River Health Assessment Research Articles

Towards developing a river health index

A number of physical, chemical and biological water quality parameters are measured to understand quality conditions of a riverine environment. Various aggregation techniques have been used to reflect the combined effect of the existing or proposed quality levels. Water Quality Index (WQI) has been developed primarily for fresh water environments. Organic pollutants are not considered in many WQIs because analyses of organics are rather expensive. In general, fecal coliform and total coliform counts are measured to reflect biological contamination of water. With growing consensus on considering rivers as ecological entity, rather than merely a source of water for human consumptions, the emphasis is changing from water quality index (WQI) to River Health Index (RHI). As benthic macroinvertebrate species are differentially sensitive to many biotic and abiotic factors in river environment, macroinvertebrate community structure has commonly been used as indicator of stream water condition. A number of river health assessment methodologies have been proposed in past and several indices such as Ecological Health Index (EHI), Ecological Quality Index (EQI), Overall Index of Pollution (OIP) and River Pollution Index (RPI) have been developed using water quality variables and aquatic species for evaluating the ecological health of river systems. This paper attempts to review and summarize some of these indices with particular emphasis on measurable parameters included in such formulations. The analyses suggest that with sufficient scientific experience and understanding in this area, it is possible to define a River Health Index (RHI) by including algae, macroinvertebrates and fish species as measurable parameters along with routine physico-chemical characteristics of river water. One such formulation on RHI has been proposed by the authors in this paper. The novelty of the proposed formulation include simple calculations and presentation of RHI value on 0–100 scale. The biological indices used in ACEDP (2011) requires biological expertise which is not normally available with water resource managers. Hence species identification and counting based simple biotic indices have been proposed so that it can be easily done by non experts also. River Health Level (RHL) can be categorized as ‘critical’ or ‘excellent’ based on RHI value <=20 or >80. Thus RHI values can be used to identify the healthy or unhealthy stretches of the river. RHI can serve as scientific tool to assess the current status, need and effectiveness of any intervention required to improve the condition of the river. Application of this RHI formulation on main stream of river Ganga (India) is under study.

Quantitative response of leaf‐litter decomposition rate to water abstraction in a gradient: Implications for environmental flow management

AbstractWater abstraction significantly impacts streams and rivers, in turn affecting ecosystem structure and function. Previous studies have mostly focused on the response of structural indicators (e.g., invertebrate community composition) to water abstraction but have often neglected the indicators of ecosystem processes (e.g., decomposition rates). In this study, we investigated the relationship of leaf‐litter decomposition rate (k) with flow reduction in a manipulated ecosystem experiment. The flow reduction rate across our experimental reaches was about 25%. The results showed that water diversion significantly reduced the discharge, width and depth of the stream, but did not affect water quality. The leaf‐litter decomposition rate varied from 0.001day‐1 to 0.026 day‐1 and decreased along with flow reduction. The results elucidate the impact of water abstraction on the decomposition of leaf‐litter in streams. A quantitative relationship between the flow rate (Q) and the decomposition rate (k), mathematically expressed as k = 0.0231 exp(ΔQ1.232), was derived. Furthermore, a framework was developed for setting the minimum environmental flow based on the assessment of river health by using leaf‐litter processing rates.

