Definitions and Mapping of East African Wetlands: A Review <s> Our Methodological Approach <s> The further development of two-dimensional finite element models of river flood flow is currently constrained by a lack of data for rigorous parameterization and validation. Remote sensing techniques have the potential to overcome a number of these constraints thereby allowing a research design for model development. This is illustrated with reference to a case study of a two-dimensional finite element model applied to the Missouri River, Nebraska and compared with a synchronous Landsat TM image of flood inundation extent. The case study allows research needs for the integration of hydraulic modelling and remote sensing to be defined. © 1997 John Wiley & Sons, Ltd. <s> BIB001 </s> Definitions and Mapping of East African Wetlands: A Review <s> Our Methodological Approach <s> Abstract Water level fluctuations of continental lakes are related to regional to global scale climate changes. Water level fluctuations reflect variations in evaporation and precipitation over the lake area and its catchment area. Over such inland water bodies, the satellite altimetry technique offers both a world-wide coverage and a satisfying accuracy. We present here results of lake level variations of 12 African lakes based on 7 years of Topex/Poseidon (T/P) altimetry data acquired between 1993 and 1999. Among the 12 African lakes presented in this study, three are reservoirs whose level fluctuations are mainly driven by anthropogenic usage of the water. Either closed or open, the nine remaining lakes are sensitive indicators of the climate evolution over Africa during the 1990s. Seasonal signals of each lake are clearly identified and filtered out to focus on the interannual fluctuations. Clear correlated regional variations are reported among the east African lakes: several lakes exhibit a regular level decrease between 1993 and 1997, probably due to intense droughts. However, the most spectacular feature is an abrupt water level rise occurring in late 1997–early 1998 and affecting most of the lakes located within the Rift Valley. This major anomalous pattern, explained by a large excess rainfall anomaly occurring in late 1997, is quantified in both space and time domains through an EOF analysis of the lake level height time series. The spatial distribution of the leading mode of lake level height correlates with the dominant mode of precipitation computed over the same time span. Nevertheless, similar rainfall anomaly, but with lesser intensity, occurred in late 1994 without any noticeable consequence on lake level. The precipitation anomaly appears related to the equatorial Indian Ocean warming reported during the 1997–1998 ENSO event. <s> BIB002 </s> Definitions and Mapping of East African Wetlands: A Review <s> Our Methodological Approach <s> A method for computing flooded areas in relation to precedent climatic conditions in a plain area is evaluated. The studied area includes the most important production area for cattle breeding in Argentina; therefore, waterlogging periods create significant economic losses. In order to conduct this study, Landsat images that represent different hydrological conditions were used. The method is based on the frequency analysis of rainfall records of the 30, 60 and 120 days prior each image, thus obtaining a seasonally weighted mean frequency. In order to minimize biases of individual images, the images were combined linearly so as to obtain composed images with the desired antecedent precipitation frequency. Then, the flooded areas were associated with the frequency of the antecedent rainfall. Therefore, frequencies equal to or higher than 50% are associated with semi-permanent or permanent lentic waterbodies. Consequently, lower frequencies are associated with waterlogged areas reaching 35% of flooded area for a 20% precipitation frequency. <s> BIB003
An analysis of 245 scientific references was performed in the search for a generally applicable definition for the term wetlands. The principal sources for these references were peer reviewed journals focused on remote sensing, including some of the highly contributing journals, like Remote Sensing, International Journal of Remote Sensing, Remote Sensing of Environment and Photogrammetric Engineering and Remote Sensing. Furthermore, journals, like Wetlands Ecology and Management, Vegetation and Wetlands, were incorporated to consider definitions coming from a non-remote sensing perspective. The selected journal articles were identified via Google Scholar © on diverse keyword searches. As wetlands are referred to with manifold terminologies (see the next section), keyword searches were not limited to wetlands only. We searched for terms like floodplain, swamp and mires and subsequently used reference lists of the identified literature for additional sampling of the literature. Non-peer reviewed wetland-related publications issued within the East African region, as well as scientific monographs or important wetland publications by international institutions were also examined. These were reviewed at the online library facilities of the University of Bonn. Additional important national and international programs on wetlands were incorporated, even if only online resources were available. They could be found via customary search engines after the identification in the relevant specialized literature. Our literature search was not limited to publication years and covered a range between 1971 and the end of 2014. Literature focusing solely on water surface detection was excluded from the analysis, as it could often only be indirectly linked to wetland research (e.g.  BIB001 BIB002 BIB003 ). An analysis of the availability of wetland definitions in scientific publications and a classification matrix for applied definitions within their study context are discussed in Section 2.2. The detailed grouping and a list of all used references for this analysis can be found in the supplement accompanying this review article. Our approach to researching the availability of wetland maps included two elements. Land use/land cover classification systems were initially evaluated for their utility in wetland mapping, for which we provide an overview of existing wetland maps and data layers covering the East African region. Wetland inventories of the East African region were identified with the advice of the partnering researchers within the countries. We catalogue and describe available wetland maps covering the East African region at global, continental and national spatial scales.