1961-2010年辽河三角洲潜在蒸散时空变化趋势

Spatial Distribution and Temporal Trends in Potential Evapotranspiration(ET_0) Over Liaohe Delta in the Period 1961-2010

基于辽河三角洲及周边区域19个气象站点的实测气象数据和FAO56Penman-Monteith模型估算了1961-2010年该区域潜在蒸散,分析了半干旱区、半湿润区以及滨海湿地区潜在蒸散的空间分布特征和时间演变规律.结果表明,辽河三角洲不同区域具有不同的气候变化趋势和ET0变化特征.总体上,滨海湿地区以及半湿润区年ET0处于减小的趋势,彰武、阜新及其西北的半干旱区ET0处于增加的趋势.此外,滨海湿地区气温的增高趋势大于半干旱区和半湿润区,2m高风速和太阳辐射的降低趋势也同样半干旱区和半湿润区.在气象因子的综合作用下,滨海湿地区ET0的下降趋势大于半湿润区,分别为-17.5和-12.3mm/10a,半干旱区呈微弱增加趋势.

Potential evapotranspiration （ET0 ） ,as an estimate of the evaporative demand of the atmosphere ,has been an important index of climate change ,and its variation is prominent between different climate zones .In this paper ,Penman-Monteith formula is employed to calculate the potential evapotranspiration over Liaohe Delta from 1961-2010 ,using the daily field measure meteorological data .The spatial distribution and temporal trends of the coastal wetland zone ,the semi-arid zone and the semi-humid zone are analyzed .The results show that at the regional scale there were variations of climate trends and potential evapotranspiration characteristics among the three climate zones in this period .Generally ,in the past 50 years ,potential evapotranspiration decreased in the coastal wetland zone and the semi-humid zone and increased in Zhangwu and Fuxin and the semi-arid zone to their northwest .The trends of increased temperature and decreased wind velocity and solar radiation were more obvious in the coastal wetland zone than in the semi-arid zone and the semi-humid zone .Influenced by various meteorological factors ,the extent of decrease in ET0 was greater in the coastal wetland zone （-17.5 mm/10a） than in the semi-humid zone （-12.3 mm/10a） ,while ET0 in the semi-arid zone slightly increased .