水文指数法确定河流生态需水

河流水文情势是河流生态系统的自然动力学特征，而径流情势是水文情势的重要特征。根据生物种群和环境因子之间的关系，从反映河流水文情势的径流情势中筛选水文指数，构建河流生态需水的计算方法。从径流情势中提取流量、频率、历时、发生时间、变化率5个水文指数确定河流生态需水。采用水文指数法实际计算了广东省河流的生态需水，并和Tennant法进行比较分析，结果表明，采用水文指数法计算河流生态需水是可行的。     

面向河流生态完整性的黄河下游生态需水过程研究

提供适宜的生态流量对维护河流健康和支撑人类社会发展具有重要意义。尽管栖息地模拟法物理机制清晰、应用广泛,但对生物群落考虑不足、生命节律信号缺失等问题长期存在。以维护河流土著生物群落完整性为目标,本文将天然水文情势作为参照系统,结合栖息地模拟与水文参照系统特征值,建立了一种面向河流生态完整性的生态需水过程评估方法,兼顾指示物种生存繁衍和土著生物群落基本生存。黄河下游利津断面评估结果显示:利津断面年最小生态需水量119亿m~3,适宜生态需水量130～137亿m~3,涨水期需提供1～2次持续时间不低于7 d、流量不低于1220 m~3/s的高流量脉冲。对比历史实测流量过程与本文生态需水成果,发现利津断面水量充足,但流量过程不满足生态需求。黄河需加强水库群调度,协调径流年际和年内分布,塑造适宜的生态流量过程,并适时塑造高流量脉冲。     

黄河河口生态需水研究进展与展望

黄河河口生态需水包括河流生态需水、湿地生态需水和近海生态需水。系统梳理了近20年来黄河河口生态需水目标、需水类别和需水量计算结果;结合黄河河口演变特点,提出生态需水研究的重点和主要方向。河流生态需水以满足重要渔业物种生境为主,重点研究指示物种对天然径流量节律的响应特征,量化水文-生态响应关系,在某种程度上恢复自然水文情势的生态功能。湿地生态需水应深入研究植被、土壤、水体的水盐平衡和蒸散发规律,从植被和鸟类生态位的合理设计以及生物多样性维持出发构建生态系统结构,确定湿地合理规模。近海生态需水应研究入海冲淡水对渔业物种低盐产卵育幼场的塑造和维持机制,以及重要渔业物种习性、适宜营养盐水平与磷酸盐输送扩散机制。小浪底水库运用以来,利津断面径流量满足已有生态需水径流量各项研究成果要求的年份比例为37%～58%,春季经流过程经常缺乏流量脉冲。初步分析以湿地、河道鱼类和近海鱼类为主要目标的全年生态需水量为86亿m~3,径流过程需要阶段性场次洪水。建议对小浪底水库调度方案进行多年优化调整,兼顾春季流量脉冲的塑造,在更大程度上满足河口生态需求。     

考虑水文变异的漾弓江干流生态流量计算

气候和人类活动改变了河道径流的一致性,因此考虑水文变异的河流生态流量计算对保护河流生态系统具有现实意义。以云南省漾弓江为例,采用4种时间序列检验法对三义断面和金河断面1959～2019年径流序列进行突变检验,利用平水年逐月最小生态径流法和逐月频率年内展布法计算不同时期的生态流量,并用改进的Tennant法进行评价。结果表明：变异年份确定为1997年和2011年,计算得到两断面在天然状态、次天然状态、现状和不考虑水文变异条件下最小和适宜的生态流量,次天然状态的生态流量更利好河流生态系统,现状河流生态系统遭到了一定的破坏,不考虑变异的生态径流过程与天然状态接近。生态流量的确定应更多考虑天然状态的生态径流过程并参考次天然状态。最后提出了2020～2030年漾弓江生态流量保障工作目标及建议。     

