黄河三角洲水土盐形成演化与分布特征

在研究黄河三角洲形成与演化规律基础上,研究了浅层地下水赋存分布与水质特征以及土壤含盐量分布特征,重点探讨了地下淡水、微咸水形成与演化规律。主要认识和结论如下:(1)黄河三角洲是由黄河携带泥沙填海造陆而成,据三角洲形成年代,将黄河三角洲划分为古黄河三角洲、近代黄河三角洲和现代黄河三角洲;(2)近年来,人类活动成为影响河口三角洲发育不可忽视的因素;(3)黄河三角洲咸水含水层广布,浅层地下淡水和微咸水主要赋存在黄河现代河床、古河道带和决口扇高地;(4)黄河三角洲地下淡水、微咸水的分布与形成演化及土壤含盐量分布状况与三角洲形成的早晚、黄河河道的变迁、所处微地貌部位及现代河道与渠系分布等因素密切相关;(5)三角洲形成时间越晚,浅层淡水和微咸水分布面积越小,水量越贫乏。

DISTRIBUTION AND EVOLUTION OF THE YELLOW RIVER DELTA PLAIN AND GROUND WATER AS WELL AS SALTS IN THE YELLOW RIVER DELTA

Based on research on the formation and evolution of the Yellow River Delta,this paper discussed the hydrogeological characteristics and formation and evolution of shallow ground fresh water and brackish water,as well as the characteristics of soil salinity.In response to the forming phase,the Yellow River flood plain can be divided into 3 types: the old delta,the recent delta and the present delta.Human activities are becoming an important factor affecting the evolution of the Yellow River Delta.Salt groundwater is widespread.Fresh and brackish waters can be found on the sides of the present river course,as well as along the old river course and crevasse splay in the old delta,and along the old courses on the top parts of the recent delta.Except along the past river course,there was narrow banded brackish water,it is all saline ground water in the present delta.Formation and evolution of the shallow ground fresh water and brackish water as well as soil salt contents are correlated with the forming time of the delta,the change of the Yellow River and the characteristics of microtopography,as well as the distribution of present courses and channels in the alluvial-marine plain.