Caractérisation de la baisse hydrologique actuelle de la rivière Oubangui à Bangui, République Centrafricaine

Nguimalet, Cyriaque-Rufin; Orange, Didier

doi:10.1051/lhb/2019010

Cited by 17 publications

(18 citation statements)

References 6 publications

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“…The end of 2019 was marked by an extreme rising stage on Ubangi River at Bangui, with a daily discharge of 12,400 m 3 s −1 in November, which correspond to a return period of a dozen years. This event seems to confirm a new humid period announced by the discontinuity in 2014 [3]. One month later, this flood reached Brazzaville-Kinshasa, where the maximum December discharge of the annual hydrologic cycle reached 70,000 m 3 s −1 for an mean monthly flow in this month of around 56,000 m 3 s −1 .…”

Section: Rainfall and Discharge Trends In The Congo River Basinsupporting

confidence: 60%

“…In the Northern hemisphere, on the right bank, the Ubangi River is the second-most important tributary in terms of discharge [3], after the major tributary, the Kasaï, located further downstream on the left bank (Figure 1). Just upstream of the major hydrometric stations of Brazzaville-Kinshasa, the Congo flows through Malebo Pool (ex.…”

Section: Geographical Presentation Of the Congo River Basin (Crb)mentioning

confidence: 99%

“…In CAR, the pluviometric database was completed through the PIRAT and PEGI programs [16] and then Callède et al (2009) [17] produced a monograph on the Ubangi basin. In this basin, Nguimalet and Orange (2019) [3] studied a rainfall series from 1940 to 2015.…”

Section: Rainfall Networkmentioning

confidence: 99%

“…Nguimalet and Orange (2019) [3] suggest that rainfall runoff ratios over the Ubangi Basin at Bangui do not vary in time and also comment on the impact of phreatic drought. They studied rainfall data from 1935 to 2015 over the basin and confirmed a single discontinuity in 1971 causing a decrease (<5%) in the rainfall data series (Figure 5).…”

Section: Hydroclimatologial Studiesmentioning

confidence: 99%

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Recent Budget of Hydroclimatology and Hydrosedimentology of the Congo River in Central Africa

Laraque¹,

N’kaya

Orange

et al. 2020

Water

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Although the Congo Basin is still one of the least studied river basins in the world, this paper attempts to provide a multidisciplinary but non-exhaustive synthesis on the general hydrology of the Congo River by highlighting some points of interest and some particular results obtained over a century of surveys and scientific studies. The Congo River is especially marked by its hydrological regularity only interrupted by the wet decade of 1960, which is its major anomaly over nearly 120 years of daily observations. Its interannual flow is 40,500 m3 s−1. This great flow regularity should not hide important spatial variations. As an example, we can cite the Ubangi basin, which is the most northern and the most affected by a reduction in flow, which has been a cause for concern since 1970 and constitutes a serious hindrance for river navigation. With regard to material fluxes, nearly 88 × 106 tonnes of material are exported annually from the Congo Basin to the Atlantic Ocean, composed of 33.6 × 106 tonnes of TSS, 38.1 × 106 tonnes of TDS and 16.2 × 106 tonnes of DOC. In this ancient flat basin, the absence of mountains chains and the extent of its coverage by dense rainforest explains that chemical weathering (10.6 t km−2 year−1 of TDS) slightly predominates physical erosion (9.3 t km−2 year−1 of TSS), followed by organic production (4.5 t km−2 year−1 of DOC). As the interannual mean discharges are similar, it can be assumed that these interannual averages of material fluxes, calculated over the longest period (2006–2017) of monthly monitoring of its sedimentology and bio-physical-chemistry, are therefore representative of the flow record available since 1902 (with the exception of the wet decade of 1960). Spatial heterogeneity within the Congo Basin has made it possible to establish an original hydrological classification of right bank tributaries, which takes into account vegetation cover and lithology to explain their hydrological regimes. Those of the Batéké plateau present a hydroclimatic paradox with hydrological regimes that are among the most stable on the planet, but also with some of the most pristine waters as a result of the intense drainage of an immense sandy-sandstone aquifer. This aquifer contributes to the regularity of the Congo River flows, as does the buffer role of the mysterious “Cuvette Centrale”. As the study of this last one sector can only be done indirectly, this paper presents its first hydrological regime calculated by inter-gauging station water balance. Without neglecting the indispensable in situ work, the contributions of remote sensing and numerical modelling should be increasingly used to try to circumvent the dramatic lack of field data that persists in this basin.

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Section: Rainfall and Discharge Trends In The Congo River Basinsupporting

confidence: 60%

Section: Geographical Presentation Of the Congo River Basin (Crb)mentioning

confidence: 99%

Section: Rainfall Networkmentioning

confidence: 99%

Section: Hydroclimatologial Studiesmentioning

confidence: 99%

See 2 more Smart Citations

Recent Budget of Hydroclimatology and Hydrosedimentology of the Congo River in Central Africa

Laraque¹,

N’kaya

Orange

et al. 2020

Water

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“…In the 3 studied basins, there are the same range of the depletion coefficient than for the Ubangi at Bangui (Nguimalet and Orange, 2019) 198419841951-1983: 26 Wet +19 1984-1993 Very dry −61 37 196837 196837 195137 -196737 : 57 Wet +43 196837 -1993 Dry −22 -1951-1990: 17 Dry −6 1991-1991: 66 More +67 1992-1993 Mean wet +44 3748 197019701950-1958: 4044 Mean wet +8 1959-1969: 4877 Wet +30 1970-1980: 3618 Dry −3 1981-1994: 2729 The period ratio is the discharge amount of one period divided by the interannual discharge average. in 1990 on Ubangi.…”

Section: Dynamics Of the Depletion Coefficientmentioning

confidence: 86%

Hydroclimatic variability in Tomi at Sibut, Gribingui at Kaga-Bandoro and Fafa at Bouca basins, in the Central African Republic

Nguimalet

Orange

2020

Proc. IAHS

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Abstract. The research of ruptures on rainfall and discharge serial data from 1950 to 1995 of three small catchments (from 2000 to 6000 km2) of the Central African Republic, at the boundary between Chad and Congo basins, has shown a high spatial variability. The rupture observed in 1970 at the subcontinental scale, which started the drought period in West and Central Africa, is observed only on the Northward basin, the driest. Then it was difficult to compare the hydroclimatic periods from a basin to another one. However, all the studied basins have shown a degradation of the hydrological regime from the end of the 1980s onward, with a severe level since the end of 1980s. The depletion coefficients have the same range for the 3 studied basins than for the Ubangi River basin, widening the drought impact.

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Investigating the Role of the Cuvette Centrale in the Hydrology of the Congo River Basin

Datok

Fabre

Sauvage

et al. 2022

Congo Basin Hydrology, Climate, and Biogeochemistry

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Caractérisation de la baisse hydrologique actuelle de la rivière Oubangui à Bangui, République Centrafricaine

Cited by 17 publications

References 6 publications

Recent Budget of Hydroclimatology and Hydrosedimentology of the Congo River in Central Africa

Recent Budget of Hydroclimatology and Hydrosedimentology of the Congo River in Central Africa

Hydroclimatic variability in Tomi at Sibut, Gribingui at Kaga-Bandoro and Fafa at Bouca basins, in the Central African Republic

Investigating the Role of the Cuvette Centrale in the Hydrology of the Congo River Basin

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