Search

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The digital twin watershed is an important part of the digital twin earth. Clarifying the theoretical definition and connotation of the digital twin watershed is the premise and foundation for the research and construction of the digital twin watershed, and it is of great significance for the intelligent management of the watershed. Based on the digital twin theory and technology, the following research has been carried out in this paper. ① The definition of a digital twin watershed is given, and it is considered that a digital twin watershed is a new infrastructure and new paradigm serving the entire life- cycle management of the watershed, which is the interactive mapping, co- intelligence evolution, and virtual reality integration between physical and virtual watersheds driven by the full amount of data and domain knowledge, and the differences between a digital twin watershed and traditional modeling and simulation are analyzed. ② The connotation of a digital twin watershed is to realize the full life- cycle control of physical watershed objects by loading the physical watershed into the virtual watershed, mapping the physical watershed with the virtual watershed, and then managing and controlling the physical watershed using the virtual watershed. Its characteristics include high fidelity, evolution autonomy, real-time synchronization, closed- loop interaction, and symbiotic evolution. ③ The basic model of a digital twin watershed is composed of a physical watershed, a virtual watershed, the real-time connection and interaction, the digital enabling service, the twin watershed data, and the twin watershed knowledge. Its core capabilities include physical watershed perception and control, digital expression of all of the water-related elements, visual dynamic presentation of real scene, watershed data fusion supply, watershed knowledge fusion supply, watershed simulation and deduction, and self- learning and optimization of digital twin watershed. ④ This paper puts forward the key scientific problems and key technical systems to be solved in the digital twin watershed, and looks forward to the development direction of the digital twin watershed from the perspective of a perception network, data network, knowledge network, model network, and service network, and expounds the enabling field of the digital twin watershed. This paper aims to provide theoretical guidance for the application of digital twin watershed technology through the new research paradigm of digital twin watershed theory and to provide useful inspiration and reference for future smart watershed research and the application of digital technology in watershed governance and management. [ABSTRACT FROM AUTHOR]

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

For rivers flooded by rain, the annual sediment load is mainly derived from one or several rainstorms in the flood season and is of research significance. Based on the theory of runoff erosion power, the M-K method and the daily measured runoff and sediment data for the Xiaoheba, Luoduxi, Wusheng and Beibei stations in the Jialingjiang River basin, this paper analyzed the sediment transport characteristics during flood events in different periods and regions. The results of this paper are as follows: the runoff and sediment discharge during the flood season mainly came from the main stream of the Jialingjiang River. In general, the runoff discharge of flood events in different regions showed no significant decreasing trend, while the sediment transport modulus (sediment load) showed a significant decreasing trend except at Xiaoheba station in 2013-2020. With the gradual increase in runoff erosion power, the variation ranges of the sediment transport modulus (sediment load) in different periods in the Jialingjiang River basin were correspondingly narrowed. The degrees of influence of human activities on the sediment transport processes were weakened in the order of the Wusheng station in mainstream Jialingjiang River, Luoduxi station in Qujiang River and Xiaoheba station in Fujiang River. Affected by the Wenchuan earthquake and rainstorms, the average sediment loads in flood event of the Xiaoheba and Beibei stations in 2013-2020 were higher than those in 1998-2012, while the rate of increase rate at the Beibei station was less than that of the Xiaoheba station. [ABSTRACT FROM AUTHOR]

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The hyporheic zone is a region where surface and subsurface water mix in rivers. It is an important area for the exchange of mass and energy and an essential habitat for aquatic organisms. However, the deposition of colloidal particles in the hyporheic zone can modify the hydrodynamics and ecological environment of the river system. Through recirculating flume experiments and numerical simulations, this paper aims to investigate the transport of colloidal particles between stream and streambed, and clarify the pattern of colloidal particles′ deposition in the hyporheic zone as well as the influence of different factors over particles′ deposition. The results show that the colloidal particles in the overlying water will gradually retain in the streambed and accumulate in the shallow layer. The horizontal distribution of the retained particles tends to be higher on the stoss- side and lower on the lee- side. Hyporheic exchange, settlement of particles and retention of streambed are 3 most important factors in the deposition of colloids in the hyporheic zone. This paper can be helpful for understanding ecological and environmental functions of colloidal particles in hyporheic zone, and it can provide theoretical support for environmental and ecological restoration and health management of rivers. [ABSTRACT FROM AUTHOR]

