Difference between revisions of "Nyong River Basin Cameroon"
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== Location == | == Location == | ||
| − | latitudes | + | |
| + | latitudes 2°48’ N and 4°32’ N and longitudes 9°54’ E and 13°30’ E | ||
== Catchment size == | == Catchment size == | ||
| − | + | 27 800 km² | |
== Climate == | == Climate == | ||
| − | Sub-Humid to Equatoria | + | *Sub-Humid to Equatoria |
| + | *the seasonal rainfall variations exhibit a typical bimodal distribution with MAR values between 1600-1800 mm/a in the north and northwest, to an equatorial climate with four seasons (MAR from 1600-2500 mm/a | ||
| + | *downstream (westwards), the climate passes progressively to an equatorial monsoon climate (2000–3000 mm/a P). | ||
== Geology == | == Geology == | ||
| + | The Nyong River flows in the low-relief South Cameroon Plateau landscape and then joins the coastal plain by a series of falls corresponding to the scarp of the passive margin. The basement of the Nyong River basin is mostly silicates, composed of dominant granito-gneis (Precambrian and Panafrican in age) intermingled with less abundant mafic to ultramafic rocks from Precambrian greenstone belts (Regnoult, 1986). | ||
| + | Soils are deep mature lateritic regolith (reaching up to 50m on the plateau) and hydromorphic soils in the valleys. | ||
| + | |||
| + | == Topography == | ||
| + | |||
== Vegetation/Land use == | == Vegetation/Land use == | ||
| + | *tropical rainforest | ||
| + | *upper Nyong basin is covered by semi-deciduous forest characterized by Stertuliaceae and Ulmaceae | ||
| + | *marsh forest and water meadows are found and raffias (Raphia montbuttorum) grow in the swampy depressed zones (Santoir and Bopda, 1995) for 150 km upstream of the Upper Nyong basin | ||
| + | *downstream climatic transition leads to a change in vegetation cover from semi-deciduous forest to the east to littoral forest (Lophira alata) to the west, passing by evergreen forest (Caesalpinaceae) | ||
| + | *in the whole basin, vegetation cover is significantly damaged by agroforestry, logging, and slash and burn practices; human activities include moderate industrial forestry, traditional shifting cultivation (manioc and other tubers, banana, corn, peanuts, cocoa beans and tomatoes) without significant fertilizer inputs | ||
== Context of investigation == | == Context of investigation == | ||
| + | *sediment transport | ||
| + | *isotopes | ||
| + | *land management | ||
| + | *catchment hydrology | ||
== Measurements/Equipment == | == Measurements/Equipment == | ||
| − | + | *runoff since 1960 with five stations | |
== Links to project webpages == | == Links to project webpages == | ||
| Line 25: | Line 42: | ||
== References == | == References == | ||
| − | *Braun, J.-J., Marechal, J.-C., Riotte, J., Boeglin, J.-L., Bedimo, J.-P.B., Ngoupayou, J.-R.N., Nyeck, B., Robain, H.,Sekhar, M., Audry, S., Viers, J. (2012): Elemental weathering fluxes and saprolite production rate in a Central African lateritic terrain (Nsimi, South Cameroon). Geochimica et Cosmochimica Acta, 99, 243–270, DOI: dx.doi.org/10.1016/j.gca.2012.09.024. | + | * Braun, J.-J., Marechal, J.-C., Riotte, J., Boeglin, J.-L., Bedimo, J.-P.B., Ngoupayou, J.-R.N., Nyeck, B., Robain, H.,Sekhar, M., Audry, S., Viers, J. (2012): Elemental weathering fluxes and saprolite production rate in a Central African lateritic terrain (Nsimi, South Cameroon). Geochimica et Cosmochimica Acta, 99, 243–270, DOI: dx.doi.org/10.1016/j.gca.2012.09.024. |
