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energy balance-Based SWAT Model to Simulate the Mountain Snowmelt and Runoff——Taking the Application in Juntanghu Watershed(China) as an Example

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Journal of Mountain Science 2015年第2期12卷 368-381页

作者： MENG Xian-Yong YU Dan-Lin LIU Zhi-Hui School of Resources and Environment Science Xinjiang University Key Laboratory of Oasis Ecology Ministry of Education Xinjiang University Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Department of Earth & Environmental Studies Montclair State University Institute of Arid Ecology and Environment Xinjiang University

In order to predict long-term flooding under extreme weather conditions in central Asia, an energy balance-based distributed snowmelt runoff model was developed and coupled with the Soil and Water Assessment Tool(SWAT) model. The model was tested at the Juntanghu watershed on the northern slope of the Tian Shan Mountains, Xinjiang,China. We compared the performances of temperature-index method and energy balanced method in SWAT model by taking Juntanghu river basin as an application example(as the simulation experiment was conducted in Juntanghu River, we call the energy balanced method as SWAT-JTH). The results suggest that the SWAT snowmelt model had overall Nash-Sutcliffe efficiency(NSE) coefficients ranging from 0.61 to 0.85 while the physical based approach had NSE coefficients ranging from 0.58 to0.69. Overall, on monthly scale, the SWAT model provides better results than that from the SWAT-JTH model. However, results generated from both methods seem to be fairly close at a daily scale. Thestructure of the temperature-index method is simple and produces reasonable simulation results if the parameters are well within empirical ranges. Although the data requirement for the energy balance method in current observation is difficult to meet and the existence of uncertainty is associated with the experimental approaches of physical processes, the SWAT-JTH model still produced a reasonably high NSE. We conclude that using temperature-index methods to simulate the snowmelt process is sufficient, but the energy balance-based model is still a good choice to simulate extreme weather conditions especially when the required data input for the model is acquired.

关键词： SWAT Snowmelt model The physical process energy balance Temperature-index Water balance

energy balance and Physical Activity

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Biomedical and Environmental Sciences 2001年第1期14卷 130-136页

作者： KALLAYA KIJBOONCHOO Institute of Nutrition and Faculty of Graduate Studies

The prevalence of obesity is increasing in most parts of the world and becoming one of the major global public health problems. Although the components of energy balance have not been adequately estimated over time, available evidence suggests that the increase in obesity is the result of reduced physical activity.\;Increases in physical activity have been shown to be strongly associated with improving physical fitness and body composition, with probably a positive effect on resting metabolic rate. The Surgeon General's Report on Physical Activity and Health advocates that 30 min of regular, moderate_intensity physical activity is associated with decreases in the risk of chronic diseases and may contribute to quality of life. However, the small changes that contribute 10 min for 3 times a day for aerobic training, or one set instead of three sets of repetitions on resistance training will provide individuals with health benefits. Indeed, nutrition and physical activity should be considered an integral part of fitness and good health, and should be encouraged in all age groups, particularly early in life. The question is no longer centered around the health benefit of increasing physical activity, but rather creating self awareness and behavior changes in individuals. Hence, effective intervention programs are needed that foster long term changes in physical activity. Among various interventions, the Nutrifit program was recently conducted in Thailand and found to improve health related fitness in children. The development of more effective interventions and approaches is a major challenge in this field today.

关键词： physical activity physical fitness body composition quality of life positive effect energy balance public health instead of age groups sets of

energy balance of Irrigated Intercropping Field in the Middle Reaches of Heihe River Basin

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Chinese Geographical Science 2006年第3期16卷 243-248页

作者： WU Jinkui DING Yongjian WANG Genxu SHEN Yongping Yusuke YAMAZAKI Jumpei KUBOTA Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China The Laboratory of Climate Study of China Meteorological Administration Beijing 100041 China Research Institute for Humanity and Nature Kyoto 602-0778 Japan

