Wetland water balance estimation in an arid region using remote sensing technology and hydrological modelling

Abstract

Understanding the hydrological processes associated with wetland dynamics is fundamental to studying climate change impacts and the global water cycle. This study simulates the variation of water balance in the Ghorra Playa, Eastern Tunisia, over the period extending from September 2017 to August 2020. The playa is a seasonal habitat for a number of migratory bird species and its watershed is of vital agricultural importance. Water balance estimations were performed using two different approaches: remote sensing-based analyses (Sentinel-2B, GPM and FEWS-NET) and modelling founded on field data. The playa presents an average annual water balance of 1.1 million cubic meters. Water inflows come from direct rainfall mostly in the fall and spring seasons. Groundwater flow into the playa significantly influenced the pattern of water flux (81 %). The annual, seasonal and monthly water budget simulations show reasonably good agreement between the remote sensing-based analysis and the hydrological modelling exercise.