Soil and Vegetation Spectral Coupling Difference (SVSCD) for Minerals Extraction from Hyperion Data in Vegetation Covered Area

Remote sensing data have been widely applied to extract minerals in geologic exploration, however, in areas covered by vegetation, extracted mineral information has mostly been small targets bearing little information. In this paper, we present a new method for mineral extraction aimed at solving the difficulty of mineral identification in vegetation covered areas. The method selected six sets of spectral difference coupling between soil and plant(SVSCD). These sets have the same vegetation spectra reflectance and a maximum different reflectance of soil and mineral spectra from Hyperion image based on spectral reflectance characteristics of measured spectra. The central wavelengths of the six, selected band pairs were 2314 and 701 nm, 1699 and 721 nm, 1336 and 742 nm, 2203 and 681 nm, 2183 and 671 nm, and 2072 and 548 nm. Each data set's reflectance was used to calculate the difference value. After band difference calculation, vegetation information was suppressed and mineral abnormal information was enhanced compared to the scatter plot of original band. Six spectral difference couplings, after vegetation inhibition, were arranged in a new data set that requires two components that have the largest eigenvalue difference from principal component analysis(PCA). The spatial geometric structure features of PC1 and PC2 was used to identify altered minerals by spectral feature fitting(SFF). The collecting rocks from the 10 points that were selected in the concentration of mineral extraction were analyzed under a high-resolution microscope to identify metal minerals and nonmetallic minerals. Results indicated that the extracted minerals were well matched with the verified samples, especially with the sample 2, 4, 5 and 8. It demonstrated that the method can effectively detect altered minerals in vegetation covered area in Hyperion image.

A novel constant interfacial area cell for determining the extraction kinetics of Er(Ⅲ) from chloride medium

A novel constant interfacial area cell(NCIAC),by spatially separating the agitation from liquid flow circulation of organic and aqueous two phases,was suggested to obtain detailed kinetic data for Er(Ⅲ) extraction from chloride medium by 2-ethyl-hexyl-phosphonic acid mono-(2-ethylhexyl) ester(EHEHPA).Different from the traditional Lewis cell and the constant interfacial area cell with laminar flow,the concentrations of Er(Ⅲ) in organic and aqueous two phases were uniform,and the stability of the interfacial area between the two phases could be controlled effectively.Therefore,the special requirements for the design of agitators in the traditional Lewis cell and the constant interfacial area cell for minimizing the influence of diffusion resistance could be avoided.Experimental results indicated that the extraction kinetics was mainly affected by the aqueous flow rate,interfacial area between organic and aqueous two phases,and the aqueous p H values.An extraction kinetic equation was suggested based on the experimental data.

Glacier area change and its impact on runoff in the Manas River Basin,Northwest China from 2000 to 2020

Understanding the distribution and dynamics of glaciers is of great significance to the management and allocation of regional water resources and socio-economic development in arid regions of Northwest China.In this study,based on 36 Landsat images,we extracted the glacier boundaries in the Manas River Basin,Northwest China from 2000 to 2020 using eCognition combined with band operation,GIS(geographic information system)spatial overlay techniques,and manual visual interpretation.We further analyzed the distribution and variation characteristics of glacier area,and simulated glacial runoff using a distributed degree-day model to explore the regulation of runoff recharge.The results showed that glacier area in the Manas River Basin as a whole showed a downward trend over the past 21 a,with a decrease of 10.86%and an average change rate of–0.54%/a.With the increase in glacier scale,the number of smaller glaciers decreased exponentially,and the number and area of larger glaciers were relatively stable.Glacier area showed a normal distribution trend of increasing first and then decreasing with elevation.About 97.92%of glaciers were distributed at 3700–4800 m,and 48.11%of glaciers were observed on the northern and northeastern slopes.The retreat rate of glaciers was the fastest(68.82%)at elevations below 3800 m.There was a clear rise in elevation at the end of glaciers.Glaciers at different slope directions showed a rapid melting trend from the western slope to the southern slope then to the northern slope.Glacial runoff in the basin showed a fluctuating upward trend in the past 21 a,with an increase rate of 0.03×10^(8) m^(3)/a.The average annual glacial runoff was 4.80×10^(8) m^(3),of which 33.31%was distributed in the ablation season(June–September).The average annual contribution rate of glacial meltwater to river runoff was 35.40%,and glacial runoff accounted for 45.37%of the total runoff during the ablation season.In addition,precipitation and glacial runoff had complementary regulation patterns for river runoff.The findings can provide a scientific basis for water resource management in the Manas River Basin and other similar arid inland river basins.

