基于生态保护目标的武江流域生态流量定值研究

基于武江河道内的生物多样性和物种特征,提出适宜水力学指标法计算维持河道生态系统稳定性所需的生态流量。该方法以代表鱼类为生态保护目标,根据湿周、流速与流量的关系,求得鱼类不同生命周期的生态流量。结果表明:(1)越冬期鱼类所需流速下限为0.2m/s,产卵期平均流速为0.5～0.7m/s,肥育期流速范围为0.3～0.6m/s;(2)产卵期河道生态流量为116.3～150.3 m/s,越冬期与肥育期中后阶段生态流量为49.55 m~3/s;肥育期初期(8月)生态流量为71.97 m~3/s;(3)提出的适宜水力学指标法以维持鱼类良好的生境条件为生态保护目标,计算结果符合Tennant法河流生态用水标准,且更能反映河流的丰枯变化,可为流域水资源开发利用提供参考。     

城市河流基于鱼类栖息地需求的生态需水研究——以盘溪河为例

鱼类是水生生物群落食物链的顶层生物,适合作为河流生态需水计算的指示物种。以重庆主城北部的盘溪河为例,以平均流速、平均水深、水质参数等指标,2021年2-10月在盘溪河设置4个监测断面,进行水文、水质监测,并将鱼类产卵期和非产卵期适宜的水文条件(平均水深、平均流速)与生态需水量建立关系,根据鱼类栖息地需求对盘溪河生态需水进行评估。结果表明：盘溪河4个监测断面的最小生态需水量为1.70～10.68 m³/s,最大生态需水量为3.41～29.76 m³/s。雨季仅河流上游生态状况较好,最大生态需水能满足要求;枯季河流的生态状况较差,最小生态需水无法满足需求;同时,枯季和雨季监测断面的需氧量都能达标,但氨氮无法满足生态需水的水质要求。     

苏北平原区河流生态水位阈值计算方法适用性研究

针对平原区多数河流缺乏有效的流量资料的情况,研究适用于平原区河流生态水量阈值的计算方法具有重要现实意义。本文对比分析7Q10法、保证率法、湿周法、基于Tennant改进的生态水位法等4种代表性生态水量计算方法与结果,以水文节律、生态水位满足度为判别原则,评价了上述方法的适用性。分析结果显示：（1）在水文节律相应性方面,7Q10法、Q90法、湿周法计算的生态水位值为单一的特定值,无法反映水文节律的天然变化过程;（2）在生态满足度方面,7Q10法的多年平均生态水位的满足度最小;（3）基于Tennant法改进的生态水位法的水文节律模拟效果最好、生态水位满足度最高。研究表明：在选择的4种计算方法中,相较于7Q10法、Q90法及湿周法,基于Tennant法改进的生态水位法能较好地满足水文节律相应性和生态水位满足度原则,对平原区河流生态水位（阈值）计算具有一定的适用性。该研究成果可为苏北平原河网区流量资料缺乏型河流生态需水的确定和管理提供有益的参考。     

生态水文学:生态需水及其与流速因素的相互作用

本文研究涉及生态水文学中生态需水问题的一般认知。探讨了生态系统动态变化与水流驱动力因素之间的关系，重点探讨水流驱动因素中的关键指标—流速，通过分析流速与生态系统相互作用，从生态水文学动力因素出发估算生态需水；基于生态流速和水力半径，提出考虑河道内生态需水与水力因素关系的生态水力半径法，充分利用水生生物信息（鱼类产卵洄游流速）与河道信息（水位、流速、糙率等）估算河道内生态需水；归纳生态水力半径法在生态需水计算中的初步应用:考虑污染物降解耦合水量水质的生态需水计算、考虑鱼类等生物对流速要求的生态需水计算、考虑河道冲淤平衡的输沙需水量计算等方面。本文提出的生态流速研究既包括生物生长发育适宜的流速，又包括流速大小变化所涉及的许多动力因素，旨在延伸与扩展生态水文学的内涵与应用。     

