Abstract

This study explores the statistical relationship between spectral reflectance and hydraulic conductivity (K) of fluvial sediments in two Nebraska rivers. The spectral reflectance curves of sediments are obtained through hyperspectral instruments under controlled conditions. The K values are determined by three different methodologies, grain size analysis, an in-situ permeameter test, and a lab permeameter test. The in-situ permeameter tests calculate vertical K values (K_v), whereas grain size analysis and lab tests and grain size analysis generate non-directional K values. The results show that the lab permeameter tests of repacked sediments present greater hydraulic conductivity values than in-situ tests. The non-directional K values derived from 7 empirical equations, Hazen, Slicher, Terzaghi, Beyer, USBR, Kozeny, and Sauerbrei, correlate well with the in-situ K_v values. Site specific coefficients in 7 equations are developed for the study sites. Correlation analysis is conducted aiming to establish the connection between hydraulic conductivity and spectral reflectance. Inverse trends are found between the reflectance and K values determined by Hazen, Beyer, USBR, and Sauerbrei formulae where particle size distribution is considered to be a key factor. Furthermore, four linear models are developed based on the relationship between grain size derived K and reflectance. The models are used on dried surface channel sediments in the Platte River for predicting K values as a pilot test and proved to be applicable. As direct measurement of hydraulic conductivity can be costly and time-consuming, remote sensing informed hydraulic conductivity of streambed sediments in droughts can be a promising application with further study.

中文翻译：

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光谱反射率可以告知河流沉积物的水力传导率吗？

摘要

本研究探讨了两条内布拉斯加州河流域河流沉积物的光谱反射率与水力传导率（K）之间的统计关系。沉积物的光谱反射率曲线是在受控条件下通过高光谱仪器获得的。的ķ值由三种不同的方法，粒度分析，确定原位渗透仪测试，和渗透仪测试实验室。原位渗透计测试可计算出垂直K值（K _v），而粒度分析和实验室测试以及粒度分析会生成非方向性K价值观。结果表明，与现场测试相比，重新包装的沉积物的实验室渗透仪测试显示出更大的水力传导率值。从7个经验方程式（Hazen，Slicher，Terzaghi，Beyer，USBR，Kozeny和Sauerbrei）得出的非方向性K值与原位K _v值具有很好的相关性。为研究地点开发了7个方程式中的特定地点系数。进行相关分析旨在建立水力传导率和光谱反射率之间的联系。在反射率和K之间发现反趋势由Hazen，Beyer，USBR和Sauerbrei公式确定的值，其中粒径分布被认为是关键因素。此外，基于晶粒尺寸导出的K和反射率之间的关系，开发了四个线性模型。该模型在普拉特河的干燥表层河道沉积物中用于预测K值作为先导试验，并被证明是适用的。由于直接测量水力传导率既昂贵又费时，因此在干旱条件下通过遥感得知流化沉积物的水力传导率可能是一个有前途的应用。