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Resistance of the diffusive boundary layer to salt release from saline sediments to freshwater

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Acta Oceanologica Sinica 2008年第1期27卷 23-28页

作者： GAO Zengwen zheng xilai XU Qinxuan Key Laboratory of Ministry of Education for Marine Environmental Science and Ecology Ocean University of China Qingdao 266003 China

The diffusive boundary layer （DBL） is the zone for matter exchange between surface water and aquatic sediments. To elucidate the influence of DBL on salt release from saline sediments to freshwater, two experiments with or without wind blowing were conducted. According to the experiments, a 3.5 cm DBL is formed above the smoothed sediments at a steady wind field and this thickness is greater than other studies. The observed flux of salt through the DBL is 6% larger than the calculated value from Fick＇ s first law. The results indicate that molecular diffusion is the dominant mechanism for salt transport through the DBL. The presence of DBL suppresses the hydrodynamic enhancement for matter exchange between sediments and overlying water. Therefore, salts in the sediments of a polder reservoir may influence the water quality chronically.

关键词： sediment-water interface diffusive boundary layer molecular diffusion salt transport resistance effect

The influence of slope collapse on water exchange between a pit lake and a heterogeneous aquifer

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Frontiers of Environmental Science & Engineering 2019年第2期13卷 63-71页

作者： Bo Zhang xilai zheng Tianyuan zheng Jia Xin Shuai Sui Di Zhang Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering Ocean University of ChinaQingdao 266100China Key Laboratory of Marine Environmental Science and Ecology (Ministry of Education) College of Environmental Science and EngineeringOcean University of ChinaQingdao 266100China Department of Environmental Informatics Helmholtz Centre for Environmental Research-UFZLeipzig 04318Germany Key Laboratory of Surficial Geochemistry Ministry of EducationDepartment of HydrosciencesSchool of Earth Sciences and EngineeringNanjing UniversityNanjing 210023China College of Engineering Ocean University of ChinaQingdao 266100China

Due to the increase in open pit mining,pit lakes have become common surface water features,posing a potential risk to subsurface *** this study,a pit lake–groundwater interaction model is built based on the general program MODFLOW with the LAK3 *** the first time,the effects of lake-slope collapse and aquifer heterogeneity on pit lake–groundwater interactions are analyzed by dividing the lake into six water exchange zones based on the aquifer lithology and groundwater *** investigation and simulations reveal a total water exchange from groundwater to the lake of 349000 m3/a without collapse of the pit lake slope,while the total net water exchange under slope collapse conditions is 248000 m3/a(i.e.,a reduction of 1.40-fold).The monthly net water exchange per unit width from groundwater to the lake reaches the largest in April,shifting to negative values in zone IV from June to August and in zone V in June and ***,the monthly net water exchange per unit width decreases from north to south,and the direction and magnitude of water exchange are found to depend on the hydraulic gradients between the lake and groundwater and the hydraulic conductivity of the slope collapse.

关键词： Pit lak Slope collapse Groundwater-surface water interactions Numerical simulation

Conceptual Framework of Tourism Carrying Capacity for a Tourism City:Experiences from National Parks in the United States

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维普期刊数据库

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Chinese Journal of Population,Resources and Environment 2010年第2期8卷 88-92页

作者： zheng Nasha zheng xilai Department of Environmental Science and Engineering Ocean University of China Qingdao Shandong 266100 China

There is no universally-accepted definition of tourism carrying capacity(TCC) .Numerical TCC focuses on use level and is considered as"a magic number"of the saturation point for *** are several reasons why numerical tourism capacity is ***,tourism capacity can be defined in terms of limits of acceptable change,which shifts the focus from"how much use is too much"to"how much change is acceptable".This article proposes an improved conceptual framework for evaluating carrying capacity for the tourism city based on approaches used in US national parks,which consider the impact of human use on a city's economic,environmental/resource,and socio-cultural *** on the basic data of indicator values and relevant standards,the framework monitors the current indicators and predicts future indicator values;it can also be used to assess and predict TCC.

关键词： tourism carrying capacity numerical carrying capacity limits of acceptable change US national parks

The Mechanism of Groundwater Salinization and Its Control in the Yaoba Oasis,Inner Mongolia

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Acta Geologica Sinica(English Edition) 2000年第2期74卷 362-369页

作者： WANG Bingchen QIU Hanxue XU Qian zheng xilai LIU Guanqun Comprehensive Institute of Geotechnical Investigation and Surveying Ministry of Construction177 Dongzhimennei St.Beijing 100007 Ocean University of Qingdao Qingdao 266003

The arid area is one of the most concerned areas among the water resources researchers and economists. Northwest China will be an important developing region of China in the 21st century. Yaoba is a well-irrigation oasis within this arid area, which is located in the Alxa area west of the Helan Mountains and next to the Tengger desert in the east. It has contributed greatly to the local stock raising and agriculture since its development in 1970. However, the groundwater which the oasis depends on to survive has been getting salinized gradually and more serious in recent years.

关键词： Yaoba oasis groundwater salinization reinfiltrated irrigation water flood irrigation

Numerical Simulation of the Effects of Stream Seepage on Flood Routing

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Numerical Simulation of the Effects of Stream Seepage on Flo...

Phase Characteristic Analysis of Continuous Depth Air-Gun Source Wavelet

2011 International Symposium on Water Resource and Environmental Protection(ISWREP 2011)

作者： Wu Guizhi Wu Zhouhu zheng xilai Institute of Environmental and Municipal Engineering Qingdao Technological University College of Environmental Science and Engineering Ocean University of China

ISBN: (纸本)9781612843377

To study the effects of stream seepage in arid and semiarid regions,a flood routing mathematic model is developed based on the basic stream flood water motion equations which are discretized and solved using the Preissmann four-point linear implicit *** the same time,flood routing is simulated for a prismatic stream under the effect of *** test results show that stream seepage has effect on flood *** discharge decreases,the water level falls and the peak value at the same section is *** effect becomes more obvious as the infiltration rate *** in the stream bottom slope has little effect on flood *** paper provides a feasible method for flood routing simulation for ephemeral streams in arid and semiarid regions.

