In semi-arid areas like Southeastern Anatolia, where agricultural productivity and water supply are extremely climate-sensitive, drought is a significant environmental and socioeconomic problem. Comprehensive assessment of drought and soil moisture dynamics is fundamental to sustainable agriculture and water security in semi-arid regions. This study analyzes drought patterns across seven provinces in the Southeastern Anatolia (GAP) region of T & uuml;rkiye (Ad & imath;yaman, Diyarbak & imath;r, Gaziantep, Kilis, Mardin, Siirt, and & Scedil;anl & imath;urfa) from 1963 to 2022, employing four drought indices (SPI, SPEI, CZI, and RDI) at multiple timescales (1-, 3-, and 12-month) to support evidence-based strategies for sustainable water and agricultural resource management. A more thorough evaluation is made possible by this multi-index and multi-scale method, which is rarely used concurrently at the provincial level. Additionally, the drought characterization was validated and enhanced through the analysis of ERA5-Land soil moisture data (1950-2022). According to the findings, the provinces with the lowest median index values and the highest frequency of extreme drought episodes are Diyarbak & imath;r and & Scedil;anl & imath;urfa. The SPEI-12 (THW) median values showed a neutral long-term drought-wetness balance with seasonal changes, ranging from -0.0714 (Ad & imath;yaman) to 0.188 (& Scedil;anl & imath;urfa). Particularly after 2009, soil moisture levels decreased to as low as 2-3 mm during the summer, indicating heightened evapotranspiration stress. RDI-12's reliability in long-term drought evaluation was confirmed by its strongest correlation with other indices (r = 0.87-0.97). According to spatial research, the frequency of moderate droughts in the southwest was as high as 39%, whilst the eastern provinces experienced severe and intense droughts as high as 8%. However, with frequency above 53%, wet occurrences were more common in the east, particularly in Siirt. By clarifying long-term drought and soil moisture patterns, this study provides essential insights for sustainable irrigation planning and agricultural water allocation in the GAP region.