TITLE:
Hydrodynamic Characterization of the Water Table of the Upper Dallol Maouri Basin (Niger)
AUTHORS:
Habi Hamani Abdoul-Hayou, Adamou Mahaman Moustapha, Sandao Issoufou, Alassane Hado Halidou
KEYWORDS:
Aquifer, Piezometry, Pond, Recharge, Isotopic
JOURNAL NAME:
Open Journal of Modern Hydrology,
Vol.13 No.2,
February
3,
2023
ABSTRACT: The Dallol Maouri is a valley of an ancient tributary of the Niger River.
The groundwater in this area of the upper Dallol Maouri is little known because
of the weakness of the data. The purpose of this study is to make a
hydrodynamic characterization of the water table of the upper dallol Maouri by
piezometric approach. A piezometric monitoring network made up of 65 points (54
wells and 11 piezometers) was set up. Six (6) piezometric measurement campaigns
were carried out from June 2018 to June 2021. The piezometric survey is carried
out once every six months: in January and June corresponding respectively to
the high and low water period. The results show that the water table is
multi-layered in places with a combination of alluvial and Continental Terminal
3 (CT3) aquifers, or perched aquifers and inferoflux aquifers around permanent
ponds. The flow direction of the Continental Terminal 3 (CT3) aquifer is mainly
North-East/South-West. The piezometric levels are around 219 m (in the
South-West part) and 281 m (in the North-East part). The hydraulic gradient
varies from 0.018‰ to 1.83‰. The recharge zones are located in the outcrop zone
of the aquifer and in the valleys. A lack of recharge is observed on the
plateaus despite the presence of numerous permanent ponds. The recharge
coefficient in 2020 is estimated at 25% of the total rainfall recorded.