基于pair-copula结构的珠江三角洲河网区水位空间依赖性分析

Analysis of spatial dependence of water level in river network area of Pearl River Delta based on pair-copula construction

基于1957—2016年珠江三角洲河网区15个水文站月平均水位资料,利用pair-copula结构构建水位空间依赖性模型生成样本数据,并采用F-madogram方法定量评估不同时期、不同时间尺度和不同距离范围内珠江三角洲河网区的水位空间依赖性。结果表明:珠江三角洲河网横向发育区域比东南45°方向发育区域水位空间依赖性弱;夏季丰水期水位空间依赖性比冬季枯水期水位空间依赖性显著增强,且季节尺度下水位空间依赖性比全年尺度下水位空间依赖性弱;受人类活动影响,在远距离情况下夏季丰水期1987—2016年的水位空间依赖性比1957—1986年显著增强;在较小距离范围内年极小月水位1987—2016年的空间依赖性比1957—1986年显著减弱,在远距离情况下年极大月水位1987—2016年的空间依赖性比1957—1986年显著增强。

Based on the monthly mean water level data of 15 hydrological stations in river network area of the Pearl River Delta from 1957 to 2016,a water level spatial dependence model was established using the pair-copula construction to generate samples,and the F-madogram method was used to quantitatively evaluate the spatial dependence of water level in river network area of the Pearl River Delta in different stages and distance ranges at different time scales.The results show that the spatial dependence of water level in the area with river network developing in the transverse direction is weaker than that in the 45°southeast direction in river network area of the Pearl River Delta,the spatial dependence of water level in wet season is significantly stronger than that in dry season,and the spatial dependence of water level at seasonal scale is weaker than that at annual scale.Due to the influence of human activities,the spatial dependence of water level in wet season from 1987 to 2016 was significantly enhanced compared with that in the period of 1957 to 1986 in a large distance range.In a small distance range,the spatial dependence of annual minimum monthly water level from 1987 to 2016 was significantly weaker than that in the period of 1957 to 1986,and the spatial dependence of annual maximum monthly water level from 1987 to 2016 was significantly enhanced compared with that in the period of 1957 to 1986.