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1.
陈育峰 《遥感学报》1997,1(1):74-79,84
该文以地理信息系统为支持手段 ,根据Holdridge气候—植被生命地带的分类体系 ,首先研究了在目前气候条件下中国Holdridge生命地带空间分布的基本格局 ;然后采用GFDL、GISS、OSU3个GCMs模拟的 2×CO2 情景下的气温和降水作为未来气候条件 ,揭示了 2×CO2 情景下中国Holdridge生命地带在空间分、面积以及海拔高度等方面的变化  相似文献   

2.
We used GIS‐based techniques and inductive‐spatial modelling to analyse spatial interactions between predator and prey populations, a unique example of an extension to an existing ecological approach. The approach identifies spatial predictors of predation and is demonstrated for braided riverbed habitat in the Mackenzie Basin, New Zealand. This habitat is highly modified and is the focus of intensive management because of the presence of introduced mammalian predators and their native prey (primarily nests of ground‐nesting native birds that are extremely vulnerable to predators). Native prey are currently in decline due to predation; GIS techniques therefore have the potential to augment conventional ecological techniques and management practices. Predation risk to nests of ground‐nesting birds was interpolated across an area using inverse distance weighting. A linear regression model for spatio‐temporal predictors of nest predation was deter‐mined using a predation risk surface and three separate surfaces representing predator abundance, prey abundance, and habitat structure. These measures can enhance the non‐spatial results from conventional ecological inquiry and help solve pest management problems affecting the natural environment.  相似文献   

3.
水是人类生活中广泛使用的重要资源,一旦开发利用不当,不仅会制约国民经济发展、破坏生态环境,还会引起水位持续下降、水质恶化和地面沉降等现象.而运用GRACE卫星时变重力场模型可以有效计算出陆地总水储量变化,同时结合相应水文模型还可以反演出地下水储量的变化,其相对于传统监测地下水方法具有简便、可以大范围进行监测以及预防由水...  相似文献   

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6.
人口统计数据空间化是解决统计数据与自然要素数据融合分析的有效途径。本文以张家界市永定区为研究单元,对小尺度区域的人口密度空间分布模拟进行了初步研究。文章根据2005年《永定区统计年鉴》所统计的人口数据,分析了永定区各乡镇平均人口密度与土地利用类型指数及地形指数(平均高程和平均坡度)之间的相关性。基于相关性分析,以GIS软件与SPSS统计软件为工具,运用多元回归的思想建立了人口数据空间化模型,同时生成了永定区250m×250m空间分辨率的栅格人口密度图。结果表明,模型模拟的精度较高,模拟过程具有较强的可操作性,可为县域尺度人口空间分布的应用研究提供借鉴。同时,研究结果为永定区推进城市化进程,提高人口、资源和环境的科学管理提供了理论基础。  相似文献   

7.
This study maps the geographic extent of intermittent and seasonal snow cover in the western United States using thresholds of 2000–2010 average snow persistence derived from moderate resolution imaging spectroradiometer snow cover area data from 1 January to 3 July. Results show seasonal snow covers 13% of the region, and intermittent snow covers 25%. The lower elevation boundaries of intermittent and seasonal snow zones increase from north-west to south-east. Intermittent snow is primarily found where average winter land surface temperatures are above freezing, whereas seasonal snow is primarily where winter temperatures are below freezing. However, temperatures at the boundary between intermittent and seasonal snow exhibit high regional variability, with average winter seasonal snow zone temperatures above freezing in west coast mountain ranges. Snow cover extent at peak accumulation is most variable at the upper elevations of the intermittent snow zone, highlighting the sensitivity of this snow zone boundary to climate conditions.  相似文献   

8.
本文探讨了制约地图符号设计的内在的基本规律,提出了地图符号的约定性原则和等价性原理。把作为地图符号的物质时象同传输过程中的地图符号区别开来,分析了地图符号的价值及价格,并对内涵地图符号和外延地图符号及其相互关系进行了研究,最后提出了新的地图符号分类原理。  相似文献   

