基于小波分析的海绵城市试点未来降雨变化预测分析研究

Prediction and analysis of future rainfall change in pilot project sponge city based on wavelet analysis

为有效预测海綿试点城市未来降雨变化特征,以及在面对未来降雨变化时,海绵城市将如何建设提出建议,收集整理30个海绵城市试点19832012年的年际降雨变化时间序列,采用Morlet小波函数进行小波分析,探究试点城市降雨变化的多时间尺度的周期性变化规律,并根据主周期对未来降雨变化进行了预测。结果表明,未来降雨变化体现出地区性特点,按照变化规律,30个试点可分为10类。根据预测从2018年开始,环渤海地区东北部、东南部沿海地区试点城市的降雨量会在未来5年内出现明显上升,故这2个区域应加强城市雨水系统的建设,以达到未来降雨变化情景下年径流总量控制率的要求,并根据实际情况加强超标雨水排放设施建设,有效应对未来可能出现的极端降雨事件;其他大部分地区未来58年内降雨量变化表现出微弱下降的持平或明显下降状态,在这些区域内,尤其是西北部干旱区及华北平原与华北平原中南部地区的城市,应加强源头雨水控制利用与雨水资源利用设施的建设,并加强非传统水源的收集与利用。

In order to effectively predict the characteristics of future rainfall changes in pilot project sponge cities and to make suggestions on how to cope with future rainfall changes in the process of construction of sponge cities, Morlet wavelet function was used to analyze the time series of annual rainfall changes in 30 pilot project sponge cities from 1983 to 2012, and to explore the regularity of multi-time-scale periodic variation of rainfall changes in these cities. The results show that: future rainfall changes reflect regional characteristics, 30 pilot project sponge cities can be divided into 10 categories. Since 2018, the rainfall of the pilot project sponge cities in the northeastern and southeastern coastal areas around the Bohai Sea will increase significantly in the next five years. The two regions should strengthen the construction of urban stormwater system to meet the volume capture of annual rainfall under future rainfall changes, and strengthen the construction of major drainage facilities according to the actual situation to effectively deal with the possible extremes in the future. In other areas, the rainfall changes in the next 5-8a show a slight-ly declining state or a markedly declining state. Especially in the arid areas of Northwest China and the cities in the central and southern parts of North China Plain and North China Plain, the con-struction of facilities for controlling and utilizing source rainwater and utilizing rainwater resources should be strengthened, and non-traditional water sources should be fully collected and utilized.