中国分区域生态需水研究

概略介绍了国家“十五”科技攻关重大课题“中国分区域生态用水标准研究”成果。从基础理论、应用技术、管理决策三个层面．研究提出一系列相互关联的关键技术，形成符合我国实际的生态需水理论与计算方法体系。提出了水循环生态效应理论。建立了区域生态需水类型划分的三大准则，为区域生态需水计算奠定理论基础。提出了多参数河流生态需水理论，建立了多参数全过程河道生态需水计算方法。提出了湿地生态水文结构理论，建立了湿地生态水文结构模型计算方法。以生态需水特征值建立生态用水分析机制，提出处理经济用水与生态用水关系的准则；以生态河流的标准为基础，建立河流生态调度管理机制。     

水循环生态效应与区域生态需水类型

本文从水循环基础理论出发，通过分析水文循环过程的能量转化规律，揭示水循环生态效应变化机理，提出判断生态系统演变与水循环关系的基本准则，以此区分生态需水类型。降雨分布决定了内陆河干旱区与外流域生态需水的基本格局，降雨径流关系的稳定性决定了半湿润半干旱区与湿润地区生态需水的差异，依附于地表水体的水生态系统随水量发生变化，其临界点取决于径流量的丰沛程度。我国区域生态需水类型可分为：西北内陆河干旱区植被生态系统需水；半湿润半干旱区河湖与地下水连通系统的整体生态需水；北方湿润地区河湖水生态系统需水；南方湿润地区维持河流生态服务功能最大化的流量。     

辽宁省河流生态流量计算方法与分析

传统河流生态流量计算局限于水文数据分析,没有与河流的生态分区、分期及生态系统的保护目标联系起来。文章根据辽宁省实际情况,提出辽宁省河流生态需水分区、分期、分类的划定原则,生态流量计算要素的确定方法、各种生态流量计算方法的适用条件及选取等。以辽河为例,计算辽河干流生态流量,结果表明计算成果合理,满足辽河生态需水要求,可为辽宁省河流生态流量计算工作提供依据。     

基于生态系统分析的河道最小生态需水计算方法研究(Ⅰ)

研究了河道生态系统的水文与地形子系统的最小生态需水，提出计算河道水体最小生态需水的方法——水文与河道形态分析法，并建立了计算方法体系．水文与河床形态分析法的基本思想是用尽量少的水维持尽量多的河流特征和功能，并将河流特征和功能维持在一定的水平，以维持河流的生命．还研究了水文、地形和生物子系统，提出计算该子系统最小生态需水的方法——生物空间最小需求法．生物空间最小需求法的基本思想是以鱼类为指示生物，从鱼类对生存空间的最小需求来确定最小生态需水．采用上述两种方法计算了淮河流域颍河周口水文站断面的最小生态流量，为7m^3／s，占多年平均天然流量的5．6％．     

随机流量历时曲线及其在生态流量计算中的应用

河流生态流量是生态水文研究的重要部分,其相关理论和计算方法一直是当前国内外学者研究的热点。尝试基于随机流量历时曲线计算河流系统的生态流量,给出了维持河流生态系统健康各等级流量的历时或频率,并进而估算生态需水,为流域水资源的合理配置提供参考。以松花江干流8个断面为例,研究结果表明,在随机流量历时曲线上基于Q97,10估算得到的最小生态需水量与7Q10法所得到的需水量数值接近且相关性好,而基于保证率P=75%的随机流量历时曲线可求得河道的适宜生态需水量。研究区内嫩江流域大赉断面以上河段最小生态需水量、适宜生态需水量分别为4.6亿m3和99.1亿m3,约占总水资源量的2.6%和56.2%;松花江下游佳木斯控制断面以上河道最小生态需水量、适宜生态需水量分别为79.1亿m3和388.9亿m3,约占总水资源量的13.4%和65.7%。     

保障城市生态需水应注意的几个问题

城市生态需水是指为满足生态系统正常运行并为城市提供正常生态服务的功能性需水，包括生物生态与环境需水、水文循环需水、蒸发蒸腾需水、景观需水、城市气候调节需水、环境净化和地壤及空气涵养需水，下游径流及地下补给需水等。[第一段]     

