Sakarya University Journal of Science, cilt.29, sa.4, ss.426-440, 2025 (Scopus)
In this study, the effects of flood, drought and water pollution on the main agricultural products in Bilecik Province were examined. In the study, Arap and Delikbağ streams in Gölpazarı; Gümüşdere in Pazaryeri; Çöte stream basins in Yenipazar were used. The characteristics of the watershed (such as area, length, slope, curve number) and climate data (such as precipitation, temperature and evapotranspiration) were prepared and were used in the WinTR-55 and were used in DrinC model. As a result, the R2 (Determination coefficient) value between the result of RDI drought index and hop yield reached the highest value with a value of 0.50 in Pazaryeri among the compared districts. The R2 value between the RDI drought index result and wheat yield reached the highest value with a value of 0.80 in Söğüt among the compared districts. Besides, a significant decrease was observed in drought index values in Bilecik in 2017. The years when drought was most apparent in Bozüyük were 2006 and 2007. In Pazaryeri, 2007 year was that the effect of drought was felt most intensely. The peak flow values of the 100-year return period were compared in the watershed using the WinTR-55 model. Gölpazarı-Arap Stream was the area with the highest flood risk with 66.59 m3/s. This was followed by Gölpazarı-Gümüşdere with 47.06 m3/s, Gölpazarı-Delikbağ Stream with 47.00 m³/s and Yenipazar-Çöte with 26.27 m3/s, respectively.