangerous and Dangerous.Of the 52 dammed lakes,Tangjiashan is the only one in the Extremely Dangerous level,while the XiaoJiaqiao,Laoyingyan,Shiban’gou,Tangjiaba（Nanba）,Changtan（Xiaogangjian） are 5 dammed lakes in the High Dangerous level,and the rest 46 dammed lakes are in Dangerous level. Principles for determining the potential flooded area when dam-break occurs were developed: 1.the safety,is taken as the most important objective;2.the inundation area should be determined in accordance with sufficient and reliable monitoring results and basic datasets;3.the region should not be over-extended.Further,we also developed the methods for confining the potential inundation area,by which the total acerage of the potential inundation area determined amount to 963.27 square kilometers,involving the 134 townships of 18 counties（districts）.At last,preliminary suggestions were proposed to avoid risks of the secondary disasters of dammed lakes in the reconstruction planning for heavily-affected area in ’Wenchuan Earthquake’.关键词：Wenchuan earthquake;dammed lakes;remote sensing analysis;risk evaluation
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发布时间：2021-06-16 - 摘要：The powerful earthquake occurred in Wenchuan county in northwest Sichuan province on May 12th,2008 has brought a series of ecological environmental problems,especially the soil erosion deterioration.The mountains become less crowded and cracked,geological disasters such as coast,dilapidation,mud-rock flow,and chipping flow,happen continually and lots of buildings have been destroyed in different extent,which are all special types of soil erosion.Finding out the status of the soil erosion in disaster region is very important to the rehabilitation of ecological environment after disaster.Based on the classification criterion of water soil erosion and considering the special erosion type,we construct the soil erosion classification repository and analyze the soil erosion intensity in Wenchuan earthquake disaster region.The basic source data collected include: 1) the land use map with 1∶100000 scale in 2005 provided by Institute of Remote Sensing Applications,Chinese Academy of Science,2) the multi-spectrum remote sensing images with 32 meters spatial resolution of Beijing-1 before and after the earthquake,3) the digital elevation model（DEM） with 1∶50000 scale provided by State Bureau of Surveying Mapping,4) some other materials about the status of the earthquake disaster.Utilizing remote sensing（RS） and geographic information system（GIS） as main techniques and integrating expert knowledge,we obtain the soil erosion factor’s spatial information after earthquake which is involved in the soil erosion classification criterion: 1) land use type,obtained from the modification of the land use map in 2005 through human-computer interaction interpretation which is based on the contrast of RS images before and after the earthquake;2) vegetation fraction,based on the normalized difference vegetation index（NDVI）and computed with the sub-pixel model;3) ground slope,computed from the DEM based on the terrain analysis function of GIS;4) special erosion type,obtained from human-computer interaction interpretation of remote sensing images after earthquake.Then we assess the soil erosion intensity based on the coupling model of repository and spatial information which is developed by Interactive Data Language and coupled in Ecohydrological Assessment Tools（EcoHAT） as a sub-module.The procedure takes image pixel as basic calculative unit,identifies the soil erosion factor’s spatial information with forward reasoning machine while reading the pixels one by one,and completes the estimation of soil erosion intensity with support of soil erosion classification repository.When the user enters the soil erosion spatial information and classification repository,the system estimates the soil erosion intensity automatically.The application shows that the coupling model of repository and spatial information model can be used to analysis soil erosion fleetly.This paper also makes a deep analysis of the characteristics of the soil erosion factors and the main cause of soil erosion in Beichuan county.The result shows: 1) the earthquake has deteriorated the soil erosion in Beichuan county,both area and intensity.Compared with the publicized result of remote sensing investigation of soil erosion in 2000,the area of soil erosion after the earthquake has increased about 275.13 km2,which is about 23.83% of the total soil erosion area in 2000,and the acute degree soil erosion has increased nearly 12 times.2) The special erosion type distributes in the region where aftershock occurred frequently covering 71.19 km2.3) The forestry has the largest soil erosion area,which is 724.46 km2,half of the total area of soil erosion.4) Slope is the main contributing factor of soil erosion.About 97% soil erosion takes place on the land whose slope is greater than 15°.5) Vegetation fraction is the main control factor of soil erosion.The erosion proportion is only 16.31% in the land whose vegetation fraction is greater than 75%.6)The erosion proportion of plantation is considerable high which reaches 98.95%.We can see that sloping plantation fathering is the main direction of soil erosion controlling in Beichuan county.关键词：Beichuan county;Soil erosion;repository;spatial information;coupling model;EcoHAT