Technical Study on Extraction of Procyanidins in Lycium ruthenicum Murr. Using Sub-critical Fluid 1,1,1,2-Tetrafluoroethane( R134a)and Content Determination from Different Producing Areas

[Objectives] To study the optimal conditions for extracting procyanidins fromLycium ruthenicum Murr. with sub-critical fluid R134 a( 1,1,1,2-tetrafluoroethane) in 1 L extraction kettle. [Methods]Taking the extraction rate of procyanidins as an indicator,the influence of pressure,temperature,and extraction time on extraction rate of procyanidins fromL. Ruthenicum Murr. was studied by single factor experimental methods and orthogonal array design. [Results]The order of factors affecting extraction rate of procyanidins was extraction temperature > extraction pressure > extraction time. The optimum extraction conditions were as follows: the extraction rate of procyanidins fromL. ruthenicum Murr. was the highest with extraction pressure of 1. 2 MPa,extraction temperature of 50℃ and extraction time of 90 min. The content of procyanidins in L. ruthenicum Murr. from different producing areas was determined by vanillin-HCl method under the optimal conditions. [Conclusions] The method has the advantages of easy operation,good selectivity,low extraction temperature and high extraction efficiency,which is suitable for extraction of procyanidins in L. ruthenicum Murr.

Kinetics of cerium(Ⅳ) and fluoride extraction from sulfuric solutions using bifunctional ionic liquid extractant(Bif-ILE)[A336][P204]

The extraction kinetics of Ce（Ⅳ） and Ce（Ⅳ）-F^- mixture systems from sulfuric solutions to n-heptane solution containing Bif-ILE[A336][P204]（[trialkylmethylammonium][di-2-ethylhewanxylphosphinate]） with a constant interfacial area cell with laminar flow were studied,just to elucidate the extraction mechanism and the mass transfer models.The data were analyzed in terms of pseudo-first-order constants.The effects of stirring speed,specific interfacial area and temperature on the extraction rate in both systems were discussed,suggesting that the extractions were mixed bulk phases-interfacial control process.Supported by the experimental data,the corresponding rate equations for Ce（Ⅳ） extraction system and Ce（Ⅳ）-F^- mixture extraction system were obtained.The experimental results indicated the rate-controlling step.The kinetics model was deduced from the rate-controlling step and consistent with the rate equation.

KINETICS OF ALUMINUM EXTRACTION WITH DI—2-ETHYLHEXYL PHOSPHORIC ACID

The kinetics of solvent.extraction of aluminum with di-2-ethylhexyl phosphoric acid(DEHPA)in n-heptane have been studied in a constant interfacial area cell.A HC1-KHC8H404(potassium biphthalate.KHL)buffer solution was used to maintain a constant pH during extraction.The effects of the concentration of aluminum,pH,the concentration of the extractant,the interfacial area and the temperature on the extraction rate were investigated.A method has been invented to determine amont of the extracted aluminum in the organic phase with 8-hydroxyquinoline.Based on calculation of the coordination states of the aluminum ions and their contribution to the reaction rate,a raaction mechanism which includes two main reaction paths,has been proposed to describe the process.One path starts from Al(H_(2)O)6^(+).and the other starts from Al(H_(2)O)6^(+).The reaction could take place both in the aqueous phase and at the interface.The main reaction region could be changed as the conditions of extraction were changed.When[HA]<0.03 mol/L the process was controlled by the interfacial reaction,and when[HA]>0.03 mol/L it was shifted to a homogeneous aqueous solution reaction.

基于多源数据与随机森林方法的城市建成区提取——以郑州市为例

基于夜间灯光数据的阈值分割法在城镇建成区提取研究中被广泛应用,但由于夜间灯光数据分辨率低、灯光溢出和阈值分割法无法顾及区域差异等问题,一定程度上影响了该方法的提取精度。以郑州市为例,以LJ1-01与NPP/VIIRS两种夜间灯光影像为主要数据源,结合Landsat8中分辨率遥感影像、网络城市兴趣点(POI)及路网数据,利用随机森林分类方法对郑州市2018年建成区进行提取,参考土地利用数据,对RF分类法与NTL、VANUI、BANUI、PANUI、RANUI指数等阈值法进行对比实验和精度评价,评估基于多源数据的随机森林分类方法在城市建成区提取中的优势。实验表明,RF比阈值法提取的建成区更接近真实建成区且提取精度更高,具有更好适用性;LJ1-01数据提取的效果和精度总体优于NPP/VIIRS数据;在采用RF分类时,各类特征的重要性在不同夜光数据源中表现差异较大。

