Urban Ecosystem Health Assessment Research Articles

River Ecosystem Health Assessment in Rapid Urbanization Regions (Shenzhen, China) under the Guidance of Bioremediation Objectives

As a coastal city with rapid urbanization and high-intensity human activities, Shenzhen, China has carried out a series of comprehensive treatments for water pollution control and ecological restoration in recent years. However, the restoration effect is mainly reflected in the improvement of water quality and riparian landscape, and there is still a big gap in reaching the river’s ecological restoration goals. Therefore, it is necessary to make a full investigation and evaluation of river aquatic systems that focuses on the restoration of aquatic communities and ecosystem health. We surveyed forty-seven sampling sites in nine basins to investigate water quality and aquatic organisms (algae and macroinvertebrates) during the low-water period in 2019. Under the guidance of the EU Water Framework Directive (WFD), the urban river ecosystem health assessment system, with a total of twenty indicators from six criteria layers, was established. We addressed the bioremediation objectives in this system and aquatic organism indicators as high-weight characteristic indicators. The results showed that the degradation of the river ecosystem in Shenzhen is serious, which is mainly reflected in the simple structure of the aquatic biological community and the low biodiversity. Only one “healthy” sample site, accounting for 2% of the total sampling sites; six sites of “sub-health” level, accounting for 13%; twenty-four “poor” sample points, accounting for 51%; sixteen “extremely poor” sample points, accounting for 34%. From the perspective of spatial distribution, the river ecological status of Daya Bay Basin and Dapeng Bay Basin is good, which is at the level of “health” to “sub-health”; the Guanlan River Basin, Maozhou River Basin, Shenzhen River Basin, Shenzhen Bay Basin, Pingshan River Basin, and most of the Longgang River Basin are of “poor to extremely poor” grade; the Pearl Estuary basin is of “extremely poor” grade. This assessment system can be used as an effective tool to monitor the ecological health status, especially the enhancement of biodiversity and ecosystem function of rivers. Moreover, it could provide important decision-making guidance for river management affected by high-intensity human activities.

Evaluation and improvement path of ecosystem health for resource-based city: A case study in China

Chinese resource-based cities are facing serious challenges in the aspect of ecosystem health development due to the development mode of “Treatment after pollution” and the negative effect caused by increased global competition. Research from the theory and methodology aspects must be urgently advanced. This study innovatively combines emergy analysis indicators with traditional economic-social indicators and constructs the method for urban ecosystem health assessment and improvement path. Jining is selected as an example to verify the method effectively. Research results show that the urban ecosystem health level of Jining constantly improved during 2008–2017, which increased from unhealthy to sub healthy and then to healthy. The five urban ecosystem health factors, namely, vitality, organizational structure, resilience, ecosystem service functions, and public health conditions, all show a trend of continuous improvement. Through the model of obstacle degree, this study identifies the main obstacle factors that influence the urban ecosystem health development of Jining: environmental loading rate (D22), renewable emergy value rate (D7), and the proportion of environmental protection in fiscal expenditure (D19). Moreover, several ecological development paths are proposed to improve the urban ecosystem health level of Jining based on local conditions.

Urban ecosystem health assessment and obstacle factor diagnosis using a comprehensive assessment model for Nanjing, China

AbstractAn urban ecosystem carries the burden of urbanization and records the changes in the ecological environment . A scientific evaluation of the urban ecosystem can effectively assess and identify any system damage and degradation caused by nature or by human activities. In this paper, we construct an urban ecosystem health assessment system on the basis of a pressure–state–response (PSR)/vigor–organization–resilience (VOR) model along with the socioeconomic and remote sensing data related to Nanjing. Meanwhile, the factors hindering the stainable development of the Nanjing ecosystem are discussed. The results indicated that the health of the urban ecosystem in Nanjing is generally on the rise, improving from poor in 2000 to good in 2017; from the results obtained via the PSR model, the state layer continues to decrease, whereas the pressure and response layers continue to increase; the VOR model demonstrated that the urban ecosystem in Nanjing has been relatively stable over the past 20 years, and the obstacle degree model demonstrated that, over the next 10 years, the obstacle factors will be concentrated in the response layer in the early stage and in the pressure layer in the later period, mainly because of the pressure brought about by population growth.

