The "Dong-Kang-Ejin" urban agglomeration in the middle of the Yellow River basin in China. Arid stormwater assessments often equate runoff with usable water and lack systematic evaluation. This study proposes five evaluation indicators covering the entire process of urban stormwater resource utilization and establishes a land-use-based assessment framework for stormwater resources. Using the SWMM model, the runoff processes of 152 rainfall events from 2009 to 2020 were simulated for three cities. The stormwater resource and its economic benefits across four distinct use categories were evaluated at different temporal and spatial scales. This achieves a full-process quantitative assessment of stormwater resources in arid regions, encompassing “rainfall–runoff–collection–treatment–utilization. Results show significant spatiotemporal heterogeneity in arid‑region stormwater use. Runoff collection rates are Kangbashi (61%–64%) ≥ Dongsheng (60%–63%) ＞ Ejin Horo Banner (56%–59%). Rainfall utilization (4%–10%) is below the typical urban benchmark (15%–20%). The annual utilizable runoff rate for the entire area is 3.77:1.83:1 across wet–normal–dry years. Utilizable runoff under design rainfall (p = 5a to 100a) ranges from 2.30 to 4.87 million m³ . Differentiated allocation of treated rainwater to agricultural, industrial, domestic, and ecological uses yields potential economic benefits of 94.18 (wet year), 54.51 (normal year), and 26.62 (dry year) million yuan. • Five indicators assess stormwater resource use, enabling multidimensional evaluation of potential. • Land-use-based methods with models quantify stormwater in arid cities spatiotemporally. • Stormwater economic benefit assessment for industry, agriculture, domestic, and ecology.
Ran et al. (Wed,) studied this question.