Precipitation and Temperature Trend Analysis in Mekelle City, Northern Ethiopia, the Case of Illala Meteorological Station

Abstract

Climate change has a significant impact on the environment as well as the social, economic. Tigray is one of the sensitive regions to climate variation particularly to precipitation and rainfall changes. In this study, we analysis trends in precipitation and temperature at annual, seasonal and monthly time scales for the periods of 1995-2014 for the Illala station which is located in Mekelle Agricultural research center, Tigray region. Instat⁺ software were used for analyzing the statistics as well as the excel spreadsheet and we were use the Non-parametric tests (such as Mann-Kendall and Sen’s Slope), linear regression, cumulative deviation curve techniques were used to determine climatic trends. The mean minimum temperature ranges between 10.2⁰C and 12.6 ⁰C, while, the mean maximum temperature varies between 22.3⁰C and 26.7⁰C From the analysis the monthly coefficient of variation (CV%) for both maximum and minimum temperature ranging from (6.9% in Oct) to (18.7% in Dec) for the average monthly rainfall ranging from 4.9% to 26% of coefficient of variation. from the analysis we were found that the monthly trend of precipitation which were may, June and July have an decreasing trend. While the both maximum and minimum temperature were found on the months of June, September and December   the climate trend results showed that there is no negative or positive statistically significant trend in the study area, despite of slight precipitation decrease in the area. The period of 1995-2014. Which are not statistically significant annually and seasonally temperature data showed slight increase annually even though results are not statistically significant during the period of 1995-2014.

Keywords: Climate Variation, Precipitation, Mann-Kendall,