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Journal of environmental Sciences 2018年第2期30卷 317-327页

作者： Xianglong Xu Guohua Liu Yuanyuan Wang Yuankai Zhang Hao Wan Lu Qi Hongchen Wang School of environment & natural resources Renmin University of China

A sequencing batch reactor（SBR）-anaerobic ammonium oxidation（anammox） system was started up with the paddy soil as inoculated sludge. The key microbial community structure in the system along with the enrichment time was investigated by using molecular biology methods（e.g., high-throughput 16 S r RNA gene sequencing and quantitative PCR）. Meanwhile,the influent and effluent water quality was continuously monitored during the whole start-up stage. The results showed that the microbial diversity decreased as the operation time initially and increased afterwards, and the microbial niches in the system were redistributed. The anammox bacterial community structure in the SBR-anammox system shifted during the enrichment, the most dominant anammox bacteria were Candidatus Jettenia. The maximum biomass of anammox bacteria achieved 1.68 × 10~9 copies/g dry sludge during the enrichment period, and the highest removal rate of TN achieved around 75%.

关键词： Anammox Paddy soil Community structure High-throughput sequencing qPCR

Visible-light-driven photocatalytic inactivation of bacteriophage f2 by Cu-TiO_2 nanofibers in the presence of humic acid

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Journal of environmental Sciences 2019年第3期31卷 383-391页

作者： Rong Cheng Mi Kang Zhi-peng Shen Lei Shi Xiang Zheng School of environment & natural resources Renmin University of China

Pathogenic viruses in drinking water are great threats to public health. Visible-lightdriven photocatalysis is a promising technology for virus inactivation. However, the existing photocatalytic antiviral research studies have mostly been carried out in single-component systems, neglecting the effect of natural organic matter, which exists widely in actual water bodies. In this paper, electrospun Cu-TiO2 nanofibers were prepared as photocatalysts, and their photocatalytic antiviral performance in the presence of humic acid(HA) was comprehensively studied for the first time. The properties of the reaction mixture were measured during the reaction. In addition, the safety, reliability and stability of photocatalytic disinfection in the mixed system were evaluated. The results showed that the virus removal efficiency decreased with the increase of the HA concentration. The type of reaction solution, such as PBS buffer solution or water, did not affect the removal efficiency noticeably. Under acidic conditions, the electrostatic forces between photocatalysts and viruses were strengthened, leading to higher virus removal efficiency. As the reaction time went on, the pH value in the solution increased first and then tended to be stable, the conductivity remained stable, and the dissolved oxygen increased first and then decreased. The safety test showed that the concentration of Cu ions released into the solution was lower than specified by the international standards. No photoreactivation was observed, and the addition of HA significantly reduced the reutilization efficiency of the photocatalysts.

关键词： Photocatalysis Visible light Bacteriophage f2 Humic acid

The future of mountain agriculture amidst continual farm-exit, livelihood diversification and outmigration in the Central Himalayan villages

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Journal of Mountain Science 2019年第4期16卷 755-768页

作者： Niyati NAUDIYAL Kusum ARUNACHALAM Ujjwal KUMAR School of environment and natural resources Doon University

Agrarian patterns in mountain ecosystems have seen a considerable change in the past decades with a vast proportion of the population abandoning traditional agriculture and diversifying their livelihood options, primarily through out-migration. This trend is especially common amongst the subsistence based family-farming communities in developing countries. This study aims at assessing methods of livelihood diversification and factors influencing farm-exit in Central Himalayan villages of Uttarakhand, India, while trying to understand local perspectives on challenges in pursuing agriculture as a viable livelihood option. We collected qualitative and quantitative data from 951 households across 60 villages evenly distributed across six hill districts of Uttarakhand, using key-person interviews and household surveys. The results of the study highlight that farm-exit is significantly influenced by livelihood diversification, number of migrants, number of female family members, and availability of irrigation facilities. In general, perception of the respondents towards agriculture as a viable livelihood option is rather unenthusiastic, with 87% of the respondents citing human wildlife conflict as the main challenge in pursuing farming, amongst several other challenges. Diversification is an integral component of present rural economy with 80.13% of the total population dependent on more than one source of income, to maintain their livelihoods. However, there is no statistically significant influence of livelihood diversification on annual income of the household. If agro-based entrepreneurial ventures are to be promoted in the region there is an urgent need for timely introduction of radical policy, institutional, and land-reforms. Economic uplifting of the local population through such efforts can also be a possible solution to the growing trends of out-migration in the state.

