The Jiamusi section of the Songhua River is one of the first 17 model river construction sections in China. The implementation of river health assessments can determine the health dynamics of rivers and test the management's effectiveness. Targeting seven rivers, this study conducted river zoning and monitoring point deployment to conduct sufficient field research and monitoring. The authors selected hydrological and water resources, physical structure, water quality, aquatic life, social service functions, and management as guideline layers and 15 indicator layers. Subsequently, the authors established an evaluation index system to evaluate and analyze the ecological status and social service status of each river. The results showed that the Yindamu, Alingda, and Gejie rivers scored well as healthy rivers, with health evaluation scores of 78.98, 76.06, and 75.83, respectively. The Wangsanwu, Lujiagang, and Lingdangmai rivers are generally sub-healthy rivers with scores of 71.55, 67.97, and 60.7, respectively. The Yinggetu River has a score of 54.52 and is therefore assessed as unhealthy. Based on the scientific evaluation index method, this study analyses the current river health state in Jiamusi City to provide the basis for the evaluation of the river chief's work and future river management.

  • Established a river health evaluation system using a graded index scoring method.

  • Assessed the health status of seven rivers in Jiamusi City.

  • Some measures and suggestions for the future management of water resources are given.

River systems are a vital part of the ecological environment and human life, and they are of irreplaceable importance to the Earth's material cycle and balance, as well as to human survival and development. However, with economic, industrial, and technological development as well as population growth and urbanization, human demand has caused an incremental increase in water extraction, sand dredging, land use change, and the construction of gates for power generation. Thus, increasing exploitation has damaged the health of river ecosystems. Since its introduction in the 1970s, the concept of river health has been widely researched in both Eastern and Western countries; however, no unified definition has yet been developed (Zhang & Wang 2017; Liu et al. 2018a, 2018b). Karr (1999) argues that river health is equivalent to biological integrity, whereas Meyer (1997), the former president of the Ecological Association of America, suggests that river health encompasses more than the maintenance of ecosystem structure and function, and it should also include the value of the ecosystem's social services. At present, Chinese scholars have different views on the concept of river health, but all agree that river health should include not only ecological but also social values, emphasizing that it should not only protect the health of the river's ecosystem but also sustainably satisfy the needs of humans (Dong 2007; Liu & Liu 2008; Peng 2018; Liu et al. 2021). With the development of international research on the concept of river health, river health assessments have become a research hotspot for scholars. Scientific tools and methods can be used to establish a comprehensive evaluation methodology for studying the ecological status of rivers and the changing trend of rivers' social service value to humans under natural and human activities (Liu et al. 2019). Several foreign countries have developed their own methods for river health assessment indicators, including the Rapid Bioassessment Protocol in the USA, the Australian Stream Condition Index, the UK River Habitat Survey methodology, and the South African Habitat Integrity Index (Kleynhans 1996; Barbour et al. 1999; Ladson et al. 1999; Raven et al. 2000). Research conducted in China has proposed methods for river health evaluation index systems. Tang et al. (2002) outlined the concept of river ecosystem health in 2002 and introduced a method for evaluating river ecosystem health using aquatic algae, invertebrates, and fish as the main indicators. Zhao & Yang (2005) proposed an evaluation index system using water quantity, water quality, aquatic organisms, riparian zones, and physical structure as evaluation elements. Geng et al. (2006) established a river health evaluation index system with 25 indicators based on five aspects: service, environment, flood control, exploitation and utilization, and ecological functions. Zhang et al. (2010) proposed a full-index evaluation system for river health based on ecological function zoning from the perspective of applicability to national river health evaluation. River health assessment provides an important reference for river managers at all levels for decision making on river management and protection, and it provides a reliable basis for testing the effectiveness of the work of river chiefs and river management. Additionally, river health assessment is an important means of testing the ‘name’ and ‘reality’ of the river chief system (Chen et al. 2020, 2021). However, theoretical studies and practical examples of river health assessment in China are majorly based on central city rivers or major large rivers and do not cover small- and medium-sized cities and small rivers. For example, most river studies in Jiamusi have focused on river management and protection (Hao et al. 2001; Jiang & Liu 2007), and they do not consider the function of rivers in Jiamusi City as a whole (Liu et al. 2018a, 2018b). Thus, a lack of research exists on comprehensive river health assessments.

In this study, the authors selected seven rivers as research objects and established a river health evaluation index system and method based on the concept of river health. Using ‘Technical Guidelines for River and Lake Health Assessment’, ‘Technical Guidelines for River Health Assessment in Heilongjiang Province (for trial implementation)’ (hereinafter referred to as ‘Guidelines (Heilongjiang)’), and ‘Guidelines for River and Lake Health Assessment (for Trial Implementation)’ (hereinafter referred to as ‘Guidelines’), combined with the actual water conditions and river management in Jiamusi City, the authors performed health evaluation for seven rivers. The evaluation results were analyzed and discussed through a combination of available information and surveys, which provided a reference for understanding the current health status of rivers and lakes and for the formulation of future river and lake management policies to improve the health status of rivers and lakes in Jiamusi.

Study area

Located in northeastern Heilongjiang Province, Jiamusi is in the hinterland of the Three rivers Plain, one of the world's three remaining black soil plains formed by the confluence of the Songhua, Heilong, and Ussuri rivers. Jiamusi had a total registered population of 2,279,000 at the end of 2021 and an annual GDP of 81.62 billion yuan, making it the core city in the eastern region of Heilongjiang Province. Jiamusi has a mid-temperate continental seasonal climate, influenced by the southeast monsoon in summer and the polar cold air mass in winter. Precipitation is primarily concentrated in summer and autumn, and this region experiences considerable inter-annual variation in precipitation. Jiamusi has abundant precipitation and water resources, with more than 500 mm of precipitation in normal years, a multi-year average surface water resource of 3.156 × 109 m3 and 3.61 × 109 m3 of underground water resources, resulting in a multi-year average of 5.314 × 109 m3 for total water resources.