云南安宁磷矿区水系沉积物磷赋存形态及分布特征

磷污染是水污染的重要组成部分,因其可造成水体富营养化、水质下降,从而引起人们的广泛关注。研究沉积物中不同磷赋存形态及其分布特征有助于了解沉积物中磷的行为特征及迁移能力,从而为水体富营养化防治提供支撑。磷矿的开采、冶炼对矿区内水资源环境可能产生严重影响,本文以安宁磷矿区内河流、水库为研究区域,分析了不同水系沉积物磷元素赋存形态及分布特征,并对其生态风险进行评估。采用X射线荧光光谱法测定研究区水系沉积物总磷(TP)含量,并基于顺序提取及Hupfer改进的磷形态分析方法,将研究区各水系沉积物中磷分为弱吸附态磷(NH4Cl-P)、可还原态磷(BD-P)、金属氧化物结合态磷(NaOH-P)、钙结合态磷(Ca-P)、残渣态磷(Res-P)等5种形态,采用单因子污染指数法对其进行生态风险评估。结果表明:研究区水系沉积物样品中TP含量范围为567.6~48115.5mg/kg,NH4Cl-P含量范围为0.07~115.2mg/kg,BD-P含量范围为8.84~802.5mg/kg,NaOH-P含量范围为21.3~3129.5mg/kg,Ca-P含量范围为12~45098mg/kg,Res-P含量范围为28.5~515.4mg/kg。研究区各水系沉积物样品磷形态具有相似的分布特征,即磷主要以Ca-P和NaOH-P形态存在,其他磷形态的相对含量大小顺序为NH4Cl-P<BD-P<Res-P。单因子污染指数评价结果表明,各水系沉积物中磷以重度污染为主。生物有效磷(BAP)污染评价结果表明,各水系沉积物中磷污染程度有所降低,但河流沉积物中磷仍以重度污染为主,磷释放风险较大,建议加强对磷矿区河流磷污染的监测与评估。

煤层气富集区遥感勘查研究进展与展望

煤层气是一种自生自储式非常规清洁能源,它赋存于煤层及其围岩中。传统勘查方法费时费力,而遥感技术提供了煤层气富集区快速勘查的新途径。煤层气富集区遥感勘查的基本原理是基于典型地物波谱特征与富集区烃微渗漏导致的地表物体异常波谱特征,包括岩矿蚀变、植被异常和热异常等波谱特征的对比,结合煤田地质、地震、大地电磁等物探方法获取的数据,进行多源信息提取与综合分析,逐步查明煤层气富集区分布范围与含气特性。文章综述了煤层气富集区烃类物质渗漏与地表岩矿波谱和植被波谱异常的响应机制,以及基于地表岩矿波谱与植被波谱参数反演的多种方法与地物波谱异常反演在煤层气潜在富集区的勘查应用;阐述了含煤层气地层导致地表热异常的不同解释与提高地表温度反演准确率的主要方法与应用。未来,遥感与煤田地质数据、地震探测和大地电磁探测相结合,开展立体多元信息分析与信息提取,将成为实现煤层气富集区低成本快速勘查的主要途径。

