Improvement of river network representation in Africa: application of an approach based on digital elevation data and environmental characteristics

<p>In many continental databases representing rivers across Africa, information on rivers characteristics (length, width, intermittent or perennial) is often incomplete, and small streams are largely underrepresented. Fortunately, the use of topographic information from digital elevation model...

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Autores principales:	A. P. Belemtougri, A. Ducharne, H. Karambiri
Formato:	article
Lenguaje:	EN
Publicado:	Copernicus Publications 2021
Materias:	Environmental sciences GE1-350 Geology QE1-996.5
Acceso en línea:	https://doaj.org/article/cc7f9969bb2c486e9194193d000b20fc
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spelling	oai:doaj.org-article:cc7f9969bb2c486e9194193d000b20fc2021-11-16T06:46:14ZImprovement of river network representation in Africa: application of an approach based on digital elevation data and environmental characteristics10.5194/piahs-384-19-20212199-89812199-899Xhttps://doaj.org/article/cc7f9969bb2c486e9194193d000b20fc2021-11-01T00:00:00Zhttps://piahs.copernicus.org/articles/384/19/2021/piahs-384-19-2021.pdfhttps://doaj.org/toc/2199-8981https://doaj.org/toc/2199-899X<p>In many continental databases representing rivers across Africa, information on rivers characteristics (length, width, intermittent or perennial) is often incomplete, and small streams are largely underrepresented. Fortunately, the use of topographic information from digital elevation models (DEMs) provides an opportunity to have more detailed information on rivers, particularly small streams in broad areas. A common approach to extract streams from DEM is to consider as a stream all DEM cells that drain at least a certain upstream surface, commonly known as the minimum contributing area (<span class="inline-formula"><i>A</i><sub>min</sub></span>). This parameter (<span class="inline-formula"><i>A</i><sub>min</sub></span>) is generally defined uniformly over large areas and this independently of the very variable climate and landscape conditions so that the generated streams have a rather uniform spatial distribution. To address this issue, using a 3<span class="inline-formula"><sup>′′</sup></span> (approx. 90 m <span class="inline-formula">×</span> 90 m) DEM of Burkina Faso, the relationship between <span class="inline-formula"><i>A</i><sub>min</sub></span> and the observed drainage density (Dd<span class="inline-formula"><sub>obs</sub></span>) was established with satisfactory performance (<span class="inline-formula"><i>r</i><sup>2</sup>=0.86</span>). In ongoing work, the functional relationship between the observed drainage densities (Dd<span class="inline-formula"><sub>obs</sub></span>) and environmental variables (lithology, climate, geology, vegetation cover) should allow for the establishment of the relationships between <span class="inline-formula"><i>A</i><sub>min</sub></span> and the environmental variables. This relationship allows for spatially variable <span class="inline-formula"><i>A</i><sub>min</sub></span> values depending on landscape characteristics. Before extracting river networks in Africa, the next step will be to validate or update these relationships in several countries.</p>A. P. BelemtougriA. DucharneH. KarambiriCopernicus PublicationsarticleEnvironmental sciencesGE1-350GeologyQE1-996.5ENProceedings of the International Association of Hydrological Sciences, Vol 384, Pp 19-23 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	Environmental sciences GE1-350 Geology QE1-996.5
spellingShingle	Environmental sciences GE1-350 Geology QE1-996.5 A. P. Belemtougri A. Ducharne H. Karambiri Improvement of river network representation in Africa: application of an approach based on digital elevation data and environmental characteristics
description	<p>In many continental databases representing rivers across Africa, information on rivers characteristics (length, width, intermittent or perennial) is often incomplete, and small streams are largely underrepresented. Fortunately, the use of topographic information from digital elevation models (DEMs) provides an opportunity to have more detailed information on rivers, particularly small streams in broad areas. A common approach to extract streams from DEM is to consider as a stream all DEM cells that drain at least a certain upstream surface, commonly known as the minimum contributing area (<span class="inline-formula"><i>A</i><sub>min</sub></span>). This parameter (<span class="inline-formula"><i>A</i><sub>min</sub></span>) is generally defined uniformly over large areas and this independently of the very variable climate and landscape conditions so that the generated streams have a rather uniform spatial distribution. To address this issue, using a 3<span class="inline-formula"><sup>′′</sup></span> (approx. 90 m <span class="inline-formula">×</span> 90 m) DEM of Burkina Faso, the relationship between <span class="inline-formula"><i>A</i><sub>min</sub></span> and the observed drainage density (Dd<span class="inline-formula"><sub>obs</sub></span>) was established with satisfactory performance (<span class="inline-formula"><i>r</i><sup>2</sup>=0.86</span>). In ongoing work, the functional relationship between the observed drainage densities (Dd<span class="inline-formula"><sub>obs</sub></span>) and environmental variables (lithology, climate, geology, vegetation cover) should allow for the establishment of the relationships between <span class="inline-formula"><i>A</i><sub>min</sub></span> and the environmental variables. This relationship allows for spatially variable <span class="inline-formula"><i>A</i><sub>min</sub></span> values depending on landscape characteristics. Before extracting river networks in Africa, the next step will be to validate or update these relationships in several countries.</p>
format	article
author	A. P. Belemtougri A. Ducharne H. Karambiri
author_facet	A. P. Belemtougri A. Ducharne H. Karambiri
author_sort	A. P. Belemtougri
title	Improvement of river network representation in Africa: application of an approach based on digital elevation data and environmental characteristics
title_short	Improvement of river network representation in Africa: application of an approach based on digital elevation data and environmental characteristics
title_full	Improvement of river network representation in Africa: application of an approach based on digital elevation data and environmental characteristics
title_fullStr	Improvement of river network representation in Africa: application of an approach based on digital elevation data and environmental characteristics
title_full_unstemmed	Improvement of river network representation in Africa: application of an approach based on digital elevation data and environmental characteristics
title_sort	improvement of river network representation in africa: application of an approach based on digital elevation data and environmental characteristics
publisher	Copernicus Publications
publishDate	2021
url	https://doaj.org/article/cc7f9969bb2c486e9194193d000b20fc
work_keys_str_mv	AT apbelemtougri improvementofrivernetworkrepresentationinafricaapplicationofanapproachbasedondigitalelevationdataandenvironmentalcharacteristics AT aducharne improvementofrivernetworkrepresentationinafricaapplicationofanapproachbasedondigitalelevationdataandenvironmentalcharacteristics AT hkarambiri improvementofrivernetworkrepresentationinafricaapplicationofanapproachbasedondigitalelevationdataandenvironmentalcharacteristics
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Improvement of river network representation in Africa: application of an approach based on digital elevation data and environmental characteristics

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