Impact Evaluation of Sustainable Land Management (SLM) in Tunisia: The Efficiency of GIS and Remote Sensing Data
The challenge of land degradation is particularly felt in Tunisia, where soil erosion rate is high and affects 50% of its total surface. The land and water conservation has been the focus of national policies for almost 30 years, With a climatic variety going from arid – approximately 77% of the whole area – to semi-arid, the degradation of land and water resources remains a challenge. Multiple national strategies have been implemented since 1990, with the support of law enforcement to decrease this threat, and a special unit (DG-ACTA), which was created in 2001 to support the Ministry of Agriculture. The overall measures taken led to an increase of SLM practices in the Tunisian landscape for better performance.
The key elements triggering a successful land recovery are still under study. Since the process is very slow, the return on investment is, at first glance, not appealing. Therefore, the Economics of Land Degradation (ELD) Initiative was launched to sustain and advocate SLM practices as an integral part of decision-making and policy strategies. ELD highlights the opportunities and benefits of such investment. An ICARDA project “Impact evaluation of SLM options to achieve land degradation neutrality”, funded by GIZ and in partnership with the CGIAR Research Programs on Dryland Systems and Water, Land and Ecosystems, may be offering a turning point. The project is aiming to provide an Impact Evaluation tool for SLM practices that can reliably predict agronomic and economic outcomes of SLM interventions.
SLM Options by Context (OxC) is an online geographic information system that continuously monitors impact on target areas through local assessments made with remote sensing technology. Based on the options by context approach, the tool will provide support to private and public stakeholders, answering common questions on land use and its management at different scales. These questions include:
How to target more relevant geographies and prioritize investments, given limited resources?
How to identify geographical domains that capture key biophysical, economic, and social drivers of land restoration and related outcomes?
How to anticipate future impacts of SLM in terms of land ecosystem services and benefited population?
The project started in August 2016 by collecting global and country-specific datasets and assessing and enlarging the knowledge base of SLM projects in Tunisia. A standardized SLM options-by-context (SLM OxC) template has already been finalized. It facilitates SLM researchers, project managers and on-ground practitioners to document SLM technological, environmental, economic and social aspects in their respective contexts. Later in 2017, the site-specific SLM OxC data for Tunisia will be stored in a national database and analysed to estimate the efficacy of SLM practices over time. The SLM OxC data will be also used to power another tool, the user-friendly Global Geoinformatics Context and Options (GeoCOs), which will enable stakeholders to investigate the efficacy of several SLM practices within different contexts simultaneously.
All the SLM and Web GIS competences will be conveyed to future NARS implementers in Tunisia later this year, within planned trainings and technology transfer workshops.
The aims of this project are being achieved thanks to the synergic efforts of GIZ, the CGIAR Research Programs on Dryland Systems and Water, Land and Ecosystems, the International Center for Agricultural Research in the Dry Areas (ICARDA), and the ICARDA Geoinformatics Unit.
Article author: Fajr Fradi – ICARDA, Junior Project Officer
Photo authors: Taoufik Hermassi – Assistant Professor, National Research Institute for Rural Engineering (INGREF) & Waleed Ben Khelifa – Ph.D. student, National Research Institute for Rural Engineering (INGREF).