关键词： Agriculture Diversification Rural livelihoods Migration Himalaya

Spatio-temporal changes of underground coal fires during 2008-2016 in Khanh Hoa coal field(North-east of Viet Nam) using Landsat time-series data

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Journal of Mountain Science 2018年第12期15卷 2703-2720页

作者： Tuyen Danh VU Thanh Tien NGUYEN Department of Training Hanoi University of Natural Resources and Environment Faculty of Surveying Mapping and Geographic Information Hanoi University of Natural Resources and Environment

Underground coal fires are one of the most common and serious geohazards in most coal producing countries in the world. Monitoring their spatio-temporal changes plays an important role in controlling and preventing the effects of coal fires, and their environmental impact. In this study, the spatio-temporal changes of underground coal fires in Khanh Hoa coal field(North-East of Viet Nam) were analyzed using Landsat time-series data during the 2008-2016 period. Based on land surface temperatures retrieved from Landsat thermal data, underground coal fires related to thermal anomalies were identified using the MEDIAN+1.5×IQR(IQR: Interquartile range) threshold technique. The locations of underground coal fires were validated using a coal fire map produced by the field survey data and cross-validated using the daytime ASTER thermal infrared imagery. Based on the fires extracted from seven Landsat thermal imageries, the spatiotemporal changes of underground coal fire areas were analyzed. The results showed that the thermalanomalous zones have been correlated with known coal fires. Cross-validation of coal fires using ASTER TIR data showed a high consistency of 79.3%. The largest coal fire area of 184.6 hectares was detected in 2010, followed by 2014(181.1 hectares) and 2016(178.5 hectares). The smaller coal fire areas were extracted with areas of 133.6 and 152.5 hectares in 2011 and 2009 respectively. Underground coal fires were mainly detected in the northern and southern part, and tend to spread to north-west of the coal field.

关键词： Underground coal fires Spatio-temporal changes Khanh Hoa coal field (Viet Nam) Landsat time-series data

Comparison of two remote sensing models for estimating evapotranspiration: algorithm evaluation and application in seasonally arid ecosystems in South Africa

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Journal of Arid Land 2019年第4期11卷 495-512页

作者： Sebinasi DZIKITI Nebo Z JOVANOVIC Richard DH BUGAN Abel RAMOELO Nobuhle P MAJOZI Alecia NICKLESS Moses A CHO David C LE MAITRE Zanele NTSHIDI Harrison H PIENAAR Council for Scientific and Industrial Research Natural Resources and Environment

Remote sensing tools are becoming increasingly important for providing spatial information on water use by different ecosystems. Despite significant advances in remote sensing based evapotranspiration(ET) models in recent years, important information gaps still exist on the accuracy of the models particularly in arid and semi-arid environments. In this study, we evaluated the Penman-Monteith based MOD16 and the modified Priestley-Taylor(PT-JPL) models at the daily time step against three measured ET datasets. We used data from two summer and one winter rainfall sites in South Africa. One site was dominated by native broad leaf and the other by fine leafed deciduous savanna tree species and C4 grasses. The third site was in the winter rainfall Cape region and had shrubby fynbos vegetation. Actual ET was measured using open-path eddy covariance systems at the summer rainfall sites while a surface energy balance system utilizing the large aperture boundary layer scintillometer was used in the Cape. Model performance varied between sites and between years with the worst estimates(R20.80 mm/d) observed during years with prolonged mid-summer dry spells in the summer rainfall areas. Sensitivity tests on MOD16 showed that the leaf area index, surface conductance and radiation budget parameters had the largest effect on simulated ET. MOD16 ET predictions were improved by:(1) reformulating the emissivity expressions in the net radiation equation;(2) incorporating representative surface conductance values;and(3) including a soil moisture stress function in the transpiration sub-model. Implementing these changes increased the accuracy of MOD16 daily ET predictions at all sites. However, similar adjustments to the PT-JPL model yielded minimal improvements. We conclude that the MOD16 ET model has the potential to accurately predict water use in arid environments provided soil water stress and accurate biome-specific parameters are incorporated.

