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基于ASTER数据遥感影像的决策树分类 总被引：6，自引：0，他引：6
以黑龙江省北安市为研究区域,尝试利用ASTER视反射率值进行便利、准确的土地利用分类研究。对ASTER数据进行波段相关分析,确定最佳组合波段;然后重点分析转换为视反射率值的影像特征和光谱特征,从中提取各种典型地物的光谱曲线; 并依据提取的光谱曲线建立基于地物反射率值大小关系或阈值的决策树模型,对研究区不同地物类型进行分类,并对结果进行精度评价。应用效果表明,该方法简单有效,但对于混合光谱容易错分。 相似文献
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地表塌陷积水和煤堆的识别与区分是煤矿开采区环境保护的重要工作内容。本文利用HJ-1A卫星CCD遥感影像数据,以神东矿区为例,在深入分析矿区煤堆、塌陷积水、其它水体和工矿用地等地物的光谱特征基础之上,通过波段反射率差异和归一化水体指数(NDWI)构建了矿区内煤堆和塌陷积水的遥感提取与识别决策树模型。模型分析表明,塌陷积水的NDWI指数范围为[0.02,0.13],与部分裸土/工矿用地容易混合,需要利用红光通道阈值进行剔除。煤堆与其他非水体地物都有较明显的区分但与塌陷水体较为一致,需进一步通过红色通道阈值加以区分,当阈值为0.14时研究区提取结果最佳。研究区内共提取出煤堆373个,面积4.96 km2,塌陷积水11个,面积0.51 km2。通过与2.5 m空间分辨率的SPOT卫星目视解译验证表明,本文利用HJ-1A CCD影像数据识别总精度可达97.77%,构建的决策模型适用于矿区内煤堆及水体信息的自动提取。 相似文献
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用卫星高光谱数据提取江西德兴铜矿矿山废水的pH值污染指标 总被引：3，自引：0，他引：3
在对德兴铜矿矿山废水的光谱特征深入分析研究的基础上,总结了不同类型水体(酸性水、碱性水以及河流水)的特征光谱,并利用地物谱特征开展矿山废水pH值污染指标提取研究。针对水体光谱反射率低、特征光谱不明显的特点,采用矿区卫星Hyperion高光谱数据,应用ISA算法和掩膜技术识别出水体分布并进一步与MNF变换有效结合,根据波段散点图进行不同pH值水体的有效分割。为矿山废水污染的诊断和监测提供了新技术和理论支撑。 相似文献
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新疆西准噶尔包古图斑岩铜矿蚀变岩石的光谱特征及其意义 总被引：2，自引：1，他引：1
地物的光谱特征是遥感识别地物的主要依据,不同地物的反射光谱具有其特定的吸收特征谱带。利用ASD和PIMA反射光谱测试仪对新疆西准噶尔包古图斑岩铜矿Ⅱ号、Ⅴ号斑岩铜矿岩体的蚀变围岩(地表采样与钻井采样)进行测试,并对结果进行分析总结。根据反射光谱特征谱带获得蚀变矿物的种类,确定了岩体的蚀变矿物组合,得到反射光谱的吸收谷在ASTER数据中所处的波段;对反射光谱曲线进行数学积分,获得ASTER数据中的强吸收波段。将以上2种分析得到的吸收性波段组合应用于蚀变遥感异常信息提取,结果表明蚀变遥感异常与野外地质特征吻合程度较高。反射光谱分析表明确定岩石矿物的反射光谱特征谱带是进行遥感信息提取工作的前提,波段组合选取对提取蚀变遥感异常信息非常重要。 相似文献
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以皖南山区秋浦河流域为研究对象,综合利用OLI影像和DEM数据,针对山区水体提取中出现的阴影问题和河流断线问题提出一种新的解决思路。首先通过比较单波段阈值法、NDWI水体指数法、谱间关系法以及SWI阴影水体指数几种水体提取方法,显示SWI能够剔除大部分山体阴影;其次使用基于数学形态的膨胀滤波和Pavlidis图像细化算法对SWI提取结果进行处理,较短水体的断线得到连接;最后对于水体断线严重的上游河流,利用DEM进行河网的提取,并以提取的河网代替水体指数的提取结果。结果表明,基于OLI和DEM数据进行山区水体的提取,方法简单,提取的面状水体齐全,线状水体连续,精度达到83.2%,该方法可为其他山区地形水体提取提供一定的借鉴。 相似文献
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ASTER遥感影像数据在土壤盐渍化评价中的应用 总被引：4，自引：0，他引：4
本文通过运用ASTER遥感影像数据，对不同地物进行光谱分析，根据不同地物在不同波段的光谱特征曲线，分别提取植被和水体信息，然后进行非监督分类。并结合物探试验和土样分析结果，进行聚类分析，定性和定量的评价了焉耆盆地内土壤盐渍化程度分布状况。评价结果为：在焉耆盆地的平原区内，非盐渍化土壤，457．65km^2；轻度盐渍化土壤，335．61km^2；中度-重度盐渍化土壤，580．93km^2；盐土，41．11km^2。根据野外实际调查，评价结果的精度达到了85％以上。 相似文献
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基于长江与洞庭湖一、二维耦合水动力模型,模拟了三峡水库蓄水前后洞庭湖湖区的水文过程,定量分析了蓄水期三峡水库蓄水与洞庭湖出湖水量的响应关系。结果表明:蓄水期三峡水库蓄水减少了荆江三口进入洞庭湖的水量,同时也改变了洞庭湖湖容变化的速度;相比还原情况,各典型年下9-10月洞庭湖出湖水量均明显减少,且10月份减少幅度大于9月份,11月变化不显著;9-10月荆江三口水量变化是洞庭湖出湖水量变化的主导因素,而11月主导因素是湖容的变化。通过多元回归分析,构建了三峡水库蓄水量与洞庭湖出湖水量、湖容变化量的响应关系,在湖容不变情况下,洞庭湖出湖水量减少量约为三峡水库蓄水量的23%。 相似文献