Jiamusi has a well-developed water system with more than 130 rivers of various sizes, including the Heilongjiang River and its main tributaries, the Yalu, Lianhua, and Nongjiang rivers, the Songhua River and its main tributaries, the Yoken and Tangwang rivers, the Ussuri River and its main tributaries, and the Naoli, Neiqixing, and Belahong rivers. As shown in Figure 1, seven rivers were selected for this study: the Wangsanwu, Gejie, Lingdangmai, Yinggetu, Yindamu, Lujiagang, and Alingda. Among them, the Gejie and Alingda rivers are mountain streams and are left-bank tributaries of the Songhua River, located in the central portion of Tangyuan County. The Lindangmai River is a first-class tributary of the Songhua River, which flows through the southern edge of the eastern part of the urban area, downstream into Huachuan County, and merges with the Songhua River. The Yinggetu River is a first-class tributary of the Songhua River, originating at an elevation of 285 m southwest of Sihetun in the suburban area of Changfa Town. The Yindamu River is also a first-class tributary of the Songhua River, with a length of 6.72 km and a watershed area of 432.8 km2 within the city. The Lujiagang and Wangsanwu rivers are first-class tributaries on the left-bank of the Yindamu River and second-class tributaries of the Songhua River. Table 1 shows the main information on the rivers.
Table 1

Main messages for evaluating rivers

TypesEvaluated riversLength (km)Basin area (km2)
Regional rivers Gejie 57 429 
Lingdangmai 70 637 
Alingda 76 550 
Urban rivers Yinggetu 26 225.4 
Yindamu 6.72 432.8 
Lujiagang 12 45 
Wangsanwu 8.2 
TypesEvaluated riversLength (km)Basin area (km2)
Regional rivers Gejie 57 429 
Lingdangmai 70 637 
Alingda 76 550 
Urban rivers Yinggetu 26 225.4 
Yindamu 6.72 432.8 
Lujiagang 12 45 
Wangsanwu 8.2 
Figure 1

Study area, rivers, and monitoring sites.

Figure 1

Study area, rivers, and monitoring sites.

Close modal

River zoning and monitoring site placement

Segmentation of longer rivers reduces errors by refining river segments, thus making health assessment results highly accurate and reasonable. As shown in Table 2 and Figure 1, according to the ‘Technical Guidelines for River and Lake Health Assessment’, ‘Guidelines (Heilongjiang)’, and ‘Guidelines’, the lengths of the Wangsanwu, Yinggetu, Yindamu, and Lujiagang rivers are less than 50 km and therefore only one evaluation section was established for all these rivers. In contrast, the lengths of the Gejie, Lingdangmai, and Alingda rivers are greater than 50 km; thus, two evaluation sections were set up for each river. One monitoring point was set up for each river section, and each point was monitored monthly for over two months. To facilitate the statistics and presentation of the data, the monitoring points of each river were numbered, and the ID number, location, and latitude and longitude information of each monitoring site is shown in Table 2.

Table 2

River conditions and zoning

Sites IDNumber of river sectionsMonitoring sitesRiver nameLatitude and longitude of monitoring sites
Intersection of Shenglixi Road and the Yinggetu River Yinggetu (130.299509 E, 46.794517 N) 
Near Beixing village Gejie (130.032474 E, 46.949253 N) 
Near the Gejie River Bridge (130.083047 E, 46.811138 N) 
Intersection of Heping Bridge and the Wangsanwu River Wangsanwu (130.386243 E, 46.799201 N) 
Shouwangdiqiangzi Alingda (130.493133 E, 47.020859 N) 
Hesi Road (130.272086 E, 47.071335 N) 
Intersection of 075 Township Road and the Yindamu River Yindamu (130.435418 E, 46.819254 N) 
Near the Xinfeng village, Huachuan County Lingdangmai (130.609205 E, 46.664173 N) 
Bridge next to the G1011 highway (130.481373 E, 46.776677 N) 
10 Intersection of Daxian Road and the Lujiagang River Lujiagang (130.431723 E, 46.780558 N) 
Sites IDNumber of river sectionsMonitoring sitesRiver nameLatitude and longitude of monitoring sites
Intersection of Shenglixi Road and the Yinggetu River Yinggetu (130.299509 E, 46.794517 N) 
Near Beixing village Gejie (130.032474 E, 46.949253 N) 
Near the Gejie River Bridge (130.083047 E, 46.811138 N) 
Intersection of Heping Bridge and the Wangsanwu River Wangsanwu (130.386243 E, 46.799201 N) 
Shouwangdiqiangzi Alingda (130.493133 E, 47.020859 N) 
Hesi Road (130.272086 E, 47.071335 N) 
Intersection of 075 Township Road and the Yindamu River Yindamu (130.435418 E, 46.819254 N) 
Near the Xinfeng village, Huachuan County Lingdangmai (130.609205 E, 46.664173 N) 
Bridge next to the G1011 highway (130.481373 E, 46.776677 N) 
10 Intersection of Daxian Road and the Lujiagang River Lujiagang (130.431723 E, 46.780558 N) 

Data sources

Among the six criteria layers selected for this study, the indicators in hydrology and water resources, social services, and management were mainly obtained from the ‘One River, One Policy’ program for each river issued by Jiamusi City, whereas the indicators of physical structure, aquatic life, and water quality were obtained from existing monitoring data combined with field surveys. As the condition of some indicators of physical structure, aquatic life, and water quality varies considerably over time, a combination of available monitoring data information and field surveys was used to obtain the data. To obtain accurate and comprehensive findings, a long series of multichannel monitoring and surveys were conducted for certain indicators of physical structure, water quality, and aquatic life guidelines.

Evaluation indicator system and methodology

Evaluation indicator system and weighting of each indicator

River health assessment indicators are required to accurately determine the ecological conditions and social provision of rivers (Lv et al. 2017). The evaluation standard was chosen based on previous research and the study area (Leopold et al. 1965). Some early researchers considered only the biochemical and physical characteristics of the river when establishing the evaluation index system (Zhang et al. 2018; Wang et al. 2019; Du et al. 2021), but as the understanding of river health has evolved, more and more studies are considering both the ecological health status and social service functions of the river (Shan et al. 2021; Zhang et al. 2021; Chen et al. 2022; Xi et al. 2023). In this study, the assessment indicators were selected using principles of scientific knowledge, data acquisition, assessment criteria, and relative independence. As shown in Figure 2, in accordance with the above principles, a three-tiered system of target, guideline, and indicator layers was proposed as a river health indicator for Jiamusi City. The target layer includes two aspects: ecological and social service status; the guideline layer includes six aspects: hydrological and water resources, physical structure, water quality, aquatic organisms, social service functions, and management. The indicator layer includes 15 indicators, including water resource development and utilization rates, ecological flow, and water satisfaction level. Based on the guidelines, and accounting for the main functions and location characteristics of the rivers, 14 indicators were selected for the regional rivers, except for the nutritional status (the degree of standardization of sewage outlet was not mentioned in the ‘One River, One Policy’ plan for the Gejie River, Lingdangmai River, and the Alingda River, and thus 13 indicators were selected for the three rivers), and 10 indicators were selected for the urban rivers, except for water resources utilization rate, ecological water level satisfaction, fish retention index, water supply guarantee rate, and the degree of standardized management of water intake.
Figure 2

River health assessment indicator system (refer to ‘Guidelines (Heilongjiang)’).