Assessing the ecological health of rivers when they are dry

Rivers and streams that dry up are found on every continent, and can form a large proportion of river networks. When rivers are dry, traditional indicators of river health – such as aquatic macroinvertebrates, fish or water quality – cannot be measured. Aquatic health indicators are widely used to assess wetted habitats, but currently no universally applicable indicators have been developed or applied to assess dry riverbed health. Dry riverbeds are often the ‘typical’ state of many intermittent rivers and streams; however, the ecological health of these habitats is rarely, if ever, assessed in monitoring programs. Resource managers have called for indicators of intermittent river health during the dry phase. The use of terrestrial invertebrate biota (e.g. ants, beetles, and spiders) as indicators in this study provides a novel solution to assessing rivers when they are dry.We developed a conceptual model of human-induced stressors (i.e. disturbance by livestock and feral mammals) on dry riverbed biota, which guided the selection of potential health indicators. Livestock and feral mammals are one of the most significant stressors on riverine ecosystems in Queensland, and impact riverbeds by altering the substrate through compaction, rooting and pugging. We trialled the use of metrics of terrestrial invertebrate assemblages as indicators of dry riverbed health in four Australian dryland catchments: Bulloo, Paroo, Warrego and Nebine. We used quantile regression and found that terrestrial invertebrate communities responded negatively (and significantly, p<0.05) to a gradient of disturbance, defined by on-the-ground field measurements of livestock and feral mammal impacts. This response to stressors was predicted by the initial conceptual model.We conclude that terrestrial invertebrates in this study are suitable indicators of dry riverbed health, as they are impacted by disturbance from livestock and feral mammals. They can be used in the same way that indicators, such as aquatic macroinvertebrates, are traditionally used to assess river health. We also successfully combined indicators of wet and dry habitats to provide a holistic assessment of the health of intermittent river ecosystems incorporating all sections of the river network. We suggest that this approach should be adopted by other river health monitoring programs in rivers around the world.

An integrated method for waterway health assessment: a case in the Jingjiang reach of the Yangtze River, China

More and more importance has been placed on inland navigation due to the low costs, environmental friendliness, low use of energy per ton kilometer, and high degree of safety of this mode of transportation. A river typically serves multiple functions or provides multiple services in addition to inland navigation. River health assessment for waterways requires that the navigation function be developed in harmony with the other river functions. In the case of the Jingjiang waterway in the middle reaches of the Yangtze River, river functions or services were analyzed, and an integrated method for waterway health assessment was proposed. Using this method, a hierarchical assessment indicator system was constructed, the weights for those indicators contributing to their parent indicators were obtained via the Analytical Hierarchy Process (AHP), and the Waterway Health Index (WHIc), a multimetric index reflecting the effect of the cask short board, was proposed alongside the commonly used linearly weighted summation index (WHI). Waterway health changes in the Jingjiang Reach were assessed in the context of a waterway regulation project. The results highlight potential mutual improvement between the ecosystem health and navigation functions using certain waterway regulation approaches.

Predictive model based multimetric index of macroinvertebrates for river health assessment

Improving the stability of integrity of biotic index (IBI; i.e., multi-metric indices, MMI) across temporal and spatial scales is one of the most important issues in water ecosystem integrity bioassessment and water environment management. Using datasets of field-based macroinvertebrate and physicochemical variables and GIS-based natural predictors (e.g., geomorphology and climate) and land use variables collected at 227 river sites from 2004 to 2011 across the Zhejiang Province, China, we used random forests (RF) to adjust the effects of natural variations at temporal and spatial scales on macroinvertebrate metrics. We then developed natural variations adjusted (predictive) and unadjusted (null) MMIs and compared performance between them. The core me-trics selected for predictive and null MMIs were different from each other, and natural variations within core metrics in predictive MMI explained by RF models ranged between 11.4% and 61.2%. The predictive MMI was more precise and accurate, but less responsive and sensitive than null MMI. The multivariate nearest-neighbor test determined that 9 test sites and 1 most degraded site were flagged outside of the environmental space of the reference site network. We found that combination of predictive MMI developed by using predictive model and the nearest-neighbor test performed best and decreased risks of inferring type I (designating a water body as being in poor biological condition, when it was actually in good condition) and type II (designating a water body as being in good biological condition, when it was actually in poor condition) errors. Our results provided an effective method to improve the stability and performance of integrity of biotic index.

Water Quality Interaction with Alkaline Phosphatase in the Ganga River: Implications for River Health.

Carbon, nitrogen and phosphorus inputs through atmospheric deposition, surface runoff and point sources were measured in the Ganga River along a gradient of increasing human pressure. Productivity variables (chlorophyll a, gross primary productivity, biogenic silica and autotrophic index) and heterotrophy (respiration, substrate induced respiration, biological oxygen demand and fluorescein diacetate hydrolysis) showed positive relationships with these inputs. Alkaline phosphatase (AP), however, showed an opposite trend. Because AP is negatively influenced by available P, and eutrophy generates a feedback on P fertilization, the study implies that the alkaline phosphatase can be used as a high quality criterion for assessing river health.

