降雨级别对农田蒸发和土壤水再分布的影响模拟  

Effective of Simulated Different Rainfall Intensities on Soil Evaporation and Water Redistribution in Crop Field

作　　者：刘战东[1] 秦安振[1] 宁东峰[1] 赵犇[1] 刘祖贵[1] 南纪琴[1] 巩文军 刘向东 张宵 段爱旺[1] 

机构地区：[1]中国农业科学院农田灌溉研究所农业部作物需水与调控重点开放实验室,河南新乡453002 [2]河南省焦作市广利灌区管理局,河南沁阳454550

出　　处：《灌溉排水学报》2016年第8期1-8,共8页Journal of Irrigation and Drainage

基　　金：国家自然科学基金项目(51309226);公益性行业(农业)科研专项(201203077;201503117);国家863计划项目(2011AA100509)

摘　　要：在野外人工模拟了6级降雨强度（小雨P1、中雨P2、大雨P3、暴雨P4、大暴雨P5和特大暴雨P6），通过分析麦田0-100cm土壤含水率在3个时期的变化。旨在探讨不同降雨强度土壤蒸发和雨水入渗土壤后的水分分布规律。结果表明，气象条件一致时。不同降雨级别处理的土壤蒸发过程具有相同的变化趋势。土壤日蒸发量随降雨级别的增加均呈对数函数方式增长；不同处理白天土壤蒸发有显著的差异，晚上土壤蒸发差异不显著：冬小麦各生育期日均土壤蒸发量及阶段蒸发量由大到小依次为返青期、拔节期和灌浆期。在3个生育期，不同降雨级别冬小麦土壤蒸发占降雨量的比例（国P）大小排序相同，均为P1处理〉P2处理〉P3处理〉P4〉处理P5处理〉P6处理。降雨入渗后土壤水分再分布规律相似，供水结束后，表层0～20cm内土壤含水率急剧降低，大雨级别以上处理20~60cm土层的含水率呈先增大后减少的趋势，60cm以下土层的含水率变化较小。降雨级别越大，土壤水再分布影响的土层就越深，同时水分再分配过程所需的时间越长。另外，同一降雨级别，土壤初始含水率较低时，土壤水分运移再分布较慢。受作物根系生长发育影响，返青期0~100cm土层土壤水分变化幅度不如拔节期、灌浆期变化明显。降雨级别越大。转化成土壤水的水量越多，大雨和暴雨转化效率最高。Artificial simulations of six rainfall intensities including light rain （P1）, moderate rain （P2）, heavy rain （P3）, rainstorm （P4）, downpour （P5） and extraordinary rainstorm （P6） were conducted in a winter wheat field so as to explore the regulation of soil evaporation and soil water redistribution in wheat field under different rainfall conditions. The results showed that soil evaporations of different rainfall-intensity treatments had similar trends under the same meteorological condition. There was a logarithmic increasing trend of daily soil evaporation with the increase of rainfall intensity. Soil evaporation at different rainfall intensity varied significantly during day- time, while the difference was not significant during nighttime. The amounts of daily and cumulative soil evapora- tion at different growth stages were found in the order of returning green stage〉jointing stage〉 filling stage. The order of the soil evaporation to rainfall （E/P） ratio of different treatments was P1 〉P2 〉P3 〉P4 〉P5 〉P6 and was similar during three growth stages. After rainfall infiltration, soil water redistributions of different rainfall treat- ments were similar. After water supplying ceased, water content of 0-20 cm soil layer decreased significantly, wa- ter content of 20-60 cm soil layer increased first and then decreased under heavy rain or above heavy rain levels, water content below 60 cm soil layer showed a little variation. The larger of rainfall intensity, the deeper of soil layers were affected by soil water redistribution, meanwhile, more time was needed for the process of soil water redistribution. In addition, under the same rainfall intensity, the soil water redistributions were slower when soil initial water content was lower. The variations of soil water content during jointing and filling stages were more significant than those in reviving stage. The larger of rainfall intensity, more rainfall transformed into soil water, heavy rain and rainstorm showed the largest

关 键 词：冬小麦 模拟降雨 降雨强度 蒸发 土壤水分 再分布 

分 类 号：S152.7[农业科学—土壤学]