Abstract: The construction of ecological security pattern based on the "source-corridor" model is of great significance for improving regional ecological security. Nanchuan District, a typical desertification mountainous area, was taken as an example to construct the ecological security pattern. The core ecological source area was firstly identified based on the importance of ecosystem services, the eco-environmental sensitivity and the degree of inhabitants' ecological demands from ecological and human well-being perspective. The multi-factor comprehensive analysis method was then applied to detect the resistance surface of ecological source expansion using natural environmental factors, human interference factors and biological factors as evaluation indicators. Finally, the least cumulative resistance model and the hydrological analysis method were applied to identify the ecological corridors, so as to construct the regional ecological security pattern. It was found that the core ecological source area is dominated by forest with an area of 389.25 km², and the forest area decreases from the central to the north and the south in space. Six key corridors and a series of potential corridors were also successfully identified. In the key corridors, three of them traverse from west to east, and the others traverse from north to west. The potential corridors mainly distribute in hilly area with good environment, and form a network of regional species migration and energy circulation together with the key corridors. It is suggested that to construct an ecological network framework with one vertical and two horizonal ecological corridors to strengthen the regional ecological security pattern in Nanchuan District.

Key words: ecological security pattern, minimum cumulative resistance model, ecosystem service value, ecological sensitivity, ecological demand