目前对察尔汗盐湖蒸发量的研究主要集中在气象-水文因素与卤水蒸发量定量关系,缺乏在不同时间尺度下盐湖蒸发量的驱动因素动态变化研究.利用2020年11月5日—2023年5月1日察尔汗盐湖盐田的空气温度、露点温度、风速、相对湿度、总辐射日累计以及盐田的蒸发量、水温、水位等监测数据,结合获取的察尔汗盐湖补给河流格尔木河流量等水文资料,采用相关性分析、多元回归模型等方法探讨了不同时间尺度下盐田蒸发作用与气象-水文因素之间的关系.研究表明,不同盐田的水温、水位、淡水蒸发量变化保持一致,卤水蒸发量变化与盐田密度有关.随着时间尺度的增大,蒸发量与气象要素之间的相关性增强.察尔汗盐田蒸发量在逐小时与逐月尺度主要受到环境温度的影响,日尺度下主要受到太阳辐射的影响.在极端天气作用下河流水文与盐湖微气象因子呈同步变化,对蒸发量的影响具有滞后性.这一研究结果可为盐田生产工艺优化提供理论指导.
At present,studies on evaporation in the Qarhan Salt Lake mainly focus on the influence of meteorological factors on brine evaporation.Whereas,the relationship between brine evaporation and meteorological factors in different time scales is less constrained.In this study,we observed meteorological factors such as temperature,dew point temperature,wind speed,relative humidity,daily solar radiation in the Qarhan Salt Lake,as well as fresh water and brine evaporation rates,water temperature and water depth of salt ponds with different brine densities from November 5,2020 to May 1,2023.We also moni-tored hydrological factors such as flow rate of the replenishing river,Golmud River,in the Qarhan Salt Lake.Correlation analysis,multiple regression modeling techniques are applied to simulate evaporation at hourly,daily,and monthly intervals.The findings indicate a consistent pattern in the variations of water temperature,water level,and freshwater evaporation rates across different salt ponds.The fluctuations in brine evaporation show direct correlation with the densities of the salt ponds.Additionally,the correlation between evaporation and meteorological factors is enhanced with the increase of time scale.The evapora-tion of the Qarhan salt ponds is mainly affected by ambient temperature on hourly and monthly scale,and by solar radiation on daily scale.Under extreme weather condition,it exhibits synchronous variations between the hydrological factors of river and micro-meteorological factors of the salt ponds,while,a subsequent lag effect on evaporation.The results can provide theoretical guidance for the production of salt pans.