摘要
降水资源是农作物的主要水分来源,农作物通过吸收土壤中的水分维持正常的生长发育,但由于未考虑农作物冠层对降水截留作用,在水资源评估和农田水分平衡研究中往往高估降水作用。该文通过2018年玉米生长季在辽宁锦州农业气象试验站开展的降水模拟试验系统分析了玉米冠层对降水的截留效应,结果表明:在降水量一定条件下,玉米冠层截留量与叶面积指数的二次多项式拟合相关最佳;在叶面积指数一定条件下,玉米冠层截留量与降水量的幂函数拟合相关最佳。综合叶面积指数和降水量分析表明:玉米冠层截留量与叶面积指数平方及降水量对数函数拟合呈正相关。根据我国玉米传统种植方式,高产玉米的叶面积指数最大一般为5~6,因此,对一次降水的最大截留量通常约为1.5~2.3 mm,当叶面积指数小于1时,对降水的截留可忽略不计。
Rainfall is the main water source of crops.Crops maintain their normal growth and development by absorbing water from the soil.However,the role of rainfall is often overestimated in water resource evaluation and farmland water balance research because the rainfall interception effect of crop canopy is not considered.It is difficult to calculate crop interception quantitatively,which seriously restricts the impact assessment of rainfall on crops.Therefore,in order to determine the interception effect in different growth stages of maize under different rainfall,the rainfall interception experiment of maize is carried out at Jinzhou Agricultural Meteorological Experimental Station of Liaoning Province in 2018.A total of 10 rainfall levels(rainfall over 20 mm is designed for the measurement of saturated interception)and 8 leaf area indexes(representing 8 different growth periods)are examined in the experiment.The rainfall interception effect of maize canopy is systematically analyzed by simulation.Results show that under certain rainfall,the relationship between the interception of maize canopy and leaf area index conforms to the relationship of quadratic polynomial,exponential function and power function,among which the quadratic polynomial has the highest explanation rate.Under the assumption of fixed leaf area index,the rainfall interception of maize canopy is in accordance with the quadratic polynomial,exponential function,power function and logarithmic function.When leaf area index is above 3,the explanation rate of power function is the highest,and the relationship between saturated interception of maize and leaf area index is in accordance with the quadratic polynomial,exponential function and power function,among which the explanation rate of quadratic polynomial is the highest.The comprehensive leaf area index and rainfall analysis indicate a positive correlation between canopy interception and the square of leaf area index and the logarithm of rainfall.According to the traditional planting mode of maize in China,the maximum leaf area index of high-yield maize is generally about 5-6.Therefore,the maximum interception of a rainfall process is usually 1.5-2.3 mm.When leaf area index is less than 1,the rainfall interception of maize can be ignored.Results are of practical significance for the evaluation of the effectiveness of rainfall resources and the study of farmland water balance.
作者
郭建平
栾青
王婧瑄
张丽敏
Guo Jianping;Luan Qing;Wang Jingxuan;Zhang Limin(Chinese Academy of Meteorological Sciences,Beijing 100081;Collaboratioe Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science&Technology,Nanjing 210044;Shanxi Climate Center,Taiyuan 030006;Huludao Meteorological Bureau of Liaoning Province,Huludao 125000)
出处
《应用气象学报》
CSCD
北大核心
2020年第4期397-404,共8页
Journal of Applied Meteorological Science
基金
中国气象科学研究院科技发展基金(2019KJ006)。
关键词
玉米冠层
降水截留
拟合模型
maize canopy
rainfall interception
fitting model