关键词： MOD16 ET drought stress model validation Penman-Monteith Priestley-Taylor sensitivity analysis

Quantification of the effects of management factors on maize (Zea mays L.) and cotton(Gossypium hirsutum L.) residues decomposition rate

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Journal of environmental Sciences 2002年第2期14卷 165-172页

作者： JONES Chilima, HUANG Chang yong, WU Ci fang (College of natural resources and environment, Zhejiang University, Hangzhou 310029, China. College of natural resources and environment Zhejiang University Hangzhou 310029 China

Efforts to quantify management effects on decomposition rate of added substrates to the soil is important especially where such information is to be used for prediction in mathematical or simulation models. Using data from a short term (60 days) greenhouse simulation study, a procedure for quantifying effects of management on SOM and substrate decomposition is presented. Using microbial growth rate u (q), microbial efficiency in substrate utilization e (q), specific decomposition rates for added plant residues to two contrasting soils, red earth (Ferrasol) and black earth (Acrisol) were estimated. The treatments included straw addition + buried, (T1); straw addition + mineral N (T2); and straw addition + tillage, (T3). Sampling was done every 15 days. Straw decomposition rate was affected by external mineral N sources (Urea 46% N). Addition of an external N source significantly increased decomposition rates. The study could not, however, fully account for the effect of tillage on residues because of the limited effect of the tillage method due to the artificial barrier to mechanical interference supplied by the mesh bags. It is concluded that using few decomposer parameters, decomposition rates and consequently SOM trends in a soil system can be monitored and quantification of the influence of perturbations on decomposition rate of added substrates possible.

关键词： management factors residue decomposition rate maize cotton red soil black soil

Predicting the provisioning potential of forest ecosystem services using airborne laser scanning data and forest resource maps

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Forest Ecosystems 2018年第3期5卷 325-343页

作者： Jari Vauhkonen natural resources Institute Finland (Luke) Bioeconomy and Environment Unit

Background: Remote sensing-based mapping of forest Ecosystem Service(ES) indicators has become increasingly popular. The resulting maps may enable to spatially assess the provisioning potential of ESs and prioritize the land use in subsequent decision analyses. However, the mapping is often based on readily available data, such as land cover maps and other publicly available databases, and ignoring the related ***: This study tested the potential to improve the robustness of the decisions by means of local model fitting and uncertainty analysis. The quality of forest land use prioritization was evaluated under two different decision support models: either using the developed models deterministically or in corporation with the uncertainties of the ***: Prediction models based on Airborne Laser Scanning(ALS) data explained the variation in proxies of the suitability of forest plots for maintaining biodiversity, producing timber, storing carbon, or providing recreational uses(berry picking and visual amenity) with RMSEs of 15%–30%, depending on the ES. The RMSEs of the ALS-based predictions were 47%–97%of those derived from forest resource maps with a similar resolution. Due to applying a similar field calibration step on both of the data sources, the difference can be attributed to the better ability of ALS to explain the variation in the ES ***: Despite the different accuracies, proxy values predicted by both the data sources could be used for a pixel-based prioritization of land use at a resolution of 250 m~2, i.e., in a considerably more detailed scale than required by current operational forest management. The uncertainty analysis indicated that maps of the ES provisioning potential should be prepared separately based on expected and extreme outcomes of the ES proxy models to fully describe the production possibilities of the landscape under the uncertainties in the models.

关键词： Forestry decision making Spatial prioritization Light detection and ranging(LiDAR) Remote sensing

Soil surface roughness change and its effect on runoff and erosion on the Loess Plateau of China

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Journal of Arid Land 2014年