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发布时间：2021-06-16 - 摘要：The main suffering area of the Wenchuan Earthquake locates in the mountainous area of western Sichuan,an area which is very prone to mountain hazards such as landslides and debris flows because of the mountains and deep valleys,complex geological structure as well as well developed fault zones there.The Wenchuan Earthquake had directly induced massive secondary disasters such as collapse and landslides which destructed large area of farmlands.At the same time,the Wenchuan Earthquake also induced more than 30 barrier lakes making some farmlands be inundated and destructed.In order to make a scientific evaluation of the disaster situation and provide scientific basis for reconstruction and rational settlement of people in the suffering area,it is necessary to acquire the information of the destructed farmlands.In this paper,satellite remote sensing data as well as appropriate information extraction methods were used to acquire the distribution information of farmlands before the Wenchuan Earthquake and information of collapse,landslides,barrier lakes after Wenchuan Earthquake based on information such as landform features in mountainous area,landuse information and imagery characteristics of seasonal aspect.Spatial analysis was applied to evaluate the farmland loss to provide reference for the reconstruction planning.In this paper,Tangjiashan area of Beichuan county was taken as a case study area for evaluating the farmland loss caused by secondary disasters.NDVI was derived from the SPOT image data of November 10th,2007.Based on NDVI and landform information,the farmlands were identified and the distribution information of farmlands was obtained.Manual corrections were then used to eliminate possible errors in the previous farmland identification.The FORMOSAT-II image of May 14th,2008 and the ALOS image of June 4th,2008 were used to acquire the information of these secondary disasters such as collapse,landslides as well as barrier lakes induced by the Wenchuan Earthquake based on man-computer interactive interpretation.Based on GIS technology,the rapid evaluation of farmland destruction was carried out according to the comprehensive analyses of farmland distribution before the Wenchuan Earthquake and the distribution information of these secondary disasters induced by the Wenchuan Earthquake.Then the temporal and spatial characteristics of farmland loss were analyzed.The results show that the secondary disasters such as collapse,landslides as well as barrier lakes were very serious in the study area.There were 533 sites of collapse and landslides which had a total area of 1408.20 hm2,as well as barrier lakes with an area of 604.69 hm2 in the study area.The area of the farmlands destructed by secondary disasters were 86.88 hm2 accounting for 8.84% of the total farmland area.The distribution of collapse,landslides and destructed farmlands was consistent with the distribution of fault zone.And the destruction rate of the farmland on the fault zone was 18.74%,accounting for 74.53% of the farmlands destructed in the study area.The secondary disaster induced by the main shock had seriously destructed the farmlands while the aftershocks furthered the destruction.With the advent of rain season,the secondary disaster will still be of great threats to the farmlands so it is necessary to strengthen the dynamic monitoring of the farmland in the study area.As there is good forest coverage in this area,suitable seasonal aspects with vegetation index were used to extract the distribution information of farmlands before the Wenchuan Earthquake with the assist of landform information.In the FORMOSAT-II and ALOS imagery the distribution information of collapse and landslides induced by the earthquake was quickly extracted by visual interpretation according to the hue,shape information in the imagery,landform features and reference to the satellite imagery before the earthquake as well,then the farmland loss information was acquired using GIS.However,the rapid acquirement of the collapse and landslides information by automated classification needs further study.关键词：Wenchuan earthquake;collapse;landslide;barrier lake;remote sensing;farmland
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发布时间：2021-06-16 - 摘要：Based on the practical experiences we learned from "5·12" Wenchuan Earthquake relief works,the paper discusses some key technical issues on data acquisition and post-processing arising from the airborne LIDAR system when it is applied to rapid response.After briefly introducing the basic principles of LIDAR technology and its post-data processing work flow,several key technical issues concerning data acquisition and processing are expounded:（1） Ssystem calibration,which is actually important to all scenarios when LIDAR system is to be used;（2） Flight planning,the first and is also the key step as for high accuracy data acquisition.A good flight plan is of great importance,especially when LIDAR system works in hilly areas with high relief,where weather condition is often complicated as well;（3） Ground GPS base station setting up.GPS base station,which is necessary if POS system is adopted and high positioning accuracy is demanded.Several requirements should be satisfied;（4） Conditions for observation,including topographical condition,weather condition and forestry covering,all of which can influence the accuracy of the final results;（5） The choice of LIDAR hardware systems.Though several commercial LDIAR systems can be selected,we should bear in mind that each system has its pros and cons.Observation conditions have to be taken into consideration,especially when the LIDAR system