In the historical period, the good forest covering, the sufficient water resource and the clouding and humid environment provided the essential condition for malaria's production in Sichuan area.
历史时期，四川地区良好的森林覆盖、充足的水源补给以及湿热封闭的环境都为瘴气的产生提供了必要的条件；
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This paper revealed a warm and humid environment during the initial stage of the last deglacial period in the Pumoyum Co Lake of the southern Tibet and analyzed several possible reasons.