地形对凉山州夏季降雨的影响研究

Influence of Topography on Summer Rainfall in Liangshan Prefecture

利用地面区域自动站降水、GMTED2010高程、ERA5再分析等资料,通过三阶反距离平方权差分、卷积计算等求出地形、降雨指标,分析凉山州夏季(5一10月)降雨、地形特征及其复杂地形对降雨的影响。结果表明:凉山州复杂地形下降雨空间分布不均匀,总降雨量1100mm以上大值区及强降雨主要分布在河谷流域,雨日100d以上的大值区主要分布在东部山区;坡向、坡度对大雨及以上量级的强降雨都有显著影响,对中雨及以下降雨影响不明显。高精度坡度、坡向地形指标有助于在凉山州这种复杂地形下更好地评估强降雨过程的雨量,提高灾害预警质量,特别是在地形多样、对降雨敏感的河谷流域作用更加明显。

Based on the precipitation data of ground regional automatic stations,GMTED2010 elevation data and ERA5 reanalysis data,the terrain and rainfall indexes are obtained by using the third-order inverse distance square weight difference and convolution calculation.And,the rainfall,terrain characteristics and the influence of complex terrain on rainfall in Liangshan Prefecture in summer(from May to October)are analyzed.The results show that the spatial distribution of rainfall in Liangshan Prefecture is uneven under complex terrain.The large value area of total rainfall above 1100 mm and heavy rainfall are mainly distributed in the river valley basin,and the large value area of rain days over 100 days is mainly distributed in the eastern mountainous area.The aspect and slope have a significant effect on heavy rainfall and heavy rainfall above the magnitude,but the impact on moderate rain and below is not obvious.High-precision slope and aspect topographic indicators are helpful to better evaluate the rainfall during heavy rainfall under the complex terrain of Liangshan Prefecture,and improve the quality of disaster warning,especially in the river valleys with diverse terrain and sensitive to rainfall.