不同覆盖度下小麦农田土壤对NDVI影响模拟分析

发布时间：2018-05-13 06:19

本文选题：NDVI + 光谱　；参考：《遥感技术与应用》2017年04期

【摘要】：生长于不同土壤类型背景条件下的相同长势小麦农田遥感像元尺度的归一化植被指数(NDVI)有很大差异,也一直困扰着利用NDVI进行小麦长势有效监测和精确评价。拟定小麦冠层光谱不变即小麦冠层NDVI为一常数条件下,选择反射率差异较大的我国9种典型土壤类型作为土壤背景,由小麦冠层和土壤背景的不同线性混合比模拟计算遥感像元尺度上的植被覆盖度,研究不同土壤类型背景对小麦农田NDVI信息的影响。研究结果表明:同一土壤类型背景条件下,随着植被覆盖度逐渐增加,小麦农田NDVI总体表现为增长的趋势,反之亦然;不同类型土壤背景对小麦农田NDVI造成很大差异,当植被覆盖度大于25%时,随着植被覆盖度的增加对小麦农田NDVI影响差异性逐渐减小;不同类型土壤背景也导致小麦农田NDVI对植被覆盖度的敏感性有明显差异,较低反射率土壤背景条件下的敏感性随着植被覆盖度增长呈现曲线下降的趋势,较高反射率土壤背景条件下敏感性随着植被覆盖度的增长而单调增加,为不同类型土壤背景的各小麦生长期遥感NDVI信息估算频次选择提供依据。
[Abstract]:The normalized vegetation index (NDVI) on remote sensing pixel scale of the same growing wheat field grown under different soil type background conditions is very different, which has been puzzling the effective monitoring and accurate evaluation of wheat growth using NDVI. Under the condition that wheat canopy NDVI is a constant, nine typical soil types with great difference in reflectance are selected as soil background. The vegetation coverage on the scale of remote sensing pixel was calculated by using different linear mixing ratios of wheat canopy and soil background. The effects of different soil type backgrounds on the NDVI information of wheat fields were studied. The results showed that under the same soil type background, with the increase of vegetation coverage, the total NDVI of wheat farmland showed an increasing trend, and vice versa, and the different soil background had great difference on the NDVI of wheat farmland. When the vegetation coverage was greater than 25, the difference of the effect of NDVI on wheat farmland decreased with the increase of vegetation coverage, and the sensitivity of NDVI to vegetation coverage was significantly different from that of different types of soil background. Under the background condition of low reflectivity, the sensitivity of soil decreased with the increase of vegetation coverage, while the sensitivity of higher reflectivity soil background increased monotonously with the increase of vegetation coverage. It provides the basis for estimating the frequency of remote sensing NDVI information of wheat in different soil background.
【作者单位】：南京大学国际地球系统科学研究所;江苏省地理信息技术重点实验室;江苏省地理信息资源开发与利用协同创新中心;
【基金】：国家科技重大专项(30-Y20A01-9003-12/13) 国家重大科技专项GF-4星(03-Y20A04-9001-15/16)
【分类号】：S512.1;TP79

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