3流4D连通性生态模型

为了改善河湖水系间的物理连通关系和水力关系,从理论上系统描述河湖水系连通性特征概况,回顾了连通性相关生态模型的发展沿革,分析了河流在三个几何维度上的连通性特征,并阐述了以水为载体的物质流、物种流和信息流在三维空间流动的生态影响。在此基础上,从生态系统的结构、功能和过程出发,提出了3流4D连通性生态模型及其参数和判据,用以系统、整体地概括描述河湖水系连通性的生态学机理。结果表明,3流4D连通性生态模型一方面可以通过建立参照系统和分级系统对河湖水系连通性现状进行评估;另一方面可以对连通的生态过程进行仿真模拟计算,对河湖水系连通性特征进行模拟和分析,促使河湖水体恢复天然的水文及其伴随过程节律及生态系统功能,提高水生态修复工程的科学性和可靠性,达到改善水生态系统整体性、保障生态系统服务功能的目的。     

A collaborative and adaptive process for developing environmental flow recommendations

Many river restoration projects are focusing on restoring environmental flow regimes to improve ecosystem health in rivers that have been developed for water supply, hydropower generation, flood control, navigation, and other purposes. In efforts to prevent future ecological damage, water supply planners in some parts of the world are beginning to address the water needs of river ecosystems proactively by reserving some portion of river flows for ecosystem support. These restorative and protective actions require development of scientifically credible estimates of environmental flow needs. This paper describes an adaptive, inter‐disciplinary, science‐based process for developing environmental flow recommendations. It has been designed for use in a variety of water management activities, including flow restoration projects, and can be tailored according to available time and resources for determining environmental flow needs. The five‐step process includes: (1) an orientation meeting; (2) a literature review and summary of existing knowledge about flow‐dependent biota and ecological processes of concern; (3) a workshop to develop ecological objectives and initial flow recommendations, and identify key information gaps; (4) implementation of the flow recommendations on a trial basis to test hypotheses and reduce uncertainties; and (5) monitoring system response and conducting further research as warranted. A range of recommended flows are developed for the low flows in each month, high flow pulses throughout the year, and floods with targeted inter‐annual frequencies. We describe an application of this process to the Savannah River, in which the resultant flow recommendations were incorporated into a comprehensive river basin planning process conducted by the Corps of Engineers, and used to initiate the adaptive management of Thurmond Dam. Copyright © 2006 John Wiley & Sons, Ltd.     

How much groundwater can we pump and protect environmental flows through time? Presumptive standards for conjunctive management of aquifers and rivers

Groundwater is a critically important source of water for river, wetland, lake, and terrestrial ecosystems, yet most frameworks for assessing environmental flows have ignored or not explicitly included the potential impacts of groundwater pumping on environmental flows. After assessing the processes and existing policies for protecting streamflow depletion from groundwater pumping, we argue that a new groundwater presumptive standard is critical as a placeholder to protect environmental flows in rivers lacking detailed assessments. We thus extend the previous presumptive standard to groundwater pumping, a different and important driver of changes to streamflow. We suggest that “high levels of ecological protection will be provided if groundwater pumping decreases monthly natural baseflow by less than 10% through time.” The presumptive standard is intended to be a critical placeholder only where detailed scientific assessments of environmental flow needs cannot be undertaken in the near term. We also suggest a new metric, the environmental flow response time, that allows water managers to quantify the timescales of the impacts of groundwater pumping on the loss or gain of environmental flows.     

河道的生态功能及水文过程的生态效应

对河流生态功能的认识是评价水利工程建设生态影响的基础，水文过程足影响河流生态系统的控制性变量。本文介绍了河流的栖息地、过滤和屏蔽、通道、源汇等方面的生态功能，水文过程与生态环境和生物多样性的关系，以及流量与频率变化、来水时间、变化的速度、来水时间长短等水文特征变量的生态效应。     

基于生态水文学法的湘江生态流量研究

河流生态流量是维持河流生态系统健康的重要条件。选取湘江(湘潭)作为控制性断面,采用生态流量年内展布法和IHA-RVA法计算河道最小和适宜生态流量,并以Tennant法进行合理性验证。结果表明:最小生态流量为639.6 m~3/s,占多年平均天然流量的32.2%;适宜生态流量为983.4 m~3/s,占多年平均天然流量的49.5%。该方法计算的生态流量结果能够满足河流生态目标的需求,与天然河流年内丰枯变化状态相吻合,计算结果较为合理。研究可为湘江湘潭的水资源管理以及生态系统的保护和恢复提供科学依据。     