融合时序Sentinel数据多特征优选的南方丘陵区油茶种植区提取

油茶作为江西省经济林树种之一,也是江西省特色优势产业,准确获取其空间分布在产量估算、生产管理和政策制定等方面具有重要意义。本研究针对南方多云多雨气候导致光学影像不足,以及丘陵山区地形破碎问题,以江西省宜春市袁州区为研究区,采用时序Sentinel系列影像数据和SRTM DEM数据为数据源,构建和优选了光谱特征、植被-水体指数、红边指数、雷达特征、地形特征和纹理特征共125个特征变量,其中,纹理特征采用累计差法(Δf)对比15种不同尺度窗口,计算Sentinel-1和Sentinel-2影像最佳纹理特征。基于ReliefF特征优选算法和随机森林分类算法,设计了8种特征组合方案开展实验,探讨不同特征类型对油茶提取精度的影响。结果表明:利用累计差法计算出的Sentinel-1和Sentinel-2的最佳纹理特征窗口尺寸均为35×35,最佳纹理特征组合为均值(Mean)、方差(Variance)和对比度(Contrast);在光谱特征、植被-水体指数的基础上加入不同特征对油茶进行分类,不同类型特征对油茶提取的有利程度由大到小依次为S2纹理特征、S1纹理特征、地形特征、雷达特征、红边指数,相比于单一光谱和指数特征,纹理特征的加入可大幅度提高分类精度。多特征协同分类结果优于单特征分类结果,基于特征优选的油茶提取精度最高;基于ReliefF算法特征优选后的方案精度最高,总体精度为88.29%,Kappa系数为0.81。本研究利用时序Sentinel系列遥感影像和DEM地形数据,构建了针对多云雨南方丘陵山区的大范围油茶遥感提取方法,可为中国南方丘陵区域油茶资源调查与监测提供参考。

基于CNN-OBIA的黄河源区水体提取及时空变化

准确识别水体信息是分析地表水时空动态变化的重要技术手段。针对目前各种长时序水体信息提取方法精度低的问题,基于Landsat遥感影像,选用1986~2022年5484景黄河源区遥感影像,分别运用卷积神经网络结合面向对象(CNN-OBIA)和多指数水体检测规则(MIWDR)两种方法提取了黄河源区的地表水体,并对两种方法的提取精度进行了对比分析。在此基础上,探究了1986~2022年黄河源区水体信息的时空变化特征,并对其主要气候因素进行相关分析。结果表明:①CNN-OBIA的总体精度和Kappa系数分别为96.78%和0.93,MIWDR的总体精度和Kappa系数分别为94.28%和0.88,总体而言,CNN-OBIA的提取精度高于MIWDR方法。CNN-OBIA的提取结果可以很好地保持水体边界完整性和有效去除山体阴影,可以较好地对细小河流进行提取。②研究区水体总面积呈现出先减少(1986~2001年)后增加(2001~2022年)的变化趋势。③相关性分析表明,降水和气温与水体面积的变化均表现出显著正相关。

前胡药材产地干燥加工方法研究

目的比较产地不同干燥加工方法对前胡药材质量的影响,筛选其最佳产地干燥加工方法。方法分别采用传统晒干、自然阴干和电热恒温鼓风干燥、真空干燥、红外干燥和真空冷冻干燥等干燥加工方法对前胡药材进行处理,以折干率、含水量、浸出物含量、颜色色度值以及4种香豆素类成分含量为指标,采用逼近理想解排序法进行综合质量评价。结果不同干燥加工方法下,12份前胡药材样品的折干率为31.56%~40.10%,含水量为6.96%~8.58%,浸出物含量为27.56%~43.10%,红绿度值为1.80~7.50,黄蓝度值为19.90~30.20,明度值为46.90~59.90;伞形花内酯、白花前胡甲素、白花前胡乙素、白花前胡E素的含量分别为≤0.05、3.70~14.05、0.72~2.37、0.81~3.90 mg/g,总含量为5.47~19.65 mg/g;40℃电热恒温鼓风干燥下的前胡药材综合得分最高。结论40℃电热恒温鼓风干燥是前胡药材最佳的产地干燥加工方法。

基于面积加权GWT-GFT的水声目标识别

由于海洋环境的复杂性,水声目标的识别具有很大的挑战性。为解决这类复杂环境下特征提取的问题,提出了一种基于面积加权的图小波变换-图傅里叶变换(GWT-GFT)的分析方法。在完成数据预处理后,为了能够凸显顶点之间的关系,提出了一种新的基于顶点三角形面积的加权方法来构建图信号;构建好的图信号通过GWT分解为多尺度图分量;然后,利用GFT将这些分量从图域变换到特征值谱域进行分析;在此基础上,提取各分量特征值谱的特征;最后,利用基于高斯核函数的支持向量机(SVM)对获取的特征向量进行分类。基于水声信号ShipsEar数据库,采用5折交叉验证方法进行验证。与现有的其它方法相比,所提的模型以36个特征在376656个样本上取得了97.22%的准确率,证明了该分析方法的有效性和鲁棒性。