Based on the experiments conducted in an irrigated intercropping field in Zhangye Oasis in the middle reaches of Heihe River basin in 2004, the characteristics of radiation budget are analyzed. Furthermore, energy balance is cal- culated by using Bowen-Ratio energy balance (BREB) method. The results show that the ratio of the absorbed radiation to the incoming short radiation in intercropping crop canopy-soil system is increasing with growing stages, from 0.81 in the initial growing stage (IGS) to 0.86 in the late growing stage (LGS). The net radiation, which is smaller in IGS, in- creases rapidly in the first period of the middle growing stage (MGS) and reaches the maximum value in the second period of MGS. It then somewhat decreases in LGS. The ratio of net radiation to total radiation has a similar trend with the net radiation. In the whole growing stages, latent heat flux, which takes up 70% or so of the net radiation, is the dominant item in energy balance. Sensible heat flux shares 20% of the net radiation and soil heat flux has a percentage of 10%. The characteristics of heat balance vary distinctly in different growing stages. In IGS, the ratios of latent heat flux, sensible heat flux and soil heat flux to net radiation are 44.5%, 23.8% and 31.7% respectively. In MGS, with the in- creasing of latent heat flux and the decreasing of sensible heat flux and soil heat flux, the ratios turn into 84.4%, 6.3% and 9.3%. In LGS, the soil heat flux maintains 0W/m2 or so, and latent heat flux and sensible heat flux take up 61.4% and 38.6% respectively. The energy balance also shows an obvious daily variation characteristic.

关键词： radiation budget energy balance intercropping field Heihe River basin

Comparison of mesophilic and thermophilic anaerobic digestions of thermal hydrolysis pretreated swine manure: Process performance,microbial communities and energy balance

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Journal of Environmental Sciences 2023年第4期126卷 222-233页

作者： Xiaohui Liu Changmin Lee Jae Young Kim Department of Civil and Environmental Engineering Seoul National UniversitySeoul 08826Korea

Anaerobic digestion (AD) of swine manure (SM) commonly shows low biogas output and unsatisfactory economic performance. In this study, thermophilic AD (TAD, 50±1℃) was combined with thermal hydrolysis pretreatment (THP, 170℃/10 bar), to investigate its potential for maximizing biogas yield, securing successful digestion and microbial diversity, as well as improving energy balance. Four lab-scale continuously stirred tank reactors were operated for 300 days and compared with each other, i.e., reactor 1 (raw SM fed in mesophilic AD:RSM-MAD), reactor 2 (THP-treated SM fed in MAD:TSM-MAD), reactor 3 (RSM-TAD),and reactor 4 (TSM-TAD). The results showed that THP was efficient to increase methane production of SM, TSM-TAD mode led to the highest methane yield (129.8±40.5 mL-CH_(4)/gVS/day) among the tests (p 700 mg/L) or volatile fatty acids (> 6000 mg/L) accumulation compared with MAD in start-up phase, TSM-TAD treatment mode behaved a sustainable digestion process in a long-term operation. For TSM-TAD scenario, higher Shannon–Weaver (3.873) and lower Simpson index (0.061) indicated this mode ensured and enlarged the diversity of bacteria communities. Phylum Bathyarchaeota was dominant (59.3%-90.0%) in archaea community,followed by Euryarchaeota in the four reactors. RSM-MAD treatment mode achieved the highest energy output (4.65 GJ/day), TSM-TAD was less effective (-17.38 GJ/day) due to increased energy demands. Thus improving the energetic efficiency of THP units is recommended for the development of TSM-TAD treatment mode.

关键词： Thermal hydrolysis pretreatment Digestion temperature Process performances Microbial communities energy balance

Unveiling evapotranspiration patterns and energy balance in a subalpine forest of the Qinghai-Tibet Plateau:observations and analysis from an eddy covariance system

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Journal of Forestry Research 2024年第3期35卷 175-188页

作者： Niu Zhu Jinniu Wang Dongliang Luo Xufeng Wang Cheng Shen Ning Wu Ning Zhang Binghui Tian Aihong Gai Chengdu Institute of Biology Chinese Academy of SciencesChengdu 610041People's Republic of China College of Resources and Environmental Sciences Gansu Agricultural UniversityLanzhou 730070People's Republic of China Mangkang Ecological Monitoring Station Tibet Ecological Security Barrier Ecological Monitoring NetworkQamdo 854500People's Republic of China Northwest Institute of Eco Environmental Resources Chinese Academy of SciencesLanzhou 730000People's Republic of China

