汉江中下游水质时空特征及环境流量确定  

Temporal and spatial characteristics of water quality and environmental discharges in middle and lower Hanjiang River

作　　者：何术锋 佘星源 林育青[1] 杨早立 莫康乐 陈求稳[1] HE Shufeng;SHE Xingyuan;LIN Yuqing;YANG Zaoli;MO Kangle;CHEN Qiuwen(Eco-environmental Research Department,Nanjing Hydraulic Research Institute,Nanjing 210029,China)

机构地区：[1]南京水利科学研究院生态环境研究所,南京210029

出　　处：《水力发电学报》2024年第11期17-26,共10页Journal of Hydroelectric Engineering

基　　金：国家重点研发计划项目(2022YFC3203900);国家自然科学基金创新研究群体项目(52121006);长江水科学研究联合基金(U2240223)。

摘　　要：近年来,汉江中下游水质问题频发,且河道内环境流量尚未明确,严重威胁沿岸用水安全。为探明汉江中下游水质时空分布特征和河道环境流量,收集调研了2015—2019年汉江中下游黄家港、襄阳、皇庄、沙洋、潜江、仙桃和汉川等7个控制断面的pH、溶解氧、高锰酸盐指数、氨氮、总磷5项水质指标,基于水质单因子评价方法分析了水质时空变化特征。通过建立一维水动力-水质模型,构建了基于保障各控制断面水质的环境流量计算方法;根据不同水源的输入,计算了汉江中下游河道环境流量,并提出了保障方案。结果表明,汉江中下游丰水期氨氮和枯水期总磷在皇庄以下断面均未达到Ⅱ类水标准,氨氮沿程变化不明显,总磷从上游至下游逐渐升高。环境流量保障需结合引江济汉补水工程和丹江口下泄流量,丰水期和枯水期当引调长江水分别为500 m^(3)/s和350 m^(3)/s时,还需丹江口水库分别下泄214 m^(3)/s和315 m^(3)/s才能满足河道内的环境流量。研究为汉江中下游水质安全保障和合理分配丹江口水资源提供了参考。In recent years,water quality problems have occurred frequently in the middle and lower Hanjiang River and its environmental discharge is yet unclear,which threatens the safety of water use in the regions along it.To assess its water quality and environmental flows,this paper describes a single-factor method to evaluate their spatial and temporal distribution characteristics based on data observation.First,we collect field data for five water quality indicators-pH,dissolved oxygen,permanganate index,ammonia nitrogen,and total phosphorus-which were observed in 2015-2019 at seven control sections in the middle and lower reaches:Huangjiagang,Xiangyang,Huangzhuang,Shayang,Qianjiang,Xiantao,and Hanchuan.Then,we develop a one-dimensional hydrodynamic and water quality model and a corresponding method for calculating the environmental discharge that meets the requirement of water quality at each control section,and calculate the environmental discharges of the river using different water sources inputs.The results show two failure cases-ρ(NH3-N)in the high flow period,andρ(TP)in the low flow period,which are unable to meet the classⅡstandard at the section downstream of Huangzhuang.To guarantee the environmental discharge,the operation of Water Transfer Project from Yangtze River to Hanjiang River should be combined with the discharge from the Danjiangkou reservior.In the high and low flow periods,when a flow of 500 m^(3)/s or 350 m^(3)/s is diverted from Yangtze,the Danjiangkou reservoir should discharge at 214 m^(3)/s or 315 m^(3)/s respectively to meet the demand by the river environmental discharge.This study has explored the schemes and verified their improvement on water quality security and rational allocation of the reservoir water resources.

关 键 词：汉江中下游 水质评价 水动力-水质模型 环境流量 

分 类 号：X824[环境科学与工程—环境工程] X522