ABSTRACT Yan, D.; Jiang, R.; Xie, J.; Zhu, J.; Liang, J., and Wang, Y., . A multivariate and multistage streamflow prediction model based on signal decomposition techniques with deep learning. Accurate streamflow forecast plays an important role in the flood control operation of reservoir and water resource management, and how to build a prediction model with high accuracy is a research hotspot. In order to improve the prediction accuracy, this paper establishes a multivariate and multistage streamflow prediction model based on the combination of mode decomposition and deep learning models, including the variational mode decomposition (VMD), improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMD), convolutional neural network (CNN), and long short-term memory (LSTM). Taking the Wei River Basin (WRB) of China as an example, streamflow in six hydrometric stations from the main stream of the WRB is used to validate the model. The results show that the proposed model have good prediction skills, and the prediction results of multistage models are better than single-stage models; however, the most complex models do not have the best results. The VMD also preformed better prediction skills than ICEEMD, and the optimal model was VCL (VMD-CNN-LSTM). The root-mean-square error, peak percentage of threshold statistic, and Nash-Sutcliffe efficiency coefficient of VCL at Huaxian station are 43.82 m 3 /s, 10.02%, and 0.94, respectively. The models proposed in this paper are suitable for streamflow forecasting, which provide reference for streamflow forecasting and sustainable watershed management.

ABSTRACT Wang, Y.P.; Jiang, R.G.; Xie, J.C.; Zhao, Y., and Li, F.W., 2020. Water resources management under changing environment: A systematic review. In: Guido Aldana, P.A. and Kantamaneni, K. (eds.), Advances in Water Resources, Coastal Management, and Marine Science Technology . Journal of Coastal Research , Special Issue No. 104, pp. 29–41. Coconut Creek (Florida), ISSN 0749-0208. Under the influences of climate change, human activities and socioeconomic development, the water resources management (WRM) has become more complex and uncertain. The paper visualizes and quantifies the knowledge base, domain and structure of the WRM using the bibliometric analysis and knowledge map. The visualized knowledge maps are used to investigate the development trend, scientific collaboration, subject categories, core research topics and the newest research fronts of the WRM. 9028 publications on the WRM were retrieved from the Web of Science Core Collection databases for the period of 1990-2018. Results indicated that the research on the WRM maintained an increasing trend for the past 29 years. China contributed the most publication, and Germany cooperated the most with other countries/regions, which were two active contributors of the WRM research. The co-word analysis and burst detective analysis of keywords showed that climate change and ecosystem were the research hotspot of the WRM knowledge base. The co-occurrence analysis and burst detective analysis of subject categories found that the Environmental Sciences & Ecology and Green & Sustainable Science & Technology were the core direction of the WRM knowledge domain. Solving the practical problems through model simulation was the core of the WRM knowledge structure under the changing environment using the cluster analysis and document co-citation analysis. It is suggested that the WRM managers should take the sustainable and adaptive development as goal, ensure the health and integrity of the ecosystem, integrate stakeholders into the WRM, which should help to make the WRM more adaptable under changing environment.

ABSTRACT Li, W.; Jiang, R.; Zhao, Y.; Xie, J.; Zhu, J., and Cao, R., 2019. Water ecological environment protection under changing environment: A systematic review and bibliometric analysis. In : Guido-Aldana, P.A. and Mulahasan, S. (eds.), Advances in Water Resources and Exploration . Journal of Coastal Research , Special Issue No. 93, pp. 9–15. Coconut Creek (Florida), ISSN 0749-0208. Systematic review is usually used to reveal the change characteristics of the quantity and law of the citations focus on one research theme. The paper investigated the research status, development trend and hotspots of water ecological environment protection using bibliometric analysis. Based on bibliometric, mathematics and statistics, articles related to the water ecological environment protection in Web of Science for the period of 2008-2019 were selected. CiteSpace software was used to conduct the annual frequency analysis of papers, countries and research institutions analysis, co-occurring keywords analysis, clustering analysis and research frontier. Results show that: (1) The number of published papers and cited papers have increased for the past 12 years. Especially, the number of published papers has increased sharply since 2015, indicating that the research on water ecological environment protection has been transferred from the exploration stage to rapid development stage, which needs to be analyzed from the aspects of national policy. (2) China has more publications than other countries. The research institutions are mainly concentrated on universities, the cooperation among them is not close. It shows the characteristics of small distribution and large concentration. Keywords such as “model” and “water quality” are research hotspots. (3) The results of clustering analysis show that water ecological environment quality assessment, water and soil conservation, ecosystem services and aquatic ecosystem are four main research directions of water ecological environment protection. (4) Using method of burst detection, nine keywords are obtained, which indicate that water ecological environment protection has rich research perspectives. The burst strength of land use is high, it will become the research hotspot of water ecological environment protection in future. The results should be beneficial to systematically understand research progress and future trends of water ecologic environment under changing environment, and therefore it promotes ecological civilization construction.

