Drought is among the most critical challenges in the agricultural sector, significantly reducing the yield of both field and horticultural crops. Sumac (Rhus coriaria L.), a medicinal and industrial plant species, demonstrates strong resistance to drought through various physiological and molecular adaptations. This study investigated the potential of sumac as a drought-resilient crop for sustainable agriculture in the Hamadan-Bahar Plain. Climate projections for the period 2026–2050 were conducted, followed by an assessment of drought severity and frequency using standard indices over 3-, 6-, and 12-month timescales. An integrated economic model was developed to simulate the effects of climate change and water scarcity on farmers’ net profit and to determine optimal cropping patterns under future climate scenarios. The findings revealed an increasing trend of drought in the region, intensifying pressure on groundwater resources. Through simulation of drought scenarios and implementation of various irrigation management strategies, a projected expansion of 91 hectares in sumac cultivation was observed, resulting in a 14.38 billion Toman increase in the net profit of the agricultural sector. These results suggest that promoting sumac cultivation can serve as an effective adaptation strategy to climate change, enhancing both economic resilience and long-term sustainability in agriculture. The outcomes of this research offer practical implications for farmers and policymakers seeking to improve agricultural performance in drought-prone regions.