共查询到20条相似文献，搜索用时 46 毫秒
1.
基于遥感的1∶1万土地利用更新调查矢量数据的空间匹配误差是该应用能否实现的关键。实验选取浙江省绍兴市杨汛桥镇为例，利用控制点、检测点GPS野外实测数据，以及同期IKONOS数据，采用对比法，进行了基于SPOT5遥感影像的土地利用更新调查(平原区域)矢量数据的点、面的空间匹配误差的研究，最后得出了点位误差结果：水平方向7.38 m，垂直方向4.53 m，点位平面中误差8.66 m；以及面状地物空间匹配误差结果：绝大部分地类的面积吻合度及相对面积精度都可达95%左右。因此，基于SPOT5影像的1∶1万平原区域土地利用更新调查是完全可行的。 相似文献
2.
基于高光谱和高分辨率影像的土地利用数据库更新研究 总被引：4，自引：1，他引：4
探讨了基于高光谱和高分辨率影像结合下的1∶1万土地利用数据库更新方法。首先应用宜兴试验区128波段OMIS-I机载成像光谱数据，借助基期的土地利用数据库，采用土地利用类型分区控制下的光谱匹配分类获得土地利用/土地覆盖自动分类结果。通过分类结果与历史土地利用数据运算得到土地利用可疑变化区与变化类型。采用高光谱数据和SPOT2.5m全色波段融合影像为底图，在土地利用可疑变化区引导下，采用人机交互方式对变化区矢量数据更新。最后，以高精度GPS配合下进行变化区域野外调查验证，内业修改处理后生成新的土地利用数据库。 相似文献
3.
以延庆县为例,介绍根据TM、SPOT数据复合影像判读土地利用现状的方法。在遥感图像处理、解译的基础上,对各类土地利用的信息进行提取、数据库空间管理、面积求取工作,最后得到延庆全县耕地、园地、林地、水域、交通用地、居民用地、工矿用地以及未利用地等土地利用类型的遥感监测面积和地理分布情况,为县级土地利用现状调查提供方法上的参考和借鉴。 相似文献
4.
基于SPOT5-10 m多光谱数据提取研究区的植被覆盖与土地利用/土地覆盖,利用1:5万DEM数据提取研究区坡度信息,采用中华人民共和国水利部部颁标准评价研究区的水蚀风险等级,并与第二次全国土壤侵蚀遥感(Landsat TM)调查数据进行对比分析.结果表明:(1)从整体上看,区域的侵蚀状况有所好转,侵蚀面积减少了84.10km2,但极强度侵蚀面积增加了6.68 km2,剧烈侵蚀增加了0.03 km2.(2)从空间分布看,大于1 700 m的高程带侵蚀面积最小,500～800 m高程带的侵蚀面积最大,小于5°和大于35°的坡度带侵蚀面积最小,而15°～25°坡度带侵蚀面积最大.研究结果可以作为基础数据,为管理部门进行治理决策依据. 相似文献
5.
GF-1遥感大数据自动化正射校正系统设计与实现 总被引：1，自引：0，他引：1
近年来随着遥感数据的爆炸性增长,快速、稳定的自动化影像正射校正成为遥感大数据处理的重要环节。该文在分析GF-1遥感大数据组织方式与元数据特征的基础上,将有理多项式模型正反变换与数字高程数据提取结合,设计实现自动化正射校正系统,并以提高正射校正计算效率与稳定性为目标,研究待校正影像对应数字高程数据快速提取方法,待校正影像分块读取策略等关键问题。在此基础上针对20景覆盖不同地形区域GF-1 8 m多光谱正射校正影像选择均匀分布的检查点,以Google Earth影像中同名点坐标为真值,分析校正误差及收敛情况,试验结果 X(纬线方向)方向和Y(经线方向)方向最大误差均小于16.863 m,距离误差小于23 m,并且92.25%的检查点误差小于16 m(2个像元)。该文提出的自动化正射校正方案在山地地形与平原地形均表现出良好的校正精度与稳定性。 相似文献
6.