Figure 2

River health assessment indicator system (refer to ‘Guidelines (Heilongjiang)’).

Close modal

Indicator weights are expressions of the contribution of each indicator to the total, and their values reflect the role of the indicator in the system and the reliability of the value. As shown in Figure 2, the indicator weights for the target and guideline levels of river health in Jiamusi are divided according to the ‘Guidelines (Heilongjiang)’ (the indicators in the guideline level are assigned weights on an average basis), with the first half in brackets representing the indicator weights for regional rivers and the second half representing the indicator weights for the urban rivers.

Evaluation methodology

The assessment of the health of the rivers in Jiamusi was based on a graded indicator scoring method, weighting step-by-step, and scoring all metrics combined.

Hydrological and water resources
Water resource exploitation and utilization rate
Water resources exploitation and utilization rate reflect the degree of coordination between regional socio-economic development and water resources development and utilization. To achieve sustainable economic and social development must ensure a reasonable water resources exploitation and utilization rate. The water resource exploitation and utilization rate is evaluated using the percentage ratio of surface water supply to surface water resources in the river basin in which the river is located, calculated according to Equation (1):
formula
(1)
where WURI is the exploitation and utilization rate of surface water resource, %; WS is the amount of surface water withdrawal from the river and lake (reservoir) basins, m3; and WR is the total amount of surface water resources in the river and lake (reservoir) basin, m3.
Satisfaction with the ecological flow/water level
Ecological flow is the minimum flow required to maintain the structure and function of a river ecosystem. For rivers with continuous daily runoff monitoring data, the degree of ecological flow satisfaction was evaluated as the proportion of days with satisfactory flow to the number of days in the year, calculated according to Equation (2):
formula
(2)
where C is the score assigned to the indicator of the degree of ecological flow satisfaction of the river; is the number of days when the daily runoff during the freezing period of the river was greater than or equal to the ecological flow or ecological water demand during the freezing period, d; is the number of days when the daily runoff during the non-flood period of the river was greater than or equal to the ecological flow or ecological water demand during the non-flood period, d; represents the number of days when the daily runoff of the river during the flood season was greater than or equal to the ecological flow or ecological water demand during the flood season, d; and N is the number of days in the year, d.
The ecological water level refers to the minimum water level that can maintain the basic form and function of a river, and it serves as the minimum limit to safeguard the structure and function of the river ecosystem. For rivers where only continuous water level monitoring data are available, the degree of ecological water level satisfaction is characterized by the proportion of days meeting the ecological water level to the total number of days in the year, calculated according to Equation (3):
formula
(3)
where is the score assigned to the indicator of the degree of ecological water level satisfaction with the river; is the number of days when the daily water level of the river during the freezing period was greater than or equal to the ecological water level during the freezing period, d; is the number of days when the non-flood daily water level of the river was greater than or equal to the non-flood ecological water level; is the number of days during which the daily flood level of the river was greater than or equal to the ecological level of the flood; and is the number of days in the year.
Physical structure

The physical structure of rivers is the most essential and important characteristic of rivers, which determines the ecological environment of river organisms, and different river structures also influence the confluence and flooding processes in the watershed. In this study, three indicators are used to characterize the physical structure of rivers and urban inland rivers, namely the river longitudinal connectivity index, bank zone condition, and soil conservation rate, with weights of 0.34, 0.33, and 0.33, respectively.

River longitudinal connectivity index

The longitudinal connectivity of rivers has important implications for fish distribution, population structure, reproductive success, and the dispersal of many species. The river longitudinal connectivity index was evaluated in terms of the number of structures or facilities per 100 km of river that affected the connectivity of the entire river in units of one per 100 km.

Riparian conditions

The condition of the riparian zone reflects the river's ability to maintain its structural stability, and good riparian conditions are a basic requirement to safeguard the ecological functions of the river as well as its flood control, navigation, and other service functions. This condition used weightings of 0.4 and 0.6 for the bank stability and the vegetation cover of the bank zone, respectively.

Bank stability was evaluated in terms of the current state of erosion that has occurred or can potentially occur on the bank, with elements including bank dip, bank vegetation cover, bank height, substrate (type), and bank scour condition.

The vegetation cover of the bank slope was evaluated as the proportion of the vertical projection of vegetation to the area of the bank zone, in percentage.

Soil and water conservation rate

The proportion of the area with good soil and water conservation status (less than mild erosion intensity in the watershed) to the total area of the country was evaluated in percentages.

Water quality

Water quality is the most basic and important element of rivers, and healthy water quality is important for safeguarding human health and the healthy growth of plants and animals, and is essential for maintaining the normal functioning of the ecosystem and supporting economic and social development. The river water quality indicator layer contained only one indicator, the quality compliance rate of the water functional area, with a weight of 1. The water quality indicator layer of urban rivers contained two indicators: the water quality compliance rate of the water functional area and the nutrient status, with weights of 0.5 each.

Water quality compliance rate

An evaluation of the number of functional water areas satisfying the water quality standards as a percentage of the total number of functional water areas was conducted.

Nutritional status

The nutrient status evaluation includes total phosphorus, total nitrogen, chlorophyll a, permanganate index, and transparency. It is evaluated using the index method, which involves applying linear interpolation to convert the concentration values of each item into a score value. The average score value of each item is then calculated, and the trophic level is determined according to the trophic status index.

