High Levels Of Coupling Research Articles

On-orbit transportation with non-conserved momenta by cooperative space robots

The demands of on-orbit transporting large structures via multiple space robots are emerging in space applications to increase the limited transportation capability of single space robots. However, the high level of system coupling arising from the increased number of individuals and physical interaction between structures and robots brings great challenges to the consequent control. This paper focuses on the motion planning of collaboratively transporting a large space structure using rigidly connected space robots. First, the system model is established at a kinematic level with non-conserved momenta due to the effects of thrusters on the bases of robots. Then, a cooperative control model is formulated to minimize the fuel consumption by balancing the thrusts and torques respectively acting on the bases and redundant arm joints of space robots. The physical limitations of space robots and mission related constraints such as joint angle limits, control input saturation and collision avoidance for multiple space obstacles are also taken into account in the optimization. Afterwards, the effectiveness of the proposed control scheme is validated and demonstrated by numerical case studies.

Research on the coupling test and organizational collaboration relationship between emergency plans and emergency responses—Based on the social network analysis method

Emergency plan is the action guide of emergency response, and the high coupling level and smooth organizational collaboration between emergency plan and emergency response are the necessary conditions for successful response to emergencies. Based on the case of “4–18″ fire accident in Beijing Changfeng Hospital, use social network analysis to quantify and visualize the coupling level and organizational collaboration relationship between emergency plan and emergency response from the overall network and individual central network. The results of the study found that in the overall network, the emergency plan and emergency response organization collaborative relationship network, has a high level of coupling and organizational collaboration. In the individual central network, the network of emergency plan and emergency response organization collaborative relationship has a low level of coupling and organizational collaboration. The results of this study reveal a noteworthy finding that the function of media organizations is unusually prominent in the network of emergency response organization collaboration, while it is not found in the network of emergency plan organization collaboration. As global risks continue to evolve, the results of the study provide valuable insights for other countries and regions seeking to establish emergency plan networks and emergency response networks with high levels of coupling and organizational collaboration, which are essential for enhancing global disaster prevention, mitigation, and response capabilities.

Construction and evolutionary pattern of the coupling relationship network of regional sustainable development in China

Climate change poses a serious threat to the survival and development of humankind. Accordingly, sustainable socioeconomic transformation has become a major global concern. This study quantitatively assesses the process and speed of regional-level sustainable development in China, as well as the degree of coupling and the degree of coupling coordination among Sustainable Development Goals (SDGs). To this end, based on regional development and data monitoring in China, we construct a regional sustainable development assessment system containing 111 indicators, which combines existing sustainable development assessment indicators with the indicators of the 2030 Agenda for Sustainable Development. On that basis, using network topology construction and modal transformation, we propose a framework for analyzing the coupling relationships and evolutionary patterns of regional sustainable development. The study found that the score for SDGs at the national level increased from 50.80 in 2010 to 60.86 in 2020, showing a good development trend and the differences between provinces and regions was gradually reduced. The development speed of regional sustainable transformation shows a change from decreasing to increasing. In recent years, there is a significant change in the acceleration of regional sustainable development in China, with the vast majority of provinces having positive acceleration and only three provinces having negative acceleration. China's regional sustainable development shows that mutual coordination and promotion among provinces was higher in the eastern area than in the central region, which was higher than in the western area. The sustainable processes of each region and the coordination of sustainable development steadily increased toward a high level of coupling, all achieving coordinated development. The degree of coupling coordination and the SDG scores in each region were positively correlated with economic development, reflecting the role of economic development in the promotion of sustainability. However, this positive correlation showed a tendency of strengthening and then weakening. The correlation of the evolution patterns in the eastern–central, eastern–western, and central–western regions over time presented a trend of first weakening, then strengthening, and then weakening. Although the process of promoting sustainable development in western and central regions over time is weak synergistic consistency with that in eastern regions, overall, China's regional sustainable development presents a development model of multi-province linkage and multi-goal coordination.

β-cell intrinsic dynamics rather than gap junction structure dictates subpopulations in the islet functional network.