生态水文学:生态需水及其与流速因素的相互作用

本文研究涉及生态水文学中生态需水问题的一般认知。探讨了生态系统动态变化与水流驱动力因素之间的关系，重点探讨水流驱动因素中的关键指标——流速，通过分析流速与生态系统相互作用，从生态水文学动力因素出发估算生态需水；基于生态流速和水力半径，提出考虑河道内生态需水与水力因素关系的生态水力半径法，充分利用水生生物信息（鱼类产卵洄游流速）与河道信息（水位、流速、糙率等）估算河道内生态需水；归纳生态水力半径法在生态需水计算中的初步应用：考虑污染物降解耦合水量水质的生态需水计算、考虑鱼类等生物对流速要求的生态需水计算、考虑河道冲淤平衡的输沙需水量计算等方面。本文提出的生态流速研究既包括生物生长发育适宜的流速，又包括流速大小变化所涉及的许多动力因素，旨在延伸与扩展生态水文学的内涵与应用。     

河流生态需水计算及空间满足率分析——以济南市为例

随着经济社会发展,用水量增大,导致河流生态需水常常得不到满足。生态需水作为河流生态系统的重要指标,对维持生态系统可持续具有关键作用。充分考虑河流生态系统的生物需求,采用食物网模型(Ecopath)识别了鱼类关键物种,在此基础上确定生态流速,结合无人机反演河段大断面,采用改进的生态水力半径法(AEHRA)计算生态需水,在生态需水计算结果的基础上采用River2D模型模拟河段流量,进而计算河段的生态需水满足率。计算结果表明汛期各河段生态需水基本能够得到满足,非汛期绝大多数河段生态需水不能得到满足,并且满足率极低,导致生态系统健康无法维持。因此,应加强非汛期的河流生态调度以满足河流生态需水。研究提出的计算河段生态需水的新方法可为水生态修复提供方法基础,研究结果可为济南市河流水生态修复与管理提供重要的科学依据。     

基于多种水文学法分析大汶河干流生态基流

分析估算大汶河干流生态基流量是解决其生态环境恶化问题的基础。根据大汶口水文站历年径流资料,采用Tennant法、基流比例法等多种水文学法推求生态基流值,通过计算不同水平年的年际、年内不同水期和鱼类产卵育幼期生态基流量,在分析了各种方法应用区间和适用条件的基础上,综合考虑拦蓄引水工程和河道生态基流缺失等因素确定了大汶河干流生态基流。认为:基流量为1.1~14.1m~3·s~(-1)能更好地代表该区域不同水期的河道生态需水,经分析其生态基流保障程度基本达到90%以上,说明本文采取的方法在计算代表北方季节性、雨洪型河流的生态基流时是合理、可行性的,并进一步提出了生态基流的保障措施。     

清江最小和适宜生态流量的计算与评价

确定河流生态流量既是保护河流生态系统的根本举措,又是开展梯级水库生态调度的重要依据.基于逐月最小生态流量法、RVA法、DC法和逐月频率法,分别计算了清江水布垭和隔河岩水库坝址的生态流量过程,并采用Tennant法对结果进行合理性分析.结果表明:RVA法优于逐月最小生态流量法和DC法,计算得到的最小生态流量在一般用水期和...     

资水河道内生态需水量研究

河道取水、水库蓄水、跨流域调水等水资源开发方式改变着河流自然水文情势,保留适宜的河道内生态需水能够维持河流所需的自净扩散能力,维系河势稳定,保护和维持河湖生态系统结构和功能的完整性。本文采用Qp法、田纳特法(Tennant Method)、逐月频率计算法、逐月最小生态径流计算方法、最小月平均实测径流法5种方法对资水河道内生态需水量进行计算分析和比较。结果表明逐月频率计算法结果较为合理,设定资水逐月河道内生态需水量,确定年生态需水量应为112.1×10~8m~3。为政府部门提供了更具操作性的分时段水量控制参考标准。     

水库对河流径流过程的影响分析——以故县水库为例

水流情势是河流生境的主要定因素之一,影响水生生物群落的组成和多样性.水利工程会改变河流的天然水流情势.本文基于Richter提出的生态水文指标体系,分析了洛河流域长水站的生态水文特征变化.结果显示总体上故县水利枢纽对河流天然径流的影响程度较大.     

