Study On The Decomposition Of Virtual Soil And Water Trade And The Decomposition Factor Of China 's Provincial Agricultural Products

Having the largest population in the world, the contradiction between people and water, land is gradually sharp. The issue of setting up a series of guidelines and policies to use water and soil resources rationally and effectively is throughout a hot topic. Applying the study frame of virtual water, this paper analyses virtual water trade and virtual land trade hidden behind agricultural products trade between 30 provinces in 1980-2013. Influences of trade and policies also are studied in this paper.Specifically, virtual water content, virtual land content and trade volumes are first calculated by Product Tree Method and Material Flow Analysis in 30 provinces between 1980 and 2013. Then, the variations and factors of trade are studied where contribution rates of factors in variations are also calculated applying Structural Decomposition Analysis. At last, this paper proposes suggestions so as to execute strategies of virtual water and virtual land.Results:(1) In 1980-2013, most provinces in China are net importers of virtual water and the net import volumes are larger and larger. Only Heilongjiang, Jilin, Inner Mongolia, Ningxia and Xinjiang are net exporters of virtual water. Besides, net exporters are in northeast and northwest of China where are scarce of water, whereas areas with abundant water in southeast, south China and Lower-Middle Yangtze are net importers. The two situations are contrary to the strategies.(2) On the whole, the utilization of virtual land resources in China is better than that of virtual water: most provinces in China are net importers of virtual land; the net import volumes are larger and larger; net exporters are mainly in north of China. However, the situations contrary to virtual land strategy are also existent: Henan and Hubei are land-scarce areas while they are virtual land exporters. That situation exacerbates the shortage of land resources in two places. Besides, Liaoning, Hebei, Gansu, Qinghai, Shaanxi, Guizhou and Yunnan have relatively rich soil while they importer large amount virtual land.(3) In 1980-2013, scale effect which means the growing trade volume of agricultural products, drive the variations in virtual water and virtual land flows mainly and the influence direction is almost the same with trade variation.Based on the empirical results, this paper proposes suggestions: maintain a moderate scale of agricultural product trade; reduce water and soil intensity in agricultural products effectively; optimize the structure of agricultural production; coordinate the development of agricultural industry and non-agriculture industries.