Diabetes is caused by the inability of electrically coupled, functionally heterogeneous β-cells within the pancreatic islet to provide adequate insulin secretion. Functional networks have been used to represent synchronized oscillatory [Ca2+] dynamics and to study β-cell subpopulations, which play an important role in driving islet function. The mechanism by which highly synchronized β-cell subpopulations drive islet function is unclear. We used experimental and computational techniques to investigate the relationship between functional networks, structural (gap junction) networks, and intrinsic β-cell dynamics in slow and fast oscillating islets. Highly synchronized subpopulations in the functional network were differentiated by intrinsic dynamics, including metabolic activity and KATP channel conductance, more than structural coupling. Consistent with this, intrinsic dynamics were more predictive of high synchronization in the islet functional network as compared to high levels of structural coupling. Finally, dysfunction of gap junctions, which can occur in diabetes, caused decreases in the efficiency and clustering of the functional network. These results indicate that intrinsic dynamics rather than structure drive connections in the functional network and highly synchronized subpopulations, but gap junctions are still essential for overall network efficiency. These findings deepen our interpretation of functional networks and the formation of functional subpopulations in dynamic tissues such as the islet.

Extended state observer based dynamic iterative learning for trajectory tracking control of a six-degrees-of-freedom manipulator

With the development of industrial automation comes an ever, broadening number of application scenarios for manipulators along with increasing demands for their precise control. However, manipulator trajectory tracking control schemes often exhibit problems such as those related to high levels of coupling, complex calculations, and in various difficulties in application for industrial environments. For the problems of low accuracy in control and poor robustness of multiple-jointed robotic trajectory tracking, iterative learning control (ILC) with model compensation (MC) based on extended state observer (ESO) has been proposed for the trajectory tracking control of six-degrees-of-freedom (six-DOF) manipulators. The scheme has excellent features to overcome uncertainties in repetitive tasks, including unknown bounded perturbations that are external to the model or dynamic perturbations that are internal to the model. The proposed control strategy combines ESO, iterative learning, and MC, for precise control of trajectory tracking. Here, ESO is used to estimate disturbances, iterative learning allows fast and accurate control in repeated tasks, and the model-compensated control algorithm alleviates the necessary for many inverse operations. The convergence of our proposed control scheme is proved through Lyapunov function and time-varying approximation theory. Simulation and experimental results verify the validity of the proposed scheme.

Technological diversification, technological coupling and invention performance

PurposeTo investigate the relationship between technological diversification and firm performance as a function of varying levels of technological coupling and internal technological change.Design/methodology/approachA longitudinal study of US-based bio-pharmaceutical companies.FindingsTechnological diversification improves invention performance. However, high levels of technological coupling reduce this effect.Practical implicationsFirms with highly diversified technological portfolios should strive to keep their technologies at low levels of technological coupling.Originality/valueThis is the first study to show that technological coupling reduces the positive effect of technological diversification on firms' invention performance.

Coupling Coordination Degree between Ecological Environment Quality and Urban Development in Chengdu–Chongqing Economic Circle Based on the Google Earth Engine Platform

Rapid urbanization often exerts massive pressure on the resources relied upon by the ecological environment. It is necessary to quickly evaluate the interaction and mutual influence between regional urbanization and the ecological environment. This paper uses the Google Earth Engine (GEE) platform, integrates MODIS and night light remote sensing data sets, and computes the remote sensing-based ecological index (RSEI) and the coupling coordination degree (CCD) to measure the coupling coordination and analyze the spatiotemporal changes in the Chengdu–Chongqing Economic Circle (CCEC) for 2010, 2015, and 2020. Our results demonstrate four key findings. Firstly, the CCD varies spatially; it peaks at the Chengdu and the West Chongqing Plains, decreasing outwards along the mountains, with the lowest degree of coupling in the central, southern, and northern edge areas of the CCEC. Additionally, it has shown a trend of maintaining unchanged first and then increasing, mainly responding to policy decisions. Secondly, the changes between the different coupling levels were almost stable and mainly occurred between adjacent levels. Thirdly, the coupling level of towns spreads outwards from the centers at Chengdu and Chongqing and has an overall upward trend in time. Fourthly, in the most recent year, the coupling types present a distribution pattern of one developing axis connected with two peaks. Specifically, the environment system lagging type aggregates in Chengdu, Chongqing, and their surrounding areas, and the others mainly are economic system lagging type. The high internal coupling type also mainly occurs in the high and low coupling levels. Under this context, constructive suggestions for developmental optimization in the study area were proposed.