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The field of deep learning research in hydrology primarily aims to enhance prediction capabilities. However, the intricate structure of deep learning models often leads to predictions that are difficult to explain and trust, making the development of trustworthy deep learning models a challenging and increasingly important topic. In this paper, we present a novel hybrid model that combines the strengths of deep learning and physical-based hydrological models to improve predictions in hydrology. Utilizing a framework of a residual error model, our approach develops a VB- LSTM (variational Bayesian deep learning model) to quantify hydrological uncertainty and enhance predictive reliability. We applied our model to predict streamflow in the source area of the Yellow River from 1961 to 2015, and the results demonstrate its superiority over traditional methods. Compared to long- short term memory networks (LSTM), the VB-LSTM model achieved stable performance and higher predictive accuracy in the validation period. Additionally, it outperforms the traditional probabilistic hydrological post- processing method that relies on a “linearnormal” assumption, by providing higher predictive accuracy and reliability, and reducing predictive uncertainty. [ABSTRACT FROM AUTHOR]

Sediment transport in tidal estuaries is complex and changeable. How to scientifically classify the forms of sediment transport and evaluate its impact on channel sedimentation is the key to clarify the source of sediments deposited in the channel and formulate channel siltation reduction measures. In this paper, a new method identifying three forms of sediment transport, that is the bed load (BL), the suspended load ( SL) and the bed-suspended conversion load (BSCL), was proposed based on analyzing the grain size of surficial bed sediment ( SBS) and near bottom suspended sediment (NBSS) . The sediment samples were collected along the Deepwater Navigational Channel (DNC) in the Yangtze Estuary (YE) during the flood and dry seasons of 2015 and 2018, and the contributions of three forms of sediment transport to the channel sedimentation was quantified. The results show that the upper turning point of grain size cumulative frequency curve is able to well represent the sediment transport form transition from BL to SL. There exists a significant sediment exchange between SBS and NBSS at the South Channel ( SC) as well as the North Passage (NP) of YE. The sediment transport in DNC are not only in forms of BL and SL, but also in BSCL, which accounts for the proportion of 50% to 60% of the channel sedimentation. The contribution of BL to the channel deposition at SC segment of DNC in flood and dry season are 36% and 26% respectively, which is higher than that of SL occupying 6% and 13% . In contrast, the contribution of SL to the channel deposition at NP segment of DNC ranges from 44% to 48%, which is much higher than that of BL only accounting for 3% to 6% . The proposed method based on the grain size analysis provides a new sight on understanding the characteristics of sediment movement in tidal estuary and identifying the source of sediments deposited in the channel. [ABSTRACT FROM AUTHOR]

Sewage discharged through an underground spout into the ocean often contains a certain quantity of suspended solids, which exhibit complex diffusion and sedimentation characteristics near sewage outlet, and with representative transport processes of a sediment-laden jet. This paper therefore systematically reviews the research progress of sewage sediment-laden jet in still water, crossflow, wave and wavy-crossflow environment, and finds that there are significant differences in sediment deposition patterns for sediment-laden jets in different dynamic environments. Methods on how to accurately describe the multiple dynamic coupling processes of wave-current jet interaction and its influence on sediment transport and sedimentation processes have been a difficult task in the study of sewage discharged sediment-laden jets. Therefore, a recommendation for systematically studying the motion law of sediment-laden jet under the joint action of wave and current based on PIV/PLIF solid-phase separation physical experiment, particle tracking two-phase flow numerical model, and Lagrange integral model is proposed. It is intended to provide an important reference for the optimal design of ocean sewage disposal projects. [ABSTRACT FROM AUTHOR]

The main and branch channels are positioned vertically in irrigated areas, and damage occurs at the side wall structure near the bleeder, owing to scouring and deposition of sediment particles. The divergence and confluence angles of natural rivers typically acute. In this paper, the open channel at a 30° water separation angle was used as the research object. The three-dimensional instantaneous velocity was measured using an acoustic Doppler velocimeter, and the distribution of the average velocity, circulation intensity, turbulence intensity, turbulence kinetic energy and bed shear stress at typical cross-sections were analyzed. The experimental results showed that for the 30° water separation angle, the lateral velocity of the water flow at the water outlet varied significantly along the canal width, and easily formed circulations, causing local erosion and deposition. The turbulent intensity near the branch channel changed sharply and irregularly, and the maximum value was observed at the forefront section of the bleeder. The kinetic energy of the lower flow significantly exceeded that of the upper flow at the water outlet, and the higher value was mostly concentrated near the water inlet of the side channel. The bed shear stress at the end of the water diversion section of the main channel was high, eroding the side wall and reducing stability. Compared to the right bleeder, the 30° water separation angle adversely caused the sediment particles to enter the side channel and decreased the erosion rate of the water flow to the bottom and side walls of the channel. This study provides a reference for channel design and operation in irrigation areas. [ABSTRACT FROM AUTHOR]

