ABSTRACT

Disentangling the meteorological and human drivers of drought is a critical challenge. A key difficulty is identifying natural conditions against which human impacts can be analysed. Here, a combination of approaches is used: a hydrological model is developed for an upstream unmodified location and is then applied to a downstream site subject to irrigation-related abstractions: i.e. an upstream–downstream/observation–model approach. The relative importance of climate change is also investigated. The study location (the Lindis River, New Zealand) has a continental climate, and the lower river frequently runs dry during summer. Output from the hydrological model indicates that despite the warm and dry summer conditions there is a substantial influence of abstractions on Lindis River low flows – without abstractions, dewatering would likely be rare rather than regular. Increases in precipitation associated with climate change could reduce the occurrence of dewatering, but this eventuality will be strongly influenced by water management strategy.

摘要

弄清干旱的气象和人类驱动因素是一项严峻的挑战。一个关键的困难是确定可以分析人为影响的自然条件。在这里，使用了多种方法：为上游未修改的位置开发了一种水文模型，然后将其应用于受灌溉相关抽象影响的下游站点：即上游-下游/观测-模型方法。还研究了气候变化的相对重要性。研究地点（新西兰林迪斯河）为大陆性气候，下游河流在夏季经常干frequently。水文模型的输出结果表明，尽管夏季温暖干燥，但是抽象对Lindis河的低流量产生了重大影响-没有抽象，脱水很可能很少发生，而不是经常发生。与气候变化相关的降水增加可以减少脱水的发生，但是这种可能性将受到水资源管理策略的强烈影响。