【摘要】 选用甘肃省景电灌区1988-2017年逐日降水观测资料,采用线性倾向分析法、Mann-Kendall检验法及滑动t检验法研究了灌区降水量在不同时间尺度的变化特征。结果表明:景电灌区30年降水量呈丰枯交替变化,整体呈缓慢上升的趋势,倾向率为4.18。降水量年内分布多集中于7～8月,2、3、6、8月的降水量呈逐年减少趋势,其中3月份的降水量降低趋势通过了0.05显著性检验,其余月份降水量均呈逐年增高的趋势,7月增长幅度最大,倾向率为3.554。春灌与秋灌降水量年际间呈下降趋势,夏灌、冬灌及停灌期降水量年际间呈增长趋势,但均未通过0.05水平显著性检验,夏灌降水量在2001年发生了由低到高的突变,秋灌降水量在1997年发生了由高到低的突变,停灌期降水量在1999年发生了由低到高的突变。该研究结果对掌握景电灌区降水变化规律,提高天然降水利用率,合理制定灌溉制度和水资源高效利用具有水分重要的意义。更多还原

【Abstract】 The daily precipitation data from 1988 to 2017 in Jingdian Irrigation District of Gansu Province were selected. The linear propensity analysis method, Mann-Kendall test method and sliding t-test method were used to study the variation characteristics of precipitation in different time scales. The results show that the precipitation in the Jingdian Irrigation District is alternating between abundance and dryness, and the overall trend is slowly rising, with a tendency rate of 4.18. The precipitation is concentrated in July-August during the year, and the precipitation in February, March, June, and August is decreasing year by year. The precipitation reduction trend in March has passed the 0.05 significant test, and the precipitation in other months is yearly. The trend of increase was the largest in July, with a tendency rate of 3.554. The precipitation of spring irrigation and autumn irrigation showed a downward trend during the inter-annual period. The precipitation in summer irrigation, winter irrigation and stop irrigation showed an increasing trend during the year, but none of them passed the 0.05 level significance test. The precipitation in summer irrigation occurred in 2001. Low-to-high mutations, high-to-low mutations occurred in autumn irrigation in 1997, and low-to-high mutations occurred in 1999 during the irrigation period. The research results have important significance for mastering the law of precipitation variation in Jingdian Irrigation District, improving the utilization rate of natural precipitation, and rationally formulating irrigation system and efficient use of water resources.更多还原