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The ecological state of the Inari Lake–Pasvik River system, the largest in northern Fennoscandia (in the near-border territories of Russia, Norway, and Finland) was assessed based on studying concentrations of heavy metals (HM) in the bottom sediments (BS). The water body (Kuetsjarvi Lake) contaminated with liquid wastes from the Pechenganickel smelter contains the highest HM (Ni, Cu, Co, Zn, Pb, Cd, Hg, and As) concentrations in the uppermost BS layers. In water bodies down and up the Pasvik River of the discharge site of waste waters from the smelter, the uppermost BS layers do not contain elevated concentrations of contaminating HM typical of the area (Ni, Cu, Co, Zn) but do contain higher concentrations of chalcophile elements (Pb, Cd, Hg, and As), which come mostly from trans-border sources. In the lakes receiving domestic wastes, phosphorus concentrations increase up the vertical section of the BS, which may suggest the development of eutrophication processes. They result in reducing conditions in the bottom waters and uppermost BS layers and, consequently, the transfer of ionic species of elements susceptible to variations in the redox potential from BS to waters. This process leads to depletion of the uppermost BS layers, first of all, in Fe and Mn and also in HM adsorbed on the surface of Fe and Mn oxides and hydroxides. In the water bodies that have preserved their oligotrophic nature, the uppermost BS layers were determined to accumulate Fe and Mn, whose concentrations are up to 50 times higher than the Earth’s crust average and the background values. Quantitative parameters of the factors and degrees of contamination are determined, as also are the ecological risk indexes for the contamination of the water bodies with HM, using the L. Håkanson method adapted to the regional conditions. The nonessential metals Hg and Cd, which are the most toxic and dangerous for hydrobionts, are determined to be the most ecologically hazardous in all of the water bodies. Nickel is a highly ecologically hazardous element in a single water body: Kuetsjarvi Lake. In all other water bodies of the Inari Lake–Pasvik River system, elements emitted and discharged by the smelter (Ni, Cu, Co, Pb, and As) are moderately and low ecologically hazardous for the aquatic systems. 相似文献
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利用统计分析的方法,根据2001年获取的13景鄱阳湖区无云MODIS影像中的9景提取的水体面积,并结合同步观测的水文数据分别采用线性、对数和指数3种模型模拟湖面积-水位之间关系。结果显示对数模型相关性最好（R2=0.918）,其次为线性和指数模型。利用另外4景MODIS影像对模型进行检验表明,该模型精度较高,模拟的最大误差为3.36%。本研究显示,可根据鄱阳湖水位观测值,利用该模型预测鄱阳湖洪涝期洪水淹没面积,以弥补云天状况下光学遥感难以监测到洪水淹没范围的不足。本研究为利用遥感影像实时监控鄱阳湖水情空间动态变化提供了可行的方法,对湖泊、水库的泛洪监测、调洪功能分析具有重要意义。 相似文献
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A. P. Lisitzin Yu. K. Vasil’chuk V. P. Shevchenko N. A. Budantseva E. D. Krasnova A. N. Pantyulin A. S. Filippov Ju. N. Chizhova 《Doklady Earth Sciences》2013,449(2):406-412
