“Peak carbon and neutrality”, also known as dual carbon, is the key to solving the problems of energy and industrial low-carbon transformation, and is also fundamental to promoting the development of new industries that protect the environment and conserve resources. Among the cities along the Yellow River Basin, the city of Luoyang in Henan province is strategically vital in the coordinated development of the regional economy. Thus, researching the coupling of urbanisation and ecological protection is an important way to realise the dual carbon goal. To explore the coupling and coordination (CC) between urbanisation and the ecological environment, an index system is built for comprehensively assessing urbanisation and ecological environment (UEE) systems in Luoyang, and a coupling model to measure their coordination degree, quantitatively analyzed the CC process and evolution trend of Luoyang’s UEE, and explored the driving factors causing their changes through regression analysis. The results show that the integrated urbanisation development index of Luoyang ranges from 0.7571–0.9497; however, the contribution of the city’s population to urbanisation is the lowest at only 5.231%. Therefore, it is suggested that the government and other institutions should pay more attention to coordinating the human–land relationship when planning for urban development. The integrated ecological environment development index ranges from 0.7512–0.8266. The contribution ratio of the ecological environment state and pressure on the ecological environment is relatively high, at 27.9% and 48.7%, respectively. Therefore, the city of Luoyang city should reduce the emission of industrial pollutants and improve the environmental level. In addition, the CC degree of UEE of Luoyang ranges from 0.8131–0.9296 during 2016–2021, with an overall trend of steady increase, and the coupling correlation coefficient of R² = 0.9335, with a good overall coupling effect. The results show that Luoyang needs to further accelerate its industrial transformation and upgrading and spatial development strategy, and strive to become an environment-optimised city. This study provides scientific and practical suggestions for the CC development of urbanisation and environment in the city of Luoyang, Henan province, and has reference value for accelerating the realisation of the two-carbon strategy.

Soil salinization and freshwater scarcity are two of the most pressing challenges limiting sustainable agriculture in arid and semi-arid regions worldwide. Magnetized irrigation has been proposed as a physical water treatment that introduces no chemical additives and may improve water infiltration and mitigate secondary salinization; however, its effectiveness under contrasting irrigation water sources remains poorly understood, particularly in undisturbed saline–alkali soils. This study investigated the effects of magnetized irrigation water from two sources—Yellow River water (HW) and subsurface drainage water (DW)—on soil water infiltration and water–salt transport in the Hetao Irrigation District, Inner Mongolia. Undisturbed soil columns were irrigated under three magnetic field intensities: 0, 3500, and 5000 Gauss (Gs). Cumulative infiltration, infiltration rate, wetting front advancement, soil moisture, salt storage, and ion redistribution were analyzed. Magnetization affected infiltration and water–salt redistribution, and the magnitude of the response differed between the two water sources. Mean infiltration rate increased by 11.6–13.9% under magnetization relative to non-magnetized controls (p < 0.001), and infiltration duration decreased by 6.1–7.1% (p = 0.020), with no significant difference between the 3500 and 5000 Gs treatments (p = 0.903). The water source × magnetic intensity interaction was not significant for infiltration rate or duration. Salt storage in deep layers was reduced under magnetized treatments: by 24.74% at 40–50 cm under HW at 5000 Gs and by 29.18% at 50–60 cm under DW at 3500 Gs (both p < 0.05 relative to the respective non-magnetized controls). Magnetized irrigation was associated with reduced Na⁺ and Cl⁻ accumulation in the 0–30 cm layer and with a higher relative proportion of Ca²⁺ and Mg²⁺ in the soil water extract. These findings provide experimental evidence on how the response to magnetized irrigation varies with irrigation water source in undisturbed saline–alkali soils and support further evaluation of subsurface drainage water reuse in salinized farmland.