土地利用是区域水土流失动态监测重要的基础数据，是进行土壤侵蚀模数计算、水土保持功能评价和深度分析的前提，以矢量格式为主。为进一步分析土地利用空间分布特征及其与其他水土流失影响因子的关系，需将矢量格式转换成栅格格式。以黄泛平原风沙区河南省兰考县为例，基于ArcGIS 10.2平台，分析2种转换原则、5种栅格尺度下不同土地利用类型的转换特征及差异，探索县域土地利用栅格化最优原则和尺度。结果表明：综合考虑土地利用类型等因素，黄泛平原风沙区县域尺度土地利用矢量数据栅格化时，宜选择RCC原则、10 m尺度。 相似文献
7.
海湾型城市土地利用动态演变及其生态环境效应研究 总被引：2，自引：0，他引：2
土地利用变化研究可为区域可持续发展和生态城市建设提供参考.以厦门市1989年,1997年 LandsatTM 影像以及2004年SPOT影像解译数据基本信息源,结合遥感影像和区域特点,确定土地利用分类系统.在遥感和GIS技术支持下,建立厦门土地利用数据库,并处理各种属性数据、图形数据等信息.对厦门市过去16 a间土地利用的空间分布及其动态变化进行研究,并分析土地利用变化导致的生态环境影响.研究结果表明:厦门土地利用动态表现为耕地面积大量减少,而村镇及建设用地等持续增大,并趋向集中.目前厦门土地利用类型中以林业和耕地为主,其中同安和翔安区拥有丰富的后备土地资源.土地利用变化导致了诸如生物栖息地的丧失、生物多样性破坏、生态环境质量退化、环境容量降低等生态效应. 相似文献
8.
基于无人机影像的农情遥感监测应用 总被引：32，自引：21，他引：11
该文以中国农业科学院（万庄）农业高新技术产业园及周边地区4.2×3.1 km的范围为研究区域,利用无人机搭载RICOH GXR A12型相机进行了航拍试验,主要测试了定位定向系统（positioning and orientation system,POS）数据辅助下光束法区域网平差方法平面定位及面积测量精度,以及无人机影像的作物面积识别精度。结果表明,在无控制点约束条件下,直接采用POS数据进行光束法区域网平差后,以中误差表示的平面定位精度为X轴方向（东西方向）中误差为2.29 m,Y轴方向（南北方向）中误差为2.78 m,整体平面中误差3.61 m;采用3阶一般多项式模型进行几何精校正,X轴方向中误差为1.59 m,Y轴方向中误差为1.8965 m,整体平面中误差为2.32 m,符合《数字航空摄影测量空中三角测量规范》中对1∶10 000平地的平面精度要求,能够满足农作物面积遥感监测中作物面积调查定位精度的要求;采用监督分类和面向对象分类2种方法,对面积评价区域种植的春玉米、夏玉米、苜蓿和裸土4种地物类型进行分类,以差分GPS调查结果为评价标准,4种作物总体识别精度分别达到了88.2%（监督分类）和92.0%（面向对象分类）,单独分类精度分别为88.9%、86.7%、93.0%、86.6%和90.35%、92.61%、94.93%、93.30%。研究结果说明了无人机遥感影像获取小范围、样方式分布的作物影像方面具有广泛的应用前景,推广后能够满足全国农作物地面样方对高空间分辨率影像的需求,可以部分替代现有人工GPS测量的作业方式。 相似文献
9.
松花江流域哈尔滨段土地利用时空格局演变特征分析 总被引：7，自引：3，他引：4
利用1996年、2005年Landsat TM/ETM+遥感影像和野外调查数据,运用ArcGIS分析土地利用变化,并基于DEM探究松花江流域哈尔滨段土地利用空间格局的时空演变。结果表明：区域土地利用空间位置转换面积小于其数量变化,土地利用变化面积大小顺序为：林地＞耕地＞草地＞水域＞未利用地＞建设用地;土地利用转化过程以耕地-林地、草地－林地和未利用地－林地为主,其中耕地－林地相互转换最为剧烈,林地、水域和建设用地具有较高的保留率,草地、未利用地和耕地具有较高的转换率;海拔300～600 m、坡度大于25°的区域,以林地－耕地和草地－耕地为主,局部存在滥垦草地、毁林开荒等现象。该区域是黑龙江省重要粮食产区,此研究有助于加强土地资源的保护和实施退耕还林、还草等农林复合经营措施,对缓解人地矛盾、实现土地资源合理利用及维持区域生态平衡具有重要意义。 相似文献
10.
