The ephemeral inundation of floodplains in semi-arid and arid zone climates is an essential driver of biological productivity. Natural biota depend on floodplain inundation to support critical reproductive life phases. In historical times, grazing industries have developed taking advantage of phases of high productivity associated with the overbank flow. However, the modelling of inundation in lowland floodplains is challenged by the complexity of topographic and hydrodynamic constraints. Here we apply a spatially explicit fine-scale inundation model to compare floodplain inundation regimes associated with current hydrological development on the Darling River floodplain, Australia, and pre-development, conceptualised as the removal of hydrological control structures. Our results suggest that hydrological developments in the Darling River catchment have substantially increased inter-flood period, an effect particularly pronounced during dry climatic phases. The result explains the decline in waterbird utilisation in this section of the Darling River, the low resilience of outer floodplain vegetation to the recent drought, and the reduction in grazing capacity. Water resource development had less impact on large inundation events.

在半干旱和干旱地区的气候中，泛滥平原的短暂泛滥是生物生产力的重要驱动力。天然生物区系取决于洪泛区的淹没，以支持关键的生殖生命阶段。在历史时期，放牧业的发展利用了与高潮相关的高生产率阶段。然而，地形和水动力约束的复杂性对低地洪泛区的淹没建模提出了挑战。在这里，我们应用空间显式的精细淹没模型来比较与澳大利亚达令河洪泛区当前的水文发展以及预开发（被概念化为水文控制结构）相关的洪泛区淹没状况。我们的结果表明，达令河流域的水文发展已大大延长了洪水泛滥期，这一影响在干旱气候阶段尤为明显。结果解释了达令河这一段水鸟的利用率下降，洪泛区植被对近期干旱的抵抗力低以及放牧能力下降。水资源开发对大型淹没事件的影响较小。