STUDY ON THE SPATIAL PATTERNS OF LAND—USE CHANGE AND ANALYSES OF DRIVING FORCES IN NORTHEASTERN CHINA DURING 1990-2000

Key words: 
• land use /
• landuse change /
• spatial pattern /
• driving force /
• northeastern China

Abstract: Landuse change is an important aspect of global environment change.It is,in a sense,the direct result of human activities influencing our physical environment.Supported by the dynamic serving system of nation al resources,including both the environment data base and GIS technology,this paper a nalyzed the landuse change in north eastern China in the pastten years(19902000).It divides northeastern China into five landuse zones based on the dynamic degree(DD)of landuse:woodland /grasslandarable land conversion zone,dry landpaddy field conversion zone,urban expansion zone,interlocked zone of farming and pasturing,and reclamation and abandoned zone.In the pastten years,landuse change of northeastern China can be generalized as follows:increase of cropland area was obvious,paddy field and dry land increased by 74.9and 276.0 thousand ha respectively;urban area expanded rapidly,area of town and rural residence increased by 76.8 thousand ha;area of forest and grassland decreased sharply with the amount of 1399.0 and 1521.3 thousand ha respectively;area of water body and unused land increased by 148.4and 513.9 thousand ha respectively.Besides a comprehensive analysis of the spatial patterns of land use,this paper also discusses the driving forces in each landuse dynamic zones.The study shows that some key biophysical factors affect conspicuously the conversion of different landuse types.In this paper,the relationships between landuse conversion and DEM,accumulated temperature(≥10℃)and precipitation were analysed and represented.We conclude that the landuse changes in northeast China resulted from the change of macrosocial and economic factors and local physical elements.Rapid population growth and management changes,in some sense,can explain the shaping of woodland /grassland cropland conve rsion zone.The conversion from dry land to paddy field in the dry landpaddy fie ld conversion zone,apart from the physical elements change promoting the expan sion of paddy field,results from two reasons:one is that the implementation of marketeconomy in China has given farme rs the right to decide what they plant and how they plant their crops,the other factor is originated partially from the change of dietary habit with the social and economic development.The con version from paddy field to dry land is caused prim arily by the shortfall of irrigation water,which in turn is caused by poor water allocation managed by local governments.The shaping of the reclamation and abandoned zone is partially due to the lack of environment protection consciousness among pioneer settlers.The reason for the conversion fromgrassland to cropl and is the relatively higher profits of farming than that of pasturing in the interlocked zone of farming and pasturing.In northeastern China,the rapid expansion of builtup areas results from two factors:the first is its small number of towns;the second comes from the huge potential for expansion of existing towns and cities.It is noticeable that urban expansion in the northeastern China is characterized by gentle top ographic relief and low populationd ensity.Physiognomy,transportation and economy exert great influences on the urban expansion.