is to be used over the hilly areas,such as in Sichuan Province;（6） The choice of laser power emission.As an active sensor system,LIDAR emits power by itself.However,there is a limitation as how much power is emitted.When lower power is emitted,it may lack of energy that signals can not be reflected by ground objects,so no echoes recorded.On the other hand,if raising power emission to a very high level,it is harmful to the hardware components of the system.So the optimal choice is a must.Some achievements using the Leica ALS50 second generation LIDAR system are listed in the latter section,which show the airborne LIDAR technology is an efficient and practical way to obtain high accuracy DEM data for South-western China.Some conclusions are summarized in the last section,including:（1） LIDAR system can acquire raw data under complex topographic and bad weather conditions;（2） LIDAR technology is the best choice for accurate DEM data acquisition in hilly areas with high relief and heavy forest;（3） data post-processing is time efficient and shows its satisfaction for rapid response applications.The works described in the paper is helpful to similar natural hazard relief works,and the technical issues discussed in the paper can be referenced by other similar projects.关键词：earth-quake;LIDAR technology;earth-quake lake;landslide
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发布时间：2021-06-16 - 摘要：8.0-magnitude Wenchuan Quake occurred on May 12th,2008.The quake hit Sichuan,Ganshu,Shanxi and some other provinces,which has caused destructive losses in more than 10 affected counties.The crucial problem for related government departments is how to mitigate the disaster’s effects to the casualties and economic losses in the affected areas,and to decrease the dangers caused by the secondary disasters.Continuous landslides and collapses have buried roads.The main roads connected to the outside were blocked severely,and threatened by potential disasters in the aftershocks.It was difficult to reopen of the lifeline,and to reconstruct for relief and rescue.Blocked roads became a major obstacle for the rescue of the disaster areas.Transportation access must be restored as soon as possible.The important point is to know the degree and the spots of the damaged of roads in the first time.Remote sensing technique can be used due to its features of objectivity,real-time and macro-scope view.It can provide a rapid and effective approach for monitoring the secondary disasters,dynamic monitoring its evolution process,and evaluating the damages.For example,the information about situation of roads,bridges and other road subsidiary infrastructures can be extracted.For monitoring the disaster damage to transportation airborne remote sensing was used in the previous studies of 1966 Xingtai Quake,Haicheng Quake in 1975,Tangshan Quake in 1976 and Lancang-Gengma Quake in 1988 in China.Satellite remote sensing technique was used in Nantou Quake in 1999 in Taiwan,and Jiashi Quake in 2003 in Xinjiang.This paper presents the method,workflow and results of highway damage monitoring and assessment for Wenchuan Quake based on remote sensing and its information integration,the workflow,and results.The study area includes the highways in ten counties affected severely by the quake.First,some interpretation keys are summarized for the damaged highway and their damaged causes.Next,some damage information extraction methods are tested,such as human-computer interactive interpretation,pixel based classification（supervised classification and unsupervised classification）,and object-orientation segmentation and classification have been tested.Then,the paper presents the integration way for basic information of roads with disaster information in WebGIS system,named"3 Dimension Geographical Information System for the disaster situation of Wenchuan Quake",realizing the visualization of the disaster situation using DEM,damage spots and highway map in Quake zone.Finally,analyse the whole situation for the monitoring area.The results reveals that there are 63 spots damaged by landslides,3 spots by mudslides,190 spots by collapses,6 spots by quake lakes,5 spots of bridges broken.According to Beijing-1 images and other sources,Yingxiu-Maoxian section of the national highway,Maoxian-Beichuan section of Provincial Road 302,Yingxiu-Wolong section of Provincial Road 303,and Anxian-Qingchuan section of Provincial Road 105,are seated the in the south-west end of Longmenshan fault zone,and these roads are parallel to Longmenshan hillside fault zone.The damaged roads are mostly consistent with the fault zone.In conclusion,remote sensing can monitor and assessment of damage caused by the earthquake,and it can provide the important information to related government departments,and also play a more important role in reconstruction for the decision-makers.It should be improved and developed in the following aspects:（1）to built the basic integrated database is needed;（2） to enhance the ability to integrate multi-sources data;（3） to promote the standard for transportation emergency response;（4） to develop information extraction technique for earthquake damage;（5） to develop a united platform for transportation emergency response.关键词：Wenchuan quake;transportation remote sensing;damage monitoring and assessment;information integration
