干旱地区喷洒水利用系数的田间试验研究

为了科学地评价喷灌在干旱地区的适宜性,在内蒙古包头春小麦生育期内对喷洒水利用系数进行了监测,结果指出,通过选择适宜的灌溉时间,喷洒水利用系数可以达到0.85以上。对影响喷洒水利用系数的环境因素进行分析后得出,风速的影响最大,相对湿度次之,气温的影响很小;在此基础上建立了喷洒水利用系数与上述3因子之间的回归模型。为了估算整个灌溉季节的喷洒水利用系数,对所研究地区1991～2001年灌溉季节(4～9月份)内的日平均风速进行了统计分析,发现不大于3m/s的日数占灌溉季节总日数的90%以上,因此,选择日平均风速不大于3m/s的时间灌溉可以满足作物的需水要求,这种情况下,整个灌溉季节的喷洒水利用系数可以达到0.83。由此可见,在条件与包头类似的干旱地区,从提高水的利用率的角度出发,发展喷灌也是适宜的

Field Evaluation of Sprinkler Efficiency Under Arid Conditions

A proper understanding of factors affecting application efficiency of sprinkler irrigation is important for developing water conservation strategies in arid regions. Field experiments were conducted in Baotou, Inner Mongolia, during the growing season of spring wheat to evaluate the relative importance of the environmental factors affecting application efficiency and to estimate the seasonal application efficiency. The results showed that application efficiency for an individual irrigation event can exceed 0.85 under feasible environmental conditions in arid regions. Then, application efficiency was correlated to daily values of air temperature, relative humidity and wind velocity. Wind velocity was found to be the predominant factor affecting application efficiency, followed by the relative humidity, while air temperature had the least effect. Frequency distribution functions of daily wind velocity during irrigation season (from April to September) were analyzed for 11 years of data (1991~2001) to estimate the seasonal application efficiency. It was found that more than 90% of the days during irrigation season had a daily wind velocity not exceeding 3 m/s. Therefore, sprinkler irrigation applying water in the days with wind velocity not exceeding 3 m/s can usually meet crop irrigation requirements. Seasonal application efficiency of sprinkler irrigation was estimated based on the frequency distribution of wind velocity and the relationship between application efficiency and wind velocity proposed in this article. The results indicated that the seasonal application efficiency of sprinkler irrigation can be as high as 0.83 in arid regions.