基流研究综述

Reviews on Base Flow Researches

水资源是人类生产、生活不可或缺的自然资源,随着水资源危机的加剧和水环境质量的恶化,水资源短缺已成为世界倍受关注的资源环境问题之一。基流在水安全、粮食安全、非点源污染评价,水资源评价和调查,水资源配置、工农业供水和降雨-径流关系模拟中有着重要的应用。本文首先对基流的定义进行了概述,系统的综述了基流产生机制及其影响因素;对于各类退水方程,从退水方程所反映的流域特性出发,阐明其优缺点、适用条件及应用情况,并对退水方程的建立进行了讨论。方程的参数多,则退水过程拟合得好,简单的线性方程拟合的效果不如多个线性方程组合的效果好,这在一定程度上说明了流域含水层出流的非线性。综合了多种基流划分方法,认为模型模拟和水量平衡法具有较强理论基础,图形法具有较大主观性,其精度依赖于操作者对于河道和地下水联系的了解情况。最后,本文对基流退水方程的建立,以及基流方程拟合中要注意的问题也进行了总结。

Base flow has important implications in water resources allocation, water security, food security, non point pollution assessment and investigation and water resource assessment. Base flow recession curves contain a lot of information related with hydro-settings. The paper first overviews the definitions of base flow. Then, base flow generation and loss mechanism and impact of hydrogeographical factors, rock kinds, climate condition, terrain, hydrologic condition and underlay ground were analyzed systematically. Impact of human activities, such as extraction of ground water, on different hydrogeographic settings, land use cover change （LUCC） and base flow was emphasized. Various kinds of base flow recession simulation methods, such as linear reservoir method, auto-regression simulation method, empirical function and method based on groundwater movement, were presented based on the characteristics of the basin; and the merits, demerits, and applied conditions of these function were illuminated. A series researches show non linear flow recession are more suitable than linear flow recession in recession simulation, which demonsfrates the non linear characteristics of out flow form aquifer. Base flow sepa- ration methods were reviewed. Above all, the water balance methods and the run-off simulation methods are sound based; but the graph method is subjective, which precision depends on applier＇s knowledge on the relation between ground water and river. In addition, some comments on the construction of the recession function are stated.