Assessments of geohazard danger zoning in Longxian County, Shaanxi

Based on investigation of geohazards in Longxian County and various main influence factors determined by statistical analysis, danger assessments of geohazards were carried out using the integrated information method and qualitative assessment method. The authors set up the indicator system of geohazard assessments, determined the discrimination criteria of geohazards, and performed geohazard danger regionalization. China is divided into the high danger region, moderate danger region, low danger region and very low danger region. On that basis, 12 subregions were distinguished. Of these region, the high danger regions cover an area of 619.19 km2, accounting for 25.79% of the total area; the moderate danger regions have an area of 509.74 km2, making up 21.23% of the total area; the low danger regions have an area of 711.75 km2, taking up 29.65% of the total area; and the very low danger regions occupy an area of 559.87 km2, accounting for 23.32% of the total area of the whole county.