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NUMERICAL SIMULATION OF GROUNDwater DYNAMICS FOR SONGHUAJIANG RIVER VALLEY IN CHINA

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Journal of Hydrodynamics 2004年第3期16卷 332-335页

作者： ADIL Elkrail College of water resources and environment

The study area was designed and constructed, based on the simplification of aconceptual model, to develop a three-dimensional groundwater flow model for simulation oftwo-layers system. Finite difference groundwater flow model was constructed for the CentralSonghuajiang River alluvial plain in Northeast China, with the coverage of 786. 6km^2. The gridnetworks with a spacing of 474. 4m by 509. 5m were used to cover the model area. The trial-and-errortechnique was used to calibrate the model. The sensitivity of the simulations to the modelparameters was studied -and the most sensitive parameters that controlling the residual headsdistribution in the Songhuajiang River valley were defined.

关键词： groundwater simulation model sensitivity calibration

Tunable-Q contourlet transform for image representation

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Journal of Systems Engineering and Electronics 2013年第1期24卷 147-156页

作者： Haijiang Wang Qinke Yang Rui Li Zhihong Yao Institute of Soil and water Conservation Chinese Academy of Sciences and Ministry of Water Resources College of Urban and environment Science Shanxi Normal University College of Urban and environmental Sciences Northwest University College of resources and environment North China University of Water Resources and Electric Power

A novel tunable-quality-factor （tunable-Q） contourlet transform for geometric image representation is proposed. The Laplacian pyramid in original contourlet decomposes a signal into channels that have the same bandwidth on a logarithmic scale, and is not suitable for images with different behavior in frequency domain. We employ a new tunable-Q decomposition defined in the frequency domain by which one can flexibly tune the bandwidth of decomposition channels. With an acceptable redundancy, this tunable-Q contourlet is also anti-aliasing and its basis is sharply localized in the desired area of frequency and spatial domain. Our experiments in nonlinear approximation and denoising show that the contourlet using a better-suitable quality factor can achieve a more promising performance and often outperform wavelets and the previous contourlets both in visual quality and in terms of peak signal-to-noise ratio.

关键词： contourlet quality factor (Q-factor) anti-aliasing mul-tiscale decomposition.

Comparative Analysis of Fractional Vegetation Cover Estimation Based on Multi-sensor Data in a Semi-arid Sandy Area

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Chinese Geographical Science 2019年第1期29卷 166-180页

作者： LIU Qiuyu ZHANG Tinglong LI Yizhe LI Ying BU Chongfeng ZHANG Qingfeng College of Natural resources and environment Northwest A&F University Institute of Soil and water Conservation Chinese Academy of Sciences and Ministry of Water Resources

The estimation of fractional vegetation cover(FVC) is important for identifying and monitoring desertification, especially in arid and semiarid regions. By using regression and pixel dichotomy models, we present the comparison of Sentinel-2A(S2) multispectral instrument(MSI) and Landsat 8(L8) operational land imager(OLI) data regarding the retrieval of FVC in a semi-arid sandy area(Mu Us Sandland, China, in August 2016). A combination of unmanned aerial vehicle(UAV) high-spatial-resolution images and field plots were used to produce verified data. Based on a normalized difference vegetation index(NDVI) regression model, the results showed that, compared with that of L8, the coefficient of determination(R2) of S2 increased by 26.0%, and the root mean square error(RMSE) and the sum of absolute error(SAE) decreased by 3.0% and 11.4%, respectively. For the ratio vegetation index(RVI) regression model, compared with that of L8, the R2 of S2 increased by 26.0%, and the RMSE and SAE decreased by 8.0% and 20.0%, respectively. When the pixel dichotomy model was used, compared with that of L8, the RMSE of S2 decreased by 21.3%, and the SAE decreased by 26.9%. Overall, S2 performed better than L8 in terms of FVC inversion. Additionally, in this paper, we develop a verified scheme based on UAV data in combination with the object-based classification method. This scheme is feasible and sufficiently robust for building relationships between field data and inversion results from satellite data. Further, the synergy of multi-source sensors(especially UAVs and satellites) is a potential effective way to estimate and evaluate regional ecological environmental parameters(FVC).

