REMOTE SENSING FOREST BIOMASS: AN EVALUATION USING HIGH RESOLUTION REMOTE SENSOR DATA AND LOBLOLLY PINE PLOTS     

John R. Jensen  Michael E. Hodgson 《The Professional geographer》1985,37(1):46-56

Eight-year-old Loblolly pine (Pinus taeda) plots located in South Carolina were evaluated using high resolution aircraft multispectral scanner data to determine if biomass could be accurately measured. Sixteen pine plots located on both sandy and clay soils were treated with 0, 180, or 360 kg. (approximately 0, 400, or 800 lb.) of nitrogen per plot. Indices of biomass from remote sensing data were significantly correlated with in situ biomass measurements made in each plot. A ratio of infrared (.9–1.1 μm) and red (.65–.70 μm) channels yielded the best correlation. The indices were not sensitive to differences in soil type (sandy or clay).  相似文献   

The Statistical Analysis of Migration of Strong Earthquakes-Taking the North China Region as an Example     

Qin Chengzhi 《中国地震研究》2004,18(2):178-187

The migration of strong earthquakes is an important research topic because the migration phenomena reflect partly the seismic mechanism and involve the prediction of tendency of seismic activity. Research on migration of strong earthquakes has mostly focused on finding the phenomena. Some attempts on getting regularity were comparatively subjective. This paper suggests that there should be indices of migration in earthquake dataset and the indexes should have statistical meaning if there is regularity in the migration of strong earthquakes. In this study, three derivative attributes of migration, i.e., migration orientation, migration distance and migration time interval, were statistically analyzed. Results in the North China region show that the migration of strong earthquakes has statistical meaning. There is a dominant migration orientation (W by S to E by N), a dominant distance (≤100km and on the confines of 300～700km), and a dominant time interval (≤1a and on the confines of 3～4a). The results also show that the migration will differ slightly with different magnitude range or earthquake activity phase.  相似文献   

利用高光谱数据进行植被生化成分反演方法研究   总被引：3，自引：0，他引：3  

张凤丽  万余庆 《地球信息科学学报》2001,3(4):71-75

高光谱数据包含着丰富光谱信息,能够定量地分析物质成分^[1]。由高光谱数据,可以运用多元逐步线性回归方法反演植被生化组分含量,从而达到监测植被生长状况的目的^[2]。本文具体介绍了多元逐步线性回归方法,及其在氮、木质素和纤维素含量估算中的应用。  相似文献   

MONITORING THE DIFFUSION OF SUSPENDED SEDIMENTS AND STABILITY OF TIDAL RADIAL SAND RIDGES AREA USING MULTI-SATELLITE REMOTE SENSING DATA     

黄海军  何宜军 《中国海洋湖沼学报》2001,19(4):361-367

Nine Landsat TM tapes and images and MSS images, 10 NOAA tapes and images and 1 SAR image from 1973 to 1997 were used to analyse the diffusion of suspended sediments and the change of tidal radial sand ridges in the northern part of the Changjiang River delta, the South Yellow Sea. The results showed that the diffusion of suspended sediments was controlled by the tide, net current, and submarine topography in this area. The distribution of suspended sediments had close relationship with thesubmarine topography. The old Huanghe River delta and the Changjiang River comprise the main sediment supply for the formation of radial sand ridges, whose evolution can be divided into three stages since the Huangbe River changed its course and flowed northward into the Bohai Sea.  相似文献   

ANALYSIS ON THE SPATIAL DISTRIBUTION VARIATION CHARACTERISTIC OF URBAN HEAT ENVIRONMENTAL QUALITY AND ITS MECHANISM——A Case Study of Hangzhou City     

WANGWei-wu ZHULi-zhong WANGRen-chao SHIYong-jung 《中国地理科学(英文版)》2003,13(1):39-47

Urban heat environmental quality(UHEQ) is affected by the interacting of weather condition and underlying surface framework of urban area .In the last two decades,many researchers from domestic and overseas have studied many problems at the aspect of urban heat environment such as urban heat islands ,urban air temperature and their rela-tion with urban land cover,city population,air pollution etc,In the recent years,Hangzhou,acting as a center city of Zhejiang Province in China,its urbanization quantum and quantity have both changed greatly,in particular ,representing as business affairs building,resident real property and all kins of specialty market having arisen in built-up zone,Based on Landsat TM images data in 1991 and 1999,urban underlying surface temperature value and Normalized Difference Vegetation Index (NDVI) were calculated using image interpreting and supervised classification technique by remote sensing software ERDAS image 8.4,The relation model between urban underlying surface temperature (UUST )and urban air temperature was setup according to the certain correlation patten .Reference to the relational standard of assessing human comfort and other meteorology data of Hangzhou City in summer,the spatial distribution characteristic and the spatial varia-tion degree of human comfort of heat environmental quality are estimated and mapped on a middle scale,that is ,in six districts of Hangzhou City .Then the paper reveals the main characteristic of spatial variation from 1991 to 1999.Lastly,the change mechanism is analyzed and discussed from the viewpoint of city planning,construction and environmental protec-tion.  相似文献   

REVIEWS OF GEOGRAPHIC SOFTWARE     

《The Professional geographer》1987,39(1):85-94

Reviews of geographic software in this article: DEMO-GRAPHICS: WORLD POPULATIONS AND PROJECTIONS. ESP GAUSS. CEMODEL S. Damus LIMDEP. William H. Greene MICROSTAT 4.1 OTIS PCIPS. (Personal Computer Image Processing System) . H.J. Meyers and R. Bernstein. REGRESSION ANALYSIS OF TIME SERIES (RATS) SPSS/PC+ URBAN DATA MANAGEMENT SOFTWARE (UDMS)  相似文献   

