辽宁西部农作物生长季干旱风险及降水满足度研究

Study on Drought Risk in Crop Growing Season and Precipitation Satisfaction in Western Liaoning

利用辽宁西部11个国家气象站1951—2017年气象观测数据,选用干湿指数作为干旱指标及其积分湿润指数方法,采用气候诊断分析方法,研究农作物生长季干旱变化特征,干旱风险程度,降水量对农作物的满意程度,并分析气象要素与干湿指数的相关性。结果表明:辽宁西部地区1951—2017年农作物生长季及各月时间尺度干湿指数呈减小趋势,干旱趋势明显,农作物生长季5月苗期和9月成熟期干旱程度表现最为突出,从轻旱上升到中旱等级。农作物生长季的降水量满足度明显下降,使干旱风险度明显升高。农作物生长季干湿指数年际变化在1995/1996年发生由高到低突变,突变后干旱程度升高0.8个等级;干旱风险度年际变化在1995/1996年发生由低到高突变,突变后干旱风险度升高14.0%;降水满足度年际变化在1998/1999年发生由高到低突变,突变后降水满足度下降17.7%。干湿指数与气温、日照时数、蒸发量、辐射呈负相关,与降水、风速、空气相对湿度呈正相关,其中干湿指数与气温、降水量、空气相对湿度相关显著。辽宁西部地区干旱化日趋严重,调整农业结构势在必行。

Using the meteorological data of 11 national stations in western Liaoning province during 1951-2017,we analyzed the satisfaction of crops on natural precipitation and the correlation between meteorological factors and dry-wet index,based on the adopting climate diagnostic method,choosing dry-wet index as the drought index and its integral wetness index,the characteristics of drought change in crop growing season,the degree of drought risk.The results showed that the dry-wet indexes in monthly time scale decreased in crop growth season from 1951 to 2017,which meant that the drought trend was obvious,and the drought degree was most prominent in crop growth season(May)and mature period(September),from light drought to moderate drought.The satisfaction of crops with precipitation was obviously decreasing during the growing season,and the risk of drought was significantly increased.The inter-annual variation of dry-wet index in crop growing season and drought risk occurred from high(low)to low(high)mutation in 1995-1996,which increased by from 0.8%to 14.0%after mutation.The inter-annual variation of precipitation satisfaction occurred from high to low mutation in 1998-1999,and the precipitation satisfaction decreased by 17.7%after mutation.The dry-wet index had a negative correlations with the air temperature,sunshine hours,evaporation and radiation,and positive correlations with precipitation,wind speed and air relative humidity.The dry-wet index was significantly correlated with air temperature,precipitation and air relative humidity.The aridification has become increasingly serious in western Liaoning,and it is imperative to adjust the agricultural structure.