Application of Entropy Method in River Health Evaluation Based on Aquatic Ecological Function Regionalization

With the implementation of water environment management in key basins in China, the monitoring and evaluation system of basins are in urgent need of innovation and upgrading. In view of the heavy workload of existing evaluation methods and the cumbersome calculation of multi-factor weighting method, the idea of using entroy method to assess river health based on aquatic ecological function regionalization was put forward. According to the monitoring data of songhua river in the year of 2011-2015, the entropy weight method was used to calculate the weight of 9 evaluation factors of 29 monitoring sections, and the river health assessment was carried out. In the study area, the river health status of the biodiversity conservation function area (4.111 point) was good, the water conservation function area (3.371 point), the habitat maintenance functional area (3.262 point), the agricultural production maintenance functional area (3.695 point) and the urban supporting functional area (3.399 point) was light pollution.

Geomorphic diversity as a river management tool and its application to the Ganga River, India

AbstractUnderstanding of geomorphic processes and the determination of geomorphic diversity in catchments are prerequisites for the sustainable rehabilitation of river systems and for reach‐scale assessment of river health. The Ganga River system in India is a large, complex system consisting of several long tributaries, some &gt;1,000 km, originating from 2 distinct hinterlands—the Himalaya to the north and the cratons to the south. Traversing through a diverse climatic regime across the Plain and through precipitation zones ranging from 600 mm/year near Delhi to 1,200 mm/year in the eastern plains, the Ganga River system has formed very diverse landform assemblages in 3 major geomorphic domains. We have recognized 10 different river classes for the trunk river from Gangotri (source) to Farakka (upstream of its confluence with the Brahmaputra) based on (a) landscape setting, (b) channel and active floodplain properties, and (c) channel planform parameters. The mountainous stretch is characterized by steep valleys and bedrock channels and is dominated by large‐scale sediment production and transport through hill slope processes. The alluvial part of the river is characterized by 8 different river classes of varying reach lengths (60–300 km) many of which show sharp transitions in landscape setting. We have highlighted the application of this approach for the assessment of habitat suitability, environmental flows, and flood risk all of which have been significantly modified during the last few decades due to large‐scale anthropogenic disturbances. We suggest that the diversity embedded in this geomorphic framework can be useful for developing a sustainable river management programme to “work with” the contemporary character and behaviour of rivers.

Assessment of rivers as social–ecological systems: a response to ‘The imperative need for nationally coordinated bioassessment of rivers and streams’, by Susan J. Nichols et al.

Nichols et al. in Marine and Freshwater Research (https://doi.org/10.1071/MF15329) call for a reinvestment in national-scale bioassessment in Australia. With recent transition back to single-impact and subcatchment-level assessment, Nichols et al. (2017) argued that the ability to detect larger-scale and longer-term impacts of climate change and land-use change are being lost. They called for modernising bioassessment through programs with a clear policy mandate, political context and which are fit for purpose with currency and relevance. We agree that the absence of a national-scale assessment of river health is impeding the detection of declines in river health. However, we suggest that assessment of river health in Australia should go beyond bioassessment and assess rivers as social–ecological systems. We call for modernisation through a national assessment of river resilience. Monitoring for river resilience will evaluate not only the biophysical state of a river ecosystem, but the state of social influences on river health, and the capacities of society to adapt and transform towards river-ecosystem sustainability.

Designing a risk-based multi criteria framework for river health assessment: a case study of Taleghan basin, Iran

The prerequisite of designing a water quality monitoring system is providing river health assessment (RHA) which is a complex issue. To do so, the present paper creatively employed two risk-based multi-criteria decision-making methods (MCDMs) namely, ordered weighted averaging (OWA) and compromise programming (CP) to consider different risk potentials, and mitigate uncertainty associated with water quality management. Based on the results, methodologically, a mutual relationship was observed between ranking of CP and OWA. The neutral and optimistic priorities by OWA were completely corresponded with the CPs ranking with respect to p = 1. On the other hand, ascending values of p in CP represented more similarity to the pessimistic view-point of OWA. Technically, both the models illustrated that the most hazardous water quality conditions belonged to 'Taleghan-River' which was a pivotal finding because it is the most important river of the Taleghan basin. Overall, consideration of risk-attitudes in the computational process of decision-making provided different decision priorities. Due to the fact that Taleghan-River is one of the important sources of drinking water for Tehran, Karaj, and Qazvin cities, a strict decision making is recommended.

