Large-scale groundwater monitoring in Brazil assisted with
satellite-based artificial intelligence techniques
Abstract
Here, we develop and test an artificial intelligence (AI)-based approach
to monitor major Brazilian aquifers. The approach combines Gravity
Recovery and Climate Experiment (GRACE) data and ground-based
hydrogeological measurements from Brazil’s Integrated Groundwater
Monitoring Network at hundreds of wells distributed in twelve aquifers
across the country. We use a model ensemble composed of four different
AI models: Extreme Gradient Boost, Light Gradient Boosting Model,
CatBoost and Multilayer Perceptron. The approach is further boosted with
wavelet and seasonal decomposition processes applied to GRACE data. To
determine the sensitivity of the AI approach to data availability, we
propose four experiments combining hydrogeological measurements from
different aquifers. Groundwater storage estimates from the Global Land
Data Assimilation System (GLDAS) are used as the benchmark. The AI
approach successfully reproduces groundwater storage estimates at all
Brazilian aquifers. Results show that the proposed approach outperforms
GLDAS in all experiments, with an average Nash-Sutcliff efficiency of
0.91 and an average RMSE of 0.43cm for the experiment that covers all
monitored wells in Brazil. GLDAS resulted in -1.311 and 5.84cm,
respectively. This study demonstrates that combining satellite data and
AI can be a cost-effective alternative to monitor poorly equipped
aquifers at the continental scale.