基于河流出水量的区域水文干旱特征及其水文频率分析——以黔中水利枢纽工程区为例

Analysis of Regional Hydrological Drought Characteristics and Hydrological Frequency Based on River Water Output:Taking Qianzhong Water Conservancy Project Area as an Example

为了加强区域水文干旱预测预报系统,对区域水文干旱特征变化规律作进一步分析,基于河流出水量这一视角,以黔中水利工程区1960—2016年的逐月径流数据为基础,通过河流出水量估算,采用径流距平百分率及P-Ⅲ(PearsonⅢ)型曲线、适线法等水文频率分析法进行水文干旱特征研究。结果表明:近57年来,黔中水利工程区河流年出水量波动较大,1989年达到历史极低值,出水量总体呈递减趋势;水文干旱主要发生于黔中地区的中部区域,进入21世纪之后区域水文干旱发生得较为频繁,主要以中旱为主,各干旱程度的频率趋势依次为:轻旱>中旱>重旱>特旱;根据P-Ⅲ型水文频率数学模型,河流出水量最小1个月低于52.70 m^(3)/s,最小3个月低于169.36 m^(3)/s,最小5个月低于313.90 m^(3)/s,最小7个月低于543.48 m^(3)/s时区域内发生20年一遇(P=95%)的水文干旱。

In order to strengthen the regional hydrological drought prediction and forecast system,further analysis of the regional hydrological drought characteristics change law.From the perspective of river water output,based on the monthly runoff data of the Qianzhong Water Conservancy Project Area from 1960 to 2016,the river water output was estimated by using the runoff anomaly percen-tage,and frequency analysis method for hydrological drought characteristics research,such as P-Ⅲ(PearsonⅢ)type curve,and line-fitting method.The results show these as follows.The annual water output of the rivers in the Qianzhong water conservancy engineering area fluctuates greatly,reaching a historically low value in 1989,and the overall water output is decreasing in the past 57 years;hydrological drought mainly occurs in the central part of Guizhou.After entering the 21st century,regional hydrological droughts have occurred more frequently,mainly moderate droughts.The frequency trend of each drought degree is as follows:light drought>moderate drought>heavy drought>special drought;According to the P-Ⅲhydrological frequency mathematical model,the river water output is less than 52.70 m^(3)/s for a minimum of 1 month,less than 169.36 m^(3)/s for a minimum of 3 months,less than 313.90 m^(3)/s for a minimum of 5 months,and a minimum of 7 When the month is lower than 543.48 m^(3)/s,a hydrological drought of once in 20 years(P=95%)occurs in the area.