区域土壤侵蚀遥感抽样调查方法 总被引：6，自引：1，他引：5
土壤侵蚀是全球性环境问题,土壤侵蚀调查是水土保持规划和生态文明建设的科学基础。为了完善土壤侵蚀抽样调查方法,快速、精准地估算土壤侵蚀实际速率,对基于高分辨率遥感影像进行目视解译,提取高精度土地利用和水土保持措施信息的方法进行了研究。基于现代地理信息科学,充分利用虚拟地球及其提供的公开高分辨率遥感数据资源,考虑土壤侵蚀及其治理的时空特征,采用分层不等概系统空间抽样方法布设抽样单元,通过对公开高分辨率遥感影像的目视解译,完成泛第三极地区土地利用和水保措施的遥感抽样调查。研究实现了2万个抽样调查单元的解译,提取了土地利用和水土保持措施信息;基于CSLE模型完成了典型抽样调查单元的土壤流失速率计算,并对解译结果进行了精度和实用性分析。结果表明:基于公开高分辨率遥感影像、利用分层不等概系统空间抽样方法,可快速提取土地利用和水土保持措施信息,完成区域土壤侵蚀抽样调查。 相似文献
11.
低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响 总被引：2，自引：2，他引：0
【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。 相似文献
12.
Aleš Lebeda Ivana Doležalová Eva Křístková Barbora Mieslerová 《Genetic Resources and Crop Evolution》2001,48(2):153-164
Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions. 相似文献
13.
Kyle Devey Michael Mucalo Gordon Rajendram Joseph Lane 《Communications in Soil Science and Plant Analysis》2015,46(4):72-80
Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing. 相似文献
14.
Thomas Larsen Jesper Luxhøi Jakob Magid Lars Stoumann Jensen Paul Henning Krogh 《Biology and Fertility of Soils》2007,44(1):59-68
We have studied the effect of anaerobically digested (ADMSW) and composted municipal solid waste (CMSW) on mineralization
and foodweb dynamics to verify the hypothesis that ADMSW would immobilize N right after addition to soil in contrast to addition
with CMSW. Another hypothesis was that the mesofauna (enchytraeids and microarthropods) would stimulate N release from the
decomposer community. We measured excretion of -N and urea-N from the mesofauna and hypothesized that enchytraeids would release urea. ADMSW and CMSW were amended to pots
with sandy loam and barley. The pots were divided into treatments with or without mesofauna. Mesofauna, plant N and biomass,
soil N and ergosterol (fungal biomass) were measured over a 113-day period of four equidistant samplings. Soil respiration,
N mineralization and N release by the mesofauna were modelled from concurrent studies. ADMSW- and CMSW-treated soils initially
(<20 days) immobilized N. The amendments did not increase plant growth substantially, and this was probably due to N-limitation
in the early stages of plant growth. Enchytraeid abundance was about three times higher in ADMSW- than CMSW-treated soils,
indicating that ADMSW contained more labile compounds, bacteria, and microfauna. The mesofauna did not affect N-content, but
the cumulated -N excreted by the mesofauna was estimated to be substantial and about one-fifth of total plant N in ADMSW. An explanation
for this discrepancy might be that in the absence of the mesofauna, other members of the detrivore and microbivore community
performed the mesofauna’s function. Neither enchytraeids nor microarthropods excreted urea. 相似文献
15.
《中国生态农业学报》2014,(6)
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology, 相似文献
16.
《中国生态农业学报》2014,(7)
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology, 相似文献
17.
《中国生态农业学报》2014,(8)
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology, 相似文献
18.
I.L. Boyd 《Biological conservation》2010,143(7):1664-1674
“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options. 相似文献
19.
Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage 总被引：1，自引：0，他引：1
Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate. 相似文献
20.
M.A. Callaham Jr. J.M. BlairT.C. Todd D.J. KitchenM.R. Whiles 《Soil biology & biochemistry》2003,35(8):1079-1093
The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils. 相似文献