Aquatic life

The abundance and species richness of aquatic organisms reflect the ecological health of a river, and having a diverse range of aquatic organisms is a necessary condition for a healthy river. The aquatic life indicator layer of the regional rivers in this study contains a total of three indicators: the biological integrity index of macrobenthic invertebrates, fish retention index, and phytoplankton density, with weights of 0.34, 0.33, and 0.33, respectively. The indicator layer for urban rivers consisted of three indicators: the biological integrity index of macrobenthic invertebrates, fish retention index, and phytoplankton density, and the weights are 0.33, 0.33, and 0.34, respectively.

Biological integrity index of macrobenthic invertebrates
The biological integrity index of macrobenthic invertebrates was evaluated by comparing the conditions at the reference and damaged sites and was calculated according to Equation (4):
formula
(4)
where BIBIS is the river macrobenthic invertebrate biotic integrity index score; BIBIO is the river macrobenthic invertebrate biotic integrity index monitoring values; and BIBIE represents the best expectation index of macrobenthic invertebrate biotic integrity in the aquatic ecological subzone where the river is located.
Fish retention index
The status of the difference between the number of fish species at present and the number of fish species at the historical reference point was calculated according to Equation (5):
formula
(5)
where FOEI is the fish retention index, %; FO is the number of fish species obtained from river surveys (excluding exotic species), and FE is the number of fish species (species) in the river evaluated in or before the 1980s.
Phytoplankton density

Phytoplankton density was evaluated by multiples of phytoplankton densities compared with historical reference periods or by the direct judgment assignment method.

This data was collected from rivers of a similar type in the same ecological sub-region of river geography, which are unaffected by human activities or have a minor impact. The monitoring data from the historical reference period before major changes in the river and its morphology are used as the base point, and monitoring data from or prior to the 1980s are preferred. The phytoplankton density for the evaluation year was divided by the historical base point to calculate multipliers.

The direct judgment method assigns a score based on the phytoplankton density within a certain range.

Social service function

In the process of civilization progress and economic development of human society, rivers provide the basic resources and power guarantee. The social service functions of rivers include flood control, power generation, water supply, navigation, and landscape services, which have ecological, economic, political, social, and cultural values. In this study, flood control indicators, water supply assurance, and public satisfaction are used to characterize the social service functions of regional rivers with a weight of 0.33, 0.33, and 0.34, respectively.

Flood protection

The rate of compliance with river flood protection work was evaluated as a percentage of the total length of embankments meeting the flood protection standards.

Water supply guarantee rate
Using the integrated water supply guarantee rate evaluation, the actual average daily water supply was used as the weighting to count the degree of water supply guarantee for all rivers, calculated according to Equation (6):
formula
(6)
where WSI is the integrated water supply guarantee rate, %; is the actual average daily water supply volume for the nth water supply project evaluated, m³/d; is the guaranteed rate of water supply for the nth water supply project evaluated, km; and is the number of water supply projects evaluated.
Public satisfaction

The public survey method was chosen to evaluate the satisfaction level of flood control, shoreline landscape, water environment, water ecology, water friendliness and convenience (function), management, and other aspects, and the scores were averaged from the scores given by the public around the evaluated rivers.

Management

The level of river management affects the other functions of the river. In order to protect the health condition of rivers, the degree of regulation of outfalls and abstractions must be strictly regulated. In this study, both the regional and urban river management indicator layers include the degree of standardization of outfalls and intake management, so the degree of standardization of outfalls and the degree of standardization of water intake management were selected as indicators, with a weight of 0.5 each.

Degree of standardization of outfalls

The rate of standardized construction of outfalls and the reasonableness of the layout of outfalls with weightings of 0.4 and 0.6, respectively, were used to evaluate the degree of standardization of outfalls.

The rate of standardized construction of outfalls was evaluated as a percentage of the number of outfalls planned and constructed to the total number of outfalls.

The reasonableness of the outfall layout was evaluated by the compliance of the outfall layout and the size of its mixing zone, and points were assigned according to the scoring criteria in the ‘Guidelines’.

Degree of standardization of water intake management

This criterion was evaluated using the ratio of the number of regulated abstractions to the total number of abstractions evaluated, in percentage.

Uncertainties and limitation

This study took seven rivers in Jiamusi Basin as the research object and evaluated and analyzed the ecological and social service status of each river by establishing a new river health evaluation index system with a graded index scoring method. Although this study has built a relatively perfect evaluation system, there are still some defects. The rivers in this study were mainly concentrated in the city of Jiamusi, which is small and dense, and rivers and lakes outside the city were not considered. The authors did a clear division of rivers, but in reality, there are interactions between rivers which means it can lead to incomplete evaluation results.

Results

Survey and monitoring results

Shoreline survey
Shoreline surveys and monitoring were conducted using a combination of measuring instruments and remote sensing imagery to obtain reliable, accurate, and objective results. Landsat 8 multispectral remote sensing data with a resolution of 30 m were used to calculate the normalized vegetation index by radiometric calibration using ENVI 5.6 software (Full name is ‘The Environment for Visualizing Images’ and it is developed by Exelis Visual Information Solutions, America) and to calculate the vegetation cover of the shoreline. The calculated vegetation cover results are shown in Figure 3.
Figure 3

Vegetation cover in the riparian zone of each river.

Figure 3

Vegetation cover in the riparian zone of each river.

Close modal

It can be seen that the vegetation cover of the Wangsanwu, Alingda, and Gejie rivers is good (the highest vegetation cover of 67.99% in the Wangsanwu River), while the vegetation cover of the Lingdangmai and Yindamu rivers is poor (the worst vegetation cover of 22.20% in the Lingdangmai River).

Water quality monitoring

As shown in Table 3, the authors obtained the results of water quality monitoring in the rivers through regular sampling and existing water quality monitoring sections. As shown in the table, the water quality status is divided into six classes, with monitoring points 2 and 6 having the best water quality status as Class II, which is characterized by minor exceedances of the ammonia nitrogen index and total phosphorus. Monitoring points 7, 9, and 10 have the worst water quality condition of inferior Class V, which is characterized by exceedances of ammonia nitrogen, total phosphorus, permanganate index, dissolved oxygen content, and petroleum content.

