A method for estimating watershed restoration feasibility under different treatment levels

The restoration of watershed health can be influenced by ecological, technical and socio-economic factors. The paper presents a conceptual framework and typology to assess watershed ecological restoration based on the properties and processes of sustainable watershed development. According to multiple life stages, habitat properties and existing legal frameworks and applicable valuation approaches, the bio-indicator that integrates natural, political and socio-economic dimensions is proposed. With existing assessment results and official web-pages as references, evaluation systems concerning human impacts on aquatic systems are set forth. Suitable aquatic bio-indicators can standardize the monitoring methodology with respect to water quality, organic pollutants and pesticides, generation time, migration ability, saprobic status, taxonomic composition and diversity. A large number of fish-based indexes have been developed to monitor and manage river ecosystems. Biophysical and statistical models are being used to identify influential stream variables that correlate with macroinvertebrate indices. A probabilistic fuzzy hybrid model to assess river water quality is proposed. The method and process of ecological risk assessment are provided based on adaptive management principles. The environmental sustainability index (ESI) is used to estimate the degree of environmental restoration sustainability with the emergy triangle as a


INTRODUCTION
Numerous rivers cease flow and dry up in the world with an increase of flow intermittency due to climate change and human activities. It is difficult to monitor and assess the ecological integrity of watersheds because we cannot determine the extent to which anthropogenic activities have changed the conventional indicators. Therefore, it is of significance to understand the ecological consequences of the flow intermittency of river systems (Datry et al. ). For temporary rivers, the content of environmental monitoring includes surface waters, dry riverbeds, and hyporheic zones (Steward et al. ). The hyporheic zones of watersheds nourish substantial invertebrates beneath the dry and wet channels.
Hyporheic invertebrates have long been indicators for estimating the health of temporary rivers, which is identical to the macroinvertebrate richness as indicators for overall river health. However, due to a lack of appreciation of the ecological interactions between surface and hyporheic ecosystems in most rivers, only a few cases have been made to include hyporheic invertebrates in river health assessments (Moldovan et al. ).
To assess the potential of hyporheic invertebrates in temporary rivers as ecological indicators for river health, Leigh et al. () analyzed the factors influenced by geographical location, climate zone, sampling techniques and hydrological conditions, geographical region, and conditions of surface water and surface flow. Based on relevant research results, the lowest levels of within-group taxonomic resolution are used to standardize the invertebrate records. Patterns of variation in assemblage composition among the cases, as indicated by the ANOSIM analyses, were visualized using non-metric multi-dimensional scaling ordination.
Biotic integrity may be the best tool to assess the ecological health of hyporheic rivers. Fish communities were first applied to assess biological conditions in aquatic systems.
In the IBI, metrics are scored in six qualitative classes from an absence of fish to excellent conditions (Karr ).
In many parts of the world, biological condition has largely been used in conservation studies. Therefore, assessments at the ecosystem scale include several levels of biological organization. The restoration of freshwater habitats is essential to maintain ecosystem services, especially food and drinking water supply (Millennium Ecosystem Assessment ). The integration of standardized eco-indicators is useful in converting from current single species-based to holistic community-based restoration assessments. There are naturally complex interactions among ecological, technical and socio-economic factors. The change of impact factor depends on the complexity of biological organization during restoration (Figure 1). Because of the high complexity of the goals and measures during river restoration, it is difficult to focus on a single universal factor to get successful restoration. Ecological restoration in terms of river value or improved services protection is not necessarily correlated with the improvement of river ecological function for aquatic species (Jähnig et al. ).
A feasibility study for the restoration of watershed ecosystems took a broad view. Potential solutions for watershed ecosystem health were conceptually designed, then tested for their performance using numerical simulation and analytical methods. To meet the restoration objectives in a cost-effective manner, we supplied relationships between ecological restoration and bio-indicators; identified potential restoration possibility by using ecological quality assessment and ecological risk assessment (ERA) and assessed eco-sustainable development using an environmental sustainability index (ESI) system that focuses on restoration feasibility and the potential to improve water quality, and wildlife habitat.

THE LEADING ROLE OF BIO-INDICATORS
Bio-indication and suitable indicators are feasible to detect the predominant factors driving successful restoration. To restore the ecological function of rivers, it is crucial to  Table 1. These evaluation systems can be constructed by exposing target species to ambient conditions (Schubert ). In this context, the paper aims to analyze some of the theoretical aspects of bio-indicators and to provide a review on the use of aquatic indicators. This part evaluates the methodological applications and their advantages/disadvantages with respect to traditional surveying methods.

Aquatic indicator
Suitable aquatic bio-indicators can standardize the monitoring methodology in terms of water quality, organic pollutants and pesticides, taxonomic composition and diversity. The aquatic indicator ranges from changes in physiology, behavior and morphology to survival and mortality. Therefore, factors for determining the status of river ecology should include composition, richness, tolerance, tropic measures, health condition, age structure, growth and recruitment of aquatic species. To assess the natural probability of an aquatic organism occurring in different Therefore, all life stages (eggs, juveniles and adults) should be recorded to make high numbers and standardized quality available. The early life stages of salmonid fishes are sensitive to changes in water and substratum quality (Sternecker & Geist ). The incubation systems are adapted to bio-indication requirements, but the production of other potential bio-indicators is still a challenge.
As bio-indicators, the organisms should meet some basic criteria, i.e. relevance, reliability, viability, response and

Ecological restoration
By exposing the indicator organisms to corresponding measurement units, the factors contributing to the status or performance of exposed organisms can be measured.
Aquatic bio-indication is a system for assessing substratum quality and physicochemical variables in the interstitial zone of rivers. For example, the SEFLOB was more sensitive than chemical measurements in detecting water quality (Pander & Geist ). Therefore, ERA ERA is a process using existing information relevant to cause and effect to estimate the probability of predictive assessments.

ASSESSMENT OF ECOLOGICAL SUSTAINABLE DEVELOPMENT
To realize the sustainable development of water ecology in watersheds, we use the emergy triangle to infer the degree of environmental sustainability. R represents renewable resources, N means non-renewable resources and F represents the economic input of environmentally friendly production. ESI is the environmental sustainability index, In short, the inputs of ecosystems are classified into three types: renewable resources in the watershed (R), nonrenewable resources in the watershed (N) and economic inputs of environmentally friendly production (F). F is provided by the market or economic flows. In Figure 4, the sustainability lines depart from  evaluates the sustainability of a process or system. The larger the ESI, the higher the sustainability of a system is.
The parameters used in emergy calculation are provided in

CONCLUSIONS
The paper presents a conceptual framework and typology to describe the assessment of watershed ecology restoration.
The integration of the eco-indicators standardized for monitoring management practices and structures is a useful way.
According to multiple life stages and habitat properties, the indicators that integrate natural, political and socio-economic dimensions are proposed. The ERA process aims to identify and quantify the risks associated with the stressor.
We use the emergy triangle to infer the degree of environmental sustainability. The larger the ESI, the higher the sustainability of a system is.
The method selected to estimate watershed ecological restoration cost is critically important. Technical feasibility and scientific validity are necessary for alleviating ecological damage and supplying positive protection actions to river health assessment. Further research is required on hyporheic watersheds, where meteorological effects might be mixed with pollution due to human activities.