乌兰布和沙漠灌溉农田深层渗漏特征与水量平衡

Deep Leakage Characteristics and Water Balance of Irrigated Farmland in Ulan Buh Desert

中国干旱区分布着大面积的灌溉农田,改造沙漠(包括戈壁)为灌溉农田仍为治沙的重要途径,深层渗漏是地表水温过程及优化灌溉制度的重要参数。针对乌兰布和沙漠熟化的灌溉农田,保留50 cm的耕作层熟化土壤,分别客换50~150 cm砂土、壤土和黏土,配置成为3种土壤类型样地,实时监测了当地农民对农田的实际灌溉量与灌水量、土壤含水率及深层渗漏量。结果表明:(1)2017年4月17日的单次灌水量118.64 mm后,砂土、壤土、黏土样地150 cm深层出现渗漏的时间分别为灌溉后的13、72、257 h。(2)单次灌水量118.64 mm的15 d后,砂土、壤土、黏土样地150 cm深层渗漏量分别为110.87、12.2、0.8 mm。(3)2017年生长季内(4月1日至10月30日)5次灌溉水总量为641.53 mm时,渗漏水总量为砂土449.60 mm、壤土270.60 mm;土壤的蓄水量变化为砂土-48.79 mm、壤土-35.32 mm。(4)砂土、壤土和黏土的渗漏水量差异是影响灌溉水量和频率的重要因素。

Based on the development of irrigated farmland in arid desert area has become a central issue in desert management and development,the keys of farmland development are Improving water use efficiency and establishing optimal irrigation systems.The research area was located in Ulan buh Desert.The experiment established three sites with exchanged local soil to sand,loam and clay under the tillage layer for 50 cm.The results indicated that:The deep percolation were observed 13 hours after irrigation,72 hours and 257 hours in sand,loam and clay sites at 150 cm depth with a 118.64 mm single irrigation on 17 April 2017.And deep percolation 15 days after irrigation were 110.87 mm,12.2 mm,0.8 mm for sand,loam and clay sites at 150 cm depth.Moreover,with 641.53 mm irrigation amount in growth period,the total amount of leakage water is 449.60 mm in sand and loam 270.60 mm in loam,water storage capacity were-35.32 mm and-48.79 mm for soil and sand in 2017.The difference of leakage amount occured at sand,loam and clay which affected the irrigated amount and rate.So,monitoring accurately of leakage from soil of different textures which is very important on scientific formulated of irrigation systems for farmland in desert areas.