河道内生态需水估算方法及其评述

针对目前常用的水文指标法、水力学法、整体分析法和栖息地法,4大类河道内生态需水估算方法就其适用条件和范围作了相关评述。认为不同的估算方法有其不同的适用条件和范围,在实际应用中需根据已有资料条件和研究的目的,选用不同的计算方法。     

Calculation of Environment Flow and Analysis of Spatial Environment flow Satisfaction Rate: A Case Study of Ji'nan City

With the socio-economic development, water demand has increased, resulting in river environment flow often not being met. As an important indicator of river ecosystem, environment flow plays a key role in maintaining the sustainability of the ecosystem. This study fully considered the biological needs of river ecosystems, used food web models (Ecopath) to identify key species of fish, determined the ecological flow velocity, combined the river sections, and used the Adapted Ecological Hydraulic Radius Method (AEHRA) to calculate the environment flow. Based on the calculation results of the environment flow, the River2D model was used to simulate the river flow, and the environment flow satisfaction rate of the river was calculated. The calculation results show that the environment flow of each river in the flood season can be satisfied, and the environment flow of most rivers in the non-flood season cannot be satisfied, and the satisfaction rate is extremely low, which causes the ecosystem health to be destroyed. Therefore, ecological regulation of rivers during non-flood seasons should be strengthened to meet river environment flow. The new method for calculating the environment flow of the river provided in this paper can provide a method for aquatic ecological restoration, and the research results can provide important scientific basis for the aquatic ecological restoration and management of rivers in Jinan.     

基于概率加权FDC法的河流生态需水量计算

基于河流流量过程的年内和年际变化特性,提出了一种计算河道内生态需水量的概率加权FDC(流量历时曲线)方法。该方法基于年均流量系列和逐月月均流量系列的特定频率,将年均流量系列和逐月月均流量系列划分为丰、平、枯组,通过建立年月丰枯遭遇的Copula联合分布函数,求得不同典型年下各月丰平枯的条件概率,将其作为概率权重,得到不同典型年生态需水过程的计算公式,改进了FDC法,计算出了丰、平、枯典型年的年内生态需水过程。以屏山站为例,将计算结果与Tennant法、逐月最小生态径流法、年内展布法和改进FDC法进行了对比分析。计算结果表明:由此方法得到的生态流量在Tennant法评价体系中,能很好的满足河道的生态需水要求,且较好地体现了河流径流的年内及年际变化过程,符合实际情况。     

Impact of hydrogeomorphic processes on ecological functions of brown trout habits

In recent decades, due to river regulations and their impact on river morphology, brown trout populations have been declining along Lar River downstream of Lar Dam located near Tehran, Iran. Considering the recent water scarcity in the country, development of river habitat assessment models seems necessary. Therefore, in this research, an analytically applied approach is adopted to evaluate brown trout habitat by creating a relation among the hydrologic, hydraulic, geomorphic and ecologic processes. After field survey, dimensionless shear stress of the stream flow thresholds including environmental flow, bankfull flow, surface and subsurface sediment flow thresholds was calculated for Lar, Dalichay and Sefidab Rivers using Shields formula. Then, by considering the dimensionless shear stress ranges of the stream flow thresholds, functional flows ranges and duration were calculated together with ecological efficiency of the cross sections. In addition, effects of annual water yield and entrenchment ratio of the cross sections on habitat functionality were also worked out as a result of which an exponential interaction was developed between the dimensionless shear stress and discharge. Results show that an increase in functional flows ranges and duration, together with rising of ecological efficiency, is directly proportional to an increase in median bed sediment size, entrenchment ratio and annual water yield. Therefore, flow regime, cross-sectional geometry, water-surface slope and bed sediment size could be effective on the ecological functions of the brown trout’s life cycle and functionality of river flow.     