Urban Water Ecosystem Health Evaluation Based on the Improved Fuzzy Matter-Element Extension Assessment Model: Case Study from Zhengzhou City, China

The urban water ecosystem is a core foundation for the urban construction of ecological civilization. Ecosystem health is directly related to the economic development of the region and the quality of urban residents’ lives. Evaluating the health state of an urban water ecosystem is an important prerequisite for the construction of an ecologically civilized city. This study used Zhengzhou City in China as research area. Firstly, a Pressure-State-Response (PSR) model was used to construct an urban water ecosystem evaluation index system. Secondly, after analyzing the deficiency of traditional fuzzy matter-element extension model in urban water ecosystem health assessment, an improved fuzzy matter-element extension assessment model (FMEAM) was constructed by introducing the variable weight theory. Finally, using the proposed model above and the data from 2007 to 2016, this study evaluated the water ecosystem health status of Zhengzhou based on water ecosystem health integrated index (WHI). The results showed that the state of the urban water ecosystem in Zhengzhou generally improved during the study period. However, the overall level still remained low and retained an unhealthy state throughout the timeframe. The pressure on the Zhengzhou water ecosystem mainly originates from the increasing urbanization rate, the increased consumption of ecological environmental resources, and household water. Corresponding countermeasures in Zhengzhou have achieved certain results, and the health of the state’s subsystem and response subsystem has improved. However, it remains necessary to further strengthen the protection of the ecological environment, particularly with respect to water resources.

Construction of Urban Water Ecological Civilization System

To explore the relationship between water ecological civilization construction and urban water ecosystem health, the Water-Human-Health (WHH) evaluation model that could reflect the health connotation and mechanism of urban water ecosystem model was constructed to evaluate the health level of urban water ecological system. The result showed that the health status of urban water ecosystem health in X city during 2005~2013 was evaluated and it was found that the index of the urban water ecosystem health showed fluctuating upward trend, water system health index declined slightly in fluctuation and the human system health index increased steadily. To sum up, the urban water ecosystem health assessment method and urban water ecological civilization construction framework are reasonable and feasible.

Responses of urban ecosystem health to precipitation extreme: A case study in Beijing and Tianjin

Our research explores the relationship between precipitation extreme and urban ecosystem health by using emergy analysis based on urban ecosystem health assessment and Difference-in-Difference approach. In the case study area of Beijing and Tianjin, their urban ecosystem are getting healthier with the average growth rate of the key index, urban ecosystem health, are 0.23 and 0.12 respectively, simultaneously the overall index of Beijing is a little higher than that of Tianjin. Meanwhile, urban ecosystem seemingly has nothing to do with precipitation extreme, and the health of its urban sub-ecosystem performs significantly to the precipitation extreme except the sub-ecosystems, resilience, public services and human health. Vigor, one of the urban sub-ecosystems, its ecosystem health negatively associated with precipitation extreme. And urban sub-ecosystem health of vigor will reduce 14.42 if a precipitation extreme happens. The precipitation extreme has a positive effect on organization and emergies. And urban sub-ecosystem health of organization and emergies will increase 44.11, 12.02 respectively if a precipitation extreme happens. In addition, it is apparently nonsignificant to the sub-ecosystems, resilience, public services and human health. Moreover, the extreme precipitation consumes more emergies for the city, it seems beneficial for emergy flow for that precipitation extreme negatively affects emergy/dollar ratio, environmental loading rate and positively affects total emergy. But the extreme precipitation also negatively influences emergy yield ratio. Thus, urban ecosystem health associates with precipitation extreme in a complex way, both positively and negatively. Government measures for recovering urban ecosystem health should emphasize the sub-ecosystem vigor of the city, like constructing more public facilities. And policy makers may pay more attention on environmental loading rate, like advocating improving energy use efficiency.