关键词： fractional vegetation cover (FVC) Sentinel-2A (S2) unmanned aerial vehicle (UAV)image pixel dichotomy model regression model

Effects of long-term fertilization on oxidizable organic carbon fractions on the Loess Plateau,China

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Journal of Arid Land 2016年第4期8卷 579-590页

作者： DING Shaonan XUE Sha LIU Guobin College of Natural resources and environment Northwest A&F University Institute of Soil and water Conservation Chinese Academy of Sciences and Ministry of Water Resources

The effects of long-term fertilization on pools of soil organic carbon （SOC） have been well studied, but limited information is available on the oxidizable organic carbon （OOC） fractions, especially for the Loess Plateau in China. We evaluated the effects of a 15-year fertilization on the OOC fractions （F1, F2, F3 and F4） in the 0-20 and 20-40 cm soil layers in flat farmland under nine treatments （N （nitrogen, urea）, P （phosphorus, monocalcium phosphate）, M （organic fertilizer, composted sheep manure）, N＋P （NP）, M＋N （MN）, M＋P （MP）, M＋N＋P （MNP）, CK （control, no fertilizer） and bare land （BL, no crops or fertilizer））. SOC content increased more markedly in the treatment containing manure than in those with inorganic fertilizers alone. F1, F2, F4 and F3 accounted for 47%, 27%, 18% and 8% of total organic carbon, respectively. F1 was a more sensitive index than the other C fractions in the sensitivity index （SI） analysis. F1 and F2 were highly correlated with total nitrogen （TN） and available nitrogen （AN）, F3 was negatively correlated with pH and F4 was correlated with TN. A cluster analysis showed that the treatments containing manure formed one group, and the other treatments formed another group, which indicated the different effects of fertilization on soil properties. Long-term fertilization with inorganic fertilizer increased the F4 fraction while manure fertilizer not only increased labile fractions （F1） in a short time, but also increased passive fraction （F4） over a longer term. The mixed fertilizer mainly affected F3 fraction. The study demonstrated that manure fertilizer was recommended to use in the farmland on the Loess Plateau for the long-term sustainability of agriculture.

关键词： long-term fertilization oxidizable organic carbon fractions farmland soil Loess Plateau

Overview of in-situ oxygen production technologies for lunar resources

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 233-255页

作者： Youpeng Xu Sheng Pang Liangwei Cong Guoyu Qian Dong Wang Laishi Li Yusheng Wu Zhi Wang College of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China CAS Key Laboratory of Green Process and Engineering National Engineering Research Center for Green Recycling of Strategic Metal ResourcesInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China Innovation academy for Green Manufacture Chinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China

The rich resources and unique environment of the Moon make it an ideal location for human expansion and the utilization of extraterrestrial ***,crucial for supporting human life on the Moon,can be extracted from lunar regolith,which is highly rich in oxygen and contains polymetallic *** oxygen and metal extraction can be achieved using existing metallurgical ***,the ample reserves of water ice on the Moon offer another means for oxygen *** paper offers a detailed overview of the leading technologies for achieving oxygen production on the Moon,drawing from an analysis of lunar resources and environmental *** delves into the principles,processes,advantages,and drawbacks of water-ice electrolysis,two-step oxygen production from lunar regolith,and one-step oxygen production from lunar *** two-step methods involve hydrogen reduction,carbothermal reduction,and hydrometallurgy,while the one-step methods encompass fluorination/chlorination,high-temperature decomposition,molten salt electrolysis,and molten regolith electrolysis(MOE).Following a thorough comparison of raw materials,equipment,technology,and economic viability,MOE is identified as the most promising approach for future in-situ oxygen production on the *** the corrosion characteristics of molten lunar regolith at high temperatures,along with the Moon's low-gravity environment,the development of inexpensive and stable inert anodes and electrolysis devices that can easily collect oxygen is critical for promoting MOE technology on the *** review significantly contributes to our understanding of in-situ oxygen production technologies on the Moon and supports upcoming lunar exploration initiatives.