9.
The main aim of present study is to compare three GIS-based models, namely Dempster–Shafer (DS), logistic regression (LR) and artificial neural network (ANN) models for landslide susceptibility mapping in the Shangzhou District of Shangluo City, Shaanxi Province, China. At First, landslide locations were identified by aerial photographs and supported by field surveys, and a total of 145 landslide locations were mapped in the study area. Subsequently, the landslide inventory was randomly divided into two parts (70/30) using Hawths Tools in ArcGIS 10.0 for training and validation purposes, respectively. In the present study, 14 landslide conditioning factors such as altitude, slope angle, slope aspect, topographic wetness index, sediment transport index, stream power index, plan curvature, profile curvature, lithology, rainfall, distance to rivers, distance to roads, distance to faults and normalized different vegetation index were used to detect the most susceptible areas. In the next step, landslide susceptible areas were mapped using the DS, LR and ANN models based on landslide conditioning factors. Finally, the accuracies of the landslide susceptibility maps produced from the three models were verified using the area under the curve (AUC). The validation results showed that the landslide susceptibility map generated by the ANN model has the highest training accuracy (73.19%), followed by the LR model (71.37%), and the DS model (66.42%). Similarly, the AUC plot for prediction accuracy presents that ANN model has the highest accuracy (69.62%), followed by the LR model (68.94%), and the DS model (61.39%). According to the validation results of the AUC curves, the map produced by these models exhibits the satisfactory properties.  相似文献   

10.
GPS内部频偏的一种估算法   总被引:1,自引:0,他引:1  
许琛  王解先 《测绘通报》2001,(12):16-17
GPS卫星和地面接收机产生的内部频偏,会使观测的载波相位产生一偏差,这相当于增加了信号在传播路线上的时延,其值构为米级。为了提高GPS定位精度,必须对此偏差进行求解,介绍一种估算法,能快速的解出内部频偏值。  相似文献   