This study aimed to analyze the oxygen isotope composition of water, ice, and snow in water bodies isolated from the White Sea and to identify the structural peculiarities of these pools during the winter period. The studies were performed during early spring in Kandalaksha Bay of the White Sea, in Velikaya Salma Strait and in Rugoserskaya Inlet. The studied water bodies differ in their degree of isolation from the sea. In particular, Ermolinskaya Inlet has normal water exchange with the sea; the Lake on Zelenyi Cape represents the first stage of isolation; i. e., it has permanent water exchange with the sea by the tide. Kislo-Sladkoe Lake receives sea water from time to time. Trekhtsvetnoe Lake is totally isolated from the sea and is a typical meromictic lake. Finally, Nizhnee Ershovskoe Lake exhibits some features of a saline water body. The oxygen isotope profile of the water column in Trekhtsvetnoe Lake allows defining three layers; this lake may be called typically meromictic. The oxygen isotope profile of the water column in Kislo-Sladkoe Lake is even from the surface to the bottom. The variability of δ18O is minor in Lake on Zelenyi Cape. A surface layer (0–1 m) exists in Nizhnee Ershovskoe Lake, and the oxygen isotope variability is well pronounced. Deeper, where the freshwater dominates, the values of ?18Îvary insignificantly disregarding the water depth and temperature. This fresh water lake is not affected by the seawater and is not stratified according to the isotope profile. It is found that applying the values of ?18Î and profiles of temperature and salinity may appear as an effective method in defining the water sources feeding the water bodies isolated from the sea environment. 相似文献
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Holocene Saline Sedimentary Record in Tibetan Dong Co (Lake) and Its Significance on Palaeoclimate 总被引：2，自引：0，他引：2
HOLOCENE SALINE SEDIMENTARY RECORD IN TIBETAN DONG CO(LAKE) AND ITS SIGNIFICANCE ON PALAEOCLIMATE 相似文献
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Water surface variations monitoring and flood hazard analysis in Dongting Lake area using long-term Terra/MODIS data time series 总被引：4，自引：0，他引：4
Dongting Lake is the second largest freshwater lake in China, and its water surface area varied very significantly during
last decade. Remote sensing technology has more advantages in macro monitoring of lake water surface area than the traditional
methods. In the paper, an integrated threshold method of water body extraction based on MODIS data is given, which synthesizes
several factors, including vegetation index—NDVI, spectrum characters of water body, cloud and shadow, and the SRTM digital
elevation information. With this method and 356 scenes MODIS 8-Day composite (MOD09Q1) image, water surface area of Dongting
Lake was dynamically monitored from 2000 to 2009. The result shows that during 1 year, the water area variation in Dongting
Lake area had a typical seasonal (monsoon) behavior, and during last decade, the water area decreased gradually and obviously.
Based on variation monitoring, yearly max-submersion time index has been suggested to analyze flood hazard in study area.