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发布时间：2021-06-16 - 摘要：As active remote sensing sensor,spaceborne Synthetic Aperture Radar（SAR） with merits of broad range image,all-weather work time and strong penetration which is widely used in mapping,geology,hydrology,agriculture,forestry and so on,is an important part of the Modern radar technology.The application of SAR needs to know the exact location of the corresponding space information which must be carried out on the geometric rectification of SAR image processing geometric correction,elimination various geometric deformation exist in the SAR images.RPC model is a mathematical sense of the imaging geometry model,which is independent of the sensor and platform.The model establish the relationship between the ground coordinates of any image and the corresponding geology coordinates.A lot of work has been done on RPC model for optical sensor by many researchers.On the basis of summarizing the research work about the Range Doppler Geolocation Model of SAR,This paper focuses on the study of RPC model for SAR images and geometric rectification of SAR images.In this paper,TerraSAR-X,COSMO high-resolution SAR data are used as an example to establishing the Range Doppler Geolocation Model which can calculate the geology coordinates from the image coordinates.This can explain the feasibility of the RPC Model on SAR images.And one experiment has been done to prove it.The RPC Model has more than one percent pixel accuracy.关键词：synthetic aperture radar;range doppler geolocation model;RPC model;geometric rectification
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发布时间：2021-06-16 - 摘要：The strong Wenchuan Earthquake causes serious damage to the road infrastructure,which has bad influence on the disaster-relief work after the earthquake.Therefore,it is very important to evaluate the damage loss of the road in the disaster area quickly and accurately,especially in the emergency time of disasters.This paper introduces a method to evaluate the damage of roads from satellite remote sensing images with high spatial resolution in Wenchuan earthquake of 8.0 magnitudes.The study uses twenty nine high resolution satellite remote sensing images after the earthquake,including EROS-B,QuickBird,SPOT-5,ALOS data etc.These images are all panchromatic data.The spatial resolution is at least 3 meters.The study area includes 20 counties in the damaged area of Wenchuan Earthquake.The terrain conditions are complex for all counties except several of the Chendu city.The study method includes three steps.First,remote sensing imagery is geometrically corrected.Meanwhile,clouds are eliminated by the threshold of high gray values.Second,road regions in high resolution remote sensing imagery are segmented by geographic information of road.Third,damaged roads are detection by the following steps.Each road is segmented by a fixed length interval into several segments.Then for each segment,grey and texture feature in a neighborhood window are calculated.According to the model of damaged road,grey and texture feature are used to identify damaged roads.At last,the result of damaged road detection is used to calculate assessment indexes including damage distribution and damage grade of each county.The grading standard is setted in three levels,which are severely damaged,moderately damaged and lightly damaged,according to the damage rate of national roads and provincial roads.The result shows that the earthquake affected road infrastructure in all the twenty counties of the study area.Six counties are severely damaged,including Wenchuan county and Beichuan county;three counties are moderately damaged;and eleven counties are lightly damaged.It is proved that,comparing the results of this study and the ground investigation data,the assessment method of this paper could get a quick and relatively accurate evaluated result of the damage loss of the roads in the disaster areas using the high resolution satellite remote sensing images.The damaged road assessment method is very useful and feasible in the serious situation,especially when we cannot get the ground investigation information.关键词：Wenchuan earthquake;disaster remote sensing;high resolution remote sensing imagery;damaged road assessment
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发布时间：2021-06-16 - 摘要：The deadly Wenchuan Earthquake hit Wengchuan,a small city southwest of Sichuan Province,China,with a magnitude of 8.0,at 14∶28 local time of May 12.It shook more than half of China and brought devastation to more than fifty counties.The earthquake has not only caused numerous personnel casualties and destroyed kinds of facility directly,but also induced a lot of mountain hazards,and superimposed the hazards more severely.The extraction of earthquake-induced moutain hazards using remote sensing images has important significance for earthquake relief,assessment of bearing capacity of disaster area and reconstruction work after earthquake.The extraction of disaster area is realized by a method combination of information enhancement,information fusion and visual interpretation.According to the active characteristic and material combination of debris flows and landslides,we compare and analyze the spectral feature difference of different images and take ETM+ image as main data source.Debris flows and landslides have two distinct properties of higher water content and lower vegetation cover.The reflective features on remote sensing images are soil moisture and vegetation coverage,which can be reflected by wetness index and green index.After the extraction of wetness index and green index,tasseled cap transformation,image difference reinforcement,density slide and mask technology are used to build the