Water erosion leads to significant environmental, social, and economic challenges, such as the loss of fertile soil, reduced agricultural productivity, and water pollution. This study evaluates erosion-prone areas in the Oltu Basin, northeastern Türkiye, using the RUSLE model for the reference year (2023) and future climate scenarios (SSP245 and SSP585, 2041–2060/2061–2080). The average erosion rate for 2023 was determined as 49.90 t/ha/year, classifying 36.71% of the basin as severe or higher erosion risk. The critical vulnerability is attributed to the basin’s steep topography, with an LS factor (~ 9.87) significantly exceeding the European average. Under future climate scenarios, average erosion rates remain relatively stable (49.87–52.53 t/ha/year). However, notable spatial variations emerge, particularly in the western basin, where high-risk erosion areas are expected to increase. These changes are driven by shifts in rainfall erosivity (R factor), with a decline in maximum values but a rise in minimum values. The R factor decreased from 148.64 MJ mm/ha/h/year in 2023 to 144.90 MJ mm/ha/h/year under SSP245 (2061–2080); however, soil loss increased slightly from 49.90 t/ha/year to 50.57 t/ha/year due to the uneven spatial distribution of the R factor within the basin. This study emphasizes the spatial shifts in erosion sensitivity rather than overall averages, providing critical insights for targeted erosion control strategies. The findings will assist decision-makers in mitigating soil erosion risks and developing climate-adaptive land management policies.

This study investigates the stability of hydrological drought trends in the Euphrates Basin from 1960 to 2020 using three-dimensional (3D) graphical representations based on innovative trend analysis (ITA) and triple Wilcoxon test (WT) methods. Unlike traditional ITA and WT, which are widely used for trend identification but do not inherently provide trend stability information, this study employs a novel approach to assess and visualize trend stability. The Triple WT method divides the data into three equal segments, examining differences without altering the time series. Drought indices are calculated for 3-month, 6-month, and 12-month time scales using historical streamflow data from five stations. The research identifies trends and their stabilities across three distinct periods: 1967–1984, 1985–2002, and 2003–2020. Results show that as the time scale increases, trend differences between extreme drought conditions diminish. One station consistently exhibits significantly decreasing trends, while three stations show unstable trends with notable variations in the standardized streamflow index (SSFI). The use of 3D-ITA and Triple WT effectively captures the dynamics and stability of drought trends, offering a deeper understanding of hydrological drought in the Euphrates Basin. These findings provide a reference for future studies on drought trend mechanisms in various climatic regions.

Climate change and agricultural activities are significant sources of stress to the natural environment and water resources. These also affect erosion and the associated estimation of sediment yields, which is also a crucial task in the hydrological models. The presented study is significant for the development of sustainable watershed management practices. It also aims to determine the effects of climate change and different agricultural best management practices (BMPs) on the sediment loads of the North Aegean Basin in Türkiye by using the Soil and Water Assessment Tool (SWAT) model. While sediment calibration was performed for 2014, streamflow calibration and verification were performed using the SWAT Calibration and Uncertainty Program (SWAT-CUP) for the period 2012–2013 and 2014–2015, respectively. The obtained results showed that the climate change scenarios reduce the surface waters of the basin and sediment yield in accordance with the hydrological transport processes. During the 2012–2030 time period, runoff in the basin for the RCP4.5 and RCP8.5 climate change scenarios decreased by 38.5% and 31.8%, respectively, and the basin sediment yield decreased by 55.7% and 50.7%, respectively. The sediment yields to water resources had distinctive reductions due to BMPs such as zero tillage, vertical tillage, cover crop, and terracing. Considering the RCP4.5 and RCP8.5 scenarios, BMPs reduced the sediment yield in the range of 0.93–4.03% and 0.89–3.85%, respectively. Determining the sediment transport by using hydrological modeling and the effects of climate change for different agricultural practices on erosion will be useful for decision-makers.