潮汐与降雨对滨海湿地地下水位的影响  

Tides and Rainfall Affect Water Table Depth of Coastal Wetland

作　　者：谢潇[1] 朱文渤 郭海强[1] 赵斌[1] 

机构地区：[1]复旦大学生物多样性与生态工程教育部重点实验室长江河口湿地生态系统野外科学观测研究站,上海200433 [2]德州大学阿灵顿分校机械与航天学院

出　　处：《复旦学报（自然科学版）》2013年第6期801-806,F0003,共7页Journal of Fudan University：Natural Science

基　　金：上海市科委项目(10dz1200603);国家自然科学基金(31100409;30870409;31170450)资助项目

摘　　要：滨海湿地地下水位高度同时受到潮汐、降雨及地形等多个环境因子的影响,因此其动态特征较为复杂,测量比较困难.我们引入了美国陆军工程兵团提供的方法来准确测定滨海湿地地下水位变化,然后使用交叉小波变换、分类回归树法等方法分析了2011年9—11月在上海崇明东滩湿地获得的水位数据和气象数据以及相应的潮汐数据,发现:1)滨海湿地地下水位在12h和24h周期上与潮汐交替呈现出相关和不相关的关系,反映了滨海湿地地下水位在双峰、上升和下降3种模式之间的规律性切换;2)这3种模式是在潮汐、降雨以及日平均地下水位本身的综合作用下形成的.同时,我们还发现,当潮差小于3.185m,且降雨量小于1.2mm时,地下水位会下降;而同样条件下,当降雨量大于1.2mm时,地下水位则倾向于上升;当潮差大于3.185m,且当日平均地下水位高于-0.017m时,地下水位则会表现为双峰式的变化.如果日平均水位低于-0.017m,潮水则会补充地下水位.Water table depth （WTD） of coastal wetland is affected by tides, rainfall, topography and other environmental factors, and therefore its dynamic is complex and its measurement is difficult. We introduced a method provided by U. S. Army Corps of Engineers to accurately measure WTD in Dongtan wetland of Chongming Island, and then the obtained data and other environmental observations and corresponding forecast tidal data were analyzed via cross wavelet transform and classification and regression tree method. We found that： 1） there were cyclic variations in the correlations between WTD and forecast tidal elevation in 12 hour and 24-hour period. The changing of correlations was caused by shifting of WTD between three daily patterns, bimodal-cure, increasing and decline; 2） These patterns were regulated by tide, rainfall and the diel mean WTD. If tidal range was less than 3. 185 m and meanwhile rainfall was less than 1.2 mm, WTD would decrease with time. （）n the same tidal range but rainfall was higher than 1.2 mm, WTD tended to rise with time. When the tidal range was larger than 3. 185 m and the diel mean WTD was higher than --0. 017 m, the daily pattern of WTD was a bimodal curve. If the diel mean WTD was less than --0. 017 m, surface water brought by tides recharged the groundwater which would induced increase in WTD.

关 键 词：滨海湿地 地下水位 潮高 朔望-方照潮 降雨 

分 类 号：Q958.8[生物学—动物学]