Urban Ecosystem Health Assessment: Perspectives and Chinese Practice

The concept of ecosystem health is a way to assess the holistic operations and development potential of urban ecosystems. Accelerated by the practical need for integrated ecosystem management, assessment of urban ecosystem health has been greatly developed and extensively applied in urban planning and management. Development is aimed at comprehensively evaluating the performance of urban ecosystems, identifying the limiting factors, and providing suggestions for urban regulation. The time has come for reviewing and establishing an instructional framework for urban ecosystem health assessment to shed light on certain essential issues of urban ecosystem health. Based on literature reviews and series of practice, a holistic framework of urban ecosystem health assessment is proposed. The framework covers the essential elements of urban ecosystem health and integrates three dimensions: theoretical foundation, assessment method, and practical application. Concrete assessment methods are also established, focusing on both external performance and internal metabolic processes. The practice of urban ecosystem health assessment in China is illustrated to briefly demonstrate the application of the established framework and methods. Some prospects are discussed for urban ecosystem health assessment and its application in urban planning and management.

Urban Ecosystem Health Assessment and Its Application in Management: A Multi-Scale Perspective

Urban ecosystem health assessments can be applied extensively in urban management to evaluate the status quo of the urban ecosystem, identify the limiting factors, identify key problems, optimize the scheme and guide ecological regulation. Regarding the multi-layer roles of urban ecosystems, urban ecosystem health should be assessed at different scales with each assessment providing a specific reference to urban management from its own viewpoint. Therefore, a novel framework of multi-scale urban ecosystem health assessment is established on global, national, regional and local scales. A demonstration of the framework is shown by using a case study in Guangzhou City, China, where urban ecosystem health assessment is conducted in the order of global, national, regional, and local scales, from macro to micro, and rough to detailed analysis. The new multi-scale framework can be utilized to generate a more comprehensive understanding of urban ecosystem health, more accurate orientation of urban development, and more feasible regulation and management programs when compared with the traditional urban ecosystem health assessment focusing at the local scale.

Relative Urban Ecosystem Health Assessment: A Method Integrating Comprehensive Evaluation and Detailed Analysis

Regarding the basic roles of urban ecosystem health assessment (i.e., discovering the comprehensive health status, and diagnosing the limiting factors of urban ecosystems), the general framework integrating comprehensive evaluation and detailed analysis is established, from both bottom-up and top-down directions. Emergy-based health indicators are established to reflect the urban ecosystem health status from a biophysical viewpoint. Considering the intrinsic uncertainty and relativity of urban ecosystem health, set pair analysis is combined with the emergy-based indicators to fill the general framework and evaluate the relative health level of urban ecosystems. These techniques are favorable for understanding the overall urban ecosystem health status and confirming the limiting factors of concerned urban ecosystems from biophysical perspective. Moreover, clustering analysis is applied by combining the health status with spatial geographical conditions. Choosing 26 typical Chinese cities in 2005, relative comprehensive urban ecosystem health levels were evaluated. The higher health levels of Xiamen, Qingdao, Shenzhen, and Zhuhai are in particular contrast to those of Wuhan, Beijing, Yinchuan, and Harbin, which are relatively poor. In addition, the conditions of each factor and related indicators are investigated through set pair analysis, from which the critical limiting factors of Beijing are confirmed. According to clustering analysis results, the urban ecosystems studied are divided into four groups. It is concluded that the proposed framework of urban ecosystem health assessment, which integrates comprehensive evaluation and detailed analysis and is fulfilled by emergy synthesis and set pair analysis, can serve as a useful tool to conduct diagnosis of urban ecosystem health.

Urban forest eco-system health assessment based on fuzzy synthetic appraisal: Taking Zhuzhou city, Hunan as an examplc

Based on the index system of health assessment of the urban forest ecosystem, the weight of each index was obtained by AHP method, and then the modal of fuzzy synthetic appraisal was established to evaluate it. An empirical analysis was conducted on the four areas: Hetang, Lushong, Tianyuan and Shifeng in Zhuzhou city, with the result of the urban forest ecosystem health appraisla, unhealthy (value, 0.359 4), unhealthy (value, 0.370 8), unhealthy (value, 0.369 8) and good health (value, 0.783 3)respectively. The result agrees with the reality.

