气候及土地利用变化对嘉陵江流域实际蒸散发量的影响

Influence of Climate Change and Land Use on Actual Evapotranspiration of Jialingjiang Basin

根据嘉陵江流域内12个气象站点1956~2012年的逐日气象资料,分别采用改进前后的平流干旱模型对嘉陵江三个子流域的实际蒸散发进行模拟,提出了一种基于气候变化和土地利用变化的实际蒸散发（Ea）贡献率计算方法。结果表明,与水量平衡法的估算结果相比,改进后模型对Ea的估算精度高于原始模型,且修正后模型参数α与土地利用类型具有相关性;三个子流域的年际实际蒸散发变化主要受下垫面因素变化的影响,是气候变化对其影响的2~5倍。此外,气候变化导致涪江流域的Ea在整个评估期内减少,另外两个子流域的Ea增加;下垫面变化导致涪江和嘉陵江子流域Ea减小,渠江Ea增加。

Based on the daily meteorological data at 12 meteorologic stations in the Jialingjiang Basin from 1956to2012,the original and modified advection-aridity models were used to calculate the actual evapotranspiration（Ea）in the three sub-basins of Jialingjiang Basin.Based on the climate change and land use change,a method of calculating actual evapotranspiration（Ea）contribution rate was proposed.Compared with Eafrom the water balance calculation,the Easimulated by the modified model was proven better than that of the original model,and the calibrated parameter of the modified model was found to be related with the land use categories.The annual changes of actual evapotranspiration of the three sub-basins were mainly affected by underlying surface condition.Factors of land use changes were 2-5times as many as that of climate variation all over the three sub-basins.Besides,climate variation caused Eain Fujiang basin decreased but led the other two basins＇ Eaincreased.While land use change caused Eain Fujiang basin and sub-basin of Jialingjiang basin decreased but led the Qujiang basin＇Eaincreased.