Scarcity of information on the water productivity of different water, land, and other ecosystems in Africa, hampers the optimal allocation of the limited water resources. This study presents an innovative method to quantify the spatial variability of biomass production, crop yield, and economic water productivity, in a data scarce landscape of the Pangani Basin. For the first time, gross return from carbon credits and other ecosystem services are considered, in the concept of Economic Water Productivity. The analysis relied on the MODIS satellite data of 250 m and eight-day resolutions, and the SEBAL model, utilizing Monteith's framework for ecological production. In agriculture, irrigated sugarcane and rice achieved the highest water productivities in both biophysical and economic values. Rainfed and supplementary irrigated banana and maize productivities were significantly lower than the potential values, reflecting a wide spatial variability. In natural landscapes, forest and wetland showed the highest biomass production. However, the transition to economic productivity was low but showed the potential to increase significantly when non-market goods and services were considered. Spatially explicit information, from both biophysical and economic water productivity, provides a holistic outlook of the socio-environmental and the economic water values of a land-use activity, and can identify areas for improvement, and trade-offs in river basins.

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Ecosystems provide social, ecological and economic benefits and are linked through the landscape. Landscape degradation and loss of biodiversity undermine ecosystem functioning especially in vital ecosystems such as the Mara Basin in Africa. Holistically monitored and assessed landscape provide values to support conservation strategy which could enhance sustainable resource utilisation. The study relied on high resolution 10-m Sentinel 2A, Landsat 30-m and SEBAL to generate biophysical parameters for valuation in the landscapes. A household survey was used to derive forest benefits to local livelihoods. The well conserved Trans Mara forest provided high ecological benefits but few social benefits to the local community. Tea buffers have proven to be an effective conservancy strategy for the forest ecosystem. The long term carbon-based benefits in conservation areas of rural Africa is hindered by communities’ high dependency on firewood and charcoal energy. The land policy on limited livestock access to the pastoralists in the conservancies should be based on the livestock carrying capacity of the lands. Further, the valuation maps can be used for land use planning where critical wildlife protection areas, movement corridors and mixed use zones of high livestock value can be identified. The holistic assessment of value of African landscape based on key functionalities and linked spatially over the landscape using remotely sensed data is indeed crucial to improve decision making and conservation strategy towards sustainable ecosystem management.@en