Conclusions

The ENSO episodes of 1997-1998 and 2000 and the drought of 2001 were extreme events of climate variability. They were important because of their magnitude and the economic, health and social problems they created.

• The greater part of the southern sector of the basin suffers impacts because of climate variability.
• La Cruz, Upala, Los Chiles, Guatuzo, and San Carlos were the cantons most affected.
• The severe drought that plagued the region during the first semester of 1998 provoked losses of 22,366,800 colons, in Costa Rica.
• In the northern part of the basin, the municipalities that were the most affected by climate variability were Tipitapa, Granada, Cardenas, San Lorenzo, Rivas, and San Carlos.