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A key skill that geomorphologists possess is the ability to use multi‐scale perspectives in their interpretations of landscapes. One way to gain these perspectives is with the use of nested hierarchical frameworks. In fluvial geomorphology, such frameworks help with assessment of large‐scale controls (e.g., tectonic activity, climate change) on the pattern and dynamics of smaller‐scale physical features (e.g., channels, floodplains, bars), and conversely illustrate how these smaller‐scale features provide the building blocks from which to make interpretations of fluvial processes and dynamics over larger spatial and temporal scales. Given the rapid pace of technological developments, the range of relatively inexpensive tools available for visualising and mapping landscapes at different spatial scales is expanding exponentially. In this paper, which focuses on the World Heritage‐listed Okavango Delta in Botswana, we demonstrate how various visualisations generated by different technologies at different spatial scales (catchment, landscape unit, reach, site and geomorphic unit) are providing critical baseline information to enhance interpretation and communication of fluvial geomorphology, with potential application in water resources management. In particular, our nested hierarchical approach could be used as an interactive communication tool for non‐specialists and embedded within existing and future management plans for the Delta. The construction of nested hierarchies that synthesise information and analyses can be a valuable addition to the environmental manager's toolkit.

Data-poor tropical wetlands constitute an important source of atmospheric CH 4 in the world. We studied CH 4 fluxes using closed chambers along a soil moisture gradient in a tropical seasonal swamp in the Okavango Delta, Botswana, the sixth largest tropical wetland in the world. The objective of the study was to assess net CH 4 fluxes and controlling environmental factors in the Delta's seasonal floodplains. Net CH 4 emissions from seasonal floodplains in the wetland were estimated at 0.072 ± 0.016 Tg a −1 . Microbial CH 4 oxidation of approximately 2.817 × 10 −3  ± 0.307 × 10 −3  Tg a −1 in adjacent dry soils of the occasional floodplains accounted for the sink of 4% of the total soil CH 4 emissions from seasonal floodplains. The observed microbial CH 4 sink in the Delta's dry soils is, therefore, comparable to the global average sink of 4–6%. Soil water content (SWC) and soil organic matter were the main environmental factors controlling CH 4 fluxes in both the seasonal and occasional floodplains. The optimum SWC for soil CH 4 emissions and oxidation in the Delta were estimated at 50% and 15%, respectively. Electrical conductivity and pH were poorly correlated ( r 2  ≤ 0.11, p  < 0.05) with CH 4 fluxes in the seasonal floodplain at Nxaraga. This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part1)'.

Climate change and adaptive land management in southern Africa-assessments, changes, challenges, and solutions. Biodiversity & Ecology, 6, Klaus Hess Publishers, Göttingen & Windhoek.

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