Designing a risk-based multi criteria framework for river health assessment: a case study of Taleghan basin, Iran

The prerequisite of designing a water quality monitoring system is providing river health assessment (RHA) which is a complex issue. To do so, the present paper creatively employed two risk-based multi-criteria decision-making methods (MCDMs) namely, ordered weighted averaging (OWA) and compromise programming (CP) to consider different risk potentials, and mitigate uncertainty associated with water quality management. Based on the results, methodologically, a mutual relationship was observed between ranking of CP and OWA. The neutral and optimistic priorities by OWA were completely corresponded with the CPs ranking with respect to p = 1. On the other hand, ascending values of p in CP represented more similarity to the pessimistic view-point of OWA. Technically, both the models illustrated that the most hazardous water quality conditions belonged to 'Taleghan-River' which was a pivotal finding because it is the most important river of the Taleghan basin. Overall, consideration of risk-attitudes in the computational process of decision-making provided different decision priorities. Due to the fact that Taleghan-River is one of the important sources of drinking water for Tehran, Karaj, and Qazvin cities, a strict decision making is recommended.

A novel approach for river health assessment of Chambal using fuzzy modeling, India

A novel approach for river health assessment of Chambal using fuzzy modeling, India

Statistical analysis of macroinvertebrate assemblage structure in relation to river-health assessment of an urban river, Eastern Cape, South Africa

Urban rivers in developing countries, including South Africa, are increasingly being impacted by human activities. The Bloukrans and Palmiet Rivers, where the current study was undertaken, are no exception. The Bloukrans River, the main object of this study, was impacted by wastewater effluent discharges and run-off from informal settlements and agricultural activities. The present study was aimed at evaluating the ecological health of the Bloukrans River using macroinvetebrate-based biomonitoring approaches, including the biotic index (i.e. the South African Scoring System version 5), multimetric and multivariate analyses of the assemblage structure. 18 metrics were selected and their potential for discriminating between the control and impaired sites evaluated. Macroinvertebrates were sampled bi-monthly (April – August 2013) at one control site (i.e. Site 1) in the Palmiet River and four impaired sites (i.e. Sites 2, 3, 4 and 5) in the Bloukrans River. The Scoring index indicated that the river health condition at the control site was good, whereas apart from Site 5, conditions at Sites 2, 3 and 4 were either poor or critically modified. Twelve metrics discriminated between Site 1 and the four impaired sites. Canonical correspondence analysis indicated that dissolved oxygen, electrical conductivity, nutrients and turbidity exerted the greatest influenced on the assemblage structure. Overall, the study indicated that pollution in the Bloukrans River had significant impact on the river health, influencing metrics in the diversity, composition and richness categories. The 12 metrics that proved sensitive to deteriorating water quality, enabling the discrimination of the control site from the impacted sites, could be used with the Scoring index to assess river health in the Bloukrans River. However, although using metrics in addition to the Scoring index provided greater understanding, where analytical resources are limited the summary biotic Scoring index can provide an acceptable rapid indication of river health.

Evolving Human Dimensions and the Need for Continuous Health Assessment of Indian Rivers

River health assessment (RHA) protocols are the tools used globally that emphasize upon factors which contribute for ecological fitness of the river such as catchment health, floodplain health, channel health, flow health, quality health and biotic health indicators. Human intervention by constructions of dams, excess water abstraction, channel diversion and several other factors contribute to the depletion of diverse flora and fauna of a river. For the societal well being, it appears that RHA programmes associated with a culturally sensitive river such as River Ganga in India need a move beyond top-down technocratic approach towards one that creates inclusive spaces for collaboration and public participation. Moreover, there appears a need for continuous RHA of the river to bridge the gap between science and the sacred. Based on available literature we propose a community-based comprehensive RHA model which anchors on the premise that people's relationship with the river and human values are central to any effort towards restoration and sustainable river health management in India.

