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

2.
Land-cover survey in northeast China using remote sensing and GIS   总被引:1,自引:0,他引:1  
I.INTRODUCTIONWiththerapiddevelopmentofnationaleconomyandthegrowthofthepopulationsincethe1990s,therecomesnewdemandsforexploit...  相似文献   

3.
Advances in Research on Soil Moisture by Microwave Remote Sensing in China   总被引:2,自引:0,他引:2  
Soil moisture is an important factor in global hydrologic circulation and plays a significant role in the research of hydrology, climatology, and agriculture. Microwave remote sensing is less limited by climate and time, and can measure in large scale. With these characteristics, this technique becomes an effective tool to measure soil moisture. Since the 1980s, Chinese researchers have investigated the soil moisture using microwave instruments. The active re- mote sensors are characteristic of high spatial resolution, thus with launch of a series of satellites, active microwave remote sensing of soil moisture will be emphasized. The passive microwave remote sensing of soil moisture has a long research history, and its retrieval algorithms were developed well, so it is an important tool to retrieve large scale moisture information from satellite data in the future.  相似文献   

4.
“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   

5.
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   

6.
1 INTRODUCTIONGlobal change research involves much geo-objectsand geo-process, such as climate and environmentalchange, substance and energy cycling, land-use/land-cover change (LUCC), interactivity between human and nature, etc.. So it need cooperation frommany research communities including international research programs groups such as IGBP (InternationalGeosphere-Biosphere Programme IPCC (Intergovemmental Panel on Climate Change), IHDP (InternationalHuman Dimension Program o…  相似文献   

7.
STUDY ON GIS FOR YIELD ESTIMATION BY REMOTE SENSING IN JILIN MAIZE BELTSTUDYONGISFORYIELDESTIMATIONBYREMOTESENSINGINJILINMAIZ...  相似文献   

8.
UAV remote sensing images have the advantages of high spatial resolution, fast speed, strong realtime performance, and convenient operation, etc., and have become a recently developed, vital means of acquiring surface information. It is an important research task for precision agriculture to make full use of the spectrum, texture, color and other characteristic information of crops, especially the spatial arrangement and structure information of features, to explore effective methods for the cla...  相似文献   

9.
本文以土库曼斯坦马雷绿洲为研究区,建立土地利用程度指数模型,利用2期遥感图像进行土地利用分类,对不同土地利用类型赋予相应属性;用正六边形网格采样,计算每个网格单元的土地利用程度综合指数;利用Kriging方法,对整个研究区进行土地利用程度综合指数插值和预测,分析马雷绿洲土地利用程度。结果表明:(1)研究区可利用土地利用类型主要为草地、耕地和撂荒地,占研究区的50%左右,呈减少态势;(2)研究区土地利用程度由中心向外围呈带状分布,土地利用程度综合指数等值线0.5为研究区绿洲与荒漠分界;(3)研究区中等及以上土地利用程度面积以年均0.079%递减,主绿洲与荒漠的面积比也由2001年的45.14∶54.86分别降为2010年的42.06∶57.94,说明研究区生态环境有恶化的趋势;(4)低、较高、高土地利用程度自身转移率均大于80%,而较低、中等土地利用程度自身转移率在50%左右。本文得到了马雷绿洲土地利用程度空间分布及变化,对研究区社会经济的发展及生态环境的保护具有指导意义,其技术流程和方法对今后的相关研究有一定的借鉴意义。  相似文献   

10.
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   

11.
STUDYONMODELFORREMOTESENSINGESTIMATIONOFMAIZEYIELDLiuZhaoli(刘兆礼)HuangTieqing(黄铁青)WanEnpu(万恩璞)ZhangYangzhen(张养贞)ChangchunInsti...  相似文献   

12.
Through analysis of perpendicular vegetation index (PVI) from combination of visible and near-infrared spectrums reflecting the feature of crop reflectance, we come to the conclusion that the index can better indicate crop instantaneous photosynthesis whereas people generally regard it as the representation of crop leaf area index (LAI). Exploration of crop photosynthesis within a day and its period of duration leads to production of photosynthetic vegetation index (PST) that can reflect the whole crop accumulated photosynthesis, which means the total biomass produced by crop, moreover the method simulating PST is put forward by employment of multi-temporal spectrum parameters. On the basis of the achievements mentioned above, a new comprehensive model for remote sensing estimation of maize yield is established, which can comprehensively show major physiological actions of maize and the course of its yield formation, organically integrate various effective ways of crop yield estimation. It lays a solid foundation for carrying out remote sensing estimation of maize yield on a large scale.  相似文献   

13.
Influenced by artificial factors, landscape pattern of Yantai City, Shandong Province changes continu-ously. Revealing its landscape pattern and its changing process has a practical significance for the urban development and layout. Zhifu District, Development Zone, Laishan District and Fushan District in Yantai City were selected to study the landscape pattern. Remote sensing technology was used to obtain landscape information of different peri-ods. Under the support of Geographic Information System (GIS), the spatial landscape pattern of Yantai City was an-alyzed and simulated by using various special quantitative analysis models. The analysis shows that built-up area lies in the center of Yantai City, the outside is vegetable land. irrigated land, dry land, garden land and woodland.  相似文献   