Coupling and interaction between science and technology finance and green development: Based on coupling coordination degree model and panel vector autoregression model

Exploring the coupling and coordination between science and technology finance and green development is a critical action that needs to be addressed in achieving high-quality development in China. Based on the coupling coordination degree model and panel vector autoregression (PVAR) model, this paper uses the relevant data of 274 cities in China from 2003 to 2020 to study the relationship between science and technology finance and green development. The results show that: 1) The relationship between science and technology finance and green development has changed from low coupling coordination to medium coupling coordination in the sample period. 2) The Beijing-Tianjin-Hebei, Yangtze River Delta, and Pearl River Delta regions are at a relatively high level of coupling and coordination as a whole, while other regions are at a relatively low level of coupling and coordination. 3) Through the analysis of the spatial characteristics of the coupling coordination degree, it is found that the coupling coordination degree of China’s urban science and technology finance and green development is generally positive spatial autocorrelation. Spatial correlations continue to strengthen over time. 4) By establishing a PVAR model, we examined the interaction between science and technology finance, green development, and their coupling coordination. Science and technology finance, green development and their coupling coordination degree are themselves affected. We have comprehensively and objectively grasped the matching status of China’s urban science and technology finance and green development, providing a reference for promoting the adaptation of science and technology finance to green development.

Research on the Dynamic Coupling and Coordination of Science and Technology Innovation and Sustainable Development in Anhui Province

The coupling of and coordination between science and technology innovation (STI) and sustainable development (SD) is a basic requirement for Anhui Province’s economic high-quality development. According to panel data of 16 prefecture-level cities in Anhui Province from 2010 to 2021, the entropy method was applied to quantify the comprehensive development level of the two systems. The models of coupling coordination degree, grey GM (1, 1), and ARIMA prediction were constructed to analyze the spatiotemporal dynamic evolution features of the two systems’ coupling coordination. In the time series, the two systems’ comprehensive development showed a steady increase, a high level of coupling, and an increasing overall trend of coupling coordination. Moreover, the two systems’ coupling and coordination levels show the gradient spatial differentiation characteristics of “central > east > west.” The prediction shows that the two systems’ coupling coordination degree exhibits a monotonic increasing trend and reaches the optimal coupling coordination state around 2030. This study provides a decision-making reference for the implementation of the innovation-driven development strategy of Anhui Province.

Investigation on the spatial and temporal patterns of coupling sustainable development posture and economic development in World Natural Heritage Sites: A case study of Jiuzhaigou, China

To continue directing global sustainable development efforts from 2015 to 2030, the United Nations adopted 17 global development goals known as the Sustainable Development Goals (SDGs) when the Millennium Development Goals (MDGs) from 2000 to 2015 expired. Sustainable development of World Natural Heritage Sites is one of these 17 MDGs and a crucial step toward achieving global sustainability. A scientific and systematic indicator system that can measure the sustainable development of natural World Heritage Sites more objectively and fairly is urgently needed to support the establishment of SDG11.4 on a Chinese scale and to help with the subsequent promotion of the development of natural World Heritage Sites. This study proposes a comprehensive assessment indicator system for the sustainable development of natural heritage sites based on the theoretical framework of “value contribution-environmental effect” to quantify the sustainable development of natural heritage sites. The study is based on the ecological environment and regional economic and social data of Jiuzhaigou World Natural Heritage Site from 2010 to 2020. Finally, the degree of coupling and coordination between the natural environment and economic development is assessed and studied. The results show that tourism to the World Heritage Site drove rapid economic development in Jiuzhaigou County between 2010 and 2020. As the fame of the World Heritage Site Jiuzhaigou has grown, so has the per capita income of local locals, making them unduly reliant on tourists for a living. Meanwhile, both the 2017 earthquake and the COVID-19 epidemic in 2019 have had substantial detrimental effects on the local economy. Furthermore, the Jiuzhaigou sustainable development trend from 2010 to 2020 exhibits a “W-shaped” curve, and there is a high level of positive coupling between the Jiuzhaigou sustainable development trend and economic development, and the two are mutually reinforcing.

