Sensitivity analysis of agricultural hydrological processes to climate change in the North China Plain

Introduction Climate change is profoundly altering hydrological cycles, posing serious challenges to agricultural sustainability and water resource security. Methods Quantifying the sensitivity of agro-hydrological processes to climate variability is therefore essential for developing effective adaptation strategies. In this study, a calibrated and improved Soil and Water Assessment Tool (SWAT) model, combined with sensitivity analysis was employed to evaluate the sensitivity and contributions of key climatic factors to major agro-hydrological variables in the North China Plain (NCP) during 1966–2016. Results The region exhibited a pronounced warming and drying trend, with minimum temperature rising more rapidly (0.56 °C 10 yr −1 ) than maximum temperature (0.12 °C 10 yr −1 ), while precipitation and solar radiation decreased 3.98 mm 10 yr −1 and 0.51 MJ m −2 10 yr −1 , respectively. Actual evapotranspiration (ET a ) was more sensitive to air temperature during the winter wheat growing season but more responsive to solar radiation during the summer maize season. Irrigation demand exhibited strong positive sensitivity to air temperature and solar radiation and negative sensitivity to precipitation; whereas water yield demonstrated exceptionally high sensitivity to precipitation, particularly at the main watershed outlet. Contribution analysis further identified solar radiation as the dominant factor governing actual evapotranspiration variation, whereas precipitation was the primary driver controlling changes in water yield. Discussion These findings provide a quantitative foundation for crafting targeted water management strategies, such as optimizing irrigation scheduling and reinforcing flood control infrastructure, to enhance climate resilience in this vital agricultural zone.