A participatory observatory in Macaneta coastal wetland for the design of socio-environmental flows from the Incomati River (Mozambique)
WIOMSA 12th symposium, poster presentation, October 10th, 2-3pm
THEME VII Estuaries and their resources
Wetlands, Mozambique @ IRD - Stéphanie Duvail
Stéphanie Duvail, UMR PALOC, IRD (French Institute of Sustainable Development), firstname.lastname@example.org
Dercio Alberto, Université Aix Marseille and IRD (French Institute of Sustainable Development), email@example.com
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Environmental flows are a critical issue for Mozambique: it is a downstream country with most of the catchments of the highly seasonal rivers originating in upstream neighbouring countries. These transboundary rivers are regulated by storage dams and are subject to significant abstraction, mainly for irrigated sugar cane. Many of the upland grasslands have also been converted to plantations of exotic trees that have reduced runoff. Thus, Mozambique has witnessed a loss of net productivity in many of its estuaries and deltas as more dams became operational, reducing freshwater and sediment flows. This is what is happening for the coastal wetland of Macaneta, in the Marracuene District, Maputo Province, at the mouth of the Incomati River. The Piggs Peak Agreement of 1991 signed between South Africa, Eswatini and Mozambique established a minimum guaranteed cross border flow of 2 m3 s-1 while it was estimated at around 200 m3 s-1 in the 1950s.
This drastic reduction in flows has altered the landscapes of the delta and led to a reorganization of the associated farming and fishing production systems. In a collaborative project “E-flows in Mozambique” implemented by University Eduardo Mondlane, the IRD and IHE-Delft and funded by the WIOSAP program and the DIDEM project, environmental and social flow scenarios are designed to reduce the environmental degradation in order to benefit the wetland users. Understanding farmers' and fishers’ production strategies and their flexibility, as well as their salinization prevention practices is essential for the process.
Using the methodologies of geography, anthropology and history, the practices and strategies of local users and their changes over the past 50 years have been assessed. In addition, and in order to think collectively about salinity mitigation scenarios, local stakeholders were involved in an observation network. Their task was to describe their daily practices and in particular their management of the salinity variability and to share their observation and findings through social networks.
A dozen local observers reported and commented on their production strategies during 2 seasons as well as on their decision-making with regard to fishing, farming and gathering practices. The observers were brought together in workshops during which alternative scenarios were played on a fictitious river and discussed. The constraints and strategies of the local stakeholders are presented and compared with the E-flows developed by the hydrologists using modelling on the basis of hydrological data collected through monitoring, including a set of dataloggers.
Environmental flows are essential for maintaining and/or restoring the productivity of the coastal wetlands and improve the user well-being. The involvement of stakeholders through a participatory process is a mean to design flood scenarios adapted to the downstream needs.