过去 30年间 ,浙江沿海滩涂地不断地被围垦成农用地。为了科学地掌握海涂土壤的变化规律 ,讨论了地面光谱评价海涂土壤开发程度的可行性。以浙江省上虞市北部海涂围垦区作为研究区域 ,根据围垦历史时间的不同 ,将研究区划分成 4个子区域。借助GPS定位 ,样区内大致间隔 1km进行混合采样。分别在实验室内测定土壤理化性质和土壤光谱反射率。理化性质分析结果表明海涂土壤有机质含量低 ,电导率和含砂量高 ,并且随着围垦时间的增长呈现出规律性的变化。 9个吸收波段与土壤电导率、阳离子交换量和机械组成的Person相关分析表明 ,海涂土壤砂粒、粉粒含量与各波段相关性显著。依据不同围垦历史 ,对所有土样进行分组 ,并进行逐步判别分析。判别结果表明 ,处于不同围垦区并具有不同改良程度的土样 ,其光谱数据具有很好的类可分性。对原始样点数据回代到Fisher辨别函数可以获得 86 8%的判别精度 ,而对 2 8个待判土样代入判别函数可获 89 3%的判别精度。从地面光谱研究结果可见 ,相比于常规的野外耗时调查 ,星载或机载遥感探测器有可能作为大范围快速评价盐碱土开发程度的有效潜在工具

Over the past 30 years, considerable parts of coastal tideland have been enclosed and reclaimed for agricultural land uses in Zhejing province. The purpose of this work was to evaluate whether the laboratory spectral data could be used to estimate the reclamation levels of saline soils. The northern region of Shangyu City in Zhejiang Province as a study area was divided into four sub zones with different historical years of reclamation. Soil samples were collected from field at approximate 1 kilometer intervals using GPS. Soil physic chemical properties analyzed in laboratory showed that saline soils had low organic matter, high electrical conductivity and sand content, and some soil properties changed with reclamation years. These changing trends of soil chemical and physical properties can be indicated by laboratory reflectance spectra of soil samples. The Person correlation analysis showed that there existed good relationships between nine absorption bands and selected soil properties. Stepwise Discrimination Analysis (SDA) was applied to estimate the reclamation levels of saline soil. The results showed that saline soil with different reclamation years could be classified with an overall accuracy of 86 8% for 68 original grouped cases and 89 3% for 28 cases not involved in SDA according to the Fisher's discriminant functions. The study suggests that remote sensing should be potentially useful and effective tool to estimate saline soil reclamation, by comparison to the time consumed conventional field investigation.