School of Engineering and Built Environment, Griffith University, Gold Coast Campus, 4222, QLD, Australia.
School of Engineering and Built Environment, Griffith University, Gold Coast Campus, 4222, QLD, Australia.
J Environ Manage. 2023 Nov 1;345:118738. doi: 10.1016/j.jenvman.2023.118738. Epub 2023 Aug 5.
Climate change is predicted to significantly alter hydrological cycles across the world, affecting runoff, streamflow, and pollutant loads from diffuse sources. The objectives of this study were to examine the impacts of climate change on streamflow, total nitrogen (TN), total phosphorus (TP), and total suspended sediment (TSS) loads in the subtropical Logan-Albert catchment, Queensland, Australia. We calibrated the Soil Water Assessment Tool (SWAT) against event monitoring data in the Logan and Albert rivers, respectively. Hydrological and water quality effects of an ensemble of 11 dynamically downscaled high-resolution climate models were assessed with SWAT under high (Representative Concentration Pathway 8.5 - RCP8.5) and intermediate (RCP4.5) emission scenarios. Streamflow decreased most in winter and spring and decreased least in summer. This followed the predicted seasonal changes for precipitation, although decreases tended to be amplified due to increasing evaporative loss. TSS, TN, and TP loads showed a similar pattern to streamflow, with the largest decreases predicted for the dry season under RCP8.5 by the 2080s. Annual TSS load decreased by 34.3 and 54.2%, TN load decreased by 29.8 and 30.5%, and TP load by 24.9 and 4.4% for the Logan and Albert sites, respectively. The results of this study indicate that for subtropical river-estuary systems, climate warming may lead to lower streamflow and contaminant loads, reduced flushing, and greater relative importance of point source loads in urbanising catchments.
气候变化预计将显著改变全球水文循环，影响径流量、溪流流量和来自弥散源的污染物负荷。本研究的目的是检验气候变化对澳大利亚昆士兰州亚热带洛根-艾伯特集水区径流量、总氮（TN）、总磷（TP）和总悬浮泥沙（TSS）负荷的影响。我们分别对洛根河和艾伯特河的事件监测数据进行了土壤水评估工具（SWAT）校准。利用 SWAT 评估了 11 个动态降尺度高分辨率气候模型的集合对高（代表性浓度路径 8.5-RCP8.5）和中（RCP4.5）排放情景的水文和水质影响。径流量在冬季和春季下降最多，在夏季下降最少。这与降水的预测季节性变化一致，尽管由于蒸发损失增加，降幅往往会放大。TSS、TN 和 TP 负荷与径流量呈现出相似的模式，在 RCP8.5 下，到 2080 年代预测干季的降幅最大。洛根和艾伯特站点的 TSS 负荷年减少 34.3%和 54.2%，TN 负荷减少 29.8%和 30.5%，TP 负荷减少 24.9%和 4.4%。本研究结果表明，对于亚热带河流-河口系统，气候变暖可能导致径流量和污染物负荷降低、冲洗减少，以及城市化集水区中点状源负荷的相对重要性增加。