Stress Relaxation in a Cellular Model of Elements with Nonlinear Interaction

A model of stress relaxation in a system of discrete elements is analyzed. The model suggests analyzing a small-time scale of the process when external supply of additional stresses in the system are negligibly small. The nonlinear interaction of elements is similar to the interaction of elements in the open dissipative OFC model. Toppling conditions are determined by the static fatigue effect. It is shown that at a high level of element coupling, the model is characterized by a power-law decay of the drop frequency in time, similar to that observed in aftershock sequences of earthquakes. This regularity slightly depends on the initial distribution of stresses in the system, its exponent is p = 0.85–10 for the element coupling parameter α = 0–0.25. The analysis of the value of the time delay c for the formation of a power-law drop frequency decay shows that this parameter correlates with the duration of large-amplitude drops at the initial step of the relaxation process. The value c is defined in this case by the parameter α. Calculations also shows that relaxation of the mean stress σ(t) in the system of elements follows the relation \(t \propto {{e}^{{ - \gamma \sigma }}}\) with a time delay corresponding to the value for the drop frequency dependence. At the same time, there is no delay in the time series of the mean stress decrease during the drop of an individual element \(d\sigma \). The dependence \(d\sigma \left( t \right)\) is defined by the relation \(t \propto {{e}^{{ - \beta \Delta \sigma }}}\) in the entire temporal interval of the relaxation process. The value β linearly decreases with the increase of element coupling α in the model.

Spatiotemporal Differentiation of the Coupling and Coordination of Production-Living-Ecology Functions in Hubei Province Based on the Global Entropy Value Method

Rapid urbanization and industrialization have brought about regional prosperity and pressure on the ecological environment, and the disorder of development has led to competition among the production-living-ecology functions. How to build livable cities, optimize the spatial layout of land, and promote the coordinated development of the production-living-ecology functions in various regions has become an important issue in the sustainable development and utilization of land space. In order to study the spatiotemporal conflict and coordination of the production-living-ecology functions with respect to the dramatic developments associated with the 21st century, this study took Hubei Province, which is the top-ranking economic region in China in recent years, as the study area and adopted the global entropy value method, triangle model, and coupled evaluation model to delineate an index system to measure the degree of conflict and coordination of the production-living-ecology functions in Hubei Province from 2000 to 2020, and also delineate zoning management based on statistical yearbook data. The results showed the following: (1) With respect to the time scale, the indices of the production-living-ecology functions in Hubei Province increased year by year, and the degree of coordination also increased yearly, from the stage of disorder with certain conflict to the stage of coordination with a high level of coupling. (2) On the spatial scale, the development of production-living-ecology functions in Hubei Province was unbalanced, which may be related to the overall development strategy of "two circles and one belt" in Hubei Province, with the eastern part of the province having a higher degree of coordination of the production-living-ecology functions and the western part having a lower degree of coordination. (3) Among the production-living-ecology functions, the ecological function of Hubei Province as a whole exhibited minimal change and maintained stable development, while the living and production functions underwent considerable development, indicating that Hubei Province has protected the orderly development of the ecological environment in the process of urbanization and new industrialization. (4) According to the development and coordination of the production-living-ecology functions in each region of Hubei Province, four development management zones were created: high-quality development zone, secondary development zone, balanced development zone, and development potential zone. Finally, policy suggestions are given for each zone.

The Coupling and Coordinated Development of Green Builds and Financial Development in China.

As a labor-intensive industry with a strong industrial driving force and high-technology integration, green buildings offer some comparative advantages. Driven by the concept of green development, green buildings are ushering in a period of opportunity for integrated development among multiple fields. Therefore, this research will select the panel data of the financial industry and the green buildings industry in 2014 and 2018, respectively, in 31 provinces in China (excluding Hong Kong, Macao and Taiwan) and, through the method of factor analysis, will innovatively construct a financial industry development index and a green building Development Index for each province in China. Through the coupling coordination model, it studies the development level of the financial industry and green buildings in various provinces, in order to deeply explore the path and mechanism of coordinated development between the two. The results show that the financial industry and green buildings in the eastern coastal areas have a high level of coupling, and the coupling and coordinated development have a greater degree of correlation. The potential for coupling and coordination in Central China is developing for the better, while volatility in the Northeast and Northwest regions is relatively large. From the time dimension angle, the degree of coupling and coordination between green buildings and the financial industry in China is generally low, and in the transitional stage, from the brink of unbalanced development to a primary stage of coordinated development. Accordingly, this paper proposes that local government should pay attention to the coordination relationship between green buildings and financial industry development and formulate a coordination mechanism between their growth according to local conditions, so as to promote the correct interactive advancement of the two.

