This study analyses the spatial and temporal variability and trends of rainfall, mean maximum and minimum temperatures at seasonal and annual timescales over the Upper Blue Nile River Basin, Ethiopia. Statistical and geostatistical techniques were applied to 1634 points on 10 × 10 km gridded data reconstructed from weather stations and meteorological satellite records. The data were obtained from the National Meteorological Agency of Ethiopia and cover the period between 1981 and 2010. Trends were evaluated from slopes of regression lines using the least squares method. The F‐distribution test was used to determine the statistical significance of the trends. Minimum temperatures significantly increased in northern, central, southern and southeastern parts of the Basin in all seasons. At the annual scale, maximum and minimum temperatures significantly increased in over 33% of the Basin at a rate of 0.1 and 0.15 °C per decade, respectively; however, the western part (12%) of the Basin experienced declining trends on annual and seasonal timescales. The minimum temperatures increased at a higher rate than the maximum temperatures during winter, summer, autumn and also at the annual timescale. Mean annual minimum and maximum temperatures increased from 12.69 to 13.32 °C and 26.43 to 26.91 °C from 1981 to 2010, respectively. Rainfall showed statistically non‐significant increasing trends of 35 mm per decade at the annual timescale. All seasons except spring season exhibited similar statistically non‐significant trends. The spring season, however, showed a statistically non‐significant declining trend in the north eastern (11%) part of the Basin.

This study detects patterns of land-use and land-cover changes in the last three decades (1972–2004) and analyses its causative factors in the Upper Dijo River catchment, Midwest escarpment of Ethiopian Rift Valley. Data captured through the synergy of an aerial photo, satellite image and ground-based socio-economic survey were analysed by GIS and SPSS. The results showed a decline in shrub-grassland and riverine trees at 21.5 and 16.3 ha per year, respectively, and increase in plantation trees, annual crops and bare/open grasslands at 2.8, 12.5 and 24.8 ha per year, respectively. The results are interpreted in the light of population dynamics, socio-economic condition and policy framework. The findings warrant that land-use and land-cover change in the region is very rapid, and unless the existing management of land resources is up-scaled, land ownership is secured, and family planning is mainstreamed in regional and local development plans, the region's fragile ecological balance would collapse irrecoverably.