Submitted to: ASABE Annual International Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 7/7/2019
Publication Date: N/A
Technical Abstract: Critical signals of precipitation irregularity are more and more reported across the Southeastern United States. Even though the region virtually receives a relatively high annual precipitation, the irregular distributions of the precipitation events represents a threat for rainfed crops. This situation suggests a need to define precipitation zones and evaluate the patterns of precipitation deficit or excess during crop growing seasons. This study uses a spatial regionalization approach to delineate precipitation regions for the Southeast United States based on long-term precipitation data. The data include time series of seasonal precipitation totals and seasonal numbers of precipitation events > 5mm over the period 1960 to 2017. The regionalization approach combines principal components and cluster analyses. Analyses were conducted on a total of 208 precipitation stations selected across the study region which spans the States of South Carolina, North Carolina, and Georgia. Finally, three precipitation regions were delineated based on statistics and similarity criteria. A comparative analysis of the three regions shows significant differences in term of total precipitation and number of precipitation events during the seasons of the year. In addition, the differences among regions were examined using a probabilistic approach. As a result, tables of probabilities and seasonal precipitation characteristics (precipitation totals and number of events > 5mm) were generated for each region. These tables of probabilities may be used as a decision-making tool in water resources planning.