Climate change and human development have significantly altered the processes of natural water cycling, aggravating the challenge of worldwide water governance. China has initiated a new paradigm of water governance. However, the gap between concept and reality widened due to a lack of appropriate data and methodology. Current water management focuses on limiting the water withdrawals and improving the water use efficiency, and is not yet able to ensure the implementation of the new water governance paradigm. After a thorough study of the advanced development and achievement of water governance policies both at home and abroad, the conclusion has been reached that the total water consumption should be introduced as an additional management indicator to implement a dual control of water withdrawal and consumption. The paper proposes to: (1)Establish water consumption monitoring infrastructure with evapotranspiration remote sensing monitoring as its core component. (2) Implement the rigid water resources constraint by determining available water consumption targets of human activities in the basin, considering water requirements of environmental flow and ecosystem restoration, and establish a cascading system assigning targets to the sectors and/or stakeholders. (3) Implement the water consumption reduction schemes by limiting agricultural planting areas and optimizing ecosystem restoration with indigenous species. It is expected that the proposed approaches will effectively ensure the implementation of China′s new water resources governance paradigm with innovative data, methods, and measures. [ABSTRACT FROM AUTHOR]

Urban flood modeling is a hot research topic in urban flood control and disaster mitigation around the world. Existing reviews on urban flood modeling are usually based on flooding process or calculation algorithms, but lacking a demand- oriented perspective. With the deepening demands on urban flood modeling, the application scenarios have become more and more complicated. Under various application scenarios, different processes are concerned, so new modeling technical strategies are needed, and different priorities and challenges are encountered. It is difficult to clarify these differences without considering the specific application scenario. According to modeling objectives and concerns, three typical application scenarios of urban flood modeling are deduced: modeling of urban fluvial / coastal floods, modeling of urban stormwater, and modeling of urban pluvial floods. Correspondingly, four technical strategies such as urban flood routing models, urban stormwater models, semi-distributed pluvial flood models and fully distributed pluvial flood models are developed specifically. Furthermore, different integrations of modeling technologies and their priorities, as well as the encountered challenges under different application scenarios and different technical strategies are also discussed. The present paper provides a comprehensive overview on urban flood modeling technologies from the viewpoint of application demands and hence provides a new perspective for urban flood modeling applications and researches. [ABSTRACT FROM AUTHOR]

Because of global climate change and human activities, the occurrence frequency of extreme precipitation events is increasing steadily, which causes devastating flood disasters. The stability of a human body can be compromised when exposed to floodwaters, which definitely threatens the life of a human being. Therefore, the investigation into mechanisms and criteria of human instability in floodwaters can provide scientific bases for urban flood risk assessments and hazard reduction measures, and can also benefit the ability of emergency response. This paper summarizes existing studies on instability mechanisms and criteria for people in floodwaters. Based on the summarization, the application scope, advantages and disadvantages of these existing criteria for human instability are evaluated in detail. Even though the calibrated formulas based on mechanical analysis and measured data involve some simplifications, they can reflect the critical mechanical condition of human instability in floodwaters, and therefore show better universality in practice. Given the limitations and shortcomings of the existing studies as well as major threats in current urban flood disasters, this study also presents key future research directions, including the instability mechanisms and criteria of pedestrian evacuation in actual flood conditions and from flooded stairs; using big data technologies to obtain and analyze online resources of flood instability videos and images, and reasonably estimate the critical instability state to construct a dataset of body instability in floodwaters; conduct in-depth studies on the influence of body posture adjustment on flood hazard degree. Besides, it is necessary to promote the application of human instability criteria in the field of urban flooding disaster prevention and reduction, in order to minimize the disadvantageous impacts of urban flood disasters. [ABSTRACT FROM AUTHOR]

