武义县暴雨洪涝的时空变化特征

为了揭示武义县暴雨洪涝的时空变化特征，基于1970-2018年洪涝及暴雨实测数据，统计分析反映时空变化特征的一系列指标，应用多元线性回归模型，建立水位与径流、降雨的多元相关关系。研究结果表明：洪涝在20世纪70至80年代中期次数偏少，其后开始逐渐增多，且具有3a左右的年际周期变化，12a左右和25a左右的年代际周期变化；洪涝主要发生在主汛期6-8月，其中，6月中旬至7月中旬以系统性暴雨为主，洪涝占全年60%，7月下旬至8月短时暴雨明显增多，山洪占全年50%；洪涝与西部型南亚高压、西太平洋副热带高压的变化特征正相关，同时中低层冷暖气流的汇合强度亦有利于产生洪涝；构建武义江流域水位与径流、降雨多元逐步回归模型，提出一种以水位预报为目标的洪水趋势预测方法。

Spatial and temporal Variations of Rainstorm and Flood in Wuyi

In order to reveal the characteristics of rainstorm and flood in Wuyi, based on the observed data in 1970-2018, a series of indexes which reflected the characteristics of spatial and temporal variations in statistical analysis were made,then a multivariate linear regression model was established between water level, discharge and rainfall. The results show that:(1) the number of floods was few in the mid-1970s to the mid-1980s, but in the mid-1980s began to rise, and with annual variation of about 3 years, decadal variation of about 12 years or 25 years, (2)the flood mainly occurred from June to August, in which the system rainfall and 60% flood in a year accounted from the middle of June to the middle of July, from the late July to August the short-term rainstorm increased obviously, and 50% mountain flood accounted in this time,(3)the flood was positively related to the characteristics of the western type of South Asia high and the Western Pacific subtropical high, and the convergence intensity of the cold and warm air flow in the middle and lower layers was also conducive to the generation of flood,(4)a multivariate linear regression model of water level, discharge and rainfall in Wuyi river basin was established which was a flood trend prediction model aiming at water level.