Investigation and analysis of geographic landscape characteristics in Yulong plague natural focus, Yunnan Province / 中华地方病学杂志

ABSTRACT

Objective To investigate the geographic landscape features in Yulong plague natural focus.Methods Four altitudinal gradients (2 400-,2 600-,2 800-,≥3 000 m) were selected as study objects in Yulong plague natural focus from December 2015 to November 2016 to collect and analyze geographic landscape factors (topography and terrain,climate,water areas,vegetation and soil) based on the literatures about this plague focus.Results Yulong plague natural focus was an area with mid-mountain and subalpine topography in northwestern Yunnan Province,and its terrain had the character of lower in the southeast and higher in the northwest.This area belonged to plateau warm temperate monsoon climate of low latitude with an average month temperature 13.6 ℃ from 2005-2016,month air relative humidity averaged 59.4％,and rainfall averaged 884.5 mm a year,which concentrated mostly from June to September.About 98.1％ of the water area in Yulong County was controlled by Chin-sha River.The vegetation and soil were characterized by vertical distribution along with altitude gradients obviously.Conclusion The unique geographical landscape of the plague natural focus in Yulong County is one of important factors affecting the occurrence and epidemic of the plague.