Preliminary investigation of Lake Victoria groundwater situation from advanced very high resolution radiometer data

Abstract

This chapter presents a study that used the findings that lake temperatures from processed thermal-infrared data can be used to identify possible inflow zones of groundwater into a lake. Spatial and temporal temperature anomalies are assumed to indicate groundwater inflow into a lake. National Oceanic and Atmospheric Administration's advanced very high-resolution radiometer scenes of Lake Victoria catchment for different seasons of 2004 were acquired, processed, and analyzed. The surface temperature maps of the lake produced from this data indicated two major seasonal patterns of surface-temperature distribution compared to measured lake-surface temperatures. These warm and cold season patterns are indicative of possible groundwater inflow into the lake. Ground-truth studies were attempted to ascertain these inferences from infrared imagery without much success due to various limitations. However, it is hoped that the findings of this preliminary groundwater assessment may serve as a starting point for the recommended, more detailed Lake Victoria groundwater investigations including possible subsurface outflow. Critical evaluation of the lake-water balance can only be made after conclusive studies on this often-ignored water-balance component are accomplished.