Analysis of the Impact of Climate Change on River Flows and Rising Water Levels of Lake Nakuru

Abstract

Lake Nakuru has experienced flooding occasioned by climate change and catchment areas degradation. The increasing water levels to a record of 8.5m reported in April 2020 have been a great threat to livelihoods and flora and fauna, to the extent of the lake experiencing flamingoes’ migration. There have been attempts to establish the causes of flooding, with some scientists attributing the phenomenon to tectonic movements and geothermal power plant activities. This research aimed at studying the impact of climate change on the rising water levels of the lake. The objective of this study was to assess the impact of climate change in river flows and rising water levels of Lake Nakuru. Rainfall and temperature data, lake’s water level, River Njoro flows and Mau encroachment data were collected from the Kenya Meteorological Department, GIS applications, Water Resources Authority and Kenya Water Towers Agency, respectively. Statistical analysis was done using Microsoft Excel 2013 and R software and the relationship amongst various variables was determined. The statistical analysis involved a polynomial regression model equation, w= 40.90233 - 1.87230r + 0.54709r2 - 0.487155r3 - 0.65802f - 0.17135f2 -6.3386f3 + 43.23665y + 17.88745y2 - 0.06695y3, with an R2 and Nash and Sutcliffe values of 0.9343 and 0.934, respectively. The findings shows that climate change has taken places because of changes in rainfall amounts, River Njoro flows and temperature, especially in the 2010-2019 decade. It is concluded that climate change is a major contributing factor to the rising water levels of the lake. The study recommends continued monitoring of meteorological parameters, watershed management and development of a lake balance model.