Table 3

Water quality monitoring results

Sites IDWater quality conditionsIdentification of water quality
N and P exceeded the standard by 0.5 and 0.4 times, respectively. Class Ⅳ 
– Class Ⅱ 
K exceeded the standard by 0.4 times. Class Ⅳ 
N and P exceeded the standard by 0.02 and 0.5 times, respectively. Class Ⅳ 
K exceeded the standard by 0.4 times. Class Ⅳ 
– Class Ⅱ 
N and P exceeded the standard by 2.6 and 0.8 times, respectively, and O also exceeded the standard. Inferior class V 
– Class Ⅲ 
N, P, and K exceeded the standard by 6.8, 6.3, and 0.3 times, respectively, and O also exceeded the standard. Inferior class V 
10 N, P, K, and G exceeded the standard by 9.1, 9.1, 0.4, and 0.6 times, respectively, and O also exceeded the standard. Inferior class V 
Sites IDWater quality conditionsIdentification of water quality
N and P exceeded the standard by 0.5 and 0.4 times, respectively. Class Ⅳ 
– Class Ⅱ 
K exceeded the standard by 0.4 times. Class Ⅳ 
N and P exceeded the standard by 0.02 and 0.5 times, respectively. Class Ⅳ 
K exceeded the standard by 0.4 times. Class Ⅳ 
– Class Ⅱ 
N and P exceeded the standard by 2.6 and 0.8 times, respectively, and O also exceeded the standard. Inferior class V 
– Class Ⅲ 
N, P, and K exceeded the standard by 6.8, 6.3, and 0.3 times, respectively, and O also exceeded the standard. Inferior class V 
10 N, P, K, and G exceeded the standard by 9.1, 9.1, 0.4, and 0.6 times, respectively, and O also exceeded the standard. Inferior class V 

Abbreviations: N, the ammonia nitrogen index; P, total phosphorus; K, permanganate index; O, dissolved oxygen content; G, petroleum content.

Biological survey
Phytoplankton
Phytoplankton are usually referred to as planktonic algae and include six main phyla: Chrysophyta, Cryptophyta, Euglenophyta, Cyanophyta, Chlorophyta, and Bacillariophyta. Ten sites were investigated in this study, and the number of species of algae from a total of six phyla as well as the Phytoplankton biomass distribution at each site are shown in Figure 4(a) and 4(b).
Figure 4

The number of species and biomass at each site of different biology: (a)–(b) phytoplankton, (c)–(d) zooplankton, and (e)–(f) benthos.

Figure 4

The number of species and biomass at each site of different biology: (a)–(b) phytoplankton, (c)–(d) zooplankton, and (e)–(f) benthos.

Close modal

As shown in Figure 4(a), from a holistic point of view, although the hydrological and water resources and ecological and environmental factors vary among rivers, the general trend in the number of algal species in the rivers that were similar was as follows: Bacillariophyta > Chlorophyta > Cyanophyta > Euglenophyta > Cryptophyta > Chrysophyta. This occurrence may be because the rivers are all tributaries of the Yalu River and the real-time exchange of water results in extremely similar physical, chemical, and biological properties among rivers. Therefore, they have similar algal growth environments which results in similar algal distributions.

Phytoplankton biomass is defined as the total amount of phytoplankton per unit of the water column at a given time, and it is used to indicate phytoplankton growth in a water column. The phytoplankton biomass of the seven rivers is shown in Figure 3(b), where point 10 had the highest biomass (23.848 mg/L) and point 2 had the lowest biomass (2.682 mg/L). Among the six phyla detected, Bacillariophyta had the highest total biomass (35.872 mg/L) and Cryptophyta had the lowest (1.102 mg/L) among the seven rivers, indicating that the conditions were more suitable for the growth of Bacillariophyta and less suitable for Cryptophyta.

A dominant genus is generally defined as a species that can have a greater influence on some species but is less influenced by other species or has the greatest density and biomass. Dominance is often used to indicate the status and role of a species in a community. In this study, by calculating the dominance of 10 monitoring sites, the genus with a dominance greater than 0.02 was considered dominant, and the distribution of the dominant genus at each site was obtained, as shown in Figure 5. The dominant genera in the seven rivers included Phormidium, Cyclotella, Synedra, Fragilaria, Nitzschia, Melosira, and Navicula, and the number of dominant genera (16) was the highest at monitoring site 5, and lowest at monitoring sites 7 (six) and 10 (six).
Figure 5

Distribution of dominant genera at each monitoring site.

Figure 5

Distribution of dominant genera at each monitoring site.

Close modal
Zooplankton

Zooplankton are a heterotrophic group of organisms that cannot produce organic matter. Instead, they derive nutrients from existing organic matter. The zooplankton monitored in this study consisted of Rotifers, Protozoans, Cladocera, and Copepods. The distribution of each phylum at each site and the biomass at each site is shown in Figure 4(c) and 4(d). As can be seen from Figure 4(c), the number of zooplankton species at the 10 sites was approximately Rotifer > Protozoa > Cladocera > Copepods. The biomass of the four zooplankton species at the ten sites was Rotifer > Protozoa > Copepods > Cladocera, with the smallest zooplankton biomass at monitoring site 6 and the largest zooplankton biomass at monitoring site 10.

Benthic organisms

Benthos refers to a group of aquatic animals that primarily inhabit the bottom waters of bodies of water. The benthic fauna monitored in this study consisted of eight orders, and specific species' distributions at each monitoring site, as well as the biomass of various benthic fauna at different sites, are shown in Figure 4(e) and 4(f). As can be seen from Figure 4(e), the number of benthic species at each site was lower than that of phytoplankton and zooplankton, with none exceeding five species. Monitoring sites 4 and 7 have higher biomass, while sites 5 and 6 have lower biomass, and site 7 has tens of thousands of times the biomass of site 6. Taking the seven rivers as a whole, the biomass of Oligochaeta was significantly greater than that of the other species, while the Mesogastropoda biomass and species count were both zero, indicating that the rivers studied were suitable for Oligochaeta, while Mesogastropoda has difficulty surviving in these rivers.

