基于格网的青海省干旱灾害综合风险评估

Grid-based estimation of drought disaster in Qinghai Province

干旱灾害风险评估是执行区域性干旱灾害风险管理的重要举措,是有效实施气象防灾减灾工作的非工程性技术措施。随着气象现代化的逐步实施,干旱灾害风险评估技术和精度的重要性越加凸显。为科学、准确地评估青海省区域干旱的监测精度和干旱灾害风险等级,以青海省为例,采用青海省1961—2010年50个气象站潜在蒸散和降水数据,基于气象灾害风险度评估理论和方法,并根据《青海省地方干旱等级划分标准》,通过干旱灾害风险度模型和ArcGIS空间分析相结合的方法,较为系统地分析了青海省干旱灾害风险时空分布特征及其灾害风险等级。结果表明:近50 a以来,青海境内主要发生了不同程度的冬春季干旱。从时空分布特征来看,轻、中、重度干旱灾害分布和演化趋势基本一致,干旱灾害易发高发区主要分布于柴达木盆地西北部;环青海湖流域和共和盆地以及东部农业区局地处于中等风险水平,其余地区干旱灾害风险水平较低;从市、县、镇区域单元来看,茫崖、花土沟镇、冷湖及格尔木市干旱灾害风险较高,天峻、都兰、乌兰、共和、兴海、同德、贵南、同仁、化隆、循化及唐古拉等地次之,其余地区干旱灾害风险水平较低,青海境内干旱灾害的发生不仅受降水量影响,还与不同类型的下垫面密切相关。

With the gradual implementation of meteorological modernization,the technique as well as its precision about drought disaster is more prominent.While importance of the risk assessment drought is one of the global meteorological disasters to a certain extent,the agricultural and animal husbandry production,ecological environment improvement and social and economic development have been severely restricted.The risk assessment of drought disaster is an important measure to carry out the risk management of regional drought disaster,and it is the non-engineering technical measure to implement the work of meteorological disaster prevention and reduction effectively.The risk assessment of drought disaster in Qinghai Province,China was studied by some scholars,but it was based on vector data of county domain units.Therefore,the results exaggerated the risk degree and spatial distribution of drought disaster,and the accuracy of disaster risk assessment was reduced.In order to assess regional drought monitoring accuracy and the risk levels of drought disaster in Qinghai Province scientifically and accurately,this paper used the po- tential evapotranspiration and precipitation data from 50meteorology stations in Qinghai Province during the period from 1961to 2010to Systematically analyze the spatial and temporal distribution characteristics and the risk levels based on the theory and methods of meteorological disaster risk estimation.This was also done with the methods of combining the drought disaster risk degree model and ArcGIS spatial analysis,according to the regional drought grading standard of Qinghai Province.The results showed that the winter and spring drought appeared in Qinghai Province with varying degrees in the period.From the spatial and temporal distribution perspective,the distribution and evolution trends of light,medium and heavy drought were basically identical.The areas prone to drought disaster or with high incidence of drought disaster were mainly located in the northwest of Qaidam Basin,while Lake,Gonghe Basin and the eastern agricultural regions were at medium risk level.The rest shared the low Qinghai levels of drought disaster risk;from the viewpoint of the administration unit,the drought disaster risks were higher in Mangya,Lenghu,Huatugou Town and Golmud City.The drought disaster risks in the regions including Tianjun,Dulan, Wulan,Gongh rest were with were in a dry e,Xinghai,Tongde,Guinan,Tongren,Hualong,Xunhua and Tanggula,were in the medium levels.The the low levels.In addition,influenced by topography and geomorphology,the Mangya and Lenghu area state throughout the whole year,which were more consistent with the reality.Thus,it could be seen that the occurrence of drought disaster in Qinghai Province was not only related to precipitation,but also related to the underlying surface of different types.