Abstract: Based on the observed data of surface albedo in maize cropland mulched by plastic film in an arid region from June 1 to July 24,2015,the variation of surface albedo during the vegetation growth period and the relationship between surface albedo and soil moisture content were analyzed. It was found that the surface albedo variation and the correlation between surface albedo and soil moisture content were significantly different from that on underlying surface without mulching plastic film,thus a corresponding dynamic parameterization scheme of surface albedo was established.Furthermore,the modified dynamic parameterization scheme of surface albedo was applied to the land surface process model CoLM,and three simulation tests were carried out to analyze and verify the accuracy and applicability of the new scheme on cropland underlying surface mulched by plastic film.The numerical simulation results showed that the three tests could reflect the daily variation trend of land surface process,but the comparison revealed that the simulation performance of the new model was the best,because the simulation capability of the upward shortwave and longwave radiation was obviously increased,and the simulated results of soil temperature and soil moisture content in shallow soil were improved to some extent.Hence,the dynamic parameterization method of surface albedo could significantly facilitate the land surface process simulation capability on cropland underlying surface mulched by plastic film in arid region,and it could be referred in further developing and improving the land surface process models in the future.

Key words: plastic film mulching, maize cropland, surface albedo, dynamic parameterization method, numerical simulation, arid region