* Regard, V., Carretier, S., Boeglin, J.-L., Ngoupayou, J.-R.N., Dzana, J.-G., Bedimo, J.-P.B., Riotte, J., Braun, J.-J. (2016): Denudation rates on cratonic landscapes: comparison between suspended and dissolved fluxes, and 10Be analysis in the Nyong and Sanaga River basins, south Cameroon. Earth Surf. Process. Landforms 41, 1671–1683, DOI: 10.1002/esp.3939. | * Regard, V., Carretier, S., Boeglin, J.-L., Ngoupayou, J.-R.N., Dzana, J.-G., Bedimo, J.-P.B., Riotte, J., Braun, J.-J. (2016): Denudation rates on cratonic landscapes: comparison between suspended and dissolved fluxes, and 10Be analysis in the Nyong and Sanaga River basins, south Cameroon. Earth Surf. Process. Landforms 41, 1671–1683, DOI: 10.1002/esp.3939. | ||
[[Category:Experimental Catchments]] | [[Category:Experimental Catchments]] | ||
Latest revision as of 10:32, 2 December 2016
Location
latitudes 2°48’ N and 4°32’ N and longitudes 9°54’ E and 13°30’ E
Catchment size
27 800 km²
Climate
- Sub-Humid to Equatoria
- the seasonal rainfall variations exhibit a typical bimodal distribution with MAR values between 1600-1800 mm/a in the north and northwest, to an equatorial climate with four seasons (MAR from 1600-2500 mm/a
- downstream (westwards), the climate passes progressively to an equatorial monsoon climate (2000–3000 mm/a P).
Geology
The Nyong River flows in the low-relief South Cameroon Plateau landscape and then joins the coastal plain by a series of falls corresponding to the scarp of the passive margin. The basement of the Nyong River basin is mostly silicates, composed of dominant granito-gneis (Precambrian and Panafrican in age) intermingled with less abundant mafic to ultramafic rocks from Precambrian greenstone belts (Regnoult, 1986). Soils are deep mature lateritic regolith (reaching up to 50m on the plateau) and hydromorphic soils in the valleys.
Topography
Vegetation/Land use
- tropical rainforest
- upper Nyong basin is covered by semi-deciduous forest characterized by Stertuliaceae and Ulmaceae
- marsh forest and water meadows are found and raffias (Raphia montbuttorum) grow in the swampy depressed zones (Santoir and Bopda, 1995) for 150 km upstream of the Upper Nyong basin
- downstream climatic transition leads to a change in vegetation cover from semi-deciduous forest to the east to littoral forest (Lophira alata) to the west, passing by evergreen forest (Caesalpinaceae)
- in the whole basin, vegetation cover is significantly damaged by agroforestry, logging, and slash and burn practices; human activities include moderate industrial forestry, traditional shifting cultivation (manioc and other tubers, banana, corn, peanuts, cocoa beans and tomatoes) without significant fertilizer inputs
Context of investigation
- sediment transport
- isotopes
- land management
- catchment hydrology
Measurements/Equipment
- runoff since 1960 with five stations
Links to project webpages
other Links
References
- Braun, J.-J., Marechal, J.-C., Riotte, J., Boeglin, J.-L., Bedimo, J.-P.B., Ngoupayou, J.-R.N., Nyeck, B., Robain, H.,Sekhar, M., Audry, S., Viers, J. (2012): Elemental weathering fluxes and saprolite production rate in a Central African lateritic terrain (Nsimi, South Cameroon). Geochimica et Cosmochimica Acta, 99, 243–270, DOI: dx.doi.org/10.1016/j.gca.2012.09.024.
- Regard, V., Carretier, S., Boeglin, J.-L., Ngoupayou, J.-R.N., Dzana, J.-G., Bedimo, J.-P.B., Riotte, J., Braun, J.-J. (2016): Denudation rates on cratonic landscapes: comparison between suspended and dissolved fluxes, and 10Be analysis in the Nyong and Sanaga River basins, south Cameroon. Earth Surf. Process. Landforms 41, 1671–1683, DOI: 10.1002/esp.3939.