Trends of Extreme Events in Precipitation and Temperature during the 1963 - 2012 Period at Mt Makulu, Zambia
Charles Bwalya Chisanga *
Ministry of Agriculture, Box 70232, Ndola, Ndola, Zambia and Department of Soil Science, School of Agricultural Sciences, University of Zambia, Lusaka, Zambia.
Elijah Phiri
Department of Soil Science, School of Agricultural Sciences, University of Zambia, Lusaka, Zambia.
Vernon R.N. Chinene
Department of Soil Science, School of Agricultural Sciences, University of Zambia, Lusaka, Zambia.
*Author to whom correspondence should be addressed.
Abstract
The Expert Team on Sector-specific Climate Indices (ET-SCI) for daily temperature and precipitation were analyzed for Mt Makulu (Latitude: 15.550° S, Longitude: 28.250° E, Elevation: 1200 meter) in Zambia. The study objective was to evaluate the ET-SCI climate indices for extreme weather conditions on temperature and precipitation from 1963 to 2012. Quality and homogeneity of the time series data were checked using RHtestsV4 and RHtests_dlyPrcp while ClimPACT2 software package was used to compute the ET-SCI indices. The Mann-Kendall for annual maximum and mean temperature were statistically significant with a positive linear trend (p<0.05). Additionally, results showed a significant increase in absolute indices as a function of temperature. The maximum warmest daily temperature (TXx) index showed a predominant increase in the monthly and annual maximum value of daily maximum temperature at Mt Makulu. The minimum warmest daily temperature (TXn) showed a similar trend for the annual value. Results also showed that the daily mean temperature (TMm) and mean daily maximum temperature (TXm) had increased from 1963 - 2012. The Daily Temperature Range (DTR) significantly increased annually and monthly resulting in a linear slope of 0.031 and 0.003, respectively. SU (Number of days when TX > 25°C) for both monthly and annual trend had increased significantly with a slope of 1.204 and 0.009, respectively. There were much higher heat spell events during DJF and SON with probability occurrence of 0.78 and 0.98 at p<0.05, respectively. Precipitation extreme indices (PRCPTOT, R30 mm, RX5 day, and R95p) had a non-significant positive trend at p<0.05.
Keywords: ClimPACT2, climate indices, RHtest, climate change, climate extremes, heatwaves, RClimDex