Research on dynamic changes of landscape structure and land use eco-security: a case study of Jiansanjiang land reclamation area

Research on dynamic changes of landscape structure and land use eco-security is an important part of regional eco-security and sustainable use. This paper selected Jiansanjiang land reclamation area as the study area, got the landscape types of 1992, 2000 and 2008 by Remote Sensing (RS), quantitatively analyzed characteristics of changes of landscape structure of different scales of the study area and elucidated the formation mechanism of land use eco-security based on the variations of landscape structure. The paper quantitatively calculated the landscape structure stability of different scales, and established the comprehensive evaluation indicator system on eco-security of land use based on the DPSIR model to evaluate and analyze the eco-security level of land use in the study area. The results showed that: from 1992 to 2008 the landscape structure of the study area changed dramatically, the landscape matrix type of the study area turned from wetlands to rice paddies, the complexity of patch shape and landscape fragmentation was increased and patch distribution expressed as "aggregation-scattered-aggregation"; Land-use practices not only damaged the landscape structure of the study area, but also made predominant control impact on the recovery, thus the different states of the land use eco-security were formed based on the changes of the landscape structure. The landscape stability of the study area could reflect the status of land use eco-security; the overall landscape stability of the study area demonstrated the "stable-unstable-stable" complex stability and the status of land use eco-security demonstrated the "near safety-critical safety-near safety" dynamic characteristics; from 1992 to 2000, the landscape structure of dry land was the steadiest. From 2000 to 2008, the steadiest type of transformation turned from dry land to construction land, indicating that construction land was at the highest level of land use ecological security. In 2008, the wetland was the most unstable landscape, and it was also at the lowest level of land use ecological security.