14.
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   

15.
1INTRODUCTIONResearchonglobalenvironmentalchange,especiallyglobalvegetationchange,hasbeenmoreandmoreemphasizedbyscientistsandgovernments.HoWever,theinvestigationofvegetationcoveredinlargeareaneedagreatdealoffundandlaal.Asthesatelliteremotesensingdatahavebeenavailablesinceearly1980s,thesedataarebeingemployedtowardstOtheimprovementofvegetationclassification.NOAA--AVHRRdatahavebeenmoreandmoreusedbyscientistsbecauseOfitsshorttemPOralrefution,largescope,inexpensivecostandbreadwavebands.On…  相似文献   

16.
Remote sensing technique, replacing conventional sonar bathymetry technique, has become an effective complementary method of mapping submarine terrain where special conditions make the sonar technique difficult to be carried out. At the same time, as one kind of data set, multispectral remote sensing data has the disadvantage of being influenced by the variable bottom types in shallow seawater, when it is applied in bathymetry. This paper puts forward a new method to extract water depth information fi‘om multispectral data, considering the bottom classification and the true water depth accuracy. That is the Principal Component Analysis (PCA) technique based on the bottom classification. By the least square regression with significance, the experiment near Qingdao City has obtained more satisfactory bathymetry accuracy than that of the traditional single-band method, with the mean absolute error about 2.57m.  相似文献   

17.
多源遥感影像数据融合方法在地学中的应用   总被引:6,自引:2,他引:6  
应用遥感影像数据融合理论,研究了光学遥感、热红外遥感、微波遥感卫星在地质学中的应用,论述了不同类型的遥感数据及其他地学数据在不同层次上的同一传感器多波段数据融合、不同SAR图像数据融合、HIS变换、遥感影像与地球物理、地质和航磁等数据的融合。结果表明,数据融合技术在突出地质特征信息方面具有能突出线性构造、断裂构造、地形地貌的优势。  相似文献   

18.
The precision of Aster data is higher than that of Landsat series of multispectral remote sensing data, which can more accurately reveal the distribution of altered minerals. It plays an important role in prospecting, but it is rarely used in areas with complex terrain and high vegetation coverage. Based on this purpose, this study used Aster remote sensing data, and took Gongchangling iron deposit as a case study. It combined the mineral spectrum theory and the basic geologic data of the study ...  相似文献   

19.
多云多雾现象是农作物遥感分类经常遇到的问题,影响分类精度。为解决此类问题,本文提出一种基于时间序列GF-1号遥感影像识别水稻方法。利用多时相时间序列的GF-1号遥感影像提取中稻、晚稻的近红外波段(NIR)反射率、红光(R)波段反射率、归一化植被指数(NDVI)特征;拟合光谱和植被指数时间序列特征曲线;分析多时相影像离散近红外波段 、红光波段、NDVI值落在拟合中稻、晚稻近红外波段、红光波段、NDVI时间序列曲线两侧的敏感性区域的比例,该区域也可以视为水稻作物识别特征的目标特征区域,只有达到一定的比例才能视为某类水稻作物。在此情形下,需要综合3种情况进行集中投票决定其最终分类结果。研究表明:该方法可以在多云雾地区对中稻和晚稻精确识别,中稻和晚稻用户精度可达95.97%和95.95%,总体精度为95.76%,kappa系数为0.9335。实验结果表明了NIR、R、NDVI时间序列曲线拟合的有效性,以及拟合曲线目标特征区域设置的合理性。  相似文献   

20.
Taking TM images, ETM images, SPOT images, aerial photos and other remote sensing data as fundamental sources, this research makes a thorough investigation on landslides and debris flows in Sichuan Province, China, using the method of manual interpretation and taking topography maps as references after the processes of terrain correction, spectral matching, and image mosaic. And then, the spatial characteristics of landslides and debris flows in the year of 2005 are assessed and made into figures. The environmental factors which induce landslides and debris flows such as slope, vegetation coverage, lithology, rainfall and so on are obtained by GIS spatial analysis method. Finally, the relationships of landslides or debris flows with some environmental factors are analyzed based on the grade of each environmental factor. The results indicate: 1) The landslides and debris flows are mainly in the eastern and southern area of Sichuan Province, however, there are few landslides and debris flows in the western particularly the northwestern Sichuan. 2) The landslides and debris flows of Sichuan Province are mostly located in the regions with small slope degree. The occurring rate of debris flow reduces with the increase of the vegetation coverage degree, but the vegetation coverage degree has little to do with the occurrence of landslide. The more rainfall a place has, the easier the landslides and debris flows take place.  相似文献   

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