Characterization of the spatial and temporal variability of surface water in the Soudan‐Sahel region of Africa

Abstract

[1] Water is a precious resource since the lives and livelihoods of human societies depend on their ability to access this resource. This is particularly true in arid and semiarid regions like the Sahel where permanent surface waters are rare and hydrological solutions (e.g., accessing deep aquifers) are often not feasible. This work is devoted to the determination of the spatial and temporal variations of surface water extent at 250 m over 9 years (2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011) for the Soudan-Sahel region using visible and infrared imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS) from both Terra and Aqua platforms. The methodology is automatic and could be applied to other regions and sensors. We utilized a combination of two MODIS spectral indices: the Normalized Difference Vegetation Index and the Modified Normalized Difference Water Index. Accuracy assessments carried out on 743 lakes across 37 Landsat images selected in Sahelian Africa on the basis of a stratified sampling show that the new product is (i) reliably able to detect surface water bodies of approximately 50 ha and larger, (ii) improves on existing surface water body products, and (iii) can be used to monitor the seasonal distribution of surface water in semiarid regions.Citation: Kaptue´, A. T., N. P. Hanan, and L. Prihodko (2013), Characterization of the spatial and temporal variability of surface water in the Soudan-Sahel region of Africa,

Seasonality, water use and community management of water systems in rural settings: Qualitative evidence from Ghana, Kenya, and Zambia

“…Community entry is an important first step in building the social capita of the water committee. As described in Kelly et al (Kelly et al, 2017), community participation in water system construction and water committee formation builds a strong basis of social capital for the committee, which can then be used to facilitate the community sense of ownership and further participation. If the external support actors use the early stages of community engagement to identify strong leaders and skilled community members, they can use those human resources to create a strong base of social capital, which affects how successfully a water committee can mobilize resources, share information and make decisions.…”

“…There is a substantial decrease in the quantity of water available during the dry season. Groundwater availability (the water source for wells and boreholes) (Eilers et al, 2007) and surface water area (Kaptué et al, 2013) both rapidly decrease in the dry season and rainwater harvesting becomes difficult. Seasonality has been shown to influence water demand in rural households (Calow et al, 2010;Griffin & Chang, 1991), choice of primary water source (Pearson et al, 2016) and willingness to pay for water .…”

Improving the Accuracy of the Water Surface Cover Type in the 30 m FROM-GLC Product

“…However, this may require a series of trials before reaching a satisfactory result. Another possible solution is to perform dynamic water mapping with multi-temporal scenes [25,36,37], because the chances of being covered or shadowed by clouds in multiple images would be significantly lower for certain pixels where the number of cloudy days is small. By fusing multi-temporal images, the cloud issue should be easily overcome for those pixels.…”

Spatial and temporal characteristics of rainfall in Africa: Summary statistics for temporal downscaling

“…Tropical Rainfall Measuring Mission (TRMM 3B42v.7) data at 0.25° × 0.25° grid size and 3 h sampling frequency for the 1998–2012 period were used in this study. These data are widely used to understand the impact of rainfall for water resources management, land surface, and hydrological modeling [e.g., Huffman et al ., ; Fekete and Vörösmarty , ; Boone et al ., ; Kaptué et al ., ]. Over Africa TRMM retrievals have been validated with rain gauge data sets [ Nicholson et al ., ] and they have also been intercompared with other continental rainfall products [ Novella and Thiaw , ; Sylla et al ., ].…”