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1.
1INTRODUCTIONResearchonglobalenvironmentalchange,especiallyglobalvegetationchange,hasbeenmoreandmoreemphasizedbyscientistsandgovernments.HoWever,theinvestigationofvegetationcoveredinlargeareaneedagreatdealoffundandlaal.Asthesatelliteremotesensingdatahavebeenavailablesinceearly1980s,thesedataarebeingemployedtowardstOtheimprovementofvegetationclassification.NOAA--AVHRRdatahavebeenmoreandmoreusedbyscientistsbecauseOfitsshorttemPOralrefution,largescope,inexpensivecostandbreadwavebands.On…  相似文献   

2.
“West Jilin Porovince” in ths paper means Zhenlai,Baicheng,Taonan,Da‘an,Tongyu,Fuyu,Songyuan,Qian‘an ,Chandling,also includes Gongzhuling,Shuangliao,Lishu,Siping and Nong′an which have been suf-fered from desertification.In west Jilin Province there are three sand zones passing through,they are Xiang(Xianghai)-Wu(Wlan Tug)sand zone,Hai-Fent sand zone,and Tao′er River right band sand zone.The desertification area of west Jilin Province is 819 100ha,making up 12.5% of the total land area.Among desertification types,in Jilin Province light desertification is the major,then is medium dersertification,hevey desertification is the least.According to the compare-son of the interpretation results of the Landsat images of the 1980s and 1990s by remote sensing and GIS techniques,it can be seen that the diesertification area in west Jilin Province basically didn′t change on the whole,only increased 6130ha,making up 0.8% of the desertification area,change scale is less than 1%.Evidently,desertification is con-trolled mostly,but some areas are continuing deterioration.The desertification process of China can be divided into three types according to origin nature,they are sandy steppe desertification,fixed sand area(sand land) activation and dunes transfer invasion.Reasons of desertification of West Jilin Province are analyzed,they include natural factors(such as material source factors,chimate factors) and artificial factors(such as destroying grass to reclaim,steppe decreasing greatly,illegally feeling shelter forest stands,constructing reservoir to influence eco-environment etc.).Some sugges-tions are put forward as follows:establishing the social project for ecological reconstruction of degenerated land;intensify-ing planning and management of land use,reverting farmland into forestland or pasture in a planned way.The key desertifica-tion control is to depend mainly on policy and management,then control techniques.  相似文献   

3.
Due to global climate change, Dendrolimus pests and diseases seriously threaten the protection of forestry plants and the safety of crops all over the world. This paper aims to discuss the research results and frontier progress of Dendrolimus disasters based on remote sensing monitoring, trying to find the occurrence characteristics of pests. In this paper, bibliometric methods and CiteSpace knowledge graphs were used to analyze the publication trend, highly cited documents, key research institu...  相似文献   

4.
In view of the large quantities of areas,complex landform and dynamic change of resources and environ-ment in China,China has already funded abundantly a series of macro remote sensing investigation projects in land use cover change(LUCC) since 1990.Supported by the achievements of such projects,Chinese resources,environmental and remote sensing database(CRERS) was created.In this paper,we standardized the LUCC dataset of CRERS at scale of 1km,which facilitated the study of spatial features of LUCC in China.The analysis on the spatial features of LUCC and their causes of formation in China are based on the CRERS supported by the technologies of Geographic Information System(GIS) .The whole research was based on the grade index of land use,ecological environmental index and index of population density.Based on the correlation analysis,we found that the special features of LUCC were closely related with those of ecological environment and population density,which resulted form that areas with better ecological environ-ment and high production potential of land were easy and convenient for human being to live,which,furthermore,led to the aggravation of excessive exploitation of land resources there.  相似文献   

5.
1 INTRODUCTIONAsanimportantcomponentoftheglobalterres trialecosystems ,forestlinkstheatmosphere ,soilandwatertogetherthroughitspowerfulecologicalfunc tion .Inrecentyears,owingtotheglobalwarmingandhumaninfluence ,forestfireoccurmuchmorefrequently .Theannualf…  相似文献   

6.
The practice has proved that it is an economic and effective method to investigate placer gold deposit by using multi-level information sources of remote sensing and multi-variate analysis methods, especially for the area with a sparse population and difficult condition like the Da Hinggan Mountains, China.The information sources used in our work includes Landsat TM, aerial infrared photography and their mosaic image maps and enlarged photos with different scales. According to statistic data, in the study area the gold-bearing rocks are mainly granite, alaskite, granodiorite and some old metamorphic rocks. On gold-bearing geological structures, the fault zones in the four directions (NE, NNE, NW and EW) are obvious, in which NNE and EW are the most key fault zones. On fluvial geomorphology the flow courses stored placer are in the tributaries of the 4th and 5th levels, especially in straight or slight curve reaches. On the basis of analysis the interpretative signs were set up, and the interpretative wo  相似文献   

7.
1 INTODUCTIONWetlandcanperformenormousfunctionsinre sourceandenvironmentadjustment ,anditisoneoftheimportantecologicalenvironmentsthathumanbe ingsrelyon .Internationalcommunitieshavealreadypaid greatattentiontothewetlandresearch ,andsomeforeignershavedone…  相似文献   

