Quantifying multi-dimensional services of water ecosystems and breakpoint-based spatial radiation of typical regulating services considering the hierarchical clustering-based classification.

This study proposes a set of water ecosystem services (WES) research system, including classification, benefit quantification and spatial radiation effect, with the goal of promoting harmonious coexistence between humans and nature, as well as providing a theoretical foundation for optimizing water resources management. Hierarchical cluster analysis was applied to categorize WES taking in to account the four nature constraints of product nature, energy flow relationships, circularity, and human social utility. A multi-dimensional benefit quantification methodology system for WES was constructed by combining the emergy theory with multidisciplinary methods of ecology, economics, and sociology. Based on the theories of spatial autocorrelation and breaking point, we investigated the spatial radiation effects of typical services in the cyclic regulation category. The proposed methodology has been applied to Luoyang, China. The results show that the Resource Provisioning (RP) and Cultural Addition (CA) services change greatly over time, and drive the overall WES to increase and then decrease. The spatial and temporal distribution of water resources is uneven, with WES being slightly better in the southern region than the northern region. Additionally, spatial radiation effects of typical regulating services are most prominent in S County. This finding suggests the establishment of scientific and rational intra-basin or inter-basin water management systems to expand the beneficial impacts of water-rich areas on neighboring regions.

The application of integrating comprehensive evaluation and clustering algorithms weighted by maximal information coefficient for urban flood susceptibility.

Different sub-regions of Zhengzhou city have various levels of sensitivity to flood due to the impact of urbanization. Thus, an accurate flood sensitivities assessment is a key tool for flood prevention and urban planning and development. To successfully link the urban flood sensitivity assessment with the real flood situation, a method combining clustering algorithm with comprehensive evaluation is presented. The proposed method is not affected by the classification standard of sensitivities levels and has a small and undemanding demand for flood data. First, Maximal Information Coefficient between conditional factors and flood is employed to determine the weight. Then, the different results are obtained by three clustering algorithms. Finally, a four-layer evaluation structure weighted by analytic hierarchy process is established to select the best flood susceptibility map. A case study in the Zhengzhou city, China shows that the positive scale amplification strategy is relatively best and the flood sensitivity of sub-regions in Zhengzhou city should be divided into four levels obtained by K-Means clustering. Hence, it supplies the valuable insights for the urban planning and flood mitigation.

Construction of flood loss function for cities lacking disaster data based on three-dimensional (object-function-array) data processing.

Reliable loss estimation is crucial for flood risk management. As the current standard form of flood loss assessment, it is difficult to fit the Flood Inundated Depth-Loss Rate Function (FILF) due to the lack of historical data in most inland arid and semi-arid plain cities. To address the current trend of increasing flood risk, it has become increasingly important to develop a scientific and reasonable loss assessment function or model for these cities. Therefore, the flood loss rate data of several cities were transferred through amplified characteristic indices to form a loss rate transfer vector of cities lacking disaster data based on the analogy principle. Three-dimensional data processing rules were then set, including the priority sequence of object dimensional variance and the greatest correlation coefficient (CC) of the joint dimension of function and array. Finally, a FILF of cities lacking disaster data was constructed after three-level optimization. The FILF of eight property types was calculated taking Zhengzhou City, China, as the study area. The optimal function and array dimensions were F6 (Biquadratic) and D4-D6, respectively. All CCs exceeded 0.9935, with an average of 0.9971. The joint fitting results also showed that the function dimension was more sensitive to the FILF than the array dimension. The simulated total flood loss of the Jinshui District in 20 years was 2.46 billion yuan, and there was clear spatial disparity in economic loss. This study is expected to resolve the problem of the absence of a loss function in cities or regions lacking data to support urban flood risk management.

Study on the theories and methods of ecological flow guarantee rate index under different time scales.

Human activities have altered the region's natural attributes to a certain extent, leading to the competition of resources. As a result of the contradiction between water use inside and outside the river, the river ecosystems are under increasing pressure. Ecological flow has been proposed to ensure the health of the river ecosystem and habitat integrity. However, there are few special studies on its guarantee rate and lack of systematic analysis. To scientifically evaluate the ecological flow guarantee rate, this study proposed an ecological flow guarantee index for long-time by frequency analysis and an ecological flow guarantee index for short-time by Satisfaction Rate. Taking four typical sections of the mainstream of the Huai River as the research objects, we evaluated the ecological flow guarantee rate at different time scales based on the runoff sequence from 1956 to 2018. It was found that over the mid-long term scale (multi-year series), the guarantee rate of each section during the non-flood period reached 87%, while the guarantee rate during the flood period was about 83%. Over a short time scale (day series within the year), taking typical years of wet, normal, dry, and withered years to calculate the guarantee rate within the year, the average ecological flow guarantee rate reached about 70%. In practice, the joint application of the mid-long term and short-term ecological flow guarantee rate can take into account both long-term planning and short-term regulation, ensuring the sustainable development of river ecosystems in all aspects.