Nanoscale Femtosecond Dynamics of Mott Insulator (Ca0.99Sr0.01)2RuO4

Ca2RuO4 is a transition-metal oxide that exhibits a Mott insulator-metal transition (IMT) concurrent with a symmetry-preserving Jahn-Teller distortion (JT) at 350 K. The coincidence of these two transitions demonstrates a high level of coupling between the electronic and structural degrees of freedom in Ca2RuO4. Using spectroscopic measurements with nanoscale spatial resolution, we interrogate the interplay of the JT and IMT through the temperature-driven transition. Then, we introduce photoexcitation with subpicosecond temporal resolution to explore the coupling of the JT and IMT via electron-hole injection under ambient conditions. Through the temperature-driven IMT, we observe phase coexistence in the form of a stripe phase existing at the domain wall between macroscopic insulating and metallic domains. Through ultrafast carrier injection, we observe the formation of midgap states via enhanced optical absorption. We propose that these midgap states become trapped by lattice polarons originating from the local perturbation of the JT.

Research on the Temporal and Spatial Evolution of the Dynamic Coupling and Coordinated Development of Two-Way FDI in Jinan City

Under the background of "dual circulation", to implement the international investment concept of "bringing in" and "going global", it is urgent to realize the coupling and coordinated development of IFDI and OFDI. On the basis of trying to explore the coupling and coordination mechanism of two-way FDI in Jinan City, this paper uses the system coupling evaluation model to measure the coupling degree and coupling coordination degree. The results show that from 2003 to 2020, the coupling degree of two-way FDI in Jinan was at a high level of coupling, but the coupling coordination degree was low.

Wildfire decouples soil multi-element cycles: Contributions of legacy effects and temporal variations

High-severity wildfires may lead to significant impacts on biogeochemical cycling both by burning biomass and by fire legacies. However, the legacy effects of wildfires on multiple soil element cycles across temporal trajectories have rarely been discussed. Here, we evaluated the availability and stability of seven essential soil elements and their stoichiometric ratios, as well as the coupling of multiple and individual elements, over more than two years in a half-mature, severely burnt (SB) artificial Pinus tabuliformis Carr. forest in North China (Beijing) in comparison with the unburnt (UB) control. Despite element concentrations jumped up and down remarkably during the first few months, results showed that the average availability and stability of all elements in soils of the SB site were lower than those of the UB site and legacy effects of fire were consistently significant on available nitrogen (N), phosphorus (P) and sodium. Temporal trajectories (months to years) varied amongst elements, and organic carbon (C) and N depleted more than other elements did. High levels (i.e. above the null model threshold) of multi-element coupling in soils of the UB site were maintained during our monitoring periods. By contrast, a reduction in the degree of element coupling was detected over time in soils of the SB site, which was concomitant with the core role of C and the great variability of P. Fire- and time-induced shifts in cation exchange capacity, acid phosphatase activity, capillary porosity and aggregate fraction dominated the uncoupling of multiple soil elements, implying the critical contributions of fire legacy effects and temporal variations. These responses have important implications for the consideration of additional long-term studies because such biogeochemical decoupling of elements may have unpredicted consequences under global change scenarios. Meanwhile, this work is helpful to predict the direction of ecosystem succession and to provide scientific evidence for management practices.

Intelligent Modeling of the Incineration Process in Waste Incineration Power Plant Based on Deep Learning

The incineration process in waste-to-energy plants is characterized by high levels of inertia, large delays, strong coupling, and nonlinearity, which makes accurate modeling difficult. Therefore, an intelligent modeling method for the incineration process in waste-to-energy plants based on deep learning is proposed. First, the output variables were selected from the three aspects of safety, stability and economy. The initial variables related to the output variables were determined by mechanism analysis and the input variables were finally determined by removing invalid and redundant variables through the Lasso algorithm. Secondly, each delay time was calculated, and a multi-input and multi-output model was established on the basis of deep learning. Finally, the deep learning model was compared and verified with traditional models, including LSSVM, CNN, and LSTM. The simulation results show that the intelligent model of the incineration process in the waste-to-energy plant based on deep learning is more accurate and effective than the traditional LSSVM, CNN and LSTM models.

