Daily rainfall and air temperature data were collected by IGEBU. For a given station, the number of missing daily
rainfall data, MRDm (days), was determined for each month of the recording period. The monthly rainfall depth, Pm (mm), and the monthly number of rainy days, NRDm (days),were determined for each month with a complete record of daily rainfall data. For a given month, Pm was obtained by summing the daily rainfall depth values and NRDm was obtained by counting the number of days of the month characterized by a daily rainfall depth greater than zero. The number of missing daily temperature data, MTDm (days), was also determined for each month of the recording period. The mean of the daily maximum air temperatures, Tm,max (°C), the mean of the daily minimum air temperatures, Tm,min (°C), and the mean of the daily average air temperatures, Tm,ave (°C), were calculated for each month with a complete record of daily temperature data to determine the monthly maximum, minimum and average temperature, respectively. For each month of the year, the Pm and NRDm values were summarized by determining the following statistics: sample size, N (years), minimum, min, maximum, max, and mean value, M, coefficient of variation, CV. Two different data sets were considered for a given month. The first data set was obtained by selecting all the available data for a given month. The second data set was obtained by considering the years with a complete record of daily rainfall values (i.e., MRDm = 0 for all months of the year). The first approach used all available data, but the sample size changed slightly with the month, precluding a homogeneous comparison among months. By the second approach, less data than the available ones were sometimes considered for a given month. However, a homogeneous comparison among months was possible. The two approaches (i.e., all available monthly data, years with a complete record of daily values for all months of the year) were also used to summarize the Tm,max, Tm,min and Tm,ave measurements for a given month. The annual values of rainfall depth, Pa (mm), and number of rainy days, NRDa (days), were determined for each yearwith a complete record of daily rainfall values by summing the corresponding monthly values. The annual values of the maximum, Ta,max, minimum, Ta,min, and average, Ta,ave, temperatures were obtained for each yearwith a continuous record of daily temperatures by averaging the corresponding daily temperature values.
Agro-meteorological characteristics and soil propertis in the Ruyigi area, Burundi