Application of multiple biological indices for river health assessment in northeastern China

Bioassessment has become a hot topic and could provide important information for river management and restoration. In this study, we developed multiple biological indices using three groups of aquatic organisms – benthic algae, macroinvertebrates and fish – for river health assessment. The main steps for development of multiple biological indices were selection of sensitive indices, optimization of core indices, setting target and critical values for core indices, and calculation of final scores of health condition. In order to evaluate the 19 candidate indices, disturbance gradients were constructed for water contamination, sediment contamination and land use change using principal components analysis. Thirteen indices showed significant and relatively high coefficients of determination with the disturbance gradients using multiple regression analysis (P <0.05). Six indices – two indices each for benthic algae, macroinvertebrates and fish – were finally selected as the core indices using correlation analyses. River health condition scores were assigned to five categories: critical, poor, fair, good and excellent. One site was classified as critical and 10.5% of sites were in poor condition. Meanwhile, 45.6% of the sampling sites were classified as fair and 42.1% were either good or excellent. Regression analysis between the final scores and disturbance gradients confirmed the usefulness of multiple biological indices as a confident bioassessment method. Thus, we highly recommend using multiple biological indices to assess river health that will inform river management and restoration strategies.

Research of Urban River Health Assessment Model

Urban river health is the important symbol of the sustaining development of a city. Using the comprehensive index assessment method, some indicators were selected to characterize the main features and functions of urban river health to establish a comprehensive model for evaluating urban river health. These indicators included four aspects: landscape environment, natural features, environmental features and socioeconomic. Total of them are 22 indicators. And the evaluation criteria were ascertained. Projection pursuit and variable fuzzy theory method were used to determine the weight of the indicators and the comprehensive assessment model was also built. This thesis discussed the issues of the urban river health situation of Jialu river, an urban river in Zhengzhou city. The evaluation results (0.23, 0.327, 0.245, 0.198) show that the Jialu river is in sub healthy state. Based on the health assessment results of Jialu river and evaluation score of each indicator, the limiting factors were ascertained that affect the urban river health. The calculated results are consistent with the actual situation, which shows the practicability and rationality of the method. The assessment model can provide reference for urban rivers health.

綦江评价指标体系构建和健康评价研究

河流健康评价研究对河流环境的治理与保护工作具有重要的指导作用。本文采用基于层次分析法的综合评价方法，对长江一级支流重庆市綦江进行了河流健康评价研究。在确定了评价指标权重与指标标准特征值的前提下，尝试从水文水资源、水环境状况、水生生物状况、社会服务功能四个方面共13个指标，表征河流的健康状况。结果表明，綦江水体基本处于健康状态。13个评价指标中，生态流量满足程度、河流连通阻隔状况、纳污性能指数、大型底栖动物完整性指数、鱼类完整性指数得分相对较低。与此同时，由于綦江上水工建筑的兴建，阻断了鱼类洄游的路线，造成河段鱼类生态系统出现片段化现象，大型底栖动物完整性指数也受到影响。綦江上大多数水利工程还需要设置生态水量放水设施，另外綦江中段污染和人类活动的干扰稍微严重，化学需氧量和氨氮的排放量较大，需要进一步加强管理。 The study of river health assessment plays an important role in the management and protection of river environment. In this paper, a comprehensive evaluation method based on analytic hierarchy process (AHP) was used to study the health assessment of Qijiang River in Chongqing, the first-grade tributary of the Yangtze River. The weight of evaluation index and the characteristic value of the index standard had been determined. Meanwhile, 13 indicators from hydrology-water resources, water environment, aquatic condi-tions and social service functions had been used to characterize the health of the river. The results showed that the water body of Qijiang was basically in a state of health. In the 13 evaluation indexes, the ecological flow satisfaction degree, the river connectivity barrier status, the pollution index performance index, the index of the integrity of the benthic animal and the integrity index of the fish were relatively low. Mean-while, due to the construction of the Qijiang Shang Shui, blocking the route of migratory fish, fragmentation phenomenon appears in the river fish ecology system and large bottom dwelling animals’ complete index is also affected. Most of the water conservancy projects also should set ecological water drainage facilities; the middle pollution and human interference are slightly worse; emissions of COD and ammonia nitrogen are larger, which all need to further strengthen management.