Urban water environment carrying capacity based on VPOSR-coefficient of variation-grey correlation model: A case of Beijing, China

In order to gain an in-depth understanding of the change of urban water environment carrying capacity (WECC), we proposed a framework system of VPOSR (vigor, pressure, organization, state and resilience subsystem), which was used to construct an evaluation index system for urban WECC. The coefficient of variation grey correlation method was employed to analyze the urban WECC of each subsystem of Beijing, China from year 2008 to 2016. The coupling coordination degree of each subsystem were calculated. The results show that: (1) The evaluation index value of WECC in Beijing is on the rise from 0.3560 in 2008 to 0.7877 in 2016, which suggests that the index of WECC of Beijing is improving, and the social and economic development is within an affordable range of the water environment. (2) The rate of ecological water usage, the proportion of energy conservation and environmental protection in local financial expenditure and the per capita water resources are the top three indicators with great impact on WECC. (3) The correlation degree index of vigor subsystem, pressure subsystem, organization subsystem, state subsystem, and resilience subsystem with water environment carrying capacity system are 0.0958, 0.1169, 0.0252, 0.0328 and 0.2962 respectively. The subsystem with strong correlation with water environment is resilience subsystem, followed by pressure subsystem. (4) According to the index distribution of coordination degree, the coordination degree level is between 0.4032 and 0.4458, and the coupling degree of each subsystem is above 0.8, which belong to the high coupling level.

Coupling Relationship of Urban Ecological Environment in Jiangsu, China

As the contradiction between urbanization and the ecological environment becomes more prominent, a coupling degree model based on coupling theory needs to be established to calculate their comprehensive levels. The coupling degree of the 13 cities in Jiangsu reveals the spatial pattern to propose countermeasures and suggestions. The results show that the comprehensive level of urbanization presents a stepped municipal spatial pattern of “the southern is higher than the central region and the central region is higher than the northern”. The spatial pattern of the urban ecological environment is observed in two extreme cities, while the other cities are not significantly different. The degree of coupling and coordination between them has reached a high level of coupling, showing a spatial pattern of “stepped down to the north to the north”. Finally, we propose targeted development strategies for different levels of regions.

Spatio-temporal coupling coordination analysis between marsh vegetation and hydrology change from 1985 to 2019 using LandTrendr algorithm and Google Earth Engine

The interaction between marsh vegetation and hydrology has become one of the hotspots in the field of ecosystem research. Taking the Honghe National Nature Reserve as the study area, this paper integrated the GEE platform and LandTrendr algorithm to build a spatio-temporal monitoring model for marsh vegetation and hydrology change using remote sensing techniques for the first time. The temporal and spatial dynamics of disturbance and restoration of marsh vegetation and hydrology from 1985 to 2019 were monitored. The Magnitude and Duration were selected to explore the temporal and spatial dynamic evolution of marsh vegetation and hydrology in the past 35 years. At the same time, an innovative coupling coordination model of marsh vegetation and hydrology was constructed to quantitatively assess the relationship between vegetation loss and restoration and hydrology change. The sensitivity analysis of the coupling relationship between marsh vegetation and hydrology was carried out by the transfer entropy model, and the influencing factors of marsh vegetation change were determined using the transfer rate. The results showed that: (1) This paper integrates the time series Landsat series images and the LandTrendr algorithm to monitor the dynamic changes of marsh vegetation and hydrology, and the accuracy rates are 83.68% and 85.78%, respectively, which proves that this method can effectively monitor the spatiotemporal evolution of marsh vegetation and hydrology. (2) In the past 35 years, the marsh vegetation in the study area has generally shown a recovery trend, and the recovery duration is ≥ 20 years. The vegetation disturbance is fragmented and marginalized, and the disturbance duration is less than 20 years. (3) The quadratic regression model was utilized to quantify the correlation between marsh vegetation and hydrology changes. The R2 between vegetation loss and restoration, and hydrology reached 0.885 and 0.811, respectively, which indicated that there is a significant correlation between wetland hydrology and vegetation changes. (4) The relationship between marsh vegetation and hydrology were in a state of imbalance from 1985 to 2019, but there was a high level of coupling between vegetation loss and hydrological changes. (5) The transfer entropy from hydrological changes to vegetation loss and restoration is significantly larger than the transfer entropy from marsh vegetation loss and restoration to hydrological changes, which indicated that hydrological changes are the driving factor for marsh vegetation loss and restoration.