西辽河流域地表地下复合生态需水研究

针对西辽河流域水资源开发利用强度大、地下水超采、平原河流断流等严重的生态问题,将河道生态流量与地下水位作为整体来考虑,系统地确定复合型生态需水。首先以河道为对象,计算了最小生态流量、适宜生态流量;其次,以河岸为对象,以地下水与河流补排关系和避免盐碱化为依据,以河道生态流量为边界条件,确定了支撑河道生态需水的生态地下水位。西辽河流域的地表地下复合生态需水指标由河道最小生态流量和适宜生态流量以及地下生态水位构成,可为流域水资源规划和管理、生态系统保护和恢复提供科学依据。     

Competing Freshwater and Ecological Services in the River Basin Perspective

Abstract

A river basin approach focusing on upstream/downstream conflicts of interest has to involve attention both to the services that water itself provides to society, and to water-related ecosystem services, terrestrial as well as aquatic. Besides “blue water” flow, i.e., liquid water flows in rivers and aquifers, attention has to be paid to “green water” flow, i.e., the water vapor flow involved in plant production. Basically, the rainfall over the basin is what must be shared between those upstream and those downstream. To satisfy societal needs, humans have to manipulate various landscape elements. These manipulations—due to fundamental water functions—will produce side effects (“environmental impacts”). In an integrated basin approach, it is necessary to include side effects of water-impacting land use conversions upstream on water-dependent activities and ecosystem health downstream. A fundamental challenge is therefore to find ways and mechanisms by which reconciliation can be developed among land use, water use, and ecosystem health, and between upstream and downstream activities     

Stakeholder‐enhanced environmental flow assessment: The Rufiji Basin case study in Tanzania

Environmental flows are now a standard part of sustainable water management globally but are only rarely implemented. One reason may be insufficient engagement of stakeholders and their priority outcomes in the environmental flow‐setting process. A recent environmental flow assessment (EFA) in the Kilombero basin of the Rufiji River in Tanzania concentrated on a broad‐based investigation of stakeholders' use and perceptions of the ecosystem services provided by the river as a framework for the assessment of flow regimes that would maintain them. The EFA process generally followed the Building Block Methodology but within an enhanced stakeholder engagement framework. Engagement began with the involvement of institutional stakeholders to explain the purpose of the EFA and to elicit their priority outcomes. Extensive interactions with direct‐use stakeholders followed to investigate their uses of and priorities for the rivers. Results were used by the EFA specialist team in choosing flow indicators and defining measurable environmental objectives. The specialists then met to reach a consensus of the flow requirements. The EFA results were lastly reported back to stakeholders. During the Kilombero EFA, we learned that stakeholders at all levels have a good awareness of the natural services provided by a healthy river and can contribute to the setting of environmental objectives for the rivers and floodplain. These can be factored into the biophysical assessments of river flows required to maintain habitats, processes, water quality, and biodiversity. It is therefore important to allocate significant resources to stakeholder engagement. It now remains to be seen if enhanced stakeholder engagement, including the increased understanding and capacity built among all stakeholders, will increase support for the implementation of the recommended flows.     

天门市中小河流水生态环境评价与保护

为了掌握湖北省天门市水环境质量状况,制定水生态环境恢复和保护规划,选择该市主要河湖典型断面进行了水质监测分析。分析结果表明,天门市城区河流、湖泊、沟渠的水质均为劣Ⅴ类,水生态系统遭受破坏,水体的污染已经成为制约当地社会经济发展的制约因素。根据对该市水环境状况的分析,制定了水污染控制规划、城市生态水网规划、城市水体生态修复与滨水景观规划、河道综合整治规划以及水生态管理保障体系建设规划。     

Incorporation of environmental flows in water allocation in Texas

An institutional framework and supporting water availability modelling capabilities are presented for integrating ecological needs into water resources management. Concepts illustrated by the Texas experience are relevant worldwide. Environmental flow standards with subsistence, base, in-bank pulse and over-bank flow components are established through a legislatively mandated process by stakeholder committees and science teams working in collaboration with government agencies. The flow standards incorporate ecosystem needs into water allocation and associated water availability modelling. Recognizing the complexities of defining and preserving environmental stream flows, expedited present action is combined with an adaptive management process for future improvements.