中国主产区玉米冠层对降水的截留研究

Study on Canopy Interception in Main Maize Producing Areas in China

基于13个农业气象试验站2010—2017年逐日气象观测数据和玉米观测数据,采用针对玉米的截留模型,研究自然降雨条件下中国主产区玉米冠层截留及其变化规律。结果表明:在不同气候条件和生长状况下,玉米全生育期冠层截留差异较大。玉米冠层生长季平均截留量为4.3~23.5 mm,拔节到成熟期降水量≤70 mm时,截留量不足8 mm,随着降水量增加,截留量先是同时受降水量和最大面积指数制衡,后变为对最大叶面积指数更敏感。平均截留率为1.9%~11.6%,中国四大玉米主产区中的黄淮海夏播玉米区截留率最稳定,生长季降水量<120 mm的地区截留率超过10%,按玉米主产区和气候干湿度两种分类提供平均截留率范围。依据拔节到成熟期降水量、最大叶面积指数及截留变化规律可以估算不同地区玉米冠层截留量和截留率,为有效降水评估、干旱指标修正、农田水分循环等方面提供科学依据。

Based on the daily meteorological observation data and maize observation data of 13 agrometeorological experimental stations from 2010 to 2017,the canopy rainfall interception and its variation of main maize production areas in China are studied by using the rainfall interception model for maize.The results show that under different climatic conditions and growth conditions,the interception of maize canopy is quite different.The average interception is 4.3-23.5 mm.When the precipitation from jointing to matur-ity is less than 70 mm,the interception is less than 8 mm.With the increase of precipitation,the interception is first affected by both precipitation and maximum leaf area index(LAI max)and then becomes more sensitive to LAI max.The average interception rate is 1.9%-11.6%,and the interception rate is relatively stable in Huang-Huai-Hai summer maize planting area.The interception rate exceedes 10%in areas with precipitation less than 120 mm in growing season.Furthermore,the average interception rate range is given according to the classification of main maize production area and climatic dryness and wetness.The canopy interception and interception rate in different areas can be estimated according to precipitation from joining to maturity,LAI max and the rule of interception change.The interception research based on the actual growth and natural rainfall provides scientific basis for effective precipitation assessment,drought index correction,and farmland water cycle,and so on.