Inverse Analysis of Experimental Scale Turbidity Currents Using Deep
Learning Neural Networks
Abstract
Despite the importance of turbidity currents in environmental and
resource geology, their flow conditions and mechanisms are not well
understood. This study proposes a novel method for the inverse analysis
of turbidity currents using a deep learning neural network (DNN) to
better explore the properties of turbidity currents. The aim of this
study is to verify the DNN inverse method using numerical and flume
experiment datasets. Numerical datasets of turbidites were generated
with a forward model. Then, the DNN model was trained to find the
functional relationship between flow conditions and turbidites by
processing the numerical datasets. The performance of the trained DNN
model was evaluated with 2000 numerical test datasets and 5 experiment
datasets. Inverse analysis results on numerical test datasets indicated
that flow conditions can be reconstructed from depositional
characteristics of turbidites. For experimental turbidites, spatial
distributions of grain size and thickness were consistent with the
sample values. Concerning hydraulic conditions, flow depth H,
layer-averaged velocity U, and flow duration Td were reconstructed with
a certain level of deviation. Greater discrepancies between the measured
and reconstructed values of flow concentration were observed relative to
the former three parameters (H, U, Td), which may be attributed to
difficulties in measuring the flow concentration during experiments. The
precision of the reconstructions for experimental datasets was estimated
using Jackknife resampling. Although the DNN model did not provide
perfect reconstruction, it proved to be a significant advance for the
inverse analysis of turbidity currents.