基于SWAT模型的根河流域蒸散量时空分布特征

为了研究根河流域38年间蒸散(ET)、潜在蒸散(PET)的年际、年内变化过程及空间分布格局,基于SWAT模型分析了各气象要素与蒸散的相互关系。结果表明:(1)根河流域1980—2017年ET值、PET值整体呈增加趋势。(2)根河流域ET与PET的年内变化总体上均呈先增大后减小的单峰型分布。(3)根河流域的ET值在空间上呈现流域上游高,中下游低的分布格局; PET值在空间上呈现西南>东北>东南的分布规律。(4)根河流域的生长期、完全冻结期、融冻期ET值均呈现增加趋势,始冻期ET值呈降低趋势,4个时期平均ET值差异性表现为生长期>融冻期>始冻期>完全冻结期。(5)根河流域多年ET值在不同土地覆被类型的大小为林地>草地>耕地>建设用地>沼泽地; 而PET的排序为耕地>建设用地>林地>草地>沼泽地。(6)根河流域蒸散量与降水量和气温呈显著正相关。研究结果对根河流域的蒸散量变化及其冻融作用对当地的影响有着重要的参考意义。

Temporal and Spatial Distribution Characteristics of Evapotranspiration in Genhe River Basin Based on Soil and Water Assessment Tool Model

To analyze the temporal and spatial distribution characteristics of evapotranspiration and potential evapotranspiration in Genhe River Basin of Erguna River system,soil and water assessment tool model,and correlation analysis were used to study the interannual and intra annual variation process and spatial distribution pattern of evapotranspiration and potential evapotranspiration in Genhe River Basin in the past 38 years.The variation characteristics of evapotranspiration and potential evapotranspiration of different land use types were analyzed,and the relationship between meteorological factors and evapotranspiration was discussed.The results show that:(1)from 1980 to 2017,the ET and PET of Genhe River Basin showed an overall increasing trend;(2)the annual variation of ET and PET in Genhe River Basin increased first and then decreased;(3)the distribution pattern of ET in Genhe River Basin was higher in the upper reaches and lower in the middle and lower reaches,and the peak value of ET appeared in the upper reaches;the spatial distribution pattern of PET follows the sequence:southwest>northeast>southeast;there were obvious spatial differences in ET and PET in the upper,middle and lower reaches of Genhe River Basin;(4)in the Genhe River Basin,the ET in the growth period,the complete freezing period and the thawing period all showed the increasing trend,while the ET in the initial freezing period showed the decreasing trend;the average ET of the four periods showed the significant difference,which showed the order:the growth period>the thawing period>the initial freezing period>the complete freezing period;(5)in Genhe River Basin,the order of annual ET mean value in different land cover types was:woodland>grassland>cultivated land>construction land>swampland,while the order of PET was farmland>construction land>woodland>grassland>marshland;(6)there is a significant positive correlation between evapotranspiration and precipitation and temperature in Genhe River Basin.The results of this study have important reference significance for evapotranspiration change and freeze-thaw effect on the local ecosystem.