黔东南州剑河县秋季干旱指标分析

Grade Evaluation of Autumn Drought Index in Jianhe County of Qiandongnan Prefecture

为寻求适合乡镇干旱等级评价的指标,提高乡镇一般气象站为农业服务的水平,同时为黔东南州剑河县气候预测和干旱现象的研究提供参考,利用2007—2016年剑河新搬迁国家一般气象站逐日降水、蒸发记载数据,2016年9—10月乡镇区域自动站降水资料、暴雨山洪水位站水位资料及革东土壤水分站记载数据,计算降水距平百分率(Pa)、K指数、土壤相对湿度指数,并将计算结果与实况干旱资料进行对比分析。结果表明:Pa指标对乡镇干旱等级的评估时有偏重或偏轻的情况,K指数判定乡镇的旱情评估会偏重,使乡镇干旱评定的等级偏大1~2级,对乡镇干旱的评估不适合;土壤相对湿度指标判定农业气象干旱等级较符合实际,能反映土壤水分站址干旱的入旱日、旱情解除及干旱等级情况;暴雨山洪水位的变化趋势对干旱也有指示作用,特别是干旱的解除情况。

The percentage of precipitation departure （Pa）, K index and soil relative humidity index of different villages and towns in Jianhe County were calculated by using daily precipitation and evaporation data from Jianhe Meteorological Station during 2007-2016, the precipitation data from automatic stations of villages and towns from September to October in 2016, the water level data from the torrential flood water level station and the recorded data from Gedong Soil Water Station and the comparative analysis between the calculated results and actual drought data is conducted to discuss the indexes of evaluating drought grade of villages and towns, improve the agricultural service level of common meteorological stations at the town level and provide a reference for climatic forecast and drought phenomenon in Jianhe County of Qiqndongnan prefecture.Results： Pa index has the partial effect on the evaluated drought grade of villages and towns and K index increases the evaluated drought grading level of villages and towns, which indicates that Pa index and K index both are not used in drought grading evaluation of villages and towns suitably.Soil relative humidity index can correctly reflects the actual agricultural meteorological drought grade and the starting drought date, drought relief and drought grade of Gedong Soil Water Station, The variation trend of torrential flood water level has the indicative effect on drought relief especially.