Changes of Land Use and its Prediction Based on CA-Markov Model in the Coastal Zone of Yancheng

Abstract

For studying the influence of human activity on the change of land use type and ecological environment in coastal region, the coastal zone of Yancheng was selected to analyze the change of land use and spatial landscape pattern in the past 17 years by using geographic information system (GIS). The Markov model was applied to predict land use variation in the following 10 years. The results showed that: The land use structure in the coastal areas of Yancheng has undergone great changes from 1991 to 2008. It is demonstrated that the percentage of farmland area ascended from 36.42%. to 50.17%., and the artificial wetland area ascended from 9.96% to 20.22%,while the percentage of natural wetland area declined from 46.41% to 23.01%. Construction land increased five times (85.29km2) . Nature wetland, farmland and artificial wetland were the main land use types of research area with obvious reciprocal transformation. Nature wetland was mainly transferred to farmland and artificial wetland, and farmland was mainly transferred to artificial wetland and construction land in 1991-2008. The three types of time-space distribution extended to the coastal zone gradually. And the land exploitation activities became increasingly intensive. A series of landscape patterns changed because of severe human disturbance, such as obvious fragmentation, the dominance decrease, and the diversity and evenness increase, the degree of space across of the nature wetland and the artificial wetland increase. As a result of landscape fragmentation,ecological function in a landscape was declined. The simulated result by CA-Markov model indicated that cultivated land and artificial land continued to rise, the annual average increase rate of construction land was twice the earlier period and the reducing speed of natural wetland was 56.67% of the earlier stage. Between 1997 and 2018, the three types of land use (cultivated land, natural land and artificial wetland) have all extended to the coastal zone.