不同取样单元对干旱区绿洲小麦地上生物量光谱估算模型的影响  

Impact of Different Sampling Units on Ground Spectral Models for Estimating Wheat Aboveground Biomass in Oases of Arid Zone

作　　者：孙小艳[1] 常学礼[1] 张宁[1] 韩艳[1] 

机构地区：[1]鲁东大学地理与规划学院,山东烟台264025

出　　处：《中国沙漠》2012年第2期568-573,共6页Journal of Desert Research

基　　金：国家重点基础研究发展计划项目(2009CB421302);鲁东大学学科建设项目资助

摘　　要：为了更好地了解小麦高光谱特征与其地上生物量的关系,采用美国ASD公司手持便携式野外光谱仪(ASD Fieldspec HandHeld)在甘肃河西绿洲进行了小麦高光谱遥感地面观测。运用单变量线性和非线性回归分析方法,以不同绿洲为取样单元,建立4种NDVI-小麦地上生物量(ANPP)的地面光谱模型。研究结果表明,各模型均达到极显著检验水平(小样区:α=0.01,n=20;大样区:α=0.01,n=34),通过对各个模型进行误差分析,确定基于同一绿洲和不同绿洲单元构建的最优光谱模型均为指数函数模型。其中,张掖绿洲、酒泉绿洲和河西绿洲模型分别为ANPP=0.1567e12.568 NDVI(R2=0.8123)、ANPP=0.4082e11.108 NDVI(R2=0.8321)和ANPP=17.255e5.4326 NDVI(R2=0.7369)。基于同一绿洲(小样区)构建的小麦光谱生物量预测模型在不同绿洲之间可以通用,但不能用于河西绿洲小麦估产;河西绿洲小麦估产要借助不同绿洲小样区构建的小麦光谱生物量模型进行预测。For best understanding relationship between wheat hyperspectral property and aboveground biomass,we employed ASD Fieldspec HandHeld Spectroradiometer to measure the wheat reflecting spectrum in different oases in Hexi Corridor.Based on different sampling units,four ground spectral models in relation to Normalized Difference Vegetation Index(NDVI),including linear,logarithm,power,and exponent methods,of the aboveground biomass(ANPP,Aboveground Net Primary Productivity) were built.Results showed that all of the models were significant at 0.01 levels(n=20 for single oasis and n=34 for entire oases).Based on determination coefficient(R2) and error analysis,the exponential model was considered to be the best among these models in different sampling units.Among them,the models for Zhangye oasis,Jiuquan oasis and whole oases in Hexi corridor could be expressed by the equation: ANPP=0.1567e12.568NDVI(R2=8123),ANPP=0.4082e11.108NDVI(R2=0.8321) and ANPP=17.255e5.4326NDVI(R2=0.7369),respectively.The model built for single oasis might be used to other oases,but it couldn't be used to the whole region;for estimating the data in the whole region,the model should be built by data obtained from different oases of the Hexi corridor.

关 键 词：地上生物量 归一化植被指数(NDVI) 地面光谱模型 河西走廊 

分 类 号：S127[农业科学—农业基础科学]