Geospatial and remote sensing based modelling of water erosion under climate change impact in North Tunisia: Case of Medjerda Watershed 

Abstract

Abstract.The comprehension of a process variability mode and its causing factors may help decision- makers for preventive and mitigation purposes. Indeed, modelling of water erosion variability and soil loss rates estimation seem crucial in regions where this process may have serious consequences that adversely affects countries sustainable development and agricultural production. Under impact of climate changes, several previous studies deal with aggressiveness of soil erosion dynamic throughout the Mediterranean region. The present research focuses on modelling and assessment of soil loss in Medjerda watershed in North Tunisia. Indeed, erosion potential model (EPM) combined with geospatial and remote sensing techniques was adopted in order to develop spatial distribution map of erosive hazard and to quantify sediment yield. Geographic information system (GIS) and remote sensing (RS) performances were used for parameterization, calibration and validation of EPM model structure in the study area. The second part of this study is preserved to identify the potential link between water erosion variability and global climate changes indices (NAO, MO, WeMOi and ENSO) in North Tunisia. Indeed, a combined approach between spectral (continuous wavelet transform, wavelets coherence) and statistical analyses (multiple linear regression) was addressed.Finding of this research are mainly the development of mean annual soil loss spatial distribution map in Medjerda watershed will helps to identify highly vulnerable zones with estimation of soil losses rates. This map can be used as a decision support document for developing of soil and water resources management strategies in North Tunisia. In addition, regressive models expressing impacts of global climate fluctuations on spatial regionalization of water erosion process was developed.Keywords: water erosion, EPM model, GIS and RS techniques, climate changes, spectral and statistical analyses, Medjerda watershed, North Tunisia