Indicator level evaluation results

As shown in Figure 6, in terms of the number of indicators attaining 60 points in the layers of each river: the overall condition of the Gejie and Alingda rivers was good, with only three indicators under 60 points. Among the 10 indicator layers of the Wangsanwu, Lujiagang, and Yindamu rivers, six scored more than 60 points and five scored a minimum of 80 points. The Yinggetu River scored poorly, with half of the indicators failing to reach 60 points. The Yinggetu River scores poorly for phytoplankton density, nutritional status, degree of standardized management of water intakes, and flood control indicators, indicating problems with both social service and ecological functions, the Lingdangmai River also scored poorly in the indicator layer, with only seven out of 13 indicators reaching 60, specifically the river's longitudinal connectivity index, riparian condition, water quality compliance rate, phytoplankton density, flood control indicators and degree of guarantee of water supply.
Figure 6

Indicator layer scores for each river.

Figure 6

Indicator layer scores for each river.

Close modal

Considering the individual indicator layers, poor results were obtained for the river longitudinal connectivity index, with only the Yindamu and Lujiagang rivers scoring 100 and the remaining five rivers scoring 0. Phytoplankton density scores were also poor, with only the Wangsanwu River scoring over 60. The overall score for the Flood Prevention Index was also poor, with only the Alingda and Yindamu rivers scoring 100 and the remaining five rivers failing to score a minimum of 60. The indicators that scored well were public satisfaction, water quality compliance rate, soil and water conservation rates, and degree of standardized management of water intake (outfalls). Among them, the public satisfaction score of all rivers was 80 points and the soil and water conservation rate score of all rivers was 75. All six rivers scored 100 points, except for the Lingdangmai River which scored 50 points for water quality compliance rate. Of the indicators for the degree of standardized management of water intakes (outfalls), the Yinggetu River scored below 60, whereas the rest of the rivers scored above 60, and five scored 100.

Guideline level evaluation results

As shown in Figure 7, in terms of the guideline layer scores, among the six guideline layers, management scored the highest, with all rivers scoring 100, except for the Yinggetu and the Lingdangmai, which scored 44 and 60, respectively. The rivers also scored well in terms of water quality, with all rivers achieving a score of 60 except for the Lingdangmai. At the hydrological and water resources level, all three regional rivers scored over 60. At the social services level, the Alingda and Yindamu rivers performed better, while the Gejie, Lingdangmai, Lujiagang, and Yinggetu rivers did not score 60. The aquatic scores of the study rivers varied widely, with the Yindamu, Wangsanwu, and Lujiagang rivers all scoring below 50, while the remaining four rivers all scored over 70. The worst scores were for physical structure, with only two rivers, the Yindamu and Lujiagang, scoring over 60. The guideline level scores showed that Jiamusi has done an excellent job in river management and the water quality of the rivers is good. However, Jiamusi has many problems at the aquatic life and physical structure levels, which need to be addressed with more targeted measures. The physical structure obtained the lowest score, with only two rivers, Yindamu and Lujiagang, each scoring over 60 points. The Gejie, Alingda, and Yindamu rivers scored better in terms of the overall score for each river stratum, whereas the Lingdangmai and Yinggetu rivers scored lower.
Figure 7

Guideline layer scores for each river.

Figure 7

Guideline layer scores for each river.

Close modal

Target level evaluation results

River health was classified into five categories according to the river health assessment system: very healthy (90–100), healthy (75–90), sub-healthy (60–75), unhealthy (40–60), and poor (0–40) states. The classification of river health was based on a combination of assessment indicators using a percentage system. The target layer score and overall health assessment score status of each river are shown in Figure 8.
Figure 8

Target layer scores for each river.

Figure 8

Target layer scores for each river.

Close modal

Figure 8 shows that the ecological conditions of the rivers were scored as follows: Gejie River > Alingda River > Lujiagang River > Yinggetu River > Yindamu River > Wangsanwu River and the social service provision was scored as follows: Yindamu River > Alingda River > Wangsanwu River > Lujiagang River > Gejie River > Lingdangmai River > Yinggetu River. The total health evaluation scores of the rivers were as follows: Yindamu River > Alingda River > Gejie River > Wangsanwu River > Lujiagang River > Lingdangmai River > Yinggetu River. According to the classification criteria for river health, the Gejie, Alingda, and Yindamu rivers scored over 75 points and were considered healthy; the Lingdangmai, Lujiagang, and Wangsanwu rivers scored between 60 and 75 points and were considered sub-healthy; and the Yinggetu River scored less than 60 points and was considered unhealthy. The overall scores for the two indicators at the guideline level showed that although all rivers scored 60 points for ecological status, the scores were low overall. The social service scores of the rivers vary considerably, for example, the Yindamu River scores 95, while the Yinggetu River scores only 45.94. The overall scores of the rivers studied were less varied, ranging between 50 and 80, indicating that there is room for improvement in all rivers.

Overall analysis

The health assessment score for the Gejie River was 75.83, indicating that it was a healthy river. The ecological status score was 79.19, which was the highest among the seven rivers. Of the four criteria layers included in ecological status, hydrological and water resources, water quality, and aquatic life scored the highest. However, the Gejie River has a high density of dykes along its banks, a short length of dykes that meet construction standards, and a small reservoir with insufficient storage capacity to meet water demand, which are the main reasons for limiting its score.

The health assessment score for the Lingdangmai River was 60.7, indicating that it is a sub-healthy river (on the border between unhealthy and sub-healthy). The results of long-term monitoring show that several problems exist with the health status of the Lingdangmai River, including the high density of cross-rivers and river-related structures in the lower reaches, low vegetation cover, high phytoplankton density in the general riparian zone, poor water quality (poor V) in some sections of the river, inadequate embankment standards, and low water resources to meet water demand. The water quality of some sections of the river was poor, inadequate satisfaction of embankment standards were not satisfied, and extremely few water resources existed to meet the water demand.

The Alingda River (76.06) was rated as healthy. Social service status (86.14) achieved the highest score among the seven rivers, with the four indicator layers included in the target layer (flood control indicators, degree of water supply guarantee, and degree of standardization of the sewage outlet) all receiving the highest scores. However, the high density of drainage gates affected the river connectivity, and the high density of phytoplankton limited the overall health assessment score.

The health assessment score for the Yinggetu River (54.52) was the lowest of the evaluated rivers, and it was considered an unhealthy river. Physical structure, social service functions, and management scores were poor in all six criterion layers of the evaluation. The high density of flap gate facilities in the Yinggetu River affected the normal connectivity of the river. Water quality monitoring results showed that the Yinggetu River exceeded ammonia and total phosphorus standards and had a poor nutrient status. In addition, it had a high density of phytoplankton, a high number of outfalls, a low rate of standardized construction, a short length of the mainstream up to standard embankments, and low flood protection standards.

