The spatial-temporal variability of sandy bared soil evaporation before and after irrigation

The method of obtaining sandy soil daily evaporation from a function is very useful when needing a mass of data.The aim of this study is to find such a function,and to discuss the spatial-temporal variability of sandy bared soil evaporation before and after irrigation by using the accounting data.An experiment is carried out to study the problems.The results indicate that the soil evaporation one week before and three weeks after irrigation has distinct correlativity,but that in other stages does not.Whereas,the evaporation before irrigation differs much,and its spatial relationship is weak,but it reverses after irrigation.Moreover,the spatial conjunction is controlled more by spatial self-correlation but spatial heterogeneity in this stage.Also the spatial distribution of soil evaporation changes over time and space.Because of vegetation and landform of the study area,the evaporation of west zone was larger than that of east one a week after irrigation,while that in other two stages has no marked differences in the west and east.In time sequence,the evaporation of north region was stronger than that of south zone before irrigation.But a week after irrigation,the evaporation of southern part was stronger,and it changed over again three weeks after irrigation.