基于DEM的山区旱灾风险评价模型——以西南地区为例

旱灾研究中,地形导致的水热再分配容易造成地域间旱灾灾情的明显差异,因此地形因子对于旱灾风险的准确评价及灾情的客观评估至关重要。采用气象站点观测数据和DEM数据,通过模拟复杂地形影响下的下垫面真实水分情况,加入地形因子的影响,建立了以干旱致灾因子(水分条件)、孕灾环境(地形)、承灾体(农作物脆弱性曲线)综合的旱灾风险评价三度模型;并以地形复杂、旱灾多发的西南地区为例,编制了旱灾风险等级图,以期为客观评估旱灾灾情,有效开展区域旱灾风险防范提供科学依据。

Drought risk assessment model of mountainous area based on DEM:a case of southwest China

In drought research,redistribution of water and heat caused by terrain are likely to lead to significant regional differences of drought disaster situation,therefore,terrain is a vital factor for objective and accurate drought risk assessment.Based on the data of meteorological observations and DEM,and by means of simulating the real situation of surface water under impacts of complex terrain,spatial calibration of precipitation and temperature was carried out with terrain,and then a three-dimensional model of drought risk assessment was put forward,which consists of hazard(water conditions),hazard formative environment(terrain) and hazard affected bodies(featured by crop vulnerability curve).Moreover,a typical case study of the southwest China that owns complex terrain and frequent droughts was employed for drought risk assessment,and the risk map of this region was compiled.It shows that the three-dimensional risk assessment model is effective,it can give a reference to accurate drought disaster assessment and scientific drought risk prevention.