The Wangsanwu River scored 71.55, making it sub-healthy. The main reason for its low overall evaluation score was its poor ecological status score, which was the lowest among all rivers evaluated. According to the survey results, the two weirs in the river prevented river connectivity. In addition, the low ecological baseflow and poor water quality of the Wangsanwu River led to the poor survival of macrobenthic invertebrates.

The health assessment score of the Lujagang River, a sub-healthy river, was 67.97. According to the results of the monitoring survey, the nutrient status of the river was poor, with poor water quality. Ammonia nitrogen and total phosphorus significantly exceeded the standard; additionally, petroleum, permanganate index, and dissolved oxygen also exceeded the standard. Some riparian zones of the river have been encroached, resulting in poor riparian vegetation cover. River pollution has led to poor water quality and high phytoplankton densities (1,287 × 104/L). River embankment projects have low flood protection standards; thus, flood protection construction needs to be strengthened.

The health assessment score of the Yindamu River (78.98) was the highest among the evaluated rivers, indicating that it is a healthy river. In the guideline layer, both social service functions and management scored over 90, but the aquatic life score (27.45) was poor. According to the survey and monitoring results, challenges pertaining to the Yindamu River include low vegetation cover in the riparian zone and poor nutrient status of the water caused by excess ammonia nitrogen, total phosphorus, and dissolved oxygen.

Discussion

In view of the weak points shown in the health evaluation of the rivers, the following measures and suggestions are proposed in light of the actual situation in Jiamusi.

Enhancing water conservation

Some sections of the rivers in Jiamusi have low levels of water resource exploitation and utilization, and the water use structure has a large proportion of agricultural water use and is mostly water-consuming diffuse irrigation. This fact, coupled with weak awareness and a lack of incentive to save water among residents, has ultimately led to a tight demand for water supply in some areas. Therefore, it is important to adhere to the full implementation of the strict water resource planning and management and strengthen the unified dispatch of water resources. Further engineering measures should be implemented for surface water resource protection, underground resource protection, water ecology protection, and restoration.

Strengthening water pollution control

Although the water quality compliance rates of the rivers involved in the evaluation were generally good, the current water quality status of the evaluated rivers was mostly Class IV or V. Numerous evaluated rivers exceeded the standards for ammonia nitrogen, total phosphorus, and other indicators. A field survey in Jiamusi City found that some areas lacked stormwater channels, had a high ratio of rainwater to sewage flowing, and had prominent problems with waste dumping and domestic sewage discharge. Therefore, the relevant river management units in Jiamusi should increase their efforts to rectify agricultural and industrial pollution. In addition, authorities should strictly control the pollution discharge of enterprise units, improve environmental protection access and emission permit systems for industrial enterprises, and severely rectify and punish enterprises whose emissions do not satisfy the requirements. Implementing a comprehensive prevention and control project for agricultural surface source pollution, strengthening the monitoring of agricultural surface source pollution, promoting the innovation and application of agricultural fertilization technology, and adopting diverse measures to reduce the loss of chemical fertilizers and pesticides should also be future focused.

Enhancing waterfront protection

The results of the evaluation showed that some sections of the river have poor riparian vegetation cover and river connectivity, mainly because of the high density of riparian encroachment and flow-stopping structure facilities. Therefore, for areas with extremely severe riparian zone encroachment, strategies should be developed to remedy the extreme challenges and regular action should be taken to manage them. Strict control of river-crossing and flow-stopping buildings and facilities should be adopted, along with permanent supervision. Artificial planting of vegetation should be conducted according to the needs of the river to protect and restore the riverbanks.

River health assessment plays an important role in understanding river health status and checking river and lake management, but there are few studies on the health evaluation index system of small and medium-sized rivers. In this study, a new river health evaluation system was established for seven rivers in Jiamusi City, and a comprehensive evaluation of the health status of regional rivers and urban rivers in Jiamusi City was carried out by combining field visits, on-site measurements, and historical data. According to the study results, the Gejie, Alingda, and Yindamu rivers were healthy and met the health criteria. However, they did not achieve high scores, which provide potential for future improvement. The Wangsanwu, Lujiagang, Lingdangmai, and Yinggetu rivers were sub-healthy or unhealthy, with several indicator level challenges that require timely and targeted measures. Based on a scientific and comprehensive health assessment index system, this study accurately quantified the health status of each river, identified the problems and shortcomings, and suggested measures to test the effectiveness of river management, future river management, and planning for Jiamusi.

Based on the evaluation results, the study analyzed the problems of each river from the index level, and some relevant suggestions are also given in combination with the actual conditions of Jiamusi City such as enhancing water conservation, strengthening water pollution control, and enhancing waterfront protection.

This research was funded by the Chinese National Natural Science Foundation (grant no. 51979285), the Beijing Municipal Natural Science Foundation (grant no. 8222036), the Research Fund of the State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin of China Institute of Water Resources and Hydropower Research (grant no. SKL2022TS11), and the Major Science and Technology Programs of the Ministry of Water Resources (grant no. SKS-2022126, WR110145B0042023).

The author states that the manuscript is original and has not been published elsewhere.

Data cannot be made publicly available; readers should contact the corresponding author for details.

The authors declare there is no conflict.

