Regional wind pattern, a basis for defining the appropriate lapse of time for sugarcane burning in the Cauca Valley (Colombia)

摘要

Pre-harvest burning, an activity associated with manual sugarcane cutting, repels poisonous animals and makes harvesting considerably more straightforward and quicker. However, some reports from other countries that associate pre-harvest burning with human illness determined a change in the sugarcane harvest management. New crop management was based on green harvesting and the use of wind data to decide the right moment for burning. This work aimed to know the standard wind patterns to design strategies that allow sugar mills to burn sugarcane crops with minimum human health impacts. This study was based on the elaboration and analysis of 4320 wind rose plots of 30 weather stations located in the Colombian sugarcane production region. The analysis was performed at daily and monthly scales. The analysis considered the wind speed and wind direction values that increase the risk of affecting a settlement with the particulate matter when burning is done. Results showed that this region has local wind patterns that predominate direction and speed changes in response to the daily cycle. The main factor increasing the risk mentioned above is the wind speed. In this area, calm events (wind speed 1.5 m s(-1)) and high-speed winds (wind speed 5 m s(-1)) determine restrictions for crop burning 66% of the time. In the remaining 34% of the time, risk depends on the wind direction, and this is the ideal lapse of time for seeking the right moment for burning. The results are a tool for decision-making at different levels.