湖北省电线积冰微地形因子影响识别研究

The Recognization and Study of Microrelief's Influence on Wire Icing in Hubei Province

电线积冰是影响电网正常运行的重要因素,研究电线积冰与微地形因子的关系对于电线积冰风险区划、电网建设可行性论证等具有重要指导意义。本文利用湖北省1:5万基础比例尺地形图数据和湖北省电网线路冰害故障调查统计数据,对电线积冰厚度与其对应的微地形因子进行相关性分析,识别对电线积冰有显著影响的微地形因子,分析电线积冰厚度与对其影响显著的微地形因子的定量关系,解析微地形因子对电线积冰敏感性等级。结果表明:地形起伏度、海拔高度、离水体远近程度、下垫面类型等是影响积冰厚度最显著的微地形因子;地形起伏度与积冰厚度呈乘幂函数关系,海拔高度与积冰厚度呈对数函数关系,离水体远近程度与积冰厚度呈分段函数关系,下垫面类型与积冰厚度无显式的函数关系,但积冰灾害发生点具有明显的随下垫面类型分布的特征;积冰厚度随地形起伏度、海拔高度的增加而增加,而其变化率和敏感性则逐渐减小;地形起伏度小于40 m时,其对积冰风险最敏感;海拔高度在25～100 m时,其对积冰风险最敏感;积冰厚度随离水体距离的增加呈先增后减的变化趋势,其变化率绝对值和敏感性也呈先增后减的变化趋势,当离开水体距离在2～2.7 km时,其对积冰风险最敏感;电线积冰灾害多发区域的下垫面主要为水体、林地,其次为农田和草地,水体对积冰风险的敏感性等级分别是林地、农田、草地的1.5、3.6和16.7倍。

Wire icing is an important influencing factor of power grid＇s safety.It is of important directive significance for the risk division of wire icing and the feasibility demonstration of power gird construction to study the correlativity between wire icing and microrelief elements.The paper uses 1：50000 large-scale topographic maps and investigation data of wire icing disasters to study the correlativity of different microrelief elements and icing thickness,distinguish the microrelief elements which influence icing thickness remarkably and analyze quantitative relations between icing thickness and microrelief elements.Thus we obtain the sensitivity levels of the microrelief elements to different icing thickness range.The results show that,among the microrelief elements,the topographic roughness,altitude,distance from water body and land use type are the most significant elements which influence the icing thickness;the relationship of topographic roughness and design icing thickness is a power function; the relationship of altitude and design icing thickness is a logarithm function;the relationship of distance from water body and design icing thickness is a piecewise function,and the function relation of land use type and design icing thickness is not obvious.However,icing disaster is of obvious distribution configuration with land use type.While topographic roughness and altitude increase,icing thickness increases,its change rate and sensitivity descend;when topographic roughness is less than 40 m,it is the most sensitive to icing risk;when altitude is between 25—100 m,it is the most sensitive to icing risk;while distance from water body increases,icing thickness decreases after increasing trend,its change rate and sensitivity also decrease after increasing trend;when the distance is between 2—2.7 km,it is the most sensitive to icing risk.It is found that wire icing disasters mainly occur in water body,woodland,cultivated field and meadow, the sensitivity level of water body to icing risk is 1.5 times of woodland,3.6 times of cultivated field, 16.7 times of meadow respectively.