The variations in rainfall patterns observed in recent years in the north-western part of Guinea are well prefecture of Siguiri in Upper Guinea. In order to understand the trends in rainfall and hydrometric variations, we used the Standardized Precipitation Indices (SPI) method. The remote sensing method applied reflects human causes in the transformation of environmental environments (water, forests, soils, habitats, crops). The results obtained show that rainfall over the period 1981-2020 is marked by periods of deficit (drought) between 1981-1993; 1998-2002 and 2013-2020, while wet periods (surplus) occur between 1994-1997 and 2003-2012. Fluctuations in annual flow modules can be explained by a surplus period from 1980 to 2000 and a deficit period from 2001 to 2019. The statistics drawn from the land-use maps for 2000, 2010 and 2021 highlight the spatial and temporal dynamics of each thematic class. From 2000 to 2021, the Water/Wetlands (+22.55%) and gallery forests (+23.92%) classes show increases, while the Bare Soil/Cultivated Land (-20.08%), Wooded Savannah (-4.55%) and Savannah-Crop Mosaic (-21.85%) classes show decreases. Temperatures between 1981 and 2022 in the Siguiri area varied between 25.995°C and 27.72°C, with the highest values recorded in 2010.