Evapotranspiration is an important parameter used to characterize the water cycle of *** under-stand the properties of the evapotranspiration and energy balance of a subalpine forest in the southeastern Qinghai-Tibet Plateau,an open-path eddy covariance system was set up to monitor the forest from November 2020 to October 2021 in a core area of the Three Parallel Rivers in the Qing-hai-Tibet *** results show that the evapotranspira-tion peaked daily,the maximum occurring between 11:00 and 15:*** factors had significant effects on evapotranspiration,among them,net radiation the greatest(R^(2)=0.487),and relative humidity the least(R^(2)=0.001).The energy flux varied considerably in different seasons and sensible heat flux accounted for the main part of turbulent *** energy balance ratio in the dormant season was less than that in the growing season,and there is an energy imbalance at the site on an annual time scale.

关键词： Evapotranspiration energy balance Subalpine forest Three Parallel Rivers region Southeast Qinghai-Tibet Plateau

The energy balance of Plasma in a Coaxial Plasma Opening Switch

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Plasma Science and Technology 2006年第6期8卷 656-660页

作者：徐翔王友年 State Key Lab of Materials Modification by Electron Ion and Laser BeamsDepartment of PhysicsDalian University of TechnologyDalian 116023China

The two-dimensional energy balance in a coaxial plasma opening switch （POS） is studied based on the single-fluid magnetohydrodynarnic （MHD） equations coupled with the generalized Ohm＇s law. The energy transfers between the plasma and the magnetic field are considered during the penetration of the magnetic field as the Ohmic heating is included in the energy-balance equation. The focus is on the energy partition between the magnetic-field energy and the dissipated magnetic-field energy in a high-density POS with different rise-in-time electric currents at the generator boundary. The simulation code is tested in two cases： the constant-in-time current case and the linear rise-in-time current case. For the sinusoidally rise-in-time current similar to that of the experiments, it is shown that at the end of the conduction phase the dissipated magnetic-field energy is 36.5% of the input electromagnetic energy, which is consistent with the experimental results.

关键词： plasma opening switch energy balance magnetohydrodynamic (MHD) simulation

Surface energy balance of Bayi Ice Cap in the middle of Qilian Mountains,China

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Journal of Mountain Science 2018年第6期15卷 1229-1240页

作者： QING Wen-wu HAN Chun-tan LIU Jun-feng Key Laboratory of Western China＇s Environmental Systems （Ministry of Edueation） College of Earth and Environmental Sciences Lanzhou University Lanzhou 730000 China Northwest Institute of Eeo-Environment and Resources Chinese Academy of Sciences Lanzhou 730000 China

energy balance at the glacier surface is important for understanding the impacts of climate change on glaciers. Here, we analyzed the characteristics of the glacier surface energy fluxes along with their contributions to glacier melt on Bayi Ice Cap in Qilian Mountains by using a point-scale energy balance model. The half-hourly meteorological data from an automatic weather station(AWS) located on the glacier was used to drive the energy balance model. The model simulated results could accurately represent the mass-balance observations from the stake near the weather station during summer 2016. Our results showed the net radiation(86%) played an important role in the surface energy balance, and the contribution of the turbulent heat fluxes(14%) to the energy budget was relatively less important. A distinct behavior of energy balance, as compared to other continental glaciers in China(e.g., two adjacent glaciers Laohugou No. 12 Glacier and Qiyi Glacier), is the fact that a sustained period of positive turbulent latent flux exists on Bayi Ice Cap during August, causing faster melt rate in the month of August. Our study also presented the effect of frequent summer snowfall in slowing down surface melt by changing the surface albedo during the beginning of the melting season.

