塔里木河流域中游渭干河-库车河绿洲盐渍土水盐信息光谱特征研究

土壤水分、盐分时空变异强,是影响土壤光谱特征的两个重要因素。土壤水分与盐分之间的关系以及土壤水分、盐分与土壤光谱特征间的关系直接关系到利用遥感光谱信息监测土壤盐渍化的精度。该文运用多元统计学及可见光-近红外反射光谱分析方法对2010年10月渭干河-库车河三角洲绿洲盐渍土水分、盐分数据和盐渍土野外光谱数据进行分析,探讨该绿洲盐渍土表层(0～10cm)水盐信息与野外光谱特征间的关系。结果表明:1)土壤水分和土壤电导率可用Cubic曲线拟合,相关系数R=0.8503,土壤盐分和土壤电导率也可用Cubic曲线拟合,相关系数R=0.842,但土壤水分与盐分之间的显著性较弱,相关系数R=0.74。2)与原始野外光谱相比,包络线消除后光谱波段与土壤水分和土壤电导率之间的Pearson相关性都有不同程度的提高,利用包络线消除法后的波段分别建立盐渍土土壤水分、土壤电导率后向回归预测方程,为动态水盐条件下的盐渍土遥感监测提供了理论依据。

Study on Water-Salt Information and Spectral Characteristics of Saline Soil in the Weigan and Kuqa River Delta Oasis of the Middle Reaches of Tarim River

Water and salt of soils varied spatially and temporally,which were two important factors to influence the spectral characteristics of soils.To know the relationship between water and salt of soils and between water-salt and spectral characteristics of soils was very important for monitoring soil salinization using remote sensing spectral information.Based on water-salt data of 10cm depth and field spectra data of surface soils measured by Hydra Soil Moisture Probe and ASD FieldSpec Pro FR hand-held spectrometer respectively in October,2010 in the delta oasis of Weigan and Kuqa rivers,the study on water-salt and field spectral characteristics of soil salinization was carried out.The results showed that the relationship between soil moisture(WFV) and soil conductivity(Soil C) could be estimated using cubic curve,and the correlation coefficient is 0.8503,the relationship between soil salinity and soil conductivity(Soil C) also could be estimated using cubic curve,and the correlation coefficient is 0.842,but the relationship between soil moisture(WFV) and soil salinity is relatively weak.The correlation coefficient is 0.74.Compared with original spectral data,the pearson coefficients between soil moisture and field spectra after continuum-removed of surface soil and between soil conductivity and field spectra after continuum-removed of surface soil were improved,and then the predicted models for soil moisture and soil conductivity was built using the field spectral bands after continuum-removed by backward linear regression method.