With the support of ArcGIS software, authors estimated the yearly submersion time of the Dongting Lake for each year separately
and average submersion time from 2000 to 2009. The result shows 67.46% of study area is being with high flood hazard. 相似文献
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黄骅坳陷板桥地区古近系沙河街组沙二段具有典型的湖泊滩坝沉积特点,其砂体内部主要发育泥质、钙质和致密粉砂质3种类型的隔夹层。利用构型分析法,将滩坝砂体分为复合坝、单一坝和坝内增生体3个构型要素,将内部隔(夹)层分为单一坝间隔层和单一坝内夹层2个级别。单一坝间隔层具有3种成因机制:(1)基准面波动造成单一坝叠置区分布的细粒沉积;(2)风暴作用形成的滞留泥砾沉积;(3)坝后水动力低能区域形成的泥质沉积。单一坝内夹层则是波浪能量衰减形成的细粒沉积,岩性以粉砂质泥岩、泥质粉砂岩为主。通过分析夹层的井上识别特征,结合青海湖、岱海现代沉积的原型地质模式,对单一坝进行内部构型解剖。结果表明,夹层厚度为0.1～1m,靠近岸线近水平分布,向湖中心方向以低角度倾斜,倾角为2°～5°。不同级次与成因的隔(夹)层在滩坝砂体中都有特定的发育部位,其分布规律和空间配置关系不仅可以反映不同隔(夹)层的沉积时间顺序,还可以依此来推测滩坝的沉积规模与展布形态。隔(夹)层会导致含油气性的差异,认识隔(夹)层分布规律是提高滩坝储集层油气采收率的关键。 相似文献
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通过实测查干湖高光谱数据,建立透明度(Secchi Disk Depth,SDD)单波段估测模型、比值估测模型以及神经网络高光谱估测模型,并以确定性系数R2以及剩余残差RMSE为指标进行了验证.通过对单波段估测模型和比值估测模型进行比较发现,单波段模型估测结果与比值模型相差无几,而水体透明度经对数处理有利于模型精度提高,但是神经网络模型是三者中最优的.查干湖透明度高光谱定量估测模型的建立,有利于今后利用遥感影像,对查干湖水体透明度进行全面估测,对于研究和监测查干湖水体水质状况有重要意义. 相似文献
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鄱阳湖是我国重要的湿地生态系统,对调节流域的水沙变化有着重要作用。由于鄱阳湖湖区面积广,内部差异大,单一的悬浮泥沙反演模型不足以准确反演出湖区的悬浮泥沙浓度。以实测的反射光谱数据、泥沙浓度数据为基础,提出一种基于分类后的反演模型,即根据实测数据的光谱形态特征分类出5种典型的水体类型。在此基础上,将分类后的各类水体分别建立各自合适的反演模型进行反演。结果表明基于水体分类的经验模型反演达到满意效果,平均绝对误差为0.00217g/L,平均相对误差为3.022%。基于分类后的经验反演模型适用于鄱阳湖悬沙浓度分布的监测研究,有助于更加宏观、准确的掌握鄱阳湖泥沙浓度的空间分布和变化,为保持鄱阳湖资源的可持续开发与利用提供决策依据。 相似文献
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采用典型测站观测资料与水力学原理相结合,分析不同情况下城陵矶水位与洞庭湖区水位关联性强弱转化的机理和临界条件以及三峡水库对其影响等问题。理论解析表明,固定流量下,湖区水位与城陵矶水位相关关系应为单调指数函数,受到区间距离、湖槽形态等多因素影响,据此提出和率定了各湖区水位的经验计算模式。利用经验计算模式对实测数据进行延展,构建了各种可能出现的湖区来流和干流水位组合下的湖区水位特征曲线族,发现湖区水位与城陵矶水位之间的关联强度存在无影响区、影响区和决定区等状态区间,通过对临界条件的定义和计算,实现了各状态区间的定量划分,并提出了各状态区间内洞庭湖区水位的估算方法。通过对三峡水库蓄水后湖床冲淤和水文条件变化的影响分析,论证了以上方法和认识在水库蓄水后的适用性。 相似文献