11.
[35]Braun M,Rau F.Using a multi_year data archive of ERS SAR imagery for the monitoring of firn line positions and ablation patterns on the King George Island ice cap (Antarctica).The Workshop of EARSeL Special Interest Group:Remote Sensing of Land Ice and Snow.Dresden,2000(published on CD_Rom in 2001) [36]Rau F,Braun M,Friedrich M,et al.Radar glacier zones and its boundaries as indicators of glacier mass balance and climatic variability.The Workshop of EARSeL Special Interest Group:Remote Sensing of Land Ice and Snow.Dresden,2000(published on CD_Rom in 2001) [1]Bahr D B.Global distribution of glacier properties:A stochastic scaling paradigm.Water Resource Research,1997,33(7):1 669~1 679 [2]Bahr D B,Meier M F.Snow patch and glacier size distributions.Water Resource Research,2000,36(2):495~501 [3]Braun M,Schneider C.Characteristics of summer energy balance on the west coast of the Antarctic Peninsula.Annals of Glaciology,2000,31:179~183 [4]Braun M,Rau F,Saurer H,et al.The development of radar glacier zones on the King George Island Ice Cap (Antarctica) during the Austral summer 1996~1997 as observed in ERS_2 SAR data.Annals of Glaciology,2000,31:357~363 [5]Calvet J,Corbera J,Furada G.Variacion del frente glaciar en Bahia Sur y Punta Siddons entre 1956 y 1991,Isla Livingston,Islas Shetland del Sur.In: López_Martinez,J.: Geología de la Antártida Occidental.III Congreso Geológico de Espana y VIII Congreso Latinoamericano de Geología,Salamanca,Espana,1992.283~292 [6]Doake C S M,Vaughan D G.Rapid disintegration of the Wordie Ice Shelf in response to atmospheric warming.Nature,1991,350(6 316):328~330 [7]Doake C S M,Corr H F J,Rott H,et al.Break_up and conditions for stability of the northern Larsen Ice Shelf,Antarctica.Nature,1998,391:778~780 [8]Fox A J,Cooper A P R.Climate_change indicators from archival aerial photography of the Antarctic Peninsula.Annals of Glaciology,1998,27:636~642 [9]Harangozo S A,Colwell S R,King J C.An analysis of a 34_year air temperature record from Fossil Bluff (71° S,68° W),Antarctica.Antarctic Science,1997,9(3):355~363 [10]Hulbe C L.Recent changes to Antarctic Peninsula ice shelves: what lessons have been learned? Natural Science,1997,1(6) [11]Jones P D.Antarctic temperatures over the present century——a study of the early expedition record.Journal of Climate,1990,3:1 193~1 203 [12]Kieffer H and 41 others.New eyes from the skye measure glaciers and ice sheets.EOS,2000,81(24):265,270~271 [13]King J C.Recent climate variability in the vicinity of the Antarctic Peninsula.International Journal of Climatology,1994,14:357~369 [14]King J C,Harangozo S A.Climate change in the western Antarctic Peninsula since 1945: observations and possible causes.Annals of Glaciology,1998,27:571~575 [15]Klser H,Arntz W E.RASCAL (RESEARCH on Antarctic Shallow Coastal and Litoral systems).Untersuchungen zur Struktur und Dynamik eines antarktischen Küstenjosystems.Polarforschung,1994,64(1):27~41 [16]Klser H,Ferreyra G,Schloss I,et al.Hydrography of Potter Cove,a small fjord_like inlet in King George Island,South Shetands.Estuarine,Coastal and Shelf Science,1994,38:523~537 [17]Lucchitta B K,Rosanova C E.Retreat of northern margins of George VI and Wilkins Ice Shelves,Antarctic Peninsula.Annals of Glaciology,1998,27:41~46 [18]Morris E M.Surface ablation rates on Moraine Corrie Glacier,Antarctica.Global and Planetary Change,1999,22:221~231 [19]Park B K,Chang S K,Yoon H I,et al.Recent retreat of ice cliffs,King George Island,South Shetland Islands,Antarctic Peninsula.Annals of Glaciology,1998,27:633~635 [20]Rakusa_Suszczewski S.The maritime Antarctic coastal ecosystem of Admiralty Bay.Department of Antarctic Biology,Polish Academy of Sciences,Warsaw,1993.216 [21]Rakusa_Suszczewski S.The hydrography of Admiralty Bay and its inlets,coves and lagoons (King George Island,Antarctica).Polish Polar Research,1995,16(1/2):61~70 [22]Rau F,Braun M,Saurer H,et al.Multi_year snow cover dynamics on the Antarctic Peninsula using SAR imagery.Polarforschung,2000,67(1/2):27~40 [23]Rott H,Skvarca P,Nagler T.Rapid Collapse of northern Larsen Ice Shelf,Antarctica.Science,1996,271:788~792 [24]Rott H,Rack W,Nagler T,et al.Climatically induced retreat and collapse of northern Larsen Ice Shelf,Antarctic Peninsula.Annals of Glaciology,1998,27:86~92 [25]Skvarca P,Rack W,Rott H,et al.Evidence of recent climatic warming on the eastern Antarctic Penisnula.Annals of Glaciology,1998,27:628~932 [26]Simes J C,Bremer U F,Aquino F E,et al.Morphology and variations of glacial drainage basins in the King George Island ice field,Antarctica.Annals of Glaciology,1999,29:220~224 [27]Smith A M,Vaughan D G,Doake C S M,et al.Surface lowering of the ice ramp at Rothera Point,Antarctic Peninsula,in response to regional climate change.Annals of Glaciology,1998,27:113~118 [28]Smith R C,Stammerjohn S E,Baker K S.Surface air temperature variations in the western Antarctic Peninsula region.Antarctic Research Series,1996,70:105~121 [29]Splettstoesser J.Antarctic Global Warming? Nature,1992,355(6 360):503 [30]Stark P.Climatic warming in the central Antarctic Peninsula area.Weather,1994,49(6):215~220 [31]Turner J,Colwel S R,Harangozo S.Variability of precipitation over the coastal western Antarctic Peninsula from synoptic observations.Journal of Geophysical Research,1997,102(D12):13 999~14 007 [32]Warren C R.Iceberg calving and the glaciomarine record.Progress in Physical Geography,1992,16(3):253~282 [33]Wunderle S.Die Schneedeckendynamik der Antarkische Halbinsel und ihre Erfassung mit aktiven und passiven Fernerkundungsverfahren.Freiburger Geographische Hefte,1996,48:172 [34]Braun M,Saurer H,Vogt S,Simes J C,et al.The influence of large_scale atmospheric circulation on surface energy balance on the ice cap of King George Island.International Journal of Climatology,2001,21(1):21~36  相似文献   