The determination of flood damage curve in areas lacking disaster data based on the optimization principle of variation coefficient and beta distribution.

Flood loss assessment is an important part of urban flood risk management, and the establishment of disaster damage curve is the key of loss assessment. Because of the limitation of data, it is difficult for cities lacking disaster data to fit the damage curve through historical data. Generally, transferring the damage curve among regions is an effective method, but there are problems of data reference and statistical uncertainty. In view of the inland plain cities lacking disaster data, the damage factor of the data reference area can be transferred to the study area by referring to the principle of analogy. Then, based on the optimization principle of the minimum variation coefficient and the maximum beta distribution probability, the citation error and statistical error in the damage factor quotation were reduced, and the relatively accurate damage factor in the study area was obtained, and then the water depth - damage factor curve was established. Thus, a generalized damage curve fitting method for cities lacking disaster data was formed, which took the regional index values as the input parameters and the damage curves as the output results. Finally, taking Zhengzhou City, China as the study area, the loss curves of 10 property types were calculated. Compared with the original data, the average variation coefficient of the optimal scheme set was reduced by 0.1; the probability of the optimal value was increased by 1.39% compared with the average value. In addition, the method test was conducted in Jinan, China, where the data were available, and it was found that the three types of errors were significantly lower than the traditional comparison method of single city as reference object. This study is expected to provide a scientific reference for the establishment of flood damage curve in cities or areas lacking disaster data.

Study on the quantification of ecological compensation in a river basin considering different industries based on water pollution loss value.

The study on the quantification of ecological compensation (eco-compensation) in a river basin can help to make environmental protection more compatible with ecological construction. In this paper, the upstream and downstream of the river basin were treated as the subjects and objects of eco-compensation, and the mechanism of eco-compensation was clarified. The emergy analysis theory (EMA) was used to calculate the values of water resources in sub-industries (agriculture, industry, life, and recreation). The pollution loss rate theory (PLR) was adopted to calculate the water pollution loss rate in sub-industries. According to the value of water resources and pollution loss rate in sub-industries, combined with the water consumption of sub-industries in the river basin, the Ecological Compensation Quantification Model of Sub-industries (ECQ-Is Model) was constructed. Under the guidance of the aforementioned theory and model, a comprehensive research was conducted on the Xiaohong River. The results showed that the eco-compensation values of the upstream area, industry, and agriculture in the river basin were higher. Therefore, it is essential that the water resources in the Xiaohong River basin be well conserved and managed. In addition, the research results point out the direction for water pollution control, which includes promoting the coordinated development of the upstream and downstream, and maximizing the ecological benefits of the river basin.

Comprehensive evaluation of ecological compensation effect in the Xiaohong River Basin, China.

Due to the complexity of ecological compensation standards and methods, some problems cannot be expected before compensation, but the evaluation of eco-compensation effect can feedback the implementation effect of eco-compensation policies and provide reference for the improvement of eco-compensation policies. This paper constructed a comprehensive evaluation index system of eco-compensation, which covered social and economic development, pollution discharge and monitoring, and pollution treatment aspects. An eco-compensation comprehensive evaluation model was established, which consisted of the projection pursuit model (PP model) and the chaotic particle swarm optimization algorithm (CPSO algorithm). The Xiaohong River Basin in China was selected as a case study. Before and after the implementation of eco-compensation policy, the compensation effects in the four counties in the basin from 2008 to 2015 were evaluated. The results showed that through the implementation of the basin eco-compensation policies, the comprehensive indicators in the four counties showed an upward trend, which indicated that the eco-compensation of the basin had achieved certain effects. Among them, Xincai was the best, and could provide reference for other counties. The research results can provide new ideas and new methods for the evaluation of eco-compensation effects.

An ecological compensation standard based on emergy theory for the Xiao Honghe River Basin.

The calculation of an ecological compensation standard is an important, but also difficult aspect of current ecological compensation research. In this paper, the factors affecting the ecological-economic system in the Xiao Honghe River Basin, China, including the flow of energy, materials, and money, were calculated using the emergy analysis method. A consideration of the relationships between the ecological-economic value of water resources and ecological compensation allowed the ecological-economic value to be calculated. On this basis, the amount of water needed for dilution was used to develop a calculation model for the ecological compensation standard of the basin. Using the Xiao Honghe River Basin as an example, the value of water resources and the ecological compensation standard were calculated using this model according to the emission levels of the main pollutant in the basin, chemical oxygen demand. The compensation standards calculated for the research areas in Xipin, Shangcai, Pingyu, and Xincai were 34.91 yuan/m3, 32.97 yuan/m3, 35.99 yuan/m3, and 34.70 yuan/m3, respectively, and such research output would help to generate and support new approaches to the long-term ecological protection of the basin and improvement of the ecological compensation system.