Characteristics of soil profiles from the Ouémé Upper Catchment (HVO), Térou, Benin


Autoria(s): Hiepe, Claudia
Cobertura

MEDIAN LATITUDE: 9.708539 * MEDIAN LONGITUDE: 2.144435 * SOUTH-BOUND LATITUDE: 9.009990 * WEST-BOUND LONGITUDE: 1.546290 * NORTH-BOUND LATITUDE: 10.131450 * EAST-BOUND LONGITUDE: 2.721820 * DATE/TIME START: 2002-06-30T00:00:00 * DATE/TIME END: 2004-10-31T00:00:00

Data(s)

23/05/2008

Resumo

Soil degradation threatens agricultural production and food security in Sub-Saharan Africa. In the coming decades, soil degradation, in particular soil erosion, will become worse through the expansion of agriculture into savannah and forest and changes in climate. This study aims to improve the understanding of how land use and climate change affect the hydrological cycle and soil erosion rates at the catchment scale. We used the semi-distributed, time-continuous erosion model SWAT (Soil Water Assessment Tool) to quantify runoff processes and sheet and rill erosion in the Upper Ouémé River catchment (14500 km**2, Central Benin) for the period 1998-2005. We could then evaluate a range of land use and climate change scenarios with the SWAT model for the period 2001-2050 using spatial data from the land use model CLUE-S and the regional climate model REMO. Field investigations were performed to parameterise a soil map, to measure suspended sediment concentrations for model calibration and validation and to characterise erosion forms, degraded agricultural fields and soil conservation practices. Modelling results reveal current "hotspots" of soil erosion in the north-western, eastern and north-eastern parts of the Upper Ouémé catchment. As a consequence of rapid expansion of agricultural areas triggered by high population growth (partially caused by migration) and resulting increases in surface runoff and topsoil erosion, the mean sediment yield in the Upper Ouémé River outlet is expected to increase by 42 to 95% by 2025, depending on the land use scenario. In contrast, changes in climate variables led to decreases in sediment yield of 5 to 14% in 2001-2025 and 17 to 24% in 2026-2050. Combined scenarios showed the dominance of land use change leading to changes in mean sediment yield of -2 to +31% in 2001-2025. Scenario results vary considerably within the catchment. Current "hotspots" of soil erosion will aggravate, and a new "hotspot" will appear in the southern part of the catchment. Although only small parts of the Upper Ouémé catchment belong to the most degraded zones in the country, sustainable soil and plant management practices should be promoted in the entire catchment. The results of this study can support planning of soil conservation activities in Benin.

Formato

application/zip, 3 datasets

Identificador

https://doi.pangaea.de/10.1594/PANGAEA.832915

doi:10.1594/PANGAEA.832915

Idioma(s)

en

Publicador

PANGAEA

Direitos

CC-BY: Creative Commons Attribution 3.0 Unported

Access constraints: unrestricted

Fonte

Supplement to: Hiepe, Claudia (2008): Soil degradation by water erosion in a sub-humid West-African catchment: a modelling approach considering land use and climate change in Benin. PhD Thesis, Rheinische Friedrich-Wilhelms-Universität Bonn, 307 pp, hdl:10013/epic.43322.d001

Palavras-Chave #<2 µm, >9 phi; Activity; Area; Area/locality; Base saturation; Biological activity; Boundary description; Bound descr; BRD; BS; Bulk density class; C/N; Ca; Carbon, organic, total; Carbon, total; Carbon/Nitrogen ratio; Cation exchange capacity; Cation exchange capacity, potential; CEC; CEC pot; Class; Classification; Clay fraction; Color code HLS-system; Color HLS; Comment; Concretions, gravel; Crop; Date/Time; DATE/TIME; Depth; Depth, bottom/max; DEPTH, sediment/rock; Depth, top/min; Depth bot; Depth top; Description; Drainage; Elevation; Erosion category; Fertility capability classification of soil; form; Fragm; Fragments; Global Change and the Hydrological Cycle; GLOWA; Grass, cover; Grass cov; Gravel; Human influence; Interpretation; K; Landform; Land use; Latitude; LATITUDE; Lithology; Lithology/composition/facies; Longitude; LONGITUDE; Mg; Micro topography; Na; Nitrogen, total; of relief; of soil; ORSTOM; Outcrop of rock; Parent material; pH; Poros; Porosity; Position; Profile; Sample elevation; Sand; Silt; Size fraction < 0.002 mm, > 9 phi, clay; Slope; Slope inc desc; Slope inclination, descriptive; Soil comp; Soil composition; Soil hori; Soil horizon; Soil moisture; Soil type; S org; Sulfur, organic; Surface coarse fragments; TC; Texture; TN; TOC; Topo; Topography; UTM east; UTM Easting, Universal Transverse Mercator; UTM north; UTM Northing, Universal Transverse Mercator; UTM Zone; UTM Zone, Universal Transverse Mercator; Vegetation type; water; WRB; WRB soil group
Tipo

Dataset