Análisis de tendencias y variabilidad de la precipitación en las cuencas sureste del Ecuador

This study analyzes the trend and variability of precipitation in the river basins of Jubones, Puyango, and Zarumilla in southeastern Ecuador, using monthly and annual time series from 11 meteorological stations. Statistical methods such as linear regression, Mann-Kendall tests, and CUSUM were applied, along with geostatistical techniques like Kriging to represent the spatial distribution of precipitation. As a result, a significant annual trend (p-value < 0.05) was observed in eight meteorological stations. High spatial variability in annual precipitation trends was detected within the Zarumilla, Puyango, and Jubones river basins. Regarding spatial variability, the best-fitting model was the spherical one, with a coefficient of variation (CV) of 40.76%, high predictive performance (Nash = 0.982), and RMSE of 30.85 mm, highlighting spatial heterogeneity. The topographic profile revealed an irregular distribution of precipitation, with peaks at intermediate altitudes. The linear regression between altitude and mean annual precipitation was not significant, underscoring the influence of other geographic and atmospheric factors. This study strengthens water resource management and supports agricultural planning in the face of climate change.