Abstract:In this paper, the finite-time synchronization between two complex dynamical networks via the periodically intermittent adaptive control and periodically intermittent feedback control is studied. The finite-time synchronization criteria are derived based on finite-time stability theory, the differential inequality and the analysis technique. Since the traditional synchronization criteria for some models are improved in the convergence time by using the novel periodically intermittent adaptive control and periodically intermittent feedback control , the results of this paper are important. Numerical examples are finally presented to illustrate the effectiveness and correctness of the theoretical results.

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With the rapid development of urbanization, more and more cities are facing the risk of flood disasters and the threat of water environment safety during the rainy season. Sponge City, as a new urban water resources management method, has attracted extensive attention in the academic circle. In order to promote the development of Sponge City, a bibliometric analysis method based on Web of Science (WoS) database and Bibliometrix tool is proposed in this study. After refining the retrieved 26,383 papers, 1456 papers were obtained. All the article information including author, keywords and publication time was downloaded. The bibliometric analysis model was established to analyse and discuss the development of Sponge City and related researches during the period 1998-020 (data up to 15 August 2020). Research performance, research focus and development trend were displayed by bibliometric measurement indicators and visual graphics. The results show that the number of research papers on Sponge City has been increased year by year in the past 10 years (2010-2020). Sponge City and related research are increasing rapidly, and the top five countries in terms of research volume are China, the United States, the United Kingdom, South Korea and Canada. China, the United States, the United Kingdom and Australia are the countries with the most extensive international cooperation in the field of Sponge City. Keywords such as 'Sponge City', 'LID (Low Impact Development)' and 'SWMM (Storm Water Management Model)' appeared frequently. In our opinions, interdisciplinary research methods, digital information management technology and comprehensive performance evaluation are the hot research directions for Sponge City in the future. This study aims to provide directions for future research on Sponge City, as well as scientific guidance and reference for government decision makers on Sponge City.

Basin ecohydrological processes are essential for informing policymaking and social development in response to growing environmental problems. In this paper, we review watershed ecohydrology, focusing on the interaction between watershed ecological and hydrological processes. Climate change and human activities are the most important factors influencing water quantity and quality, and there is a need to integrate watershed socioeconomic activities into the paradigm of watershed ecohydrological process studies. Then, we propose a new framework for integrated watershed management. It includes (1) data collection: building an integrated observation network; (2) theoretical basis: attribution analysis; (3) integrated modeling: medium- and long-term prediction of ecohydrological processes by human–nature interactions; and (4) policy orientation. The paper was a potential solution to overcome challenges in the context of frequent climate extremes and rapid land-use change.

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Precipitation, as an important part of the hydrological cycle, is often related to flood and drought. In this study, we collected daily rainfall data from 21 rainfall stations in Shaanxi Province from 1961 to 2017, and calculated eight extreme climate indices. Annual and seasonal concentration indices (CI) were also calculated. The trends in the changes in precipitation were calculated using the M–K test and Sen’s slope. The results show that the precipitation correlation index and CI (concentration index) in Shaanxi Province are higher in the south and lower in the north. For the annual scale, the CI value ranges from 0.6369 to 0.6820, indicating that Shaanxi Province has a high precipitation concentration and an uneven distribution of annual precipitation. The eight extreme precipitation indices of most rainfall stations showed a downward trend during the study period, and more than half of the stations passed the 0.05 confidence interval test. Among them, the Z value of PRCPTOT (annual total precipitation in wet days) at Huashan station reached −6.5270. The lowest slope of PRCPTOT reached −14.3395. This shows that annual rainfall in Shaanxi Province has been decreasing in recent decades. These findings could be used to make decisions about water resources and drought risk management in Shaanxi Province, China.

As an essential part of the hydrological cycle, precipitation is usually associated with floods and droughts and is increasingly being paid attention to in the context of global warming. Analyzing the change trends and correlation of temperature and extreme precipitation indicators can effectively identify natural disasters. This study aimed to detect the correlation and change trends of temperature and extreme precipitation indicators in Inner Mongolia from 1960 to 2019. Panel vector autoregression (PVAR) models based on Stata software were used to detect the correlation between temperature and extreme precipitation indicators at 35 climatological stations throughout Inner Mongolia. The temperature and extreme precipitation indicator trends were analyzed using the Mann–Kendall test and Sen’s slope method. The spatial distribution characteristics of the annual precipitation and rainfall intensity were more significant in the southeast and more minor in the northwest, while an increase in the annual wet days was noticeable to the northeast. The Granger cause tests of the temperature and the extreme precipitation indicators showed a correlation between each indicator and temperature at the significance level of 1%. The temperature positively correlated with only the rainfall intensity while negatively correlating with the remaining indicators. There is no doubt that trend analysis showed significant increasing trends in rainfall intensity at all stations, which means increased risk in extreme precipitation events. By contrast, the annual precipitation and annual wet days showed significant decreasing trends, which means that the precipitation is concentrated, and it is easier to form extreme precipitation events. The study can provide a basis for decision-making in water resources and drought/flood risk management in Inner Mongolia, China.