quick extraction model for debris flows and landslides.The model is used to extract mountain hazards induced by Wenchuan earthquake.The distribution rule and feature of geo-hazard and genesis are analyzed by spatial overlay.Mountain hazards induced by the earthquake distribute mainly along Longmenshan Mountain earthquake zones and rivers on both hillsides.They have the following characteristics: 1.The types of mountain hazards are diverse,including collapses,landslides,rockfalls,imprisoned lakes,debris flows and so on.2.The relation is closed between the strong level of the action and the intensity of the earthquake.The mountain hazards are mainly present in the earthquake intensity area from 8 degree to 11 degree.With the intensity reduced,the gross area of geo-hazard decreased.3.The mountain hazards mainly occurred in areas 1000m to 2500m altitude.4.The gradient of the slop of generating geo-hazard mainly varied in the range from 20 to 50 degree.5.In quantity by collapseds,landslides,rockfalls primarily during aftershock and landslides,debris flows primarily during anaphase.6.Pair of ecological environment destruction is enormous.关键词：Wenchuan earthquake;mountain hazards;remote sensing;extraction
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发布时间：2021-06-16 - 摘要：Spatial data aggregation is widely practiced for "scaling-up" environmental analyses and modeling from local to regional or global scales.There is a growing literature reporting on the effects of data aggregation under the general topic of the scale effects.The measurements,such as mean,median,variance,RMSE,etc.,are used to evaluate the effect of different aggregation methods in the studies.However,these measurements based on statistics have not taken into account the spatial pattern of the remote sensing image.Despite this,the original image is set as the reference data and the aggregation method which can retain statistical characteristics of the original data better than the others is considered the desirable method.For scientific inquiry,aggregating data to a coarser resolution is often performed,because certain spatial patterns will not be revealed until the data are presented at a coarser scale.It is more reasonable that the image scanned directly from sensor at the same scale with the result resolution of aggregation operation used as reference data.The objective of this study is to compare and evaluate the effect of five aggregation methods based on new measurements and new comparing thought line.Spatial resolution and Structural SIMilarity（SSIM）are introduced as two new measurements to evaluate the effects of aggregation methods.In the five aggregation methods,except for Arithmetic Average Variability-Weighted（AAVW）,Average,Bicubic,Bilinear and Nearest are commonly used for aggregating remotely sensed data.The AAVW method is a new aggregation method based on spatial variability-weighted principle.Spatial resolution is a basic attribute of image data.The technical spatial resolution of up-scaled image can be specified precisely and explicitly by the resolution of original image and the aggregation levels.The aggregation effects are evaluated by differences between the resolution of aggregated images and the technical spatial resolution.In this study,the spatial resolution was retrieved by using linear diffuse function.The motivation of SSIM is to find a more direct way to compare the structures of the reference and the distorted images.Natural image signals are highly structured: their pixels exhibit strong dependencies,especially when they are spatially proximate,and these dependencies carry important information about the structure of the objects in the visual scene.SSIM defines the structural information in an image as those attributes that represent the structure of objects in the scene,independent of the average luminance and contrast.Two study sites from the Xinjiang Province,China were used: The Urumchi international airport and Tianshan Mountain.For each study site,the TM and ETM+ images were acquired.The multi-spectral images of ETM+ were merged with its panchromatic image.Thus,the resolution of ETM+ multi-spectral images was enhanced to 15 m.The merged ETM+ multi-spectral images were then aggregated by the five aggregation methods mentioned above using 2-by-2-pixel window size.The up-scaled images in Urumchi international airport were selected for the experiment based on spatial resolution measurement.SSIM was used in comparison of effects of the five aggregation methods in Tianshan Mountain sub-images.Experimental evaluations were conducted based on the new thought line and measurements among five aggregation methods.The TM images were used as reference data.Experimental Results show that the Bicubic and Bilinear method presented more wonderful performance than the others.The validity of the two new measurements,which based on the new thought line,was also checked through comparing the effects of the different aggregation methods.Finally,the future research about using the new evaluation measurements is also proposed.关键词：aggregation method;quality assessment;resolution;linear diffuse function;structural similarity