关键词： stream seepage infiltration rate flood routing mathematical model

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cnki会议

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Journal of Ocean University of China 2016年第5期15卷 815-824页

作者： XING Lei LIU Huaishan zheng xilai LIU Xueqin ZHANG Jin WANG Linfei ZOU Zhihui XU Yiming Key Laboratory of Submarine Geosciences and Prospecting Techniques Qingdao 266100 P. R. China Key Laboratory of Marine Environment and Ecology Qingdao 266100 P. R. China College of Marine Geosciences Ocean University of China Qingdao 266100 P. R. China

Air guns are important sources for marine seismic exploration. Far-field wavelet of air gun arrays, as a necessary parameter for pre-stack processing and source models, plays an important role during marine seismic data processing and interpretation. When an air gun fires, it generates a series of air bubbles. Similar to onshore seismic exploration, the water forms a plastic fluid near the bubble; the farther the air gun is located from the measurement, the more steady and more accurately represented the wavelet will be. In practice, hydrophones should be placed more than 100 m from the air gun; however, traditional seismic cables cannot meet this requirement. On the other hand, vertical cables provide a viable solution to this problem. This study uses a vertical cable to receive wavelets from 38 air guns and data are collected offshore Southeast Qiong, where the water depth is over 1000 m. In this study, the wavelets measured using this technique coincide very well with the simulated wavelets and can therefore represent the real shape of the wavelets. This experiment fills a technology gap in China.

关键词： wavelet Wavelet requirement cable bubble consistency continuity processed coincide viable

A New Geochemical Reaction Model for Groundwater Systems

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Acta Geologica Sinica(English Edition) 2000年第2期74卷 339-343页

作者： zheng xilai Institute of Geosciences, Qingdao Ocean University, Qingdao 266003, Shandongand WANG Bingchen Comprehensive Institute of Geotechnical Survey, Beijing 100007 Ocean Univ Qingdao Inst Geosci Qingdao 266003 Peoples R China Comprehens Inst Geotech Survey Beijing 100007 Peoples R China

Through a survey of the literature on geology, hydrogeology and hydrogeochemistry, this paper presents a hydrogeochemical model for the groundwater system in a dross-dumping area of the Shandong Aluminium Plant. It is considered that the groundwater-bearing medium is a mineral aggregate and that the interactions between groundwater and the groundwater-bearing medium can be described as a series of geochemical reactions. On that basis, the principle of minimum energy and the equations of mass balance, electron balance and electric neutrality are applied to construct a linear programming mathematical model for the calculation of mass transfer between water and rock with the simplex method.

关键词： geochemical reaction model groundwater system simplex method

The Studies of Regional Water Circulation Patterns in the Yerqiang River Basin

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Journal of Ocean University of China 2006年第4期5卷 357-362页

作者： REN Jiaguo WU-Qianqian zheng xilai XU Mo Key Laboratory of Marine Environmental Science and Ecology Ministry of Education Ocean University of China Qingdao 266003 P. R. China National Laboratory of Geo-hazard Prevention ＆ Geo-environment Protection Chengdu University of Technology Chengdu 610059 P.R. China

Based on the characteristic of ‘one river one oasis’ in the arid areas, the Yerqiang River Basin, which is the largest irrigated area of Xinjiang, is taken as an example in this paper, and the regional water circulation pattern is investigated through the analysis of 60 groups of isotope data in the basin. From the phreatic evaporation data analysis of different soils, we study the law of phreatic evaporation, complete the research of the main consumption path of the groundwater, and improve the assessment precision of water resources. The transformation mount of regional water resources are predicted by calculation, which provides a scientific basis for water resources assessment and allocation in arid regions, and offers a new method for the study of regional water circulation patterns.

关键词： Yerqiang River Basin water circulation transformation pattern

地下水硝酸盐污染源解析及氮同位素分馏效应研究进展

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现代地质 2022年第2期36卷 563-573页

作者：于璐郑天元郑西来中国海洋大学环境科学与工程学院山东青岛266100 青岛大学威海创新研究院生态环境研发中心山东威海264200 中国海洋大学海洋环境与生态教育部重点实验室山东青岛266100

地下水硝酸盐污染已成为世界范围内最严重的环境地质问题之一。全面并准确识别硝酸盐污染源,对地下水的有效管理及污染防治具有重要的指导意义。从地下水硝酸盐来源、同位素检测方法、污染源同位素特征、定量解析模型构建、硝酸盐主要... 详细信息

地下水硝酸盐污染已成为世界范围内最严重的环境地质问题之一。全面并准确识别硝酸盐污染源,对地下水的有效管理及污染防治具有重要的指导意义。从地下水硝酸盐来源、同位素检测方法、污染源同位素特征、定量解析模型构建、硝酸盐主要转化过程及同位素分馏效应等方面进行总结,比较不同解析方法在硝酸盐溯源中的应用与发展,建议采用多学科、多方法相结合的方式,提高对硝酸盐污染源的全面理解。同位素富集系数是定量解析硝酸盐污染源的重要参数,在源解析过程中探讨硝酸盐转化及同位素分馏机制,能够更好地诠释地下水硝酸盐来源和迁移转化过程,提高源解析的准确性,为地下水硝酸盐污染的准确溯源与有效防治提供参考。

关键词：硝酸盐源解析氮循环同位素同位素分馏