Mangrove cover change detection in the Rufiji Delta in Tanzania

Abstract

The Rufiji Delta is a critical ecosystem that comprises 50% of mangrove cover in mainland Tanzania, providing a plethora of ecosystem services that support diverse livelihood options. However, the rate of mangrove loss, espe- cially due to rapid expansion of rice farming in the delta, is alarming. Landsat imagery from 1991, 2000, 2009 and 2015 was used to estimate total current mangrove area in the delta. There has been loss of mangroves from 51,941 ha estimated in 1991 to 45,519 ha in 2015, which is an annual loss rate of 0.52%. Clearance for rice farming expanded from 5,344 ha in 1991 to 12,642 ha in 2015. The average mangrove annual loss and gain from 1991 to 2015 were esti- mated to be 378 ha and 109 ha respectively. The consequences of this loss are not well appreciated. The present anal- ysis serves as an updated baseline to inform the urgent need for coordination of multiple stakeholders to address the complex drivers of mangrove loss to secure the future of mangroves and ecosystem services in the delta.