Spatiotemporal Analysis Of Evaporation In Liaoning Province

Water is the source of life, it support the activitties of all living organisms. In recent years, with the increasing of population, the water problem is more and more serious. The whole world is faced with the problem of shortage of water resources, and Liaoning province is one of the most prominent contradiction regions. It is known that the main factor of energy balance is evaporation, which is an important part of the surface water cycle. Under the condition of serious shortage of water resources, the study of evaporation guide agricultural irrigation and drought monitoring, and also has a profound impact on water circulation, regional economic and social development.This paper analyzes the impact on the actual evaporation in different land types from their contributions to evaporation and potential evaporation abilities in Liaoning province by superimposing the land utilization data onto the deciphered evaporation satellite image for each of the six land types in 2000. The average daily potential evapotranspir is analyed detailed from spatial and temporal by Penman-Moteith formula in the 33 years according to 23 weather stations in Liaoning province.(1) Characteristics of evaporation in different land use types in Liaoning provinceThough the evaporation potential of different land types makes differences in four seasons, the common features are biggest water potential, much fewer potential values of the forest land, grassland and farmland, much fewer potential values of the unused land and urban construction land. The varying curve of month evaporation acts as a single peak value that the maximum appeares in June and the minimum appeares in January or December. The rank of evaporation contribution is almost consistent with land area percentage. The higher value contribution area is collocated with the land concentrating area.(2) Spatiotemporal variation of potential evaporation in Liaoning provincePotential evapotranspiration is obscure in time, and the overall rising is mainly caused by the evaporation which rised in spring and autumn. The rule of potential evaporation shows highest values in summer, followed by spring and autumn, with the lowest contents in winter. Energy concentration of 17~27 year is the most obvious in the change of the cycle. Evaporation in annual, spring, summer and autumn have included a main cycle of 21.5 year and a time cycle of 12 year. Evaporation included a main cycle of 21.5 year and a time cycle of 12 year and 4 year in winter.The spatial distribution of the annual potential evaporation is obvious regional difference, which performances decreasing from inland west to the east coastal area. The spatial distribution in spring is same with summer, overall performances decreasing from the northwest to the southeast. The spatial distribution in autumn is same with winter, overall performances increasing from the southwest to the northeast. The analysis of the spatial heterogeneity is performanced increasing from the northwest to the southeast.