河北省棉花连阴雨灾害的时空分布特征及其未来变化趋势的研究

Spatiotemporal Characteristics and Change Trend of Continuous Rainfall during Cotton’s Growing Stages in Hebei Province

利用1971-2020年河北省棉花种植区气象资料和棉花生长观测资料,采用线性分析、Mann-Kendall分析、重标极差分析(R/S)、非周期循环分析等方法,分析了棉花连阴雨灾害的时空分布特征和未来的变化趋势。结果表明:连阴雨危害河北省棉花生长的主要时段为6月下旬-9月上旬,其中,以7月上旬-8月中旬的危害最突出;棉区以花铃期连阴雨的站次和强度最大,现蕾期和吐絮期次之,播种期最小,其中,保定南部、衡水西部、石家庄、邢台、邯郸棉区以花铃期和吐絮期的连阴雨为主,其他棉区以花铃期和现蕾期的连阴雨为主;以邯郸、邢台、衡水南部、石家庄西部、保定中西部、唐山和秦皇岛两市北部棉区连阴雨的站次较多,其他棉区连阴雨的站次相对较少;连阴雨日数和阴雨日的日照时数在1989年出现明显的突变,之后,阴雨日数进入高值期、阴雨日的日照时数进入低值期,这导致了连阴雨的站次在1990年之后明显增多;近50年来的阴雨日数显著上升、阴雨日的日照时数显著下降,未来10年的变化趋势与过去50年的基本一致,并存在一个9~11 a的循环周期,这导致了棉花连阴雨的站次在近50年来显著上升和未来10年左右仍呈上升趋势。因此,随着未来连阴雨灾害风险的增加,应加强防御措施的准备工作。

Based on meteorological data and observed cotton growing data of cotton growing area in Hebei Province from 1971 to 2020,the spatiotemporal characteristics and change trend of continuous rainfall(CR)were analyzed by linear regression analysis,Mann-Kendall trend test,re-scaled range(R/S)analysis and non-periodic cycle analysis,etc.The results showed that the CR with high intensity and heavy impacts occurred mainly from late June to early September,and the most prominent period was from early July to mid-August.The probability and intensity of CR from high to low were flower-boll stage>squaring stage>boll opening stage>seeding stage.The CR in south of Baoding,west of Hengshui,Shijiazhuang,Xingtai and Handan mainly occurred during flower-boll stage and boll opening stage,while the CR in other cotton planted areas mainly occurred during flower-boll stage and squaring stage.Handan,Xingtai,south of Hengshui,west of Shijiazhuang,mid-west of Baoding,north of Tangshan and Qinhuangdao were worse-hit areas of CR,while the other cotton planted areas were the light-hit areas of CR.As obvious mutation of rainy days and sunshine duration during continuous rainfall process occurred in 1989,the rainy days entered high value period,sunshine duration entered low value period and occurrence station times of CR entered obvious rising period.The rainy days and sunshine duration during continuous rainfall process showed significant upward and downward trends respectively in past 50 years.The future trends are consistent with the past trends,and the average cycle durations are 9~11 years.The variation of rainy days and sunshine duration resulted in the continuous increasing trend of the occurrence station times of CR in the past 50 years and the next 10 years.Overall,the risk of CR will increase in the future and the defensive measure should be strengthened.