关键词： Surface melting energy balance Turbulent latent flux Summer snowfall Glacier

Effect of reduced energy density of close-up diets on dry matter intake,lactation performance and energy balance in multiparous Holstein cows

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Journal of Animal Science and Biotechnology 2015年第1期6卷 47-54页

作者： Wenming Huang Yujia Tian Yajing Wang Aminamu Simayi Amingguli Yasheng Zhaohai Wu Shengli Li Zhijun Cao State Key Laboratory of Animal Nutrition College of Animal Science and TechnologyChina Agricultural University

energy intake prepartum is critically important to health, milk performance, and profitability of dairy cows. The objective of this study was to determine the effect of reduced energy density of dose-up diets on dry matter intake （DMI）, lactation performance and energy balance （EB） in multiparous Holstein cows which were housed in a free-stall barn and fed for ad libitum intake. Thirty-nine dry cows were blocked and assigned randomly to three groups fed a high energy density diet [HD, n = 13; 6.8 MJ of net energy for lactation （NEL）/kg; 14.0% crude protein （CP） ], or a middle energy density diet （MD, n = 13; 6.2 MJ NEh/kg; 14.0% CP）, or a low energy density diet （LD, n = 13; 5.4 MJ NEh/kg; 14.0% CP） from d 21 before expected day of calving. After parturition, all cows were fed the same lactation diet to d 70 in milk （DIM）. The DMI and NEE intake prepartum were decreased by the reduced energy density diets （P 〈 0.05）. The LD group consumed 1.3 last 24 h before calving. The milk yield and the postpartum kg/d （DM） more diet compared with HD group in the DMI were increased by the reduced energy density diet prepartum （P 〈 0.05）. The changes in BCS and BW prepartum and postpartum were not affected by prepartum diets HD group had higher milk fat content and lower lactose content compared with LD group during the first 3 wk of lactation （P 〈 0.05）. The energy consumption for HD, MD and LD groups were 149.8%, 126.2% and 101.1 % of their calculated energy requirements prepartum （P 〈 0.05）, and 72.7%, 73.1% and 7.5.2% during the first 4 wk postpartum, respectively. In conclusion, the low energy density prepartum diet was effective in controlling NF_L intake prepartum, and was beneficial in increasing DMI and milk yield, and alleviating negative EB postpartum.

关键词： Dietary energy density Dry matter intake energy balance Lactation performance Transition cow

Monitoring thermal field,humidity field and energy balance over heterogeneous surfaces in the typical valley-city

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Journal of Geographical Sciences 2020年第12期30卷 2015-2032页

作者： LI Guodong ZHANG Junhua MIRZAEI Parham A. DING Shengyan DING Yapeng LIU Man College of Environment and Planning Henan UniversityKaifeng 475004HenanChina Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions(Henan University) Ministry of EducationKaifeng 475004HenanChina Department of Architecture and Built Environment The University of NottinghamNottingham NG72RDUK

Land use and land cover(LULC)alteration has changed original energy balance and heat fluxes between land and atmosphere,and thus affects the structure characteristics of temperature and humidity fields over urban heterogeneous surfaces in different spatio-temporal *** is the most typical river valley city of China,it is chosen as the case *** river valley terrain,rapid urbanization and severe air pollution have caused unique urban climate and urban heat island(UHI)effects in ***,the spatial structure characteristics and dynamic evolution of temperature and humidity fields in autumn are simulated by mobile measurement experiment and GIS spatial analysis *** results show that temperature and humidity fields have significant dynamic change within a day,and have multiple center and multiple intensity level ***,LULC and normalized difference vegetation index(NDVI)are extracted from remote sensing images,the distribution patterns of temperature and humidity fields have close relationships with LULC and ***,there is a significant positive correlation between impervious surface area and thermal field intensity.A positive correlation between NDVI value and humidity field intensity has been found as well as a negative correlation between NDVI value and thermal field ***,heat fluxes and energy balance characteristics between ground and atmosphere are analyzed based on the Bowen-ratio System *** study could provide theoretical support and practical guidance for urban planning,urban eco-environment construction and air pollution prevention of river valley city.

关键词： thermal field humidity field energy balance heat fluxes LULC valley-city