In Search of a Soil Moisture Content Simulation Model: Mechanistic and Data Mining Approach Based on TDR Method Results.

Andrzej Brandyk,Bartosz Szeląg,Marcin Krukowski,Grzegorz Majewski,Adam Kiczko,Jerzy Piotrowski,Adam Kozioł

doi:10.3390/s21206819

Abstract

Soil moisture content simulation models have continuously been an important research objective. In particular, the comparisons of the performance of different model types deserve proper attention. Therefore, the quality of selected physically-based and statistical models was analyzed utilizing the data from the Time Domain Reflectometry technique. An E-Test measurement system was applied with the reflectogram interpreted into soil volumetric moisture content by proper calibration equations. The gathered data facilitated to calibrate the physical model of Deardorff and establish parameters of: support vector machines, multivariate adaptive regression spline, and boosted trees model. The general likelihood uncertainty estimation revealed the sensitivity of individual model parameters. As it was assumed, a simple structure of statistical models was achieved but no direct physical interpretation of their parameters, contrary to a physically-based method. The TDR technique proved useful for the calibration of different soil moisture models and a satisfactory quality for their future exploitation.

Highlights

The importance of soil moisture as an environmental variable is evident from the viewpoint of its role in the hydrological cycle
We focused on the performance of various models for soil moisture content simulation, taking advantage of the measurement data obtained by the TDR method
All of the models that were approached in this work, as well as the coefficients describing their structure, encountered difficulties in their physical interpretation, but this was found only by this particular study and cannot be generalized

Summary

Introduction

The importance of soil moisture as an environmental variable is evident from the viewpoint of its role in the hydrological cycle. Soil moisture impacts rainfall-runoff processes, infiltration, groundwater recharge rates, and constrains evapotranspiration as well as photosynthesis. To some extent, it governs water and energy exchange between the land, plants and the atmosphere [1,2,3,4], but embraces multiscale feedbacks as well [5]. The on-going climate changes have resulted in atmospheric and hydrological droughts that give rise to soil and physiological droughts affecting harvest yields and water supplies. The observed rise in air temperature along with precipitation shortages occur more frequently all over the world, e.g., in Europe and Poland, and affect the security of soil water resources and crop yields

Methods

Results

Conclusion