基于降水距平百分比指标的石家庄市旱情分析

Analysis of drought in Shijiazhuang City based on the index of precipitation anomaly percentage

干旱的发生会严重影响当地作物产量和人们日常生活,会对经济和民生造成较大的损失。本文以石家庄为例,分析了1956年至2020年该市的降水情况,研究了降雨的年内分布状况,并借助降水距平百分比指标对石家庄市旱情发展规律进行描述,通过年尺度、季尺度和月尺度来分析了旱情的变化特点,研究结果表明:降雨年内的分配不平均;在夏季(7-8月)降雨量最大,降水量主要来自汛期;石家庄市干旱情况最严重的是2007年与1981年,在2020年以后,干旱有一定的概率会变严重,或是干旱级别转变的节点;干旱在每个季节出现概率的大小依次是夏季<秋季<春季<冬季,轻度、中度干旱在石家庄市出现的概率都略高,和之前轻度、中度干旱在年尺度条件出现概率大致相同,这表示使用此指标可以对旱情进行很好的描述,并且表现出了稳定性。

The occurrence of drought can seriously affect the local crop yield and people’s daily life,and can cause large losses to the economy and people’s livelihood.Taking Shijiazhuang as an example,this paper analyzes the precipitation in the city from 1956 to 2020,studies the intra-annual distribution of rainfall,and describes the development pattern of drought in Shijiazhuang with the help of precipitation distance level percentage index,and analyzes the changing characteristics of drought through annual scale,seasonal scale and monthly scale,the results of the study show that:the distribution of rainfall within the year is uneven;the greatest amount of rainfall occurs in summer(June to August)The most severe drought conditions in Shijiazhuang were in 2007 and 1981,and after 2020,there is a certain probability that drought will become severe or a point of drought level change;the magnitude of the probability of drought in each season is summer<autumn<spring<winter,and the probability of mild and moderate drought is slightly higher in Shijiazhuang,and the probability of mild and moderate drought is similar to that of previous mild and moderate drought.The probability of occurrence in annual scale conditions is approximately the same,which indicates that drought conditions can be well described using this indicator and shows stability.