Work

Spatiotemporal Non-Linear Dynamics Assessment (SNLDA) of ERA5-Land precipitation in the Magdalena River Basin

Year: 2026

Type: article

Abstract: The study region is the Magdalena River basin in Colombia. The basin was divided into three distinct regions (Andean, Caribbean, and Pacific) and analyzed across different elevations. The study proposes a Spatiotemporal Non-Linear Dynamics Assessment (SNLDA) framework to compare ERA5-Land reanalysis data with in-situ rain gauge observations. It specifically examines the constraints imposed by nonlinear dynamical processes and their associated space-time complexities on the representation of precipitation, particularly in a tropical region. The SNLDA framework incorporates three main components: (i) standard performance metrics (e.g., correlations, RMSE, and dry spell duration), (ii) rainfall spatiotemporal objects (characterizing precipitation events through attributes such as volumes and start-end centroids), and (iii) non-linear dynamics complexity (reconstructing dynamical behavior from time series and evaluating attractors properties, including the Hurst and Lyapunov exponents). These elements were analyzed both individually and in combination. Daily ERA5-Land information (0.1°x0.1°) and in-situ rain gauge data comprising 558 stations from 1980 to 2020 were used, enriched by an Inverse Distance Weighting (IDW) interpolation (0.1°x0.1°) to facilitate comparison across spatial scales. Overall, ERA5-Land overestimates precipitation, producing shorter, more frequent events while poorly representing extreme wet and dry spells. Andean region: ERA5-Land overestimates rainfall, with largest errors at low elevations, driven by unresolved spatiotemporal object volumes displacements and nonlinear processes. Caribbean region: ERA5-Land shows the highest errors in nonlinear dynamics and extremes, despite lower annual bias and RMSE. Pacific region: ERA5-Land strongly overestimates precipitation volumes and RMSE, while nonlinear errors remain low; these biases are mainly driven by spatiotemporal objects displacement. • Assessment of ERA5-Land precipitation through a comprehensive methodology (SNLDA) • Incorporation of non-linear dynamics concepts to validate precipitation data • Characterize the spatiotemporal dynamics of precipitation objects • Identify regional disparities in the performance of ERA5-Land in a tropical region • Integration of multiple error metrics into a single plot for easier interpretation

Source: Journal of Hydrology Regional Studies

DOI: 10.1016/j.ejrh.2025.103083

Authors: Santiago Duarte, Gerald Corzo, Dimitri Solomatine, Remko Uijlenhoet

Institutions: IHE Delft Institute for Water Education, Delft University of Technology, Russian Academy of Sciences, Institute of Water Problems

Language: English

Topic: Precipitation Measurement and Analysis

Subfield: Atmospheric Science

Field: Earth and Planetary Sciences

Domain: Physical Sciences

SDGs: Climate action, Clean water and sanitation

Open Access status: gold

Estimated APC paid: $2,600