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A hydrogeological study of the Nhandugue River, Mozambique - A major groundwater recharge zone

Arvidsson, Kristina LU ; Stenberg, L; Chirindja, Farisse LU ; Dahlin, Torleif LU ; Owen, R. and Steinbruch, F. (2010) 11th WaterNet/WARFSA/GWP-SA Annual Symposium In Procs. WaterNet 2010
Abstract
The Nhandugue River flows over the western margin of the Urema Rift, the southernmost extension of the East African Rift System, and marks the north-western border of Gorongosa National Park, Mozambique. It constitutes one of the major indispensable water resources for the ecosystem that the park protects. Our study focused on the hydrogeological conditions at the western rift margin by resistivity measurements, soil sampling and discharge measurements. The resistivity results suggest that the area is heavily faulted and constitutes a major groundwater recharge zone. East of the rift margin the resistivity indicate that solid gneiss is fractured and weathered, and is overlain by sandstone and alluvial sediments. The top 10-15 m of the... (More)
The Nhandugue River flows over the western margin of the Urema Rift, the southernmost extension of the East African Rift System, and marks the north-western border of Gorongosa National Park, Mozambique. It constitutes one of the major indispensable water resources for the ecosystem that the park protects. Our study focused on the hydrogeological conditions at the western rift margin by resistivity measurements, soil sampling and discharge measurements. The resistivity results suggest that the area is heavily faulted and constitutes a major groundwater recharge zone. East of the rift margin the resistivity indicate that solid gneiss is fractured and weathered, and is overlain by sandstone and alluvial sediments. The top 10-15 m of the alluvial sequence is interpreted as sand. The sand layer extends back to the rift margin thus also covering the gneiss. The sandstone outcrops a few kilometers from the rift margin and dips towards east/south-east. Further into the rift valley, the sand is underlain by lenses of silt and clay on top of sand mixed with finer matter. In the lower end of the investigated area the lenses of silt and clay appears as a more or less continuous layer between the two sand units. The topmost alluvial sand constitutes an unconfined aquifer under which the solid gneiss forms a hydraulic boundary and the fractured gneiss an unconfined aquifer. The sandstone is an unconfined aquifer in the west, becoming semi-confined down dip. The lenses of silt and clay forms an aquitard and the underlying sand mixed with finer matter a semi-confined aquifer. The surface runoff decreases downstream and it is therefore concluded that surface water infiltrates as recharge to the aquifers and moves as groundwater in an east/south-eastward direction. (C) 2011 Elsevier Ltd. All rights reserved. (Less)
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publication status
published
subject
keywords
Gorongosa National Park, Groundwater recharge zone, Hydrogeology, Resistivity, Urema Rift
in
Procs. WaterNet 2010
publisher
Southern African Development Community (SADC)
conference name
11th WaterNet/WARFSA/GWP-SA Annual Symposium
external identifiers
  • wos:000296306100008
language
English
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yes
id
32bcc089-2861-45cd-a324-e41246b593c6 (old id 2208136)
date added to LUP
2011-11-28 13:24:45
date last changed
2016-04-16 07:42:00
@inproceedings{32bcc089-2861-45cd-a324-e41246b593c6,
  abstract     = {The Nhandugue River flows over the western margin of the Urema Rift, the southernmost extension of the East African Rift System, and marks the north-western border of Gorongosa National Park, Mozambique. It constitutes one of the major indispensable water resources for the ecosystem that the park protects. Our study focused on the hydrogeological conditions at the western rift margin by resistivity measurements, soil sampling and discharge measurements. The resistivity results suggest that the area is heavily faulted and constitutes a major groundwater recharge zone. East of the rift margin the resistivity indicate that solid gneiss is fractured and weathered, and is overlain by sandstone and alluvial sediments. The top 10-15 m of the alluvial sequence is interpreted as sand. The sand layer extends back to the rift margin thus also covering the gneiss. The sandstone outcrops a few kilometers from the rift margin and dips towards east/south-east. Further into the rift valley, the sand is underlain by lenses of silt and clay on top of sand mixed with finer matter. In the lower end of the investigated area the lenses of silt and clay appears as a more or less continuous layer between the two sand units. The topmost alluvial sand constitutes an unconfined aquifer under which the solid gneiss forms a hydraulic boundary and the fractured gneiss an unconfined aquifer. The sandstone is an unconfined aquifer in the west, becoming semi-confined down dip. The lenses of silt and clay forms an aquitard and the underlying sand mixed with finer matter a semi-confined aquifer. The surface runoff decreases downstream and it is therefore concluded that surface water infiltrates as recharge to the aquifers and moves as groundwater in an east/south-eastward direction. (C) 2011 Elsevier Ltd. All rights reserved.},
  author       = {Arvidsson, Kristina and Stenberg, L and Chirindja, Farisse and Dahlin, Torleif and Owen, R. and Steinbruch, F.},
  booktitle    = {Procs. WaterNet 2010},
  keyword      = {Gorongosa National Park,Groundwater recharge zone,Hydrogeology,Resistivity,Urema Rift},
  language     = {eng},
  publisher    = {Southern African Development Community (SADC)},
  title        = {A hydrogeological study of the Nhandugue River, Mozambique - A major groundwater recharge zone},
  year         = {2010},
}