Assessment of ecological instream flow requirements under climate change <Emphasis Type="Italic">Pseudorasbora parva</Emphasis>

Climate change alters ecohydrological processes on different temporal and spatial scales. The aim of this study was to estimate ecological instream flow requirements (EIFR) under climate change impacts and to ascertain optimum flow magnitude to maintain the health of river ecosystems. We used the Mann–Kendall test, the River2D Hydrodynamic model, and the frequency-weighted usable area (FWUA) model on an annual scale in the Juma River to investigate changes in EIFRs caused by climate change. Findings indicated that: (1) between 1956 and 2005, annual instream flow in the Juma River exhibited an abrupt downward trend (in 1981); (2) variation in instream flow governed the area of available fish habitat, and degrees of change for low flow threshold values and low and high FWUA threshold almost exclusively occurred in descending sequential order from winter, spring, autumn, and summer; (3) changes in hydrological regimes influenced both the quantity and quality of physical habitat area, contributing greater to quality than to the distribution of area of physical habitat for Pseudorasbora parva. Climate change, reflected in the changes in EIFR and the area of optimum physical habitat, has dramatically influenced ecological structure and function, even in the small river system investigated for this study. Findings indicated that more rational measures should be put into practice to help address climate change.     

基于生态流量阈值的河流水文健康演变定量归因

环境变化改变了河流水文情势,影响了河流的生态系统健康,亟需开展变化环境下河流水文健康演变定量归因方法研究。选取北方半干旱地区老哈河流域为研究区,依据流域内3个水文站、17个雨量站和6个气象站1964—2016年数据,基于可变下渗容量模型还原河流的天然流量序列;采用概率密度法计算河流生态流量,基于生态流量阈值推求河流水文健康等级;基于"观测-模拟"对比分析法,定量分离气候变化和人类活动对河流水文健康情势的影响。结果表明:人类活动是甸子和太平庄子流域自1980年以来河流水文健康情势退化的主要原因,其贡献率分别为86.9%和87.9%;大面积农业灌溉用水引起地表径流下降以及水利工程改变天然水文情势,影响了河流水文健康情势;90年代降水量较为充沛,研究流域受人类活动影响程度较小,河流水文健康等级维持在较高的水平。综合生态流量阈值和"观测-模拟"对比分析方法可定量识别河流水文健康情势演变原因,为适应环境变化的河流健康管理提供科学依据。     

Spatial variation in fluvial hydraulics with major bed erosion zone: a study of Kharsoti river of India in the post monsoon period

This study attempts to assess the spatial variation of fluvial hydraulics with special emphasis on hydrological components at upper, middle and lower part of the Kharsoti river basin. The study encompasses the scenario of a micro bedrock river of India in the post monsoon period. This paper includes the study of hydrological components such as discharge, velocity, shear stress, stream power, specific stream power, width-depth relation and roughness and its interrelationships with different parts of the river basin with related mathematical equations and identification of major river bed erosive zones coupled with geo-hydrological components with geological explanation. Kharsoti is a typical example of rejuvenated antecedent tributary river of Subarnarekha River basin in Chota Nagpur Plateau. It is necessary to give a new threshold to the quantitative methods regarding the fluvial hydraulic studies under a systematic scientific geographical and hydrological background. The results also involve some specific techniques, equations and GIS mapping. The result of this study will help to open the scenario of hydraulics of a micro river basin in a contemporary method.     

The application of range of variability approach to the assessment of a check dam on riverine habitat alteration

This report uses the intermediate disturbance hypothesis to assess the influence of constructing a check dam on river environment. HEC-HMS and HEC-RAS programs were used to generate hydraulic parameters such as flow discharge, water depth, velocity, water surface width and sediment discharge. Indicators of hydrologic alteration (IHA) and indicator of habitat alteration (IHabA) were used to evaluate the flow and habitat conditions before and after check dam construction. The range of variability approach was used to calculate the degree of hydrologic alteration for each IHA, degree of habitat alteration and overall alteration for IHabA. Variability of river habitats before and after check dam construction was contrasted. Alteration became larger the closer to the dam body. An assessment method for check dam construction is offered which does not require ecological investigation data and combines ecology concepts and hydraulics.     

基于物理栖息地模拟的河道内生态流量研究

结合物理栖息地模拟模型的水力学与栖息地模型,以黄河干流兰州-石嘴山河段为研究样区及该河段的关键鱼种黄河鲤鱼为对象物种,以流速及水深二水力学因子进行研究,推求该研究样区兰州、安宁渡、下河沿、青铜峡和石嘴山五断面对象物种的流量与权重可使用面积的关系。通过对上述各断面1975-1985年汛前共11年生态、水文及断面资料的分析计算,归纳出研究断面汛前适合的生态流量分别为195、220、220、220、175 m3/s,计算结果在Tennant法界定的生态流量范围之内。