8.
IntroductionThe radiance leaving the earth-atmosphere sys-tem which can be sensed by a satellite borne ra-diometer is the sum of radiation emission fromtheearth surface and each atmospheric level that aretransmittedtothe top of the atmosphere.The radia-tion emissionfromthe earthsurface andthe radianceof each atmospheric level can be separated fromtheradiance at the top the atmospheric level a satellitemeasured.Thus,the earth surface parameters willbe retrieved from the surface radiance after a…  相似文献   

9.
The radiance leaving the earth-atmosphere system which can be sensed by a satellite borne radiometer is the sum of radiation emission from the earth surface and each atmospheric level that are transmitted to the top of the atmosphere. The radiation emission from the earth surface and the radiance of each atmospheric level can be separated from the radiance at the top the atmospheric level measured by a satellite borne radiometer. However, it is very difficult to measure the atmospheric radiance, especially the synchronous measurement with the satellite. Thus some atmospheric radiative transfer models have been developed to provide many options for modeling atmospheric radiation transport, such as LOWTRAN, MODTRAN, 6S, FASCODE, LBLRTM, SHARC, and SAMM. Meanwhile, these models can support the detailed detector system design, the optimization and evaluation of satellite mission parameters, and the data processing procedures. As an example, the newly atmospheric radiative transfer models, MODTRAN will be compared with other models after the atmospheric radiative transfer is described. And the atmospheric radiative transfer simulation procedures and their applications to atmospheric transmittance, retrieval of atmospheric elements, and surface parameters, will also be presented.  相似文献   

10.
This paper puts forward an effective, specific algorithm for edge detection. Based on multi-structure elements of gray mathematics morphology, in the light of difference between noise and edge shape of RS images, the paper establishes multi-structure elements to detect edge by utilizing the grey form transformation principle. Compared with some classical edge detection operators, such as Sobel Edge Detection Operator, LOG Edge Detection Operator, and Canny Edge Detection Operator, the experiment indicates that this new algorithm possesses very good edge detection ability, which can detect edges more effectively, but its noise-resisting ability is relatively low. Because of the bigger noise of remote sensing image, the authors probe into putting forward other edge detection method based on combination of wavelet directivity checkout technology and small-scale Mathematical Morphology finally. So, position at the edge can be accurately located, the noise can be inhibited to a certain extent and the effect of edge detection is obvious.  相似文献   

11.
This paper proposes a red tide monitoring method based on clustering and modular neural networks. To obtain the features of red tide from a mass of aerial remote sensing hyperspectral data, first the Log Residual Correction (LRC) is used to normalize the data, and then clustering analysis is adopted to select and form the training samples for the neural networks. For rapid monitoring, the discriminator is composed of modular neural networks, whose structure and learning parameters are determined by an Adaptive Genetic Algorithm (AGA). The experiments showed that this method can monitor red tide rapidly and effectively.  相似文献   

12.
基于遥感资料的陕北黄土高原植被覆盖率时空特征分析   总被引:1,自引:0,他引:1  
选取黄土高原的典型区域--陕北作为监测区域,以MODIS和TM资料作为主要数据源,从可业务化的角度采用植被指数法进行了植被覆盖率的遥感反演,对4种生态气候区植被覆盖率季相变化特征进行了分析,并对陕北生态环境治理前后植被覆盖率的变化进行了对比,结果表明:生态治理后陕北黄土高原的植被覆盖率绝大多数地区都是正增长,各生态气候区植被覆盖状况都有了不同程度的改善,生态治理效果最明显的区域在陕北南部.  相似文献   

13.
面向对象的方法提取湖泊,常常面临边界识别不精确的问题.本研究在面向对象方法的基础上,利用分水岭算法,解决湖泊边界识别问题.该方法初步将遥感影像划分为确定湖泊区域、潜在湖泊区域和背景;然后通过分水岭算法对潜在湖泊区域进行二次提取.研究选择昆仑-喀喇和喜马拉雅山脉区域的3个山地湖泊发育良好的区域作为实验区,利用Landsa...  相似文献   

14.
基于优化随机森林回归模型的土壤盐渍化反演   总被引:1,自引:0,他引:1  
当前应用于土壤盐分含量(Soil Salinity Content,SSC)反演的随机森林回归(Random Forests Regression,RFR)较少关注对模型精度影响较大的反演参数子集和模型参数的同步优化.本研究选择渭-库绿洲和奇台绿洲为实验区,基于Landsat-5 TM、SRTM、MOD 11 A2.0...  相似文献   

