Single-line diagram of the basins represented

Analysis of the Single-Line Diagram of the Shown Basins

The analysis of the unifilar diagram shows the distribution and classification of river basins according to the categorization of precipitation anomalies for the period between June 9 to July 8, 2026. In the Andean headwaters (Marañon, Napo, Ucayali, and the main stem of the Amazon), positive precipitation anomalies were concentrated in the Marañón River basin, which showed a rainy trend. In contrast, the Napo River basin and the main stem of the Amazon River in Peruvian territory recorded strong negative anomalies, classified as very dry and dry. The Ucayali River basin remained within normal conditions. The main stem of the Solimões River and the basins of the Coari, Jutaí, and Tefé rivers experienced rainfall close to the climatological average for the period. The Içá, Japurá, and Javari river basins recorded a precipitation deficit, while the Juruá and Purus river basins were above the climatological average. The Madeira River basin and most of its tributaries showed positive precipitation anomalies; only the Beni and Ji-Paraná river basins recorded rainfall close to the climatological average. The Madeira and Mamoré river basins showed a rainy trend, while the Guaporé and Aripuanã river basins exhibited the largest anomalies, classified as rainy and tending toward very rainy. The Negro and Branco river basins had precipitation below the climatological average and were categorized as tending toward dry and dry. On the left bank of the Amazon River in Brazilian territory, negative anomalies were recorded in the northeast and northwest of Pará, categorized as “tending toward dry” and “tending toward very dry.” In the northeast of the state of Amazonas, conditions were normal. On the right bank, the Abacaxis, Iriri, Tapajós, and Xingu river basins were close to normal, while the Curuá-Una and Juruena river basins were categorized as very rainy, and the Teles Pires River basin as tending toward very rainy. The main course of the Amazon River within Brazilian territory experienced rainfall slightly below the climatological average and was categorized as tending toward dry conditions.