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发布时间：2021-06-16 - 摘要：The traditional ground area measurement is limited by accuracy and efficiency.Remote sensing technology helps improve both but alone still far from satisfaction.Therefore,we proposed a spatial stratified sampling method based on remote sensing.The basic idea is using up to date remote sensing images to guide the target stratified sampling by a general classification,other than by those obsolete background knowledge databases.In order to validate the improvement on accuracy of calculating the real quantity with actually it unknown（which is just our goal to estimate）,we took the early classification map from the remote sensing image（in this experiment,we used part of one scene of TM image covering Beijing area,a size of 4800×4800 pixels,and classified into 5 different types,3 of which were chosen）as the laboratorial quasi-real target（proportions vary from 7% to 32%）.The detail methods and operations are described in the following steps: Firstly,we played back simulated pre-classification result,which completely contains the target,by iteratively adding error class pixels around the outskirts of the target to a demanded proportion;secondly.Secondly,we arranged square boxes（with a size of 20×20 pixels）on the pre-classification image,excluded zero-target ones and divided the rest into 5 strata according to the proportion of in-box pre-classification target area（pixels）,randomly or systematically chose the samples.And then we estimated the gross by summing up the actual pixels in each sample pro rata.Finally,we analyzed and compared the quality and variation of estimation accuracy repetitiously with different land cover types,different pre-classification precision levels,and two methods of random and system in stratum.The results mainly presented the relationship between estimation accuracy and pre-classification accuracy in each target type,which showed that the estimation accuracy degraded when the stratified sampling method was aided with rough pre-classifications（accuracy less than 40%）,but remarkably reached higher accuracy and stabilization than those of unsupported random or systematic sampling methods with pre-classification above a certain accuracy level.For the former situation,the degradation is mainly caused by the extreme inconsistency of area distributing direction poorly classified,and does not take place in common classifications.In general,this method has its best cost-efficiency at 50% pre-classification accuracy,a case of which is that the accuracy of the estimators for each target class with all proportions at 0.5% sampling ratio level and 95% confidence level can be acquired above 92% when the accuracy of pre-classification reaches 60%.During the study,we innovated in the following aspects: first,we created a simulated classification map with an assumed given target,and this map worked properly to show up the real situation;second,with the help of pre-classification from remote sensing images,the stratified sampling method can be much more effective and precise,and less in need of prior knowledge.
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发布时间：2021-06-16 - 摘要：Image segmentation has been an important research area in image analysis and interpretation.An ideal segmentation strategy of remotely sensed data should consider problems of over-segmentation and under-segmentation simultaneously and find a good tradeoff between them.In this paper,image segmentation for IKONOS multispectral data is investigated by using techniques of mathematical morphology,and a novel hybrid segmentation algorithm is proposed by combining both edge and texture features of images.Based on the K-L transform of multispectral data,edge features are detected by morphological multiscale and multidirection gradient algorithms,and image objects are marked through morphological filtering and local variance features extracting.Finally,the marker controlled watershed algorithm is implemented.The results indicate that the performance of the proposed algorithm is superior to the gradient based watershed segmentation.Moreover,this approach is more suitable for high resolution remotely sensed data to overcome over-segmentation and under-segmentation problems effectively.关键词：image segmentation;mathematical morphology;marker controlled watershed segmentation;high resolution multispectral remotely sensed data
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发布时间：2021-06-16 - 摘要：Clouds play an important role in the radiation budget of the earth.The satellite observations under cloudy condition provide not only information of cloud absorption but also abundant information of cloud properties.Although the infrared sounder with high spectral resolution resolves the ill-posed problem in atmospheric retrieval,there are still many challenges in cloudy atmospheric retrieval.How to get soundings temperature and moisture vertical profiles under cloudy skies becomes very important.Until now our research is mainly focus on the statistical and physical algorithm of atmospheric temperature and humidity retrieval in the clear sky,less advancement in the cloudy atmospheric retrieval.AIRS（Atmospheric InfraRed Sounder）onboard the National Aeronautics and Space Administration’s Earth Observing System’s（EOS）Aqua spacecraft is selected as the representative instrument to simulate and validate the discussed algorithm.AIRS is a high spectral resolution infrared sounder with 2378 channels over the range from 650 cm-1（15 μm）to 2700 cm-1（3.7 μm）.It yields vertical profiles of atmospheric temperature and water from earth’s surface to an altitude of 40 km with a horizontal resolution of 13.5 km at nadir,with the property of high measurement precision and high spectral resolution.In this paper the simulated space-based high spectral resolution AIRS radiances with different cloud top heights and effective cloud fractions