by Prof. Dan Olago, University of Nairobi in Gro for Good newsletter 2 2016
Welcome to the second edition of our project newsletter. There has been a lot of activity in recent months including: the completion of the installation and commissioning of the climate and hydrological monitoring network; two groundwater sampling campaigns in March and June; geophysical surveys to define the aquifer geometry and structure using both electrical resistivity tomography (ERT) and vertical electric sounding (VES) approaches; an anthropological survey related to determinants of use/non-use of the shallow wells installed with smart hand-pumps; compilation of a list of data sets for the project; and stakeholder engagement, both within the county and with stakeholders such as the Kenya Meteorological Department (KMD) and Water Resources Management Authority (WRMA) at the national level. I will, however, here focus on the geophysical surveys.
The project team has been collaborating with WRMA personnel in carrying out the geophysical survey. The WRMA kindly made its ABEM SAS1000 Terrameter available to enable this exercise to proceed. The ERT surveys which were carried out in three phases in December 2015, January 2016 and May 2016 are now completed. The VES survey which started in mid July will be completed in early August. The main aim of the geophysical survey is to get a better handle on the aquifer geometry and structure, with a focus on where geological understanding is poor, and to delineate the shallow and deep groundwater systems. The outcomes of this activity will provide critical inputs to the hydrogeological flow model that is already under development. This model will be integrated into the groundwater risk management tool to promote improved groundwater governance balancing economic growth, groundwater sustainability and poverty reduction, and taking into account the competing demands for domestic, agricultural and industrial uses of the resource.
The fieldwork has not been without incident; some unknown person cut off and went away with about 70m of cable and this slowed down the working pace, and we had to take on more local personnel to guard the cable layout to avoid any further losses. Heavy rains at times also meant that work had to be delayed or stopped altogether on some days. Overall, these incidents notwithstanding, it has been a great team building experience. The daily interaction between the team members fostered valuable knowledge exchanges and lifelong skills enhancement in geophysical surveying.