12.
Shengjin Lake is the only national wetland nature reserve in Anhui Province with rare wintering waterbirds as the main protection object. In recent years, with the strengthening of human activities, the number of rare cranes has changed significantly. Taking the Shengjin Lake natural wetland as an example, this paper studied the response of crane population to land use change, which had important implications for the protection of cranes. This paper analyzed the land use of Shengjin Lake by referring to the eight periods of TM remote sensing images (1986, 1990, 1995, 2000, 2004, 2008, 2011 and 2015) and using ERDAS and ArcGIS tools. The diversity of bird habitats in Shengjin Lake nature reserve was analyzed. Combined with the changes in the number of rare cranes from 1986 to 2015, the impacts of land use and climate change on the cranes in protected areas were analyzed. The results showed that: there was a correlation between the number of cranes land use types and climate changes. The type of land of Shengjin Lake nature reserve was relatively small change in the early years in 1986. It was a relatively large change in the type of land, and the number of cranes had a significantly reducing in 1990s. It until 2000, the number of rare cranes had a slight rebound; however from 2012 to 2015, the number of cranes had dropped again. It had a greater influence on the number of cranes about the change of construction land, reeds mudflats, mudflats, marsh land and paddy fields in the wetland.  相似文献   

13.
Cropping system study is not only useful to understand the overall sustainability of agricultural system, but also it helps in generating many important parameters which are useful in climate change impact assessment. Considering its importance, Space Applications Centre, took up a project for mapping and characterizing major cropping systems of Indo-Gangetic Plains of India. The study area included the five states of Indo-Gangetic Plains (IGP) of India, i.e. Punjab, Haryana, Uttar Pradesh, Bihar and West Bengal. There were two aspects of the study. The first aspect included state and district level cropping system mapping using multi-date remote sensing (IRS-AWiFS and Radarsat ScanSAR) data. The second part was to characterize the cropping system using moderate spatial resolution multi-date remote sensing data (SPOT VGT NDVI) and ground survey. The remote sensing data was used to compute three cropping system performance indices (Multiple Cropping Index, Area Diversity Index and Cultivated Land Utilization Index). Ground survey was conducted using questionnaires filled up by 1,000 farmers selected from 103 villages based on the cropping systems map. Apart from ground survey, soil and water sampling and quality analysis were carried out to understand the effect of different cropping systems and their management practices. The results showed that, rice-wheat was the major cropping system of the IGP, followed by Rice-Fallow-Fallow and Maize-Wheat. Other major cropping systems of IGP included Sugarcane based, Pearl millet-Wheat, Rice-Fallow-Rice, Cotton-Wheat. The ground survey could identify 77 cropping systems, out of which 38 are rice-based systems. Out of these 77 cropping systems, there were 5 single crop systems, occupying 6.5% coverage (of all cropping system area), 56 double crop systems with 72.7% coverage, and 16 triple crop systems with 20.8% coverage. The cropping system performance analysis showed that the crop diversity was found to be highest in Haryana, while the cropping intensity was highest in Punjab state.  相似文献   

14.
Soil moisture estimation is considered to be one of the important parameters in hydrological studies. The extraction of information on near surface soil moisture from the synthetic aperture radar is well established. The available Advanced Synthetic Aperture Radar (ASAR) data onboard ENVISAT with multi-incidence and multi-polarization mode for soil moisture estimation on sloping terrain was investigated. Empirical models were developed to estimate near surface soil moisture in the fallow agricultural fields by incorporating the effects of surface roughness using multi-incidence angle ASAR data. Medium incidence angle (IS-4) with VV polarization of ASAR data had higher correlation coefficient to volumetric soil moisture content. The ratio of medium (IS-4) to high incidence (IS-6) angle could further reduce the effect of surface roughness. The effect of topography on the radar data is taken care by calculating local incidence angle derived from ASTER DEM data. The VV polarization in the sloping terrain provided better results in comparison to VH polarization.  相似文献   

