The team began this work by undertaking a hydrological study, assessing the water budget for the target watersheds: Joumine, Sejnane, Abid, Tessa Zouarines, Douimis, and Beja They used ground rainfall and runoff observations, as well as GIS information. Researchers also computed drought indicators at basin level, assessing the Standardized Moisture Deficit Index (SMDI) and the Standardized Evapotranspiration Index (ETDI) indicators. Time series of SMDI and ETDI were created at weekly resolution for every watershed.

In the first phase of the project, the Tunisian model was compared with ADM/VIC results to recreate a historic period of observation using runoff data (1960- 2010). Researchers then assessed the quality of satellite estimates and reanalysis data (rainfall in particular) to feed the VIC model by comparing them with historic ground estimations. In addition, the PEER team developed an application using ground observations and water balance modeling to evaluate drought indices’ quality and ability to identify well-known past drought periods. Researchers also undertook a study of remote sensing data for water balance quantification, assessing the water stress indicator and daily rainfall patterns using satellite data. The team developed tables and maps of drought indicators for both historical periods and more recent time periods in the six studied watersheds.

The researchers organized and attended several workshops to disseminate their results. At the first event, "Drought, Climate Change and Hydrological impacts,” the project team reported the results from their PEER project and another ongoing project involving France and Morocco. At the second workshop, "Green Tunisia: The Role of Hydrological Monitoring in Achieving this Objective,” the project team presented a drought risk assessment and water cycles in Tunisian forest zones and on societal engagement for enhancing vegetation cover. At the third event, "Drought identification and alert Northern Tunisia,” researchers presented their results to the engineers within the Ministry of Agriculture and other ministries with concerns about drought, including the Ministry of Finance. Representatives of farmers also participated in this event to define their needs in terms of drought assessment and mitigation.

PEER funds supported international travel and training for several team members. In March 2014, researcher Ahmed Houcine, computer manager Wadid Foudhaili, and PhD student Saoussen Dhib spent 10 days at Princeton University for training on the installation and use of the African Drought Monitor System. Saoussen Dhib also completed a two-month exchange visit to Prague University, including taking courses to help her in analyzing precipitation data, particularly those gleaned through remote sensing. Other students made short-terms visits to universities in the Netherlands and France, and the PI and other senior researchers participated in several international conferences. The team also presented at the International Conference on African Large River Basins Hydrology and organized two field visits, where they met with the regional agriculture authority representatives and presented their modeling system.

Overall, Dr. Bargaoui notes that the project has contributed to build a sustained capacity at ENIT, also resulting in the installation of data sensors and weather stations in an important river basin and the enhancement of the skills of research personnel and students. It also resulted in increasing the competence of staff from the Ministry of Agriculture at the local level in Siliana and Bizerte regions. In addition, some fundamental research findings have been achieved, and the team published three papers on their work.

Publications

Saoussen Dhib, Nathaniel Chaney, Chris M. Mannaerts, and Zoubeida Bargaoui. 2021. Comparison of two bias correction methods for TRMM 3B42 satellite daily rainfall estimates over Northern Tunisia. Arabian Journal of Geosciences 14: 626. https://doi.org/10.1007/s12517-021-06916-8

Aymen Ben Jaafar and Zoubeida Bargaoui. 2019. Generalized Split-Sample Test Interpretation Using Rainfall Runoff Information Gain. Journal of Hydrologic Engineering 25(1). https://doi.org/10.1061/(ASCE)HE.1943-5584.0001868

N. Abid, C. Mannaerts, and Z. Bargaoui. 2019. Sensitivity of actual evapotranspiration estimation using the SEBS model to variation of input parameters (LST, DSSF, aerodynamics parameters, LAI, FVC). The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XLII-2/W13, 2019 ISPRS Geospatial Week 2019, 10–14 June 2019, Enschede, The Netherlands. https://doi.org/10.5194/isprs-archives-XLII-2-W13-1193-2019

Website of Princeton University’s African Drought Monitor