Abstract:

With the aid of RS and GIS techniques,the characteristics of agricultural soil resources reduction caused by urban expansion was studied during 1984～2003 in the region along the Yangtze River of Jiangsu Province.The results indicated that during 1984～2000,agricultural soil resources in the region along the Yangtze River of Jiangsu Province mainly reduced around center urbans and the area of occupied soil was big and its spatial distribution was relatively equal.However during 2001～2003,agricultural soil resources in this region decreased faster and showed a large disproportion among cities.In this period,the agricultural soil resource reduction was mainly concentrated on Changzhou county,Jiangyin county,Taixing county and Changshu county,except for Nanjing city.From 1984～2003 the quantity of agricultural soil resources decreased by 891% and the total reduced area of agricultural soil resources was 190 713 hm2.All types of agricultural soil showed a decreasing trend in quantity,among those paddy soils was largest in area reduction.The soil resources in this region were divided into 5 classes according to fertility quality.The influence extent of urban expansion on agricultural soil resources of Ⅰ～Ⅴ classes was lowering successively during 1984～2000. However during 2001～2003 the order was Ⅴ,II,Ⅳ,III,Ⅰ because the influence extent of urban expansion on agricultural soil resources of Ⅰand III classes obviously decreased and that of II, Ⅳ and Ⅴ classes increased.

Key words: the region along the Yangtze River in Jiangsu Province, urban expansion, agricultural soil resources reduction