Implication of Ecosystem Health Assessment for Urban Management

In order to implementing theoretical urban ecosystem health assessment into practical urban management more effectively, it is necessary to find out the relationship between the urban ecosystem health status based on the internal metabolism characteristics and the external performance of the urban ecosystem. Eleven indicators are selected to describe the performance of the urban ecosystem from aspects of resources condition, social civilization, economic development and environmental load. The correlation analysis between the emergy-based urban ecosystem health status in view of energy and material flows and the ecosystem status based on the eleven indicators is conducted to reveal the relationship between the internal biophysical foundation and the external performance of the urban ecosystem. It is indicated that the resources basis and the economic development level correlate with the emergy-based urban ecosystem health status, which implies the measurement of effectively and reasonably utilizing and exploiting resources, adjusting the economic development pattern and industrial structure should be paid much attention to improve the urban ecosystem health level and optimize the urban ecosystem management.

Urban ecosystem health assessment based on emergy and set pair analysis—A comparative study of typical Chinese cities

Regarding various energy and materials flowing in the urban ecosystem and the merit of emergy as an embodied energetic equivalent for integrated ecological economic evaluation, an evaluation framework of emergy-based urban ecosystem health indicators (UEHI em) was established in view of five aspects including vigor, structure, resilience, ecosystem service function maintenance and environmental impact to depict the urban ecosystem health states. Further, set pair analysis (SPA) was employed to assess the urban ecosystem health level based on the UEHI em, by which the approximate degree of real index set to the optimal one was defined and evaluated to describe the relative health state of the concerned urban ecosystems. Choosing twenty typical Chinese cities in 2005 as cases, we evaluated and compared their urban ecosystem health levels based on UEHI em and SPA. The results showed that health levels of Xiamen, Qingdao, Shenzhen and Shanghai are pretty well, while those of Wuhan, Harbin, Yinchuan, Beijing and Urumchi are relatively weak. Moreover, the relative health levels were analyzed by SPA to discern the influences of the mentioned five aspects on the UEHI em. It is concluded that emergy synthesis combined with SPA can serve as an effective relative-measure to compare different ecosystem health levels of urban ecosystems.

Set pair analysis for urban ecosystem health assessment

Set pair analysis (SPA) is introduced to assess the urban ecosystems, through which the approximate degree of urban ecosystem health to the optimal set is calculated to describe the health level of the urban ecosystems by combining multiple health indices. The urban ecosystem health levels of Beijing, Dalian, Shanghai, Wuhan, Xiamen and Guangzhou from 1995 to 2003 are thereafter evaluated using SPA. The results show that the urban ecosystem health states of Xiamen and Guangzhou is the best during the study period, while the health states of the others changes over time. Particularly, the change of Beijing’s urban ecosystem health from 1992 to 2003 is analyzed in detail.

Emergy-based urban ecosystem health assessment: A case study of Baotou, China

Ecosystem health has been a hot topic of ecosystem management research for years. Considering the urban area as a complex ecosystem consisted of natural, societal and economic entities, urban ecosystem health assessment is necessary to be conducted for the scientific management and proper ecological restoration. Combining with the ecosystem service function of the urban ecosystem, theoretical framework and methodology of the urban ecosystem health assessment based on emergy are proposed and the temporal variation of the health level of the city are also outlined in this paper. Following the principle of ecosystem health assessment, four major factors, including vigor (V), organizational structure (O), resilience (R) and function maintenance (F), are integrated to construct a novel emergy-based urban ecosystem health index (EUEHI). Based on the EUEHI and comparing with those of five other typical Chinese cities, the case study of Baotou city shows that its urban ecosystem health level is steadily arising despite the year 2001 as a turning point. Due to the emphasis on the resource structure adjustment and utilization efficiency, Baotou has obtained a better organizational structure and service function for the total urban ecosystem.