ABSTRACT Wang, Y.; Jiang, R.; Xie, J.; Zhao, Y.; Yan, D., and Yang, S., 2019. Soil and water assessment tool (SWAT) model: A systemic review. In: Guido-Aldana, P.A. and Mulahasan, S. (eds.), Advances in Water Resources and Exploration . Journal of Coastal Research , Special Issue No. 93, pp. 22–30. Coconut Creek (Florida), ISSN 0749-0208. Under the influences of climate change and human activities, the water cycle under changing environment and distributed hydrological model based on physical mechanism have become the focus of hydrology research. Soil & Water Assessment Tool (SWAT) model is one of typical distributed models, and it has been widely used in testing and forecasting the water and sediment circulation and agriculture production with chemicals. The paper used CiteSpace to analyze the research progress based on previous literatures. The results of high frequency keywords and co-word analysis show that the research hotspots of SWAT model include water quality problem, sediment yield, model calibration, uncertainty analysis and sensitivity analysis. The literatures related to SWAT were divided into model application, model accuracy and model coupling. The paper mainly focused on the literature related to model application. The domestic and abroad research processes were reviewed from three hot application fields such as runoff simulation, hydrological impacts under changing environment (HIUCE) and non-point source (NPS) pollution. The results show that: (1) the research content of runoff simulation mainly focused on the adaptability and accuracy of the model; (2) the research content of HIUCE mainly concentrated on analysis of historical changes in hydrological effects and prediction of future changes using the scenario analysis; (3) the research content of NPS pollution mainly focused on the spatial and temporal distribution of nutrients, the influencing factors and degree of nutrients, and the prediction of future to select Best Management Practices (BMPs). The paper pointed out some existing problems, prospected the future research, and proposed research idea of model improvement to adapt to the domestic changing environment. This study should be beneficial to systematically understand the structure, principle, application fields and future development trends of SWAT model, and thus provide references for users of SWAT model in related subjects.

ABSTRACT Wang, X.; Jiang, R.; Xie, J.; Zhao, Y.; Li, F., and Zhu, J., 2019. Multiscale variability of precipitation and their teleconnection with large-scale climate anomalies: A case study of Xi'an city, China. In: Guido-Aldana, P.A. and Mulahasan, S. (eds.), Advances in Water Resources and Exploration . Journal of Coastal Research , Special Issue No. 93, pp. 417–426. Coconut Creek (Florida), ISSN 0749-0208. The changes of precipitation affect the urban rainstorm waterlogging and water resources management, which have important influences on the sustainable development of society. The primary objective of the paper is to provide theoretical basis for local water resources management and disaster prevention and reduction by analyzing the multiscale variability of precipitation and their teleconnection with large-scale climate anomalies in Xi'an city of China. The change characteristics of precipitation and extreme precipitation indices were investigated using Mann-Kendall test, Spearman's rank correlation and wavelet analysis. The cross wavelet transform and wavelet coherence were used to explore the correlations between the precipitation and large-scale teleconnection indices such as Arctic Oscillation (AO), Southern Oscillation Index (SOI), El Niño-Southern Oscillation (ENSO) and sunspot. Results indicate that: the precipitation was mainly concentrated in summer, followed by autumn. The annual, seasonal and monthly precipitation except June and August had decreasing trends, and the magnitudes of precipitation decrease were more pronounced in spring, April and November. The change patterns varied for extreme precipitation indices. The temporal variation in extreme precipitation indices indicated that the extreme precipitation events had mainly increased during 1971-1990 and 1991-2017, and decreased during 1951-1970 and 1951-2017, especially, increased more pronounced during 1991-2017 and decreased more pronounced during 1951-1970. The precipitation exhibited a fluctuant change from increase to decrease, then increase to decrease and finally increase trends, and there was an abrupt change point in 1965. The annual precipitation had statistically significant cycles of 3-5 year and 7-10 year at 5% significance level. The large-scale teleconnection indices affected the precipitation in Xi'an city. The phase differences between precipitation and teleconnection indices including AO and SOI were in-phase dominated, and anti-phase dominated between precipitation and teleconnection indices including ENSO and sunspot, indicating that the AO and SOI exerted positive climate impacts on the precipitation and vice-versa for ENSO and sunspot.