For the monitoring of water levels a network of hydrometric stations is in place in Mali and Guinea. At some of these stations data are collected on a daily basis already more than a century. The monitoring of water quantity and quality in Mali and Guinea is managed by the DNH. The operational monitoring on a local level is organised by the regional administrative levels of DNH in both countries. Water levels are measured daily using gauges; telemetric measurement is in study and development but not operational yet. The principal parameter monitored is the daily water level; discharge is derived from existing information on the bathymetry of the river at the cross section of the hydrometric stations.
In the table below the hydrometric stations are listed per country and tributary, and the year is given from which the first data are available. For most of the stations, the data are incomplete for the decennia in the first half of the 20th century.
|Ké-Macina||Inner Niger Delta||Mali||1953|
|Mopti||Inner Niger Delta||Mali||1922|
|Akka||Inner Niger Delta||Mali||1907|
|Niafunké||Inner Niger Delta||Mali||1933|
|Goundam||Inner Niger Delta||Mali||1931|
|Diré||Inner Niger Delta||Mali||1931|
|Kouroumié||Inner NIger Delta||Mali||1975|
Water levels Niger and tributaries
The water levels in the catchment of the Niger and tributaries is monitored at 6 hydrometric stations in Guinea and 15 stations in Mali. In each of the tributaries there are two or more stations. The available data for Guinea are given in the interactive graph below. In this graph you can choose the station and add are remove years with data. The measurements are daily, but in some cases interpolated for periods during which there were no data. The latter data have been deleted as far as possible. To show that these interpolation may produce wrong results, one has not been removed (see the straight line in the Mandiana graph for 2011 between 1-8 and 1-11).
The data on water levels are presented below in interactive graphs, the first graph shows the water levels per station per month, the second the water levels per station per year. Interpolated data in the interactive graphs are still present (visible as straight lines).
The data from Baro, Kankan and Mandiana represent the water levels in the upper reaches of the Niger, respectively in its tributaries Niandan, Milo and Sankarani. The other stations represent the water level further downstream. Koulikouro, Kirango and Ké-Macina give the water levels in the Niger proper. Ké-Macina is situated at the entrance of the Inner Niger Delta. The data of the latter station is used to assess the inflow of the Niger into the Inner Niger Delta; see below
The daily variation in water level (cm), summarised per month, in Baro (Niandan River) since 1970, Kankan (Milo River) since 1970, Mandiana (Sankarani river) since 1955, Dialakoro (Niger River) since 1954, Kouroussa (Niger River) since 1954 between 1 April and 1 April the next year. Further the data for Macina (Niger River) since 1953 between 1 June and 1 June the next year. To see more detail in the interactive graphs it is easy to zoom in. To go back to the orgininal graph reset zoom.
The annual variation in water level (cm) in Baro (Niandan River), Kankan (Milo River), Mandiana (Sankarani river), Dialakoro (Niger River), Kouroussa (Niger River) and Macina (Niger River, at the entrance of the delta).To see more detail in the interactive graphs it is easy to zoom in. To go back to the orgininal graph reset zoom.
Water levels Bani
There are three hydrometric station in the Bani: Douna, Bénény-Kegni and Sofara. In the past, Douna was used as main hydrometric station to capture the flow of the Bani, but since the construction of the Talo dam (2007) the stations of Bénény-Kegni and Sofara gives a better picture of the flow of the Bani. At a high flood, part of the Bani flows directly to the Niger River along the Manga tributary, from Djenné to Kouakarou. This shortcut between the Bani and the Niger is situated downstream of Bénény-Kegni and upstream of Sofara.
The daily variation in water level (cm) in Bénény-Kegni and Sofara, both in the Bani River, since 1952 between 1 June and 1 June the next year. To see more detail in the interactive graphs it is easy to zoom in. To go back to the orgininal graph reset zoom.
The annual variation in water level (cm) in Bénény-Kegni and Sofara, since 1952. To see more detail in the interactive graphs it is easy to zoom in. To go back to the orgininal graph reset zoom.
Variation in flood level in the Inner Niger Delta
The seasonal flood pulse is illustrated by the water levels at the stations in Mopti and Dire. The flood moves as a wave through the delta, which means that in the same year not all floodplains of the delta are flooded at the same time. Flooding starts in the south in August and in most years the peak in Mopti is reached in the first half of October. The water level in the centre and north of the delta is still rising at that time. In the centre of the delta the flood peak and maximal flooding in most years is reached in the second half of October or November, and in Dire about a week later. The southern floodplains already run dry at the time.
First a graph is presented of the daily water level in Mopti since 1923, to show the large variation in seasonal flood level. The rest of the data on water levels is presented below in interactive graps, the first graph shows the water levels per station per month, the second the water levels per station per year. These data cover the period 1982-2018.
The daily variation in water level (cm) in Mopti since 1923 between 1 June and 1 June the next year. When the flood is low, the peak is reached in early October, but in wet years, the peak is more than a month later. Data DNH.
The daily and annual variation in water level (cm) in Mopti, Akka and Dire between 1982-2018, between 1 June and 1 June the next year. When the flood is low, the peak is reached in early October, but in wet years, the peak is more than a month later (Mopti) or two month later (Dire). Data DNH. To see more detail in the interactive graphs it is easy to zoom in. To go back to the orgininal graph reset zoom.
The graph below shows the annual variation in the highest flood level, as measured in Mopti, Akka and Diré. The water level has been measured daily on the gauge of Mopti since 1923, Akka since 1955 and Diré since 1931. Lacking years could be reconstructed using the annual peak levels measured in other hydrometric stations, which are highly correlated (see graphs below showing the relationship between Mopti and Akka and between Diré and Akka). The peak flood levels before 1923 have been derived from the relationship between the monthly average flow at Koulikoro in september and the maximal flood level in the Inner Niger Delta in the same year.
Annual peak flood levels in Mopti, Akka and Diré since 2007.
The relationship between the peak flood level in Mopti as a function of the peak level reached in Akka in the same year.
The relationship between the peak flood level in Diré as a function of the peak level reached in Akka in the same year.