塔布河流域潜在蒸散量时空变化特征及成因

Spatial-temporal variation characteristics and attribution analysis of potential evapotranspiration in the Tabu River Basin

潜在蒸散量(ET_(0))对流域水文循环具有重要影响,分析ET_(0)时空变化规律及其与气象要素之间的响应对流域水资源管理具有重要意义。本研究基于塔布河流域及周边7个气象站1981—2023年逐日气象数据,利用Penman-Monteith(P-M)公式估算流域ET_(0)并分析其时间变化规律和空间分布;采用Beven敏感性公式计算季和年尺度ET_(0)对关键气象要素的敏感系数,并探究敏感系数的变化趋势;结合气象要素多年相对变化率定量分析影响ET_(0)变化的主导因子。结果表明:(1)塔布河流域年ET_(0)以4.09 mm·(10a)-1的速率呈不显著增加趋势,多年均值1024.51 mm;空间上,年ET_(0)自东南向西北逐渐增加。(2)年ET_(0)对各气象要素敏感系数绝对值大小排序为:相对湿度>最高气温>风速>日照时数>最低气温;春季、秋季和冬季对相对湿度最敏感,夏季对最高气温最敏感。(3)影响年ET_(0)变化的主要控制因子是最高气温和风速,贡献率分别为4.86%和-4.37%;春、夏、秋、冬四季ET_(0)变化的主要控制因素分别是最高气温、风速、风速、相对湿度。最高气温的上升和相对湿度的下降是流域ET_(0)上升的主要原因。

Potential evapotranspiration(ET_(0))has an important impact on the hydrological cycle of the Tabu River Basin.Temporal and spatial variations in ET_(0) values in response to meteorological factors can inform water resource management in basins.For this study,daily meteorological data were collected from 7 meteorological stations in the Tabu River Basin and surrounding areas from 1981 to 2023.The Penman-Monteith(P-M)formula was used to estimate the ET_(0) to analyze temporal and spatial distribution patterns.The Beven sensitivity formula was used to calculate the sensitivity coefficient of seasonal and annual changes in ET_(0) to key meteorological factors and to explore trends in the sensitivity coefficient.Quantitative analysis was performed to determine the dominant factors affecting ET_(0) changes based on the relative changes in meteorological factors over time.The annual ET_(0) in the Tabu River Basin increased by 4.09 mm·(10a)-1,with a multiyear average of 1024.51 mm.Spatially,the annual ET_(0) was lowest in the southeast and highest in the northwest.The absolute values of the sensitivity coefficient of annual ET_(0) to various meteorological factors in decreasing order are relative humidity>maximum temperature>wind speed>sunshine hours>minimum temperature.The coefficients for relative humidity were highest for spring,autumn,and winter,while temperature had the highest coefficient for summer.The main factors affecting the change in annual ET_(0) were maximum temperature and wind speed,with contributions of 4.86%and-4.37%,respectively.On a seasonal scale,the main factors affecting ET_(0) changes in spring,summer,autumn,and winter were maximum temperature,wind speed,and relative humidity.An increase in maximum temperature and a decrease in relative humidity in the basin are the main reasons for the rise in ET_(0).