Ecological security assessment and pattern construction in arid and semi-arid areas: A case study of the Hexi Region, NW China.

• Established an ecological security evaluation framework based onLULC data. • The ecological security index increased from 2000 to 2010, and decreased afer 2010. • Using the results of ecological security assessment to extract ecological sources in Hexi Region. • The protection of ecosystems in areas with intensive human activities should be strengthened. Ecological security assessments are used to reflect the regional ecological security situation because they can provide a basis for the construction of regional ecological security patterns (ESPs). Using the land use/land cover (LULC) data, the ecological security status of the Hexi Region was analyzed. On this basis, the ecological source was extracted, the ecological resistance surface was established, and the ecological corridor and node were identified, and constructed the ESP of the Hexi Region. The results show that: 1) During 2000–2015, approximately 70% of the study area's ecological security index values were <0.1. The ecosystem security levels were higher in the southeast and lower in the northwest. 2) The total area of ecological sources was 6828.75 km2, and it is less distributed in the west; the interconnection degree among the sources was low; and patch fragmentation was obvious. 3) A total of 134 ecological corridors were extracted, with a total length of 15572.8 km2, and 44 ecological nodes were identified. The distributions of the ecological corridors and nodes had spatial consistency and were mainly concentrated in the central and southern parts of the Qilian Mountains. The method of ecological security assessment based on LULC data can be popularized and applied to the evaluation of the ecological security in regions having a lack of research data or difficulty in obtaining data. This study can provide guiding significance for the optimization of ecosystem elements and the improvement of regional ESPs in the study area or other arid areas. [ABSTRACT FROM AUTHOR]