东昆仑库木库里盆地典型湖泊水量蒸发损失估算

Estimation of evaporation loss from typical lakes in the Kumukuli Basin,East Kunlun Mountains

湖泊水量蒸发损失估算对于应对干旱区水资源短缺及湖泊生态环境保护具有重要意义。计算分析了过去20 a东昆仑库木库里盆地典型湖泊实际蒸散发(ET)的时空变化特征,并基于经验公式估算了湖泊蒸发损失水量,同时利用随机森林模型,识别了影响湖泊水量蒸发损失变化的潜在因子。研究发现:(1)2001-2020年东昆仑库木库里盆地的阿牙克库木湖、阿其克库勒湖和鲸鱼湖的年ET整体呈现先增加后减少又缓慢增加的波动下降趋势,波峰和波谷均分别出现在2004年和2012年左右,空间上表现为ET整体下降而湖泊边缘呈上升趋势。(2)3个典型湖泊的ET在年内呈倒U形变化,其中阿牙克库木湖的ET在6月达到峰值,其他2个湖泊的ET均在7月达到峰值。(3)2001-2020年3个典型湖泊的蒸发水量均呈不显著的增加趋势,其中阿牙克库木湖的蒸发水量最高,平均约为10.33×10^(8)m^(3)·a^(-1),阿其克库勒湖的蒸发水量次之(4.54×10^(8)m^(3)·a^(-1)),鲸鱼湖的蒸发水量最低(3.33×10^(8)m^(3)·a^(-1))。(4)结合随机森林模型分析显示,湖泊面积是影响湖泊蒸发水量的重要因素,经向风速、最高气温和降水的增加等因素也是驱动蒸发变化的重要原因,累计贡献率超过45%。

Estimating lake water evaporation losses is of significant importance for addressing water scarcity in arid regions and for the protection of lake ecosystems.This study analyzed the spatiotemporal variations of actual evapotranspiration(ET)in three typical lakes within the Kumukuli Basin of East Kunlun Mountains over the past 20 years.Using empirical formulas,we estimated the evaporation losses and applied a random forest model to identify potential factors influencing changes in lake water evaporation.This study examines the spatiotemporal variation in ET of typical lakes in the Kumukuli Basin of East Kunlun Mountains using PML-V2 data,estimates water loss due to lake evaporation through empirical formulas,and explores the influencing factors of lake ET changes using a random forest model.Key findings include(1)From 2001 to 2020,the annual ET of Ayakkum Lake,Aqqikkol Lake,and Whale Lake exhibited a fluctuating trend,initially increasing,then decreasing,and subsequently showing a gradual increase,with peak and trough occurring in 2004 and 2012,respectively.(2)The ET of the three lakes demonstrated an inverted U-shaped pattern within the year,with Ayakkum Lake peaking in June and the other two lakes in July.Aqqikkol Lake exhibited a relatively gentle increase,while Whale Lake saw a significant rise from May to July,reaching 48.45 mm·month^(-1).(3)During the same period,the evaporation water volume of the three lakes increased,with Ayakkum Lake recording the highest at 10.33×10^(8)m^(3)·a^(-1),followed by Aqqikkol Lake at 4.54×10^(8)m^(3)·a^(-1),and Whale Lake at 3.33×10^(8)m^(3)·a^(-1).(4)Analysis using the random forest model indicates that lake area significantly influences evaporation volume.Additional factors,including increases in wind speed,maximum temperature,and precipitation,also drive evaporation changes,contributing over 45%cumulatively.