Changes in precipitation and evapotranspiration over Lokok and Lokere catchments in Uganda
Loading...
Date
2021
Journal Title
Journal ISSN
Volume Title
Publisher
Bulletin of Atmospheric Science and Technology
Abstract
This study analysed long-term (1948–2016) changes in gridded (0.25° × 0.25°) Princeton
Global Forcing (PGF) precipitation and potential evapotranspiration (PET) data over
Lokok and Lokere catchments. PGF-based and station datasets were compared. Trend
and variability were analysed using a nonparametric technique based on the cumulative
sum of the difference between exceedance and non-exceedance counts of data. Seasonal
(March-April-May (MAM), June-July-August (JJA), September-October-November
(SON), December-January-February (DJF)) and annual precipitation exhibited negative
trends (p < 0.05). Positive anomalies in precipitation occurred in the 1950s as well as in
the early 2000s till 2016. Negative anomalies existed between 1960 and 2000. Both
seasonal and annual PET mainly exhibited increasing trend with alternating positive and
negative anomalies for the entire period, except in the southern region. The H0 was
rejected (p < 0.05) for SON PET in the North and South of the study area. The H0 was
rejected (p < 0.05) for DJF PET in the North. However, H0 was not rejected (p > 0.05) for
MAM, JJA and annual PET. Positive and negative correlations were observed between
PGF and station precipitation varying from one location to another. The PGF-based PET
were lower than the observed PET at Kotido by about 40%. Besides, a close agreement
was noticeable between PGF-based and MODIS PET from May to November. This
showed the need to improve on the quality of PGF data in reproducing the observed
climatic data in areas with low meteorological stations density. Nevertheless, the findings
from this study are relevant for planning of predictive adaptation to the effects of climate
variability on the water resources management applications. Impacts of human factors
and climate change on the hydrology of the study area should be quantified in future
research studies.
Description
Keywords
Trend and variability, Precipitation, Evapotranspiration, Lokok and Lokere catchments
Citation
Mubialiwo, A., Chelangat, C., & Onyutha, C. (2021). Changes in precipitation and evapotranspiration over Lokok and Lokere catchments in Uganda. Bulletin of Atmospheric Science and Technology , 2 (1), 1-23. https://doi.org/10.1007/s42865-021-00031-y