Integrated Ecological River Health Assessments, Based on Water Chemistry, Physical Habitat Quality and Biological Integrity

This study evaluated integrative river ecosystem health using stressor-based models of physical habitat health, chemical water health, and biological health of fish and identified multiple-stressor indicators influencing the ecosystem health. Integrated health responses (IHRs), based on star-plot approach, were calculated from qualitative habitat evaluation index (QHEI), nutrient pollution index (NPI), and index of biological integrity (IBI) in four different longitudinal regions (Groups I–IV). For the calculations of IHRs values, multi-metric QHEI, NPI, and IBI models were developed and their criteria for the diagnosis of the health were determined. The longitudinal patterns of the river were analyzed by a self-organizing map (SOM) model and the key major stressors in the river were identified by principal component analysis (PCA). Our model scores of integrated health responses (IHRs) suggested that mid-stream and downstream regions were impaired, and the key stressors were closely associated with nutrient enrichment (N and P) and organic matter pollutions from domestic wastewater disposal plants and urban sewage. This modeling approach of IHRs may be used as an effective tool for evaluations of integrative ecological river health..

Assessment of river health based on an improved entropy-based fuzzy matter-element model in the Taihu Plain, China

Rivers are valuable to human beings because of their various functions. Unfortunately, ecological integrity of rivers has been seriously threatened by human activities, resulting in poor river functions. It is thus necessary to evaluate and maintain river health. Meanwhile, it is challenging to comprehensively assess river health with a single method alone. It is therefore relevant to combine the advantages of multiple methods in river health assessment. By classifying and characterizing river functions, we first established an indicator system for river health assessment in plain river network regions. We then assessed the health status of the Taihu Plain in terms of an improved entropy-based fuzzy matter-element model. We found that the overall health status of the Taihu Plain is below “good”. In particular, the health status of Yang-Cheng-Dian-Mao and Hang-Jia-Hu Region is “moderate”; the Wu-Cheng-Xi-Yu Region displays the poorest natural and social river functions. We also found that flood control is the most important influential factor in river health. Our findings suggest that rivers in the Taihu Plain must be restored to maintain their health, with the Wu-Cheng-Xi-Yu Region that must be restored preferentially, and that the river function of flood control must be improved at the scale of whole watershed. Comparing with other four commonly used comprehensive assessment methods, our improved entropy-based fuzzy matter-element model outperforms in reflecting objective fact and can be applied to river health assessment. Our results are generally consistent with existing studies, confirming that the proposed method for river health assessment is effective and feasible. Therefore, it provides a useful reference for river health assessment in other plain river network regions.

Assessing the impact of gold mining in headwater streams of Eastern Amazonia using Ephemeroptera assemblages and biological traits

Whilst the biological traits composition of invertebrate assemblages has been successfully used to monitor temperate rivers, it has been seldom tested in tropical areas. We compared the trait composition of Ephemeroptera assemblages (five traits, 21 modalities) in three categories of headwater streams of FG: reference (undisturbed) sites, sites formerly impacted by gold-mining, and sites currently impacted by gold-mining. Differences in macroinvertebrate assemblage according to environmental characteristics and disturbance were evaluated using correspondence analysis and MANOVA. Among the considered traits, food acquisition, respiration and locomotion detected both past and current disturbance associated with gold-mining in headwaters. A fuzzy correspondence analysis showed a significant segregation of currently gold-mined, formerly gold-mined, and reference sites according to species traits. Shifts in trait composition were mostly related to changes in assemblage composition. Interestingly, no significant decline in diversity indices was observed in formerly gold-mined sites compared to the reference sites, 2 years after abandonment, while the taxonomic and trait composition of communities changed at these sites. These results support the case for further fundamental quantification of species traits, and for the inclusion of sensitive, trait-related metrics in upcoming multimetric indices for the assessment of river health.