关键词： lunar resources in-situ oxygen production space metallurgy molten lunar regolith electrolysis

Diel and seasonal variation of methane and carbon dioxide fluxes at Site Guojiaba, the Three Gorges Reservoir

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Journal of environmental Sciences 2013年第10期25卷 2065-2071页

作者： Shangbin Xiao Yuchun Wang Defu Liu Zhengjian Yang Dan Lei Cheng Zhang Engineering Research Center of Eco-environment in Three Gorges Reservoir Region Ministry of EducationChina Three Gorges University Institute of Earth environment Chinese Academy of Sciences Department of water environment China Institute of Water Resources and Hydropower Research College of resources and environment Sciences Hubei University of Technology

In order to investigate the CH4 and CO2 fluxes across the water-gas interface and identify their controlling factors, four diel field campaigns and one monthly sampling campaign during June 2010-May 2011 were carried out at a site near the Three Gorges Dam, China. The averaged CH4 and CO2 fluxes across the air-water interface from the site were much less than those reported from reservoirs in tropic and temperate regions, and from the natural river channels of the Yangtze River. CH4 Fluxes at the site were very low compared to most other reservoirs or natural lakes. One of the most important reasons may be due to the oxidation of CH4 in the water column owing to the great water depth and high DO in water in the Three Gorges Reservoir. The averaged monthly CH4 and CO2 fluxes at the site during the observation year were 0.05 mg/（m^2·hr） and 104.43 mg/（m^2·hr） respectively with the maximum occurred in July 2010. The monthly CO2 fluxes during the observation year were positively correlated to the surface water temperature, and negatively correlated to the air pressure and the surface water pH. The CO2 flux showed a positive correlation with DOC to some extent, although not significantly, which indicated that allochthonous organic C was a major source of CO2 and biogeochemical processes in this reservoir were C-limited. The significantly positive correlation between the reservoir outflow and the seasonal gas flux indicate the disturbance condition of the water body dominated the seasonal gas emission.

关键词： diel flux seasonal flux methane and carbon dioxide emission the Three Gorges Reservoir methane oxidation environmental factors reservoir outflow

Prospects of Carboniferous Shale Gas Exploitation in the Eastern Qaidam Basin

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Acta Geologica Sinica(English Edition) 2014年第2期88卷 620-634页

作者： LI Yingjie SUN Yanling ZHAO Yan CHANG Chun YU Qingchun MA Yinsheng School of water resources and environment China University of Geosciences Institute of Geomechanics Chinese Academy of Geological Sciences

Shale gas is a resource of emerging importance in the energy *** countries in the world have been making big financial investments in this *** shale in the eastern Qaidam Basin shows good exploration prospects,but limited research and exploration work for shale oil and gas resources has been *** analyses were performed on shale derived from the Upper Carboniferous Hurleg Formation in the eastern Qaidam Basin,Qinghai Province,and secondary electron imaging capability of a Field Emission scanning electron microscope （FE-SEM） was used to characterize the microstructure of the *** reservoir and exploitation potential of the studied shale was assessed by comparison with research results obtained from the Barnett Formation shale in Fort Worth Basin,North America and the Basin shale of Sichuan *** results indicate that the eastern Qaidam Basin Carboniferous shale is high-quality source *** are four major microstructural types in the study area：matrix intergranular pores,dissolution pores,intergranular pores,and *** size of the micropores varies from 6-633 nm,the majority of which is between 39-200 nm,with a relatively small number of micro-scale pores ranging from 0.13-1 μ*** pore characteristics of the studied shales are similar to the North American and Sichuanese shales,indicating that they have good reservoir *** micropores are present in the organic matter,which is induced by its composition; instead we found an important lamellar structure in the organic *** micropores and microfractures are abundant,and are connected to natural visible cracks that form the network pore system,which controls the storage and migration of shale *** connectivity is favorable for shale gas exploitation,providing great scientific potential and practical value.

