湖南洞庭湖区Hargreaves公式适用性评价及系数调整  

Applicability Evaluation and Coefficient Adjustment of Hargreaves Formula in Dongting Lake District in Hunan Province

作　　者：李康勇 徐义军 陈向 盛东 张勇 LI Kang-yong;XU YI-jun;CHEN Xiang;SHENG Dong;ZHANG Yong(Hunan Institute of Water Resources and hydropower research,Changsha 410007,China)

机构地区：[1]湖南省水利水电科学研究院,长沙410007

出　　处：《节水灌溉》2024年第12期111-115,共5页Water Saving Irrigation

基　　金：湖南水利科技项目(XSKJ2023059-17)。

摘　　要：Hargreaves公式为气象资料不足时提供了计算参考作物蒸散量(ET_(0))的有效方法,但不同气候地区适用性及偏差有待评价。为探明Hargreaves公式在湖南洞庭湖区适用性,利用安乡县2001-2017年气象资料,以Penman-Monteith计算结果为参考标准,从年、月、日时间尺度对比分析两种方法计算结果偏差及原因,并调整Hargreaves公式月尺度经验系数。结果表明,两种方法计算结果变化趋势一致。Hargreaves公式年ET_(0)偏大,多年平均绝对偏差和相对偏差分别为79 mm和8%;月时间尺度上偏差明显,除7、8月略偏小,其他月份明显偏大,月ET_(0)多年平均相对偏差范围为9%至16%,日照时数偏低和相对湿度偏高是造成偏差的主要原因;逐日相对偏差波动显著,冬季偏差大于夏季,约44%以上日数相对偏差大于20%。逐月系数调整后,多年年平均绝对偏差为28 mm,年最大偏差为68 mm,多年年平均相对偏差均值为3%,最大年相对偏差为7%。调整后的月多年平均绝对偏差均值在5 mm以内,相对偏差均值在10%以内。说明调整后的Hargreaves公式可在月尺度上应用于湖南洞庭湖区ET_(0)计算。Hargreaves formula provides an effective method for calculating reference crop evapotranspiration(ET_(0))when meteorological data are limited,but its applicability and deviations need to be evaluated in different climate zones.In order to explore the applicability of Hargreaves formula in Dongting Lake district of Hunan Province,this study analysed the deviations from annual,monthly and daily time scales compared with Penman-Monteith method,using daily meteorological data of Anxiang from 2001 to 2017.The causes of deviations between the two methods were explained and the monthly empirical coefficient of Hargreaves formula were adjusted in this study.The results showed that the variation trend of the two methods was consistent.Hargreaves method annual ET_(0)was larger,the perennial average absolute deviation and relative deviation were 79 mm and 8%respectively.The deviations were obvious on the monthly time scale.The perennial monthly ET_(0)of Hargreaves method was larger except for July and August.The perennial average relative deviation of monthly ET_(0)ranged from 9%to 16%.Smaller sunshine duration and higher relative humidity were the main reasons for causing the deviations.The daily relative deviation fluctuated significantly and the deviations in winter were greater than those in summer.About 44 percent of the daily relative deviation was greater than 20%.After monthly empirical coefficient adjusting,the perennial average absolute deviation and the annual maximum deviation were 28 mm and 68 mm respectively.The perennial average relative deviation was 3%,and the maximum annual relative deviation was 7%.The monthly perennial average absolute deviation was within 5 mm,and the average relative deviation was within 10%.It is shown that the adjusted Hargreaves formula can be applied to ET_(0)calculation in Dongting Lake region of Hunan Province on monthly scale.

关 键 词：参考作物蒸散量 Hargreaves公式 PENMAN-MONTEITH公式 洞庭湖区 经验系数 

分 类 号：S271[农业科学—农业水土工程] S161.4[农业科学—农业工程] S159.2