竹叶黄酮的提取、生理机制与应用研究进展

竹叶作为药食同源的天然物质,含有多种有益成分,如黄酮类化合物、多糖、特殊的氨基酸和微量元素等。其富含的黄酮类化合物因具有抗氧化、抑菌、抑制黑色素以及保护心脑血管等多种功效而引起科研人员的广泛关注。本文概括了近年来国内外竹叶黄酮的组成、安全性及其提取分离纯化工艺;从生物活性的角度出发,重点探讨竹叶黄酮在抗氧化、抑菌、抑制黑色素以及保护心脑血管疾病等方面的研究,并阐述其生理机制;总结了竹叶黄酮在食品、医疗保健、日化品和养殖等领域的应用研究,并探讨了目前产业化应用存在的问题,旨在推动该领域深入研究和产业化应用,并为进一步深入探索天然药物和相关开发提供理论依据。

基于HJ-1星和GF-1号影像融合特征提取冬小麦种植面积

为提高基于国产环境与灾害监测预报卫星(HJ-1/CCD)影像大范围提取冬小麦种植面积的精度,以江苏省宿迁市沭阳县为研究区域,对冬小麦拔节期30 m×30 m的HJ-1/CCD多光谱影像和2 m×2 m的高分1号卫星全色影像(GF-1/PMS)进行融合与面向对象分类研究。将GF-1/PMS全色影像进行8、16和24 m重采样,得到4种空间分辨率(含2 m)的全色影像,分别与HJ-1/CCD多光谱影像利用光谱锐化法(Gram-Schmidt,GS)进行融合。通过对融合影像进行质量评价,选择适合研究区冬小麦种植田块格局的适宜尺度影像。将HJ-1/CCD多光谱影像重采样,得到与适宜尺度融合影像相同尺度的影像,在两景影像中分别选取包含光谱、纹理信息的训练融合影像样本(samples of fused image,SFI)和重采样影像样本(samples of resampling image,SRI),采用面向对象分类方法对适宜尺度融合影像(fused image,FI)和重采样影像(resampling image,RI)进行冬小麦种植面积提取。结果表明,16 m×16 m融合影像的效果优于2 m×2 m、8 m×8 m和24 m×24 m融合影像,其均值、标准差、平均梯度和相关系数分别为161.15、83.01、4.55和0.97。面向对象分类后,SFI对重采样影像RI16m分类的总体精度为92.22%,Kappa系数为0.90。SFI对融合影像FI16m分类的总体精度为94.44%,Kappa系数为0.93。SRI对重采样影像RI16m分类的总体精度为84.44%,Kappa系数为0.80。SFI对融合影像FI16m分类效果最好,说明基于融合影像和融合影像提取样本(SFI)结合的面向对象分类方法能准确提取冬小麦种植面积。另外,重采样影像和融合影像提取样本(SFI)相结合的面向对象分类方法也可较好提取冬小麦种植面积。为利用国产中空间分辨率HJ-1/CCD卫星和高分1号卫星融合影像有效提取大区域冬小麦种植面积信息提供了参考。

沿空留巷开采覆岩裂隙演化规律及卸压瓦斯抽采技术

沿空留巷开采是我国煤炭可持续发展的重要方向之一,其采动覆岩卸压瓦斯运移储集区演化与传统开采方式有所不同。为进一步准确辨识沿空留巷开采覆岩卸压瓦斯运移储集区,通过数值模拟及物理相似材料模拟,研究了切顶侧与未切顶侧的裂隙特征,分析了采动覆岩裂隙动态发育过程及应变分布规律,提出了沿空留巷开采卸压瓦斯抽采靶区位置判别方法,并进行了现场工程实践。研究结果表明:低位覆岩受切顶影响,易发生破断垮落;高位覆岩区域未切顶侧覆岩裂隙较为发育,切顶侧与非切顶侧裂隙发育高度相同。采动裂隙形态、覆岩应变形态均呈梯形,随覆岩周期破断,采动裂隙呈跃进态势向上发展。不同区域采动离层裂隙角度集中在0°~10°,竖向破断裂隙区角度主要集中在80°~120°。基于关键层判别、采动裂隙角度及数量、覆岩应变特征等,结合通风方式,提出沿空留巷开采卸压瓦斯抽采靶区判定方法,将抽采钻孔布置在“采动裂隙锐角发育区+高瓦斯体积分数”区域,判定得出试验工作面抽采靶区为与煤层顶板垂距30~46m、与辅运巷平距30~55m的区域。试验工作面开采期间整体瓦斯抽采效果良好,说明基于沿空留巷开采卸压瓦斯抽采靶区判定方法设计的抽采钻孔具有合理性,可为沿空留巷开采“Y”型通风方式下卸压瓦斯抽采钻孔设计提供一定参考。

