Title:EXPLORING MODIS IMAGERY IN MONITORING WATER QUALITY ON LAKE VICTORIA
Publication TypeJournal Article
Year of Publication2014
Authors:Anthony Gidudu, Zainab Mpakiraba, Herbert Kalibbala
Keywords:
Water Quality, Lake Victoria , Validation
Journal
Abstract:At 68,800 km2, Lake Victoria is the largest fresh water lake in Africa. It is a trans-boundary water
resource supporting the livelihoods of over 20 million people directly and indirectly. It is a source of food, recreation, domestic and industry use. This has rendered its monitoring of paramount interest
to several environmental agencies in Uganda, Kenya and Tanzania as well as along the river Nile
basin. Traditionally, the monitoring of water quality is carried out at specific points of the lake by
carrying out in-situ measurements or collection of water samples for laboratory testing. This
traditional approach of determining water quality is cumbersome, expensive and does not give a
synoptic perspective of the whole lake. This has inspired the consideration of satellite imagery as a
tool to monitor water quality on the lake. Satellite imagery offers the advantage of providing
regularly collected data, giving a synoptic view of the water quality of the whole lake. The aim of this paper was to therefore investigate how satellite derived water quality parameters compare with in situ measurements in a bid to operationalise the use of satellite images in monitoring water quality
on the lake. To wit, in-situ lake surface temperature at specific points was measured and water
samples of those points were taken to the lab to test for Chlorophyll_a. These samples were
collected within 4 hours of satellite overpass. These results were then compared with water quality
parameters derived from MODIS imagery. The results showed that there is a moderate to strong
correlation (R2 = 0.68) between satellite derived lake surface temperature and in-situ measurements
implying that MODIS satellite imagery can be depended to accurately model the spatial variation of
lake surface temperature. Unfortunately because of cloud cover coinciding with the day of in-situ
observations, no similar comparisons could be made regarding Chlorophyll_a, thus portraying one of
the challenges of operationalizing the use of satellite imagery in monitoring water quality on lake
Victoria. Given the potential of satellite imagery as a reliable source of water quality information,
further studies are urgently needed to validate it for Lake Victoria
Linkhttps://www.researchgate.net/profile/Anthony-Gidudu-2/publication/288331441_EXPLORING_MODIS_IMAGERY_IN_MONITORING_WATER_QUALITY_ON_LAKE_VICTORIA/links/567ffa3608ae1975838af09b/EXPLORING-MODIS-IMAGERY-IN-MONITORING-WATER-QUALITY-ON-LAKE-VICTORIA.pdf
DOI
EXPLORING MODIS IMAGERY IN MONITORING WATER QUALITY ON LAKE VICTORIA