are used to demonstrate the measurement sensitivity and atmospheric profile retrieval performance.The simulated cloudy retrieval of atmospheric temperature and moisture derived from the statistical eigenvector regression algorithm are analyzed with and without the cloud top height classification.Collocated cloudy AIRS and the associated clear MODIS（the Moderate Resolution Imaging Spectroradiomete）infrared observations within the AIRS field of view are also used to demonstrate the profile retrieval improvement below the cloud layer.In addition this paper has demonstrated that the use of collocated clear MODIS multi-spectral imager data along with the AIRS high spectral resolution infrared radiances can greatly improve the single FOV cloudy retrieval even under opaque cloudy condition.The results are listed as following.1.The root-mean-square error of retrieved temperature and the mixed ratio of water vapor below the cloud top increase with effective cloud fraction.2.The knowledge of cloud height is critical to sounding retrieval performance.The temperature retrieval around the cloud layer can be significantly improved if the cloud height known perfectly for the mid-and high-level clouds,while to the low level clouds the retrieval has less sensitivity to the cloud height error.The retrieval accuracy of the cloud height with 50 hPa error decrease comparing with the cloud height known perfectly.The temperature retrieval seems to be more sensitive to cloud height error than humidity retrieval.3.The cloud classified statistical or physical regression can be an alternative approach for obtaining efficient cloudy sounding retrieval given that the initial cloud height information is available.4.The use of collocated clear MODIS multi-spectral imager data along with the AIRS high spectral resolution infrared radiances can greatly improve the single FOV cloudy retrieval especially under more overcast condition.关键词：infrared;high spectral resolution;atmospheric infrared sounder;temperature and humidity profile retrieval
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发布时间：2021-06-16 - 摘要：Leaf area index（LAI）is an important vegetation biophysical variable,and has been widely applied to the estimation of crop yield evapotranspiration,and net photosynthesis.Mean while as an important input or output parameter of some dynamic process models such as crop growth model and common land model,LAI is a connecting bridge to couple the process models with remote sensing models.The Moderate Resolution Imaging Spectroradiometer（MODIS）,carried aboard the Terra and Aqua satellites,can collect the information of LAI change continuously.The MODIS LAI standard product,issued since 2000,have been used in the meteorological and hydrologic field.However,spatio-temporal discontinuity exit in the MODIS standard LAI product,which restricts its application in the crop growth monitoring and yield estimation,land surface process simulation and global change research.The paper analyzed the MODIS standard LAI product in China region,and pointed out that the spatio-temporal discontinuity of the MODIS standard LAI product in China region is caused not only by the MODIS LAI reverse algorithm but also by the MODIS reflectance data quality.Based on the TSF filter algorithm a new improved TSF filter algorithm is put forward in this paper,in which more attention is paid to the relatively serious cloud covering in the crops growth season that results in poor quality of reflection data in China region.The improved TSF filter algorithm makes full use of the data quality control information in the MODIS data product and takes further consideration of the influence of surface reflectance data quality on MODIS LAI standard product.Experimental results show that the improved TSF algorithm can better process MODIS LAI standard product.Further,the improved TSF algorithm has been used to produce a new suit of MODIS LAI product in China region with much better spatio-temporal continuity,which is more reasonable and reliable dataset for integrating the remote sensing data product with application models.关键词：MODIS LAI product;LAI product improvement;TSF filtering
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发布时间：2021-06-16 - 摘要：waterfowls habitat and population quantity has been seriously damaged due to continuously deteriorating of Wetland ecosystem.There are satisfactory variety of ecosystems,and there are resources and abundant plants or animals species in the Jiansanjiang area.Although the biodiversity of the region is rich and important,it is suffering from man-made destroy and disturbance.Analysis of high strength wetland reclamation process and environment changes was conducted to study the direct and indirect effects on wetland waterfowls habitat.People were raised to pay attention to the protection of Wetland and Biodiversity extensively.Habitat suitability method is widely applied in natural land resource management,especially it is very meaningful research for biodiversity protection and useful spaces question of animals.It has also very important significance to quickly realize and determine the best habitat position in spatial scale domain.Jiansanjiang area lies in the northwest of Heilongjiang Province in China,as for most of the year,where the climate is characterized as temperate semiarid continental monsoon.There are three large rivers in the region,including Heilongjiang River,Songhua River and Wusuli River,which are important national wetland in Sanjiang Plain.The maps of topographic and vegetation