School of Civil Engineering and Transportation, State Key Laboratory of Subtropical Building Science, South China University of Technology, Guangzhou 510641, China; Pazhou Lab, Guangzhou 510335, China.
School of Civil Engineering and Transportation, State Key Laboratory of Subtropical Building Science, South China University of Technology, Guangzhou 510641, China; Pazhou Lab, Guangzhou 510335, China.
Sci Total Environ. 2023 Apr 1;867:161483. doi: 10.1016/j.scitotenv.2023.161483. Epub 2023 Jan 9.
The adverse impacts of climate and landuse change are threatening the availability of water quantity and its quality, yet there are limited understandings in the response of water availability to changing environment at different spatio-temporal scales. Aimed at quantifying the individual and superimposed effects of climate and landuse change on streamflow and ammonia nitrogen (NH-N) load in the Dongjiang River Basin (DRB), we dynamically simulated the historical (1981-2010) and future (2030-2070) variation of runoff depth and NH-N load coupling multiple regional climate model and landuse data. The increase in runoff depth (avg. +233.9 mm) due to climate change was about 33 times greater than that caused by landuse change (avg. -7.2 mm). Especially in the downstream of DRB (Hong Kong, Shenzhen and Dongguan cities, etc.), the maximum rise of runoff depth under climate change was near twice compared with baseline period, indicating the dominant control of climate change on runoff. Also there existed higher coefficient of variation (C) value of runoff in the dry season of downstream DRB, contributing potential great fluctuation in runoff. Besides, the variation of NH-N load was jointly influenced by climate and landuse change, revealing an offset or amplification effect. Moreover, the variability of NH-N load (C value as the metric) increased from 2030, reached a maximum in 2050, following decreased to 2070. The spatial distribution of NH-N load, in general, presented a downward trend and concentrated near the water body, while the monthly average NH-N load showed distinct peaks in spring and late summer temporally. Overall, the results highlight the significance of investigating the water availability under changing environment and more adaptive strategies should be proposed for better basin water management.
气候变化和土地利用变化的不利影响正在威胁着水量和水质的供应，但对于不同时空尺度下，水的供应对环境变化的响应，人们的了解还很有限。本研究旨在量化气候和土地利用变化对东江流域（DRB）径流量和氨氮（NH-N）负荷的单独和叠加影响，通过动态模拟多种区域气候模型和土地利用数据，对历史时期（1981-2010 年）和未来时期（2030-2070 年）的径流量和 NH-N 负荷变化进行了预测。气候变化导致的径流量增加（平均增加 233.9mm）大约是土地利用变化（平均减少 7.2mm）的 33 倍。特别是在 DRB 的下游（香港、深圳和东莞等城市），气候变化下的径流量最大增幅接近基准期的两倍，表明气候变化对径流量的控制作用更为显著。此外，下游 DRB 枯水季节的径流量具有较高的变异系数（C）值，可能导致径流量的大幅波动。此外，NH-N 负荷的变化受到气候和土地利用变化的共同影响，表现出抵消或放大效应。而且，NH-N 负荷的变异性（以 C 值为指标）从 2030 年开始增加，在 2050 年达到最大值，随后在 2070 年下降。NH-N 负荷的空间分布总体上呈下降趋势，集中在水体附近，而月平均 NH-N 负荷在时间上则表现出明显的春末和夏末峰值。总的来说，研究结果强调了在变化环境下研究水资源供应的重要性，应提出更具适应性的策略，以实现更好的流域水资源管理。
