Chinese Journal of Agrometeorology

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Integrated Assessment of Eco-environment in Three Gorges Reservoir Areas Based on GIS and DEM Ⅳ.Assessment of Precipitation Changes(1951-2004)

ZHENG Gang1,2,LIU Xiang-mei1,2,GUO Zhi-hua1,XIAO Wen-fa1,WANG Jian-li2(1.Institute of Forest Ecology,Environment and Protection,Chinese Academy of Forestry,Beijing 100091,China;2.School of Geographical Science,Southwest University,Chongqing 400715)   

  • Online:2009-08-10 Published:2009-08-10

Abstract: Based on the meteorological data of the annual precipitation in 33 meteorological stations in 1951-2004 and relief map,the characteristics of climate change in the Three Gorges Reservoir in recent 50 years was studied,by using the method of linear-trend estimate and"multiple regression model + Inverse Distance Weighting(IDW) residuals".The seasonal and annual precipitation changes were analyzed.The results indicated that the trend of annual and seasonal changes of precipitation in the Three Gorges Reservoir areas was not significant(p>0.05) since 1951.The mean annual precipitation had a increasing trend from the 1950's to 1980's,while it had a decrease trend subsequently.The change range of precipitation became larger since late 1990's.For the seasonal changes of precipitation,the change range of precipitation in summer was large,and the positive and negative deviations was generally within 80mm,whereas the change range of precipitation in winter was small,and the positive and negative deviations was generally less than 10mm.In the three period of 1950's to mid-late 1970's,mid-late 1970's to mid-late 1980's and after 1980's,the Three Gorges reservoir area experienced drier wetter and drier process in the spring,while on the contrary,in summer it experienced wetter,drier and wetter process.Before the mid 1970's,climate in autumn became wetter,while it became drier after the mid 1970's.At the same time,the change of precipitation in the reservoir areas had regional differences.The precipitation in the east areas decreased 2-4mm per decade in the spring,while it decreased 4-6.3mm per decade in the southwest areas in the autumn.The precipitation in the central areas decreased 2-4 mm per decade in autumn.In summer,the precipitation had an increased trend,while in winter the precipitation also had an increased trend,but the trend was not very obvious.

Key words: Climate Change, Climate Change, Meteorological Data, Three Gorges Reservoir, GIS