To improve the current simulations of hydrothermal exchange in riparian zones that do not take into account heterogeneous heat transfer of soil, this paper constructs a hydrothermal coupling model of riparian zones that includes heterogeneous heat transfer of soil by introducing the soil effective thermal conductivity model on the basis of saturated-unsaturated seepage and porous medium heat transfer theories. This study uses COMSOL software to implement the new method and simulate the hydrothermal coupling model of a riparian zone for different effective thermal conductivity models; the new model is verified by comparing and analyzing prototype observation data of temperature and water level in a riparian zone. The results show that the new model can better reflect the hydrothermal exchange process in a riparian zone than the traditional method that does not consider the heterogeneous heat transfer of the soil. In addition, the simulation of the hydrothermal coupling model based on Johansen's effective thermal conductivity model performs the best, and the simulation results are consistent with previous experimental results. This study can provide technical support for in-depth study of hydrothermal exchange and pollutant migration processes in riparian zones. [ABSTRACT FROM AUTHOR]

The hydrodynamic of river channels in plain cities are generally of poor conditions. Accelerating water renewal and strengthening orderly flow is one of the most important ways to improve the water environment quality of river network. In this paper, a typical plain city in the lower reaches of the Yangtze River, Qidong, was studied as an example. Making full use of the natural tidal dynamic conditions, a hydrodynamic model of the river network was established. Numerical simulation experiment was carried out to quantify the improvement of hydrodynamic characteristics of the river network through water system pattern and overall arrangement optimization and water conservancy project operation. The results show that, the optimized scheme increases the ecological velocity compliance rate of the river network from 52.3% to 94.2% for the whole period under the worst tidal condition; the maximum instantaneous ecological velocity compliance rate is raised from 42.6% to 85.0%;the regional ecological velocity continuity increases to 91.8%. Meanwhile, the urban ecological water consumption reduces 67.5%. Under the optimized scheme, the diversion water volume from external regions can be reduced, and the renewal rate of urban river network significantly increases which shrinks the accumulation time of pollutants. This study provides a novel perspective and method for improving the water environment of tidal river channels in plain cities. [ABSTRACT FROM AUTHOR]

Water security is an integrated concept of multiple dimensions, including water resource utilization, water eco-environmental protection, water disaster prevention among others. In this paper, an evaluation indicator system of water security are constructed, focusing on five dimensions: water quantity, water quality, sustainability, affordability, and flood security. It is based on a summary and discussion of the definition, connotation, and evaluation of water security dimensions. We provide increased understanding of applicability and usefulness of water security evaluation systems, thereby avoiding content duplication or overlaps between different dimensions and promoting the accuracy of problem diagnosis. In doing so, we used a multi-expert decision-making method to quantify indicators weight and to standardize data. Compared with evaluating the water quantity security using indicators of water resources endowment alone, this evaluation system implies concepts of water demand and sustainable security that included in resource security, which is capable of analyzing actual reasons for water shortage. Affordability, which is seldom considered in previous studies, is supplemented to ensure system integrity of water security assessment. Finally, a case study of water security evaluation of China is carried out with cluster analysis. The main water security problems in each region of China were diagnosed well, which are in line with the current situation of China. This test indicates that the evaluation system is both reliable and practically applicable. [ABSTRACT FROM AUTHOR]

To reveal the evolutional characteristics of a stream-groundwater system, this paper takes the seasonal losing stream-groundwater system with stratified sediments as the research object. The criterion for the hydraulic connected states and the mechanism of the seepage in the system are analyzed. The variation types and mechanism of hydraulic connected states are clarified. A theoretical framework of stream-groundwater system hydraulic connected states is developed, and six stream-groundwater system models with different stratified sediment types are constructed. The evolution and variation of hydraulic connected states of the six stream-groundwater models are simulated by numerical simulations, and the results show that the wetting front curve and saturation front curve are of great importance to describe the evolutional process of the hydraulic connected states and can be regarded as characteristic curves for analysis. The difference of permeability and capillary force caused by different types of sediments is the fundamental driving force for the variation of the evolutional process. The variation types of wetting front curve include steep, gentle slope or alternate between steep and gentle slopes, and the variation types of saturation front curve include backward, forward, or alternate between backward and forward. The results of this study provide theoretical support for further research on water quantity assessment, mass transport and energy transfer in stream-groundwater systems. [ABSTRACT FROM AUTHOR]

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)