Participatory approaches to monitor water-related Sustainable Development Goal (SDG 6) in Tunisia

Abstract

The Sustainable Development Goals (SDGs) are a global initiative lead by the United Nations to achieve "a better and more sustainable future for all". Given the increasing impact of climate change on the available water resources over the past two decades, a particular attention is paid to water through SDG 6. The SDG-6 aims to "ensure availability and sustainable management of water and sanitation for all". This goal comes with a set of highly interconnected targets and indicators that are essential for its global and local implementation. Tunisia, as a member of the United Nations, adopted the framework of the SDGs with a particular interest in SDG 6 since Tunisia is considered as one of the highly water stressed countries in North Africa. Despite the growing need for a rapid, yet consistent, implementation of the goal in the country, very few scientific initiatives are working on monitoring the different indicators at the national scale using nationally-produced data. However, lower scale implementation and monitoring of SDG 6 indicators are essential to provide a consistent overview of the current state of water resources in the country. The current data infrastructure in Tunisia represents a major constraint, since the water-related information is poorly monitored and not accessible at the regional scale. This is due to the complex water institutional system, which is mostly dominated by the lack of coordination and communication between the different data providers. Nevertheless, over the past decade, participatory approaches for water monitoring have been getting more attention in many parts of the world, especially with the emergence of novel cost-effective smart technologies. Such participatory approaches are often referred to as Citizen Science (CS). With CS, citizens are involved in scientific activities, such as environmental monitoring, and they also can be a valuable part of decision making and policy formulation. Together with the generic available data, in particular from remote sensing technology, CS could be tested and implemented in Tunisia in order to improve the access to available and reliable data. The main objective of this thesis was to strengthen the scientific basis for participatory approaches in conjunction with public available environmental data to support the monitoring of water resources in Tunisia. The strengthening of water observation is expected to improve the monitoring of the SDG 6 indicators in Tunisia. The study is focused on the Medjerda catchment, which is the most important river basin in Tunisia and considered as the largest national water resource. The focus was first put on the calculation of the water stress SDG 6 indicator (6.4.2). This indicator was selected as a specific case in this study since water stress is very relevant for the considered catchment. The indicator was evaluated at the scale of the Medjerda catchment and 4 regions within for the period 2000-2016. The spatial and temporal disaggregation was based on analysis of both governmental and remote sensing data, and provided a valuable understanding of the seasonal and regional behavior of water stress. The lack of access to reliable official data was the major constraint in measuring the water stress indicator. The second research section of the thesis was then dedicated to the improvement of the water-related database of the Medjerda catchment through data collection and the creation of a publicly available and standardized online platform "Together4Water", which provides access and dynamic visualizations of the collected data as well as interactive real-time communication tool with users. Consequently, we introduced in the third section of this work the concept of CS as a complementary source of data in Tunisia. The approach was based on the engagement of everyday citizens of a test region within the Medjerda catchment in monitoring rainfall, discharge, and water quality using cost-effective tools. Focus was mainly put on rainfall and discharge monitoring. The Together4Water website was the base for reaching a wide range of citizens from different generations in the test region allowing the initiative to engage a group of volunteers in data collection. For rainfall, traditional low-cost rain gauges were used at multiple locations, while the data transmission was ensured through the Together4Water website. Results yield a good agreement between citizens' observations and the official rainfall data. For discharge, a publicly available smartphone app "Discharge app" was used to estimate river flow of the Medjerda at two locations. A Data fusion technique was then used to validate and combine citizens' estimations to generate unique yet higher quality discharge datasets for both locations. Finally, an assessment of the potential contribution of the CS initiative to the SDG 6 monitoring was performed. We conclude that around 54% of the goal's indicators could be supported by our CS initiative, which emphasizes the value of public engagement in SDG 6 monitoring.(AGRO - Sciences agronomiques et ingénierie biologique) -- UCL, 202