基于特征优选和机器学习的第四系空间信息提取研究

【目的】第四系土体是土质滑坡的主要物源,其分布及厚度是开展土质滑坡隐患识别的重要基础。随着机器学习技术的兴起,图像分类技术与人工智能算法结合已成为遥感识别的主流。【方法】以三峡库首秭归向斜盆地为研究区,以Landsat-8影像为基础数据源,以区内现有土质滑坡数据构建样本,采用机器学习软件EnMAP-Box,建立第四系厚度及空间分布信息的随机森林分类模型,筛选出用于识别第四系土体厚度的最优特征子集,得出第四系相对厚度空间分布。【结果】结果表明:Landsat-8遥感影像的光谱特征、主成分、植被指数、湿度、坡度、绿度、均值等与第四系厚度具有强相关性,可作为识别第四系土体厚度的重要特征因子;随机森林模型能有效识别第四系土体厚度信息,且对岩质区提取精度较高;经实地调查验证,模型性能均衡,预测结果合理,可用于多植被中低山区环境的第四系识别。【结论】研究成果可为土质滑坡隐患识别和风险防控提供重要数据支撑。

东昆仑东段浪木日地区地球化学异常信息提取方法研究及异常查证

青海沟里地区位于东昆仑造山带东段,根据水系沉积物地球化学测量已发现了多个矿床(点),具有较好的找矿潜力。本文选取沟里地区巴加别里赤尔幅(浪木日地区)1∶5万水系沉积物地球化学测量数据为研究对象,利用统计学方法和趋势面分析法两种方法进行异常信息提取。结果显示,趋势面分析法相较于传统统计法,圈定的异常面积更大、浓集中心更明确、分带特征更明显,且与已知矿床点的吻合度更高,整体上具有强化低背景异常的优势。同时利用趋势面分析法提取了3个元素组合,并对套合性和相关性突出,且与区内浪木日铜镍硫化物矿床相关的Cu-Zn-Cr-Co-Ni组合异常进行异常剖析。结合区内地质特征和浪木日矿区矿体分布情况,圈定了哲扎空龙洼东、龙里、瑙格木东和卡鲁南等找矿远景区,为区内下一步铜镍找矿工作提供了方向。

基于机器学习算法的扬州市冬小麦遥感分类提取

卫星遥感技术是目前较为常用的农作物监测与分类技术。为实现区域冬小麦精确分类和面积提取,以江苏省扬州市为例,以哨兵2号卫星数据及航天飞机雷达地形测量(SRTM)高程数据为数据源,利用分类与回归决策树(CART)、梯度提升决策树(GBDT)、支持向量机(SVM)和随机森林(RF)4种机器学习算法建立分类模型。同时下载并调用2021年3月22日研究区的MSI多光谱影像,提取光谱、纹理、地形特征等参数,对研究区冬小麦进行分类提取,并分析4种模型的分类效果和精度。结果表明,RF和GBDT分类方法效果最好,总体精度最高,均为0.967,Kappa系数达0.960;SVM分类方法总体精度最低,为0.514,但用户精度最高,为0.972。上述方法可以实现区域农作物的精确分类和提取。

基于多时相Sentinel-2卫星影像的冬小麦面积提取

及时准确地提取冬小麦种植信息,对开展冬小麦农情遥感监测具有重要的意义.以杭州市余杭区冬小麦越冬期(2021-12-04)、扬花期(2022-04-08)和乳熟期(2022-05-03)Sentinel-2遥感影像为数据源,分别采用最大似然法、支持向量机、归一化差值植被指数(normalized difference vegetation index,NDVI)相加和相减合成运算提取冬小麦种植面积.结合冬小麦地面调查数据与实测种植面积,对不同方法的提取结果进行精度评价.结果显示,利用越冬期影像NDVI阈值将常绿植被区(茶园、林地)掩膜处理,对非常绿植被区(建筑、水体、冬小麦)扬花期与乳熟期影像NDVI值进行和值运算,是提取余杭区冬小麦种植面积的最佳方法,面积精度为91.96%,说明基于多时相遥感影像结合植被物候特征与典型地物类型,能够实现冬小麦种植面积的高精度提取.