distribution in Jiansanjiang area following as reference materials,it is an application of GPS on field control point position established habitat suitability point cluster.The acquisition of 21 single evaluation factors is based on information extraction by remote sensing and Geography Information System spatial analysis method,and analysis of Binary Logistic regression model,which was integrated into habitat suitability module on pixel levels.Along with other factors,these was a great influence,high goodness-of-fit and big standardized residuals on 10 single suitability evaluation factors finally,synthetically evaluated by settlement density,population density,road Euclid Distance,settlement Euclid Distance,NDVI,vegetation types,wetness,texture,relief and DEM etc.These factors emphasize three aspects: humanity society,vegetation growth topography and geomorphology respectively.There is integrated classification criterion of Jiansanjiang habitat with K-means cluster analysis,effectively analyzed five levels of suitability on spatial scale.As a result,the percentage of the highly suitable habitat,suitable habitat,moderately suitable habitat,not suitable habitat and permanently not suitable habitat respectively are 24.73%,17.69%,29.8%,17.62% and 10.16%,that of the former three types was about 72.22% of the total,those who will use evidence to support their view that the abundant land of waterfowls suitable habitat in Jiansanjiang.The effective strategies based on the evaluation results can be put forward as the reference for protection of habitat suitability land and sustainable reproduction of population.The experimental results show that our method achieves high fusion accuracy（general classification accuracy: 87.3%,kappa’s coefficient: 0.852）,it gives a proof of grade separation image and actual ecological environment is very similar.The paper offered an innovation thought: application of statistical Binary-Logistic module based on pixel level in RS image.This method can be helpful for the large-scale natural ecological landscape planning,determination of human disturbance and animal protection scale domain,biodiversity sustainable development for future geographic spatial analysis.关键词：waterfowls habitat suitability;binary logistic regression model;K-Means cluster analysis;technology of RS and GIS
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发布时间：2021-06-16 - 摘要：There is difference in reflectance of the sunlight by sea water and oil on the sea,as well as from different oils.It is primarily based on the different reflectance of sea and oil spill at sea to distinguish the oil and sea that scientists monitor the oil spill at sea using satellite remote sensing,and distilling the information on oil film from satellite remote sensing.So,the awareness of the spectroscopic character curve of the oil spill at sea is the foundation of monitoring the oil spill at sea using satellite remote sensing.Basis on the testing and analysis of spectroscopic character curves of the crude oil from Persian Gulf,fuel oil,diesel oil,lubricating oil,kerosene spill at sea,we can draw the spectroscopic character curves of the different thickness and different oil.Through the analysis of the spectroscopic character curves,it was found that the reflectivity of oil film is associated with its thickness.Through the spectroscopic character curves of the oil spill at sea,we know the reflectivity of the seawater and oil spill at sea are different,but the differences are very small,and the differences at various satellite channels are also different.So only by selecting the exact satellite channels that can the reflectance of seawater and oil more readily,we can improve the successful probability of monitoring the oil spill at sea by the satellite.According to the perennial practice of the satellite images transacting,we have selected the satellite channels that the differences of reflectance between seawater and oil is big,or the channel which contributed much to the information on oil film,to increase the successful probability of the monitor of oil spill at sea.We have summarized the satellite channels combination to distill the oil information at the various oil spills.To facilitate the quantitative comparison,using the ratio of sea and oil film displays the reflectance differences between seawater and oil.We have analyzed the methods and its function of the enhance transacting and ratio expanding to transact the satellite images of the oil spill at sea.On basis of distilling the oil film information from satellite images,it has become the key technique of making sea oil spill satellite images that uses the methods of the enhance transacting and ratio expanding to extrude the oil film information at sea.The paper cited the monitoring examples of satellite remote sensing of the crude oil,fuel oil,diesel oil and lubricating oil spill at sea,and analyzed the usage situation of the technology.Also the paper analyzed the limitation of monitoring the spill oil by optical remote sensing: ①it cannot monitor the oil all the time due to cloud or at night;②it cannot monitor a small quantity of the oil spill due to lower resolving power;③it can only obtain a rough quantity of the oil spill.At last,in the paper we analyzed the disadvantages and prospect of using satellite remote sensing to monitor oil spill at sea.关键词：satellite remote sensing;information distilling;oil spill at sea
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发布时间：2021-06-16 -
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