关键词： Scanning microscopy pore structure organic geochemistry Carboniferous shale gas Hurleg Formation Qinghai-Tibet plateau

MODELING OF water DYNAMICS AND POLLUTANT SPREADING IN THE LUOMAHU RESERVOIR FOR water TRANSFER FORM SOUTH TO NORTH OF CHINA

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Journal of Hydrodynamics 2001年第4期13卷 14-23页

作者： Wang Chao College of water resources and environment, Hohai University, Nanjing 210098, China College of water resources and environment Hohai University

water quality is the key problem of the East-Line Project of water Transfer from South to North China. In this paper, the principles of a 1D and 2D-integrated mathematical model for describing the dynamics of water in a flow-through river, canals and lakes was worked out. The numerical method and model algorithm were developed. The efficiency of the model was estimated by applying it to studying water dynamics in the Luomahu reservoir and simulating the spreading process of a polluted water mass and the evolution of the concentration. The results of calculations are used to assess water environmental quality and to manage water resource in the Luomahu reservoir and the Jinghang-Canal for the Project of water Transfer from South to North China.

关键词： mathematical model integral stream function water quality water Transfer from South to North Project

Rainfall and inflow effects on soil erosion for hillslopes dominated by sheet erosion or rill erosion in the Chinese Mollisol region

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Journal of Mountain Science 2018年第10期15卷 2182-2191页

作者： SHEN Hai-ou WEN Lei-lei HE Yun-feng HU Wei LI Hong-li CHE Xiao-cui LI Xin College of resources and environment Jilin Agricultural University Songliao water resources Commission Ministry of Water Resources Key Laboratory of Mollisols Agroecology Northeast Institute of Geography and Agroecology Chinese Academy of Sciences

Erosion agents and patterns profoundly affect hillslope soil loss characteristics. However, few attempts have been made to analyze the effects of rainfall and inflow on soil erosion for hillslopes dominated by sheet erosion or rill erosion in the Chinese Mollisol region. The objective of this study was to discuss the erosive agent(rainfall or inflow), hillslope erosion pattern(sheet erosion or rill erosion) and slope gradient effects on runoff and soil losses. Two soil pans(2.0 m long, 0.5 m wide and 0.5 m deep) with 5° and 10° slopes were subjected to rainfall(0 and 70 mm h–1) and inflow(0 and 70 mm h–1) experiments. Three experimental combinations of rainfall intensity(RI) and inflow rate(IR) were tested using the same water supply of 70 mm by controllingthe run time. A flat soil surface and a soil bed with a straight initial rill were prepared manually, and represented hillslopes dominated by sheet erosion and rill erosion, respectively. The results showed that soil losses had greater differences among treatments than total runoff. Soil losses decreased in the order of RI70+IR70 > RI70+IR0 > RI0+IR70. Additionally, soil losses for hillslopes dominated by rill erosion were 1.7-2.2 times greater at 5° and 2.5-6.9 times greater at 10° than those for hillslopes dominated by sheet erosion. The loss of <0.25 mm soil particles and aggregates varying from 47.72%-99.60% of the total soil loss played a dominant role in the sediment. Compared with sheet erosion hillslopes, rill erosion hillslopes selectively transported more microaggregates under a relatively stable rill development stage, but rills transported increasinglymore macroaggregates under an active rill development stage. In conclusion, eliminating raindrop impact on relatively gentle hillslopes and preventing rill development on relatively steep hillslopes would be useful measures to decrease soil erosion and soil degradation in the Mollisol region of northeastern China.

关键词： Runoff Soil loss Slope gradient Rill erosion Mollisol region