Impacts of urbanization on urban agricultural landscape-A case study of Chang'an District, Xi'an City

There is an increasingly significant impact of urbanization on urban agricultural landscape. Knowing what changes are occurring in urban agricultural landscape patterns as a result of urbanization is critical for adjusting and optimizing the interactions between urbanization and urban agriculture. This is also critical for constructing urban landscapes which integrate into urban agriculture and thereby induce sustainable development. By using remote sensing (RS), Geographic Information System (GIS) and FRAG-STAT techniques, the dynamic changes in urban agricultural landscape (arable lands and garden plots) in the process of urbanization were analyzed in this paper. The paper used Chang'an District of Xi'an City as a case. It discussed the relationship between urbanization and urban agricultural landscape. The results show: ① Compared with 1999, the area of arable lands decreased and aggregation of arable lands declined by 2.45% in 2011 in Chang'an District. The area of garden plots increased while their aggregation increased by 10.44% in 2011 compared with those in 1999. ② The fragmentation of arable lands increased in 15 towns and subdistricts, while area and aggregation of garden plots increased. ③ Correlation analysis showed that improvement of urbanization level decreased area, and increased fragmentation of arable lands. However, the correlations between comprehensive urbanization level and patch number, shape index and aggregation index of arable lands were difficult to determine. Garden plots showed an agglomeration trend in space. Furthermore, the correlation coefficients between urbanization level and landscape indexes of garden plots were less than 0.5, which was insignificant. ④ There were different action mechanisms of urbanization levels on arable lands and garden plots. In higher and low levels of urbanization, the relationship between urbanization and arable lands landscape indexes were relatively clear. However, for garden plots, there was more complex relationship between urbanization level and landscape indexes in middle and low levels of urbanization. This relationship also was not clear. The results suggested that garden plots area increased, although with scattered distribution during urbanization. Future urban planning should lay more emphasis on this aspect of urbanization and agricultural landscape.