Barbour
M. T.
,
Gerritsen
J.
,
Synder
B. D.
&
Stribling
J. B.
1999
Rapid Bioassessment Protocols for use Instreams and Wadeable rivers: Periphyton, Benthic Macroinvertebrates and Fish
.
U.S. Environmental Protection Agency, Office of Water
,
Washington, DC
.
Chen
J.
,
Lang
M.
,
Wang
X.
,
Qu
X.
&
He
X.
2020
River-lake health assessment: Understanding and considerations
.
China Water Resources
2020
(
20
),
17
19
(in Chinese)
.
Chen
J.
,
He
X.
,
Cai
G.
&
Wang
X.
2021
Analysis of the objectives and countermeasures of river and lake health assessment work based on the river and lake chief system
.
Water Resources Development Research
21
(
6
),
34
37
(in Chinese)
.
Chen
J.
,
Kong
Y.
&
Mei
Y.
2022
Riverine health assessment using coordinated development degree model based on natural and social functions in the Lhasa River, China
.
International Journal of Environmental Research and Public Health
19
(
12
),
7182
.
Dong
Z.
2007
Interpretation of river health
.
Express Water Resources & Hydropower Information
28
(
11
),
17
19
(in Chinese)
.
Du
X.
,
Yuan
Y.
,
Meng
Y.
&
Guan
X.
2021
Comprehensive health evaluation of Huaihe River mainstream based on compound fuzzy matter element-entropy weight combination model
.
Water Resources Protection
37
(
3
),
145
151
.
Geng
L.
,
Liu
H.
,
Zhong
H.
&
Liu
C.
2006
Indicators and criteria for evaluation of healthy rivers
.
Journal of Hydraulic Engineering
37
(
3
),
253
258
(in Chinese)
.
Hao
S.
,
Zhang
C.
&
Chen
Y.
2001
Harnessing of the small rivers in Jiamusi (in Chinese)
.
Journal of Heilongjiang Hydraulic Engineering College
28
(
2
),
102
103
(in Chinese)
.
Jiang
C.
&
Liu
F.
2007
Situation and control measures of middle and small rivers in Jiamusi City (in Chinese)
.
Heilongjiang Science and Technology of Water Conservancy
35
(
2
),
145
(in Chinese)
.
Karr
J. R.
1999
Defining and measuring river health
.
Freshwater Biology
41
(
2
),
21
234
.
Ladson
A. R.
,
White
L. J.
,
Doolan
J. A.
,
Finlayson
B. L.
,
Hart
B. T.
,
Lake
P. S.
&
Tilleard
J. W.
1999
Development and testing of an index of stream condition for waterway management in Australia
.
Freshwater Biology
41
(
2
),
453
468
.
Leopold
L. B.
,
Wolman
M. G.
&
Miller
J. P.
1965
Fluvial Processes in Geomorphology
.
Liu
C.
&
Liu
X.
2008
Healthy river: Essence and indicators
.
Acta Geographica Sinica
2008
(
7
),
683
692
(in Chinese)
.
Liu
C.
,
Xu
J.
,
Zhang
J.
,
Wang
Y.
&
Zhou
X.
2018a
Review of domestic river health research
.
Haihe Water Resources
2018
(
4
),
6
12
(in Chinese)
.
Liu
R.
,
Li
Z.
,
Zhao
R.
,
Hu
X.
,
Wang
L.
,
Wang
Y.
,
Wang
B.
&
Jin
X.
2018b
Effects of benthic community seasonal dynamics on the aquatic environment quality assessment of rivers in Northern China
.
Environmental Monitoring in China
34
(
6
),
84
91
(in Chinese)
.
Liu
C.
,
Zhang
S.
,
Cui
W.
,
Lin
C.
&
Zhang
J.
2019
The review of river health assessment in China. Sustainable Development of Water Resources and Hydraulic Engineering in China, n. pag
.
Liu
Q.
,
Xiao
J.
&
Li
M.
2021
Review of domestic and international river health research
.
China Water Transport
21
(
11
),
86
88
(in Chinese)
.
Lv
Z.
,
Zhou
B.
,
Shu
C.
,
Zhu
D.
&
Yang
K.
2017
Study on the rationality of river health assessment index system
.
Jiangsu Water Resources
2017
(
9
),
10
14
(in Chinese)
.
Meyer
J. L.
1997
Stream health: Incorporating the human dimension to advance stream ecology
.
Journal of the North American Benthological Society
16
(
2
),
439
447
.
Peng
W.
2018
Research on river and lake health assessment indicators, standards and methods
.
Journal of China Institute of Water Resources and Hydropower Research
16
(
5
),
394
404
(in Chinese)
.
Raven
P. J.
,
Holmes
N. T. H.
,
Naura
M.
&
Dawson
F. H.
2000
Using river habitat survey for environmental assessment and catchment planning in the UK
.
Hydrobiologia
422–423
,
359
367
.
Shan
C.
,
Dong
Z.
,
Lu
D.
,
Xu
C.
,
Wang
H.
,
Ling
Z.
&
Liu
Q.
2021
Study on river health assessment based on a fuzzy matter-element extension model
.
Ecological Indicators
127
,
107742
.
Tang
T.
,
Cai
Q.
&
Liu
J.
2002
River ecosystem health and its assessment
.
Chinese Journal of Applied Ecology
13
(
9
),
1191
1194
(in Chinese)
.
Wang
S.
,
Zhang
Q.
,
Yang
T.
,
Zhang
L.
,
Li
X.
&
Chen
J.
2019
River health assessment: Proposing
a comprehensive model based on physical habitat, chemical condition and biotic structure
.
Ecological Indicators
103, 446–460.
Xi
H.
,
Li
T.
,
Yuan
Y.
,
Chen
Q.
&
Wen
Z.
2023
River ecosystem health assessment based on fuzzy logic and harmony degree evaluation in a human-dominated river basin
.
Ecosystem Health and Sustainability
9, 00041.
Zhang
J.
&
Wang
X.
2017
Review on index system of river health evaluation
.
Environmental Science and Management
42
(
5
),
180
184
(in Chinese)
.
Zhang
J.
,
Dong
Z.
,
Sun
D.
&
Wang
J.
2010
Complete river health assessment index system based on eco-regional method according to dominant ecological functions
.
Journal of Hydraulic Engineering
41
(
8
),
883
892
(in Chinese)
.
Zhang
Z.
,
Li
Y.
,
Wang
X.
,
Li
H.
,
Zheng
F.
,
Liao
Y.
,
Tang
N.
,
Chen
G.
&
Yang
C.
2021
Assessment of river health based on a novel multidimensional similarity cloud model in the Lhasa
River, Qinghai-Tibet Plateau
.
Journal of Hydrology
603, 127100.
Zhao
Y.
&
Yang
Z.
2005
Preliminary study on assessment of urban river ecosystem health
.
Advances in Water Resources
16
(
3
),
349
355
(in Chinese)
.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY-NC-ND 4.0), which permits copying and redistribution for non-commercial purposes with no derivatives, provided the original work is properly cited (http://creativecommons.org/licenses/by-nc-nd/4.0/).