Cup quality, Laagee Coffee, physical properties, Roasting temperature and time, Sensory attribute

Abstract

Drought is an insidious natural hazard that results from a deficiency of precipitation from normal conditions such that when it is extended over a season or longer period of time to meet the demands of human activities and the environments. A single drought analysis technique is not adequate, for Borkena river catchment there was no comparative study, instead combinations of techniques integrated together have been found preferable. Therefore, this study aimed to compare four drought analysis techniques and recommend suitable method for the study area. For this study; the comparison among Standardized Precipitation Index (SPI), Reconnaissance Drought Index (RDI), Rainfall Anomaly Index (RAI) and Precipitation Deciles Index (PDI) drought analysis techniques have been inspected to determine the relation. DrinC software was adopted for the analysis using rainfall as input for SPI, RAI and PDI techniques and both rainfall and PET for RDI to get output. Daily meteorological data were collected from NMA for 1987-2017 and annual time series scales used in the analysis. The compared results showed that all drought analysis techniques have positive correlation and very strong relation among SPI, RDI, RAI and PDI with values of R2 greater than 0.8 except Majete station. SPI and RDI drought analysis techniques showed very strong positive correlation relation and even they have strong correlation at Majete station with R2= 0.604. This implies that for selected stations only SPI and RDI showed strong correlation. The comparison result based on drought classes and frequency showed SPI and RDI perform almost similar as compared to other selected drought analysis techniques to determine drought frequency and drought classes. These lead to say SPI and RDI are the best techniques than other selected drought analysis techniques for the area. Therefore; it is advisable to use SPI and RDI for further study about drought condition for the study area