15.
普通克里金方法具有空间结构探索及插值分析(给出插值结果及其精度)的功能。但是,绝大部分的克里金方法主要用于空间插值,在时空插值方面的研究还较少。综合考虑具体的实验区域和观测数据构建基函数,使用秩修正滤波(fixed rank filtering,FRF)方法对MODIS平流层温度数据进行时空插值预测并将其结果与秩修正克里金(Fixed rank Kriging,FRK)方法的插值结果进行对比分析。实验结果表明,在空间数据(空间点)整体分布均匀且有已知点的情况下,FRK方法预测的数据精度更高,略优于FRF;而对于较大空间范围内缺失数据的情况,考虑温度在时间维上具有一定的相关性,FRF方法在缺失空间信息时能够引入更多时空信息从而获得较其他方法更高质量的插值结果。  相似文献   

16.
基于Web Services的GIS与应用模型集成研究   总被引:41,自引:1,他引:41  
于海龙  邬伦  刘瑜  李大军  刘丽萍 《测绘学报》2006,35(2):153-159,165
分析GIS与应用模型集成的研究现状及存在的问题。针对存在的问题,提出基于Web Services的GIS与应用模型集成方法。具体定义应用模型服务体系及其与空间信息服务体系的关系,讨论基于服务链的GIS-ervices与应用模型服务集成服务链样式、集成实现过程、集成开发流程,给出基于服务集成实现小流域地貌演化问题计算的服务集成分析设计与实验结果。实验结果证明本文提出的基于Web Services的GIS与应用模型集成方法正确可行。  相似文献   

17.
本文基于MAPGIS空间数据存储技术、MAPGIS二次开发技术和资源管理技术为关键技术,建立了全国矿权储量图形数据库,综合分析矿权设置的区域特点,采矿权、探矿权区块内的储量信息.利用图形数据一体化技术建立矿权储量综合管理信息系统,加强油气地质与开发方面的信息服务,有力支撑油气资源管理工作.  相似文献   

18.
A novel algorithm for estimating the rotation angle in inverse synthetic aperture radar imaging by generally considering the received signals as cubic phase signals is presented. The rotation angle is determined by the coefficients of the cubic phase signals, and the results of real data demonstrate the validity of the algorithm.   相似文献   

19.
Fertility, or the availability of nutrients and water, controls forest productivity. It affects its carbon sequestration, and thus the forest's effect on climate, as well as its commercial value. Although the availability of nutrients cannot be measured directly using remote sensing methods, fertility alters several vegetation traits detectable from the reflectance spectra of the forest stand, including its pigment content and water stress. However, forest reflectance is also influenced by other factors, such as species composition and stand age. Here, we present a case study demonstrating how data obtained using imaging spectroscopy is correlated with site fertility. The study was carried out in Hyytiälä, Finland, in the southern boreal forest zone. We used a database of state-owned forest stands including basic forestry variables and a site fertility index. To test the suitability of imaging spectroscopy with different spatial and spectral resolutions for site fertility mapping, we performed two airborne acquisitions using different sensor configurations. First, the sensor was flown at a high altitude with high spectral resolution resulting in a pixel size in the order of a tree crown. Next, the same area was flown to provide reflectance data with sub-meter spatial resolution. However, to maintain usable signal-to-noise ratios, several spectral channels inside the sensor were combined, thus reducing spectral resolution. We correlated a number of narrowband vegetation indices (describing canopy biochemical composition, structure, and photosynthetic activity) on site fertility. Overall, site fertility had a significant influence on the vegetation indices but the strength of the correlation depended on dominant species. We found that high spatial resolution data calculated from the spectra of sunlit parts of tree crowns had the strongest correlation with site fertility.  相似文献   

20.
将遥感手段和动力估产模型相结合,即通过NOAA卫星获得有效绿度模式;通过绿度-叶面积关系式,估算水稻群体叶面积指数;依据水稻生物量分配规律及环境条件对其影响,估算水稻各器官的干重,取得了较好的模拟效果。  相似文献   

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