THE IMPACT OF CLIMATE CHANGE ON THE SIZE OF LAKE LOGGO (HAYQ), ETHIOPIA

Abstract

In this study, the aim was to evaluate the contribution of rainfall and temperature variability and trend on Lake Loggo (Hayk) size/volume change, in Ethiopia using rainfall, temperature, and a map of the different years of the Lake data from 1986 to 2016. In addition, the 10-year interval Landsat map of the Lake was used to see the variability and correlation with climate change. Coefficient of variation (cv) and ArcGIS 10.5 was used to examine rainfall variability and Lake Loggo’s variability respectively. Mann-Kendall (MK) test and Sen’s slope estimator was used to test the trend. The study area has two rainfall seasons, Kiremt and Belg. Kiremt is the main rainy season which accounts for 91.66% of the annual rainfall, and Belg contributes 6.252%. The rate of change for annual mean, the maximum and minimum temperature in the study area was 0.005 ◦C, 0.049 ◦C, and -0.039 ◦C, respectively. Decadal mean rainfall amount was recorded as 1141.83 mm, 1159.43 mm, and 1124.05 mm, respectively. This clearly shows a decreasing rainfall trend from 1996 to 2016, which was about 35.83 mm per year. Decadal analysis of the mean maximum and mean minimum temperature of 25.45 ◦C, 26.12 ◦C, and 26.55 ◦C for maximum temperature and 11.02 ◦C, 10.87 ◦C, and 10.17 ◦C for minimum temperature over the last three decades, respectively. This analysis confirms increasing trends for both mean maximum and mean minimum temperature in the study area. All seasons’ mean temperature was below the long-term mean from 1986 to 2000, while it was above the long-term mean since 2001. This result verifies the recent fast increment warming trend of the area. From the seasonal analysis of rainfall, in all seasons below the mean long-term rainfall was observed since 2001. This result may be related to the Lake Hayq variability. The study concludes that there was a significant variation in rainfall and a significant increment in temperature throughout the observing period. The high variability of rainfall and significant increase in temperature could have an interconnection with the variation of Lake Hayq's size since 2001. Rainfall variation could cause flooding and outbreak of human and livestock diseases and conservation agriculture practice is imperative for overcoming the problem.