Soil Water Content Model of Inner Mongolia Based on GNSS ZTD and
Meteorological Elements
Abstract
Soil water content is an important indicator of drought in agriculture
and animal husbandry, and has an important impact on climate and
ecology. The change trend of soil water is of great significance for
regional soil erosion and climate change research. Thus, soil water
content should be investigated using other existing data. In this study,
the existing Global Navigation Satellite System (GNSS) zenith
tropospheric delay (ZTD) and humidity, sunshine, and evaporation data in
Inner Mongolia was used to investigate soil water content inversion. The
correlation between each element and soil water content was analyzed.
Noises was observed in the soil water content and GNSS ZTD data and
wavelet transform was used to eliminate the noises. After denoising, the
correlation between soil water content data and each element was
improved, and the correlation between soil water content and humidity is
the best. The average correlation between the two experimental points is
0.645. Negative correlations are observed between soil water content and
sunshine and evaporation, and their average correlations are −0.561 and
−0.547, respectively. The correlation between soil water content and
GNSS ZTD data is the smallest, with an average correlation of 0.271.
Then, a soil water content model was constructed on the basis of the
correlation between each element and soil water content, and its
reliability was verified. The verified error statistics show that the
NMWJ station model in the experimental area has the highest accuracy,
with the accuracy of 90.1%, whereas the HLAR site model has the lowest
accuracy, with 69.1%. The average accuracy of each station in the study
area is 81.35%. The soil water content model based on multivariable
elements can provide reference for the research on the change trend of
soil water content.