不同时间尺度下水资源配置效应

Effects of Time Scales on Water Resources Allocation

水资源配置是解决水资源时空分布不均的重要手段,而现有水资源配置研究中时间尺度相对单一,较少考虑到时间尺度的变化给配置方案带来的风险。针对此问题,本文以汉江流域中下游地区为研究对象,利用具有灵活调整计算时间步长功能的IRAS水资源配置模型,选择年、季、月三种时间尺度,分析不同时间尺度对水资源配置的影响。结果表明:不同地区由于水资源条件和系统调节能力不同,水资源配置具有时间尺度效应,在来水条件良好的区域,水资源配置的时间尺度效应不明显,而在水资源短缺且系统调节能力较弱区域,水资源配置的时间尺度效应比较敏感,这是由于长时间尺度配置条件平滑了来水与需水在时间上的变化性,降低了长时间尺度的配置结果的缺水率。本研究不仅将为确定水资源配置的适应性时间尺度提供依据,而且还可为新时期水资源的精细化配置和风险管理提供支撑。

The water resources allocation is an important means to solve the problem of uneven distribution of water resources in time and space. However, there are few studies on the effects of time scales on water resources allocation. The effects caused by the variation of time scale are often ignored and lead to underestimation of water shortage risks in water resources management. IRAS water resources allocation model which can adjust the time step flexibly to adapt to different time scales, is employed to the middle and lower reaches of the Hanjiang River basin as a case study. There are three types of time scales (year, season and month) to be chosen for discussing the effects of time scales on water resources allocation. The results show that the effects of time scales on water resources allocation mainly depend on water resources conditions and the regulating capacity of the water system. Water shortage is few to find in all three-time scales if the water resources are enough to satisfy the water demand. However, the effects of time scales on water resources allocation are more sensitive in areas with water shortage and weak regulating capacity of the water system. As the variability of water inflow and demand water can be smoothed at long-term scale, the water shortage ratio at long-term scale is lower than that at a short-term scale. The results of the study have not only analyzed the effects of time scales on water resources allocation, but also warned the risks of water resources management at different time scales.