15.
基于局部空间信息KFCM的遥感图像聚类算法   总被引:1,自引:0,他引:1  
针对模糊C均值(Fuzzy C-Means, FCM)算法,不能有效地对夹杂噪声的遥感图像聚类的问题,本文提出了一种基于局部空间信息核模糊C均值(Kernel Fuzzy C-Means, KFCM)的遥感图像聚类算法。首先,运用核函数将遥感图像的所有像元映射到高维特征空间,通过非线性映射优化遥感图像的有用特征;然后,根据相邻像元之间的相关性,利用一种空间函数重新定义像元的模糊隶属度,将像元的局部空间信息引入到FCM算法中,并在高维特征空间中使用这种基于局部空间信息的FCM算法对像元聚类。由于引入了像元的局部空间信息,算法可以直接应用于原始遥感图像,不需要滤波预处理。大量实验结果表明,本文提出的基于局部空间信息KFCM的遥感图像聚类算法具有较强的抗噪能力,可得到较好的同质区域,优于现有的FCM算法、模糊局部信息C均值(Fuzzy Local Information C-Means, FLICM)算法及KFCM算法。  相似文献   

16.
A new technique is introduced in this paper regarding red tide recognition with remotely sensed hyper-spectral images based on empirical mode decomposition (EMD), from an artificial red tide experiment in the East China Sea in 2002. A set of characteristic parameters that describe absorbing crest and reflecting crest of the red tide and its recognition methods are put forward based on general pictre data, with which the spectral information of certain non-dominant alga species of a red tide occurrence is analyzed for establishing the foundation to estimate the species. Comparative experiments have proved that the method is effective. Meanwhile, the transitional area between red-tide zone and non-red-tide zone can be detected with the information of thickness of algae influence, with which a red tide can be forecast.  相似文献   

17.
传统基于光谱信息的水体提取未能考虑水体形状、纹理、大小、相邻关系等问题,且存在同物异谱、异物同谱现象,导致水体提取精度较低。而传统基于分类提取水体方法设计特征过程较为繁琐,且不能挖掘深度信息特征。因此,本文提出改进的U-Net网络语义分割方法,借鉴经典U-Net网络的解编码结构对网络进行改进:① 将VGG网络用于收缩路径以提取特征;② 在扩张路径中对低维特征信息进行加强,将收缩特征金字塔上一层的特征图与下一层对应扩张路径上的特征图进行融合,以提高提取结果分割精度;③ 在分类后处理中引入条件随机场,以将分割结果精细化。在保持相同训练集、验证集和测试集的情况下,分别用SegNet、经典U-Net网络和改进的U-Net网络做对照试验。试验结果表明,改进的U-Net网络结构在IoU、精准率和Kappa系数指标上均高于SegNet和经典U-Net网络,与SegNet相比,3项指标分别提升了10.5%、12.3%和0.14,与经典U-Net网络结果相比,各个指标分别提升了5.8%、4.4%和0.05。改进的网络水体提取结果较为完整,对小目标水体能够准确提取。改进的U-Net网络能够有效地实现水体提取任务。  相似文献   

18.
随着西部大开发战略的实施以及“一带一路”战略的影响,西北地区的城市发展也发生着巨大变化,利用遥感影像更加准确地提取西北地区城市建筑用地信息对分析城市扩张趋势、规划城市建设具有重要意义。本文以2000年兰州市主城区和2003年西宁市主城区的Landsat 7 ETM +影像为数据源,结合压缩数据维的方法,通过构建三指数合成影像并利用该影像来提取城市建筑用地信息。实验首先根据兰州市主城区的影像光谱特征,创建了归一化差值裸地指数(NDBLI)。然后将该指数与比值居民地指数(RRI)、修正型归一化水体指数(MNDWI)合成为一个包含3个波段的新型三指数合成影像NRM(NDBLI、RRI、MNDWI);同时,根据集成学习思想,为增强城市建筑用地信息,将主成分分析的第一波段(PC1)、归一化差值建筑用地指数(NDBI)和比值居民地指数(RRI)合成为一个包含3个波段的新型三指数合成影像PNR(PC1、NDBI、RRI);最后分别将三指数合成影像NRM和三指数合成影像PNR作最大似然分类提取城市建筑用地信息,将其提取结果与由归一化差值建筑用地指数(NDBI)、修正型归一化水体指数(MNDWI)和土壤调节植被指数(SAVI)所创建的NMS(NDBI、MNDWI 、SAVI)影像得到的最大似然分类结果作精度比较,并利用西宁市主城区影像对本文方法进行了相应验证。结果表明,利用三指数合成影像PNR提取城市建筑用地的总精度和Kappa系数最高,其总精度达到了90%以上,适合于提取西北地区含裸地较多的城市建筑用地。  相似文献   

19.
近年来,城市发展快速,大量人口奔向城市工作生活,城市建筑物的数量有如雨后春笋般扩张,需要合理地规划城市土地资源,遏制违规乱建现象,因此基于高分辨率遥感影像,对建筑物进行准确提取,对城市规划和管理有着重要辅助作用.本文基于U-Net网络模型,使用美国马萨诸塞州建筑物数据集,对网络模型结构进行探究,提出了一种激活函数为EL...  相似文献   

20.
1 IN T R O D U C T IO NZhaoyuan C ity, located in northeast of ShandongProvince,iscalled "G old C ity"and itisone ofim portantgold production bases in C hina.The exploitation ofthegold broughtoutthe extensive vacantareas,leading tolarge-scale ground subsi…  相似文献   

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