四川汶川MS 8.0大地震地表破裂带的遥感影像解析   总被引：21，自引：1，他引：20  

付碧宏  时丕龙  张之武 《地质学报》2008,82(12):1679-1687

2008年5月12日发生于四川盆地西部龙门山断裂带的汶川MS 8.0级大地震造成巨大的人员伤亡和财产损失,并形成了空间上基本连续分布的地表破裂带（地震断层）。根据地表破裂带的解译标志及影像特征,我们充分利用震后中国科学院航空遥感飞机所获取的高分辨率航空遥感图像以及我国台湾福卫-2卫星遥感图像进行详细解译分析,并结合震后的多次野外科学考察与验证,初步查明了四川汶川MS 8.0级大地震所产生地表破裂带的空间分布特征。遥感解译分析表明汶川大地震产生的地表破裂带总计长约300 km,其几何学特征十分复杂,主要沿先存的NE走向活动断裂带呈不连续展布;变形特征以逆冲挤压为主兼具右旋走滑分量。按同震地表破裂带所在断裂带位置,可将其分为两条： 中央地表破裂带：沿映秀-北川断裂带分布,从西南开始呈北东向延伸至平武县水观乡石坎子北东一带,长约230 km,最大垂直位移量达6.0 m左右,最大右旋水平位移达5.8 m;山前地表破裂带：沿灌县-安县断裂带分布,由都江堰市向峨乡一带开始呈北东向延伸至安县雎水镇一带,长约70 km,以逆冲挤压为主,最大垂直位移量可达2.5 m。此外,遥感图像分析还表明上述地表破裂带与地质灾害分布在空间上具有十分密切的相关性,因此,挤压逆冲-走滑型地震断层的致灾效应研究是未来应该加以重视的研究课题。  相似文献   

基于EOF分析对南海西北海域水体光谱特性的研究   总被引：1，自引：0，他引：1  

付东洋  黄宇业  刘大召  廖珊  余果  张小龙 《海洋学报(英文版)》2020,39(7):107-114

This study presents an analysis of the spectral characteristics of remote sensing reflectance(R_(rs)) in northwestern South China Sea based on the in situ optical and water quality data for August 2018.R_(rs)was initially divided into four classes,classes A to D,using the max-classification algorithm,and the spectral properties of whole R_(rs) were characterized using the empirical orthogonal function(EOF) analysis.Subsequently,the dominant factors in each EOF mode were determined.The results indicated that more than 95% of the variances of R_(rs) are partly driven by the back-scattering characteristics of the suspended matter.The initial two EOF modes were well correlated with the total suspended matter and back-scattering coefficient.Furthermore,the first EOF modes of the four classes of R_(rs)(A-D R_(rs)-EOF_1) significantly contributed to the total variances of each R_(rs) class.In addition,the correlation coefficients between the amplitude factors of class A-D R_(rs)-EOF_1 and the variances of the relevant water quality and optical parameters were better than those of the unclassified ones.The spectral shape of class AR_(rs)-EOF_1 was governed by the absorption characteristic of chlorophyll a and colored dissolved organic matter(CDOM).The spectral shape of class B R_(rs)-EOF_1 was governed by the absorption characteristic of CDOM since it exhibited a high correlation with the absorption coefficient of CDOM(a_g(λ)),whereas the spectral shape of class C R_(rs)-EOF_1 was governed by the back-scattering characteristics but not affected by the suspended matter.The spectral shape of class D R_(rs)-EOF_1 exhibited a relatively good correlation with all the water quality parameters,which played a significant role in deciding its spectral shape.  相似文献   

远区台风“三巴”对长江口波浪动力场的作用机制     

任剑波  何青  沈健  徐凡  郭磊城  谢卫明  朱磊 《海洋科学》2020,44(5):12-23

针对远区台风对河口波浪动力场的影响问题,利用第三代波浪模式SWAN计算了远区台风"三巴"期间长江口波浪动力场分布,分析了陆架至河口区的波浪能量耗散和波致泥沙侵蚀的时空分布,发现波浪由外海向近岸传播过程中,波-波相互作用导致能量由高频向低频转换,周期和波长逐渐增大,近底层轨道流速增大,能量密度增高;阐明白帽破碎是维持深水区波浪能量平衡和限制波高成长的主要机制,底摩擦耗能和水深诱导的破碎耗能是长江口横沙东滩和崇明东滩邻近海域波高衰减的主要原因;提出波浪产生的底部切应力与相对水深有关,当波浪传播到浅水区时,波长和周期越大,波浪切应力越大。研究揭示了与河口相距数百公里的远区台风能够对长江口波浪动力场产生明显影响,河口水下三角洲前缘是最容易受到波浪侵蚀的区域,研究成果弥补了目前关于陆架远区台风对河口波浪动力场影响研究的不足,对深化认识远区台风对长江口动力环境、地貌演变、航运安全和滩涂保护等有重要科学意义。  相似文献   

Remote Sensing Analysis of the Suspended Sediment Transport in Lingdingyang   总被引：1，自引：0，他引：1  

You Yuming Hou Min Senior Engineer  River  Harbour Department  Nanjing Hydraulic Research Institute    Nanjing Assistant Engineer  River  Harbour Department  Nanjing Hydraulic Research Institute    Nanjing 《中国海洋工程》1992,(3)

- The data of landsat TM of multi-temporal for Lingdingyang Estuary, Pearl River in China is firstly used with suspended sediment concentration of field measurement to establish a correlative model equation. After the ratio processing of TM data and atmospheric correction, the images of suspended sediment concentration of different temporals are exported from the image processing systems AREIS II and III. These images express the characteristics of suspended sediment distribution, the mode of sediment transport and the extent of dispersion under the actions of tidal current and wind condition of different seasons.  相似文献