Abstract: Taking Xinghai Lake, a typical urban lake in arid area of Northwest China, as the research area, and based on remote sensing images in 2005, 2011 and 2016 as data sources, the wetland ecological risk index was constructed by using landscape pattern index and landscape vulnerability index. Based on ArcGIS and other software platforms, spatial interpolation and spatial autocorrelation methods were used to analyze the spatial and temporal characteristics of ecological risk in Xinghai Lake. The results showed that: (1) The landscape pattern of Xinghai Lake wetland changed significantly from 2005 to 2016. The area of all landscape types fluctuated in varying degrees. The trend of fragmentation of construction land, grassland and wetland vegetation, which were greatly influenced by human activities, was increasing while the stability of regional landscape was decreasing. (2) The distribution of ecological risk in the study area was closely related to landscape types. The main ecological risk of Xinghai Lake wetland in the three periods included moderate risk. The proportion of low-risk area decreased from 17.6% to less than 1%. The higher risk showed an obvious upward trend, and experienced a transition from below medium risk to medium risk and high risk. (3) The ecological risk of the study area had spatial aggregation effect, and the distribution of the aggregation area was related to the distribution of landscape types. Urban lake wetlands are significantly affected by human activities, so it is urgent to strengthen the management and protection of ecological risk of wetlands.

Key words: arid area, urban lakes, landscape pattern, risk assessment, Xinghai Lake, Ningxia, China