Long term rainfall analysis to guide irrigation interventions for improved maize production in Masindi district
Matila, Tom Micah
MetadataShow full item record
In Uganda, limited knowledge on computations of irrigation water requirements based on rainfall data has led to decline in maize production due to dependency on rain-fed agriculture. This study involved analysis of rainfall data (1980-2010) from a weather station in Masindi located at Longitude 31.7170 and latitude 1.6670 at an elevation of 1,140 m above sea level. The rainfall data was analyzed using the rainfall analyzer software in order to characterize rainfall distribution and intensity over years for different maize growing seasons in district, frequency analysis methods like the ranking method to establish the contribution of rainfall data in computing Net Irrigation water requirements for maize. Generally, the average rainfall amount of Masindi district decreases over the study period with most of the mean annual rainfall received between April and October and less received between November and March, with the wettest year being 2001 and the driest 2009. Therefore, the district has a bimodal rainfall pattern with two cropping seasons, (March to June) and (July to November) with a mid-dry spell from June to July. The District also has a dry season of four months from November to February with the highest amount of rainfall over the years received in April with a monthly mean amount of 159.3 mm and the lowest amount received in January (25.5 mm). The dependable rainfall for design purposes of the irrigation system was found to be 1092.78 mm/annum which is enough to meet the annual maize water requirements. The rainy days decrease slightly over the period of study with the highest having low rainfall intensity but contributing a small fraction to the total annual rainfall and fewer days of high rainfall intensity contributing substantially to the total annual rainfall-amount. Therefore, using the dependable rainfall, effective rainfall and the net irrigation requirements, sustainable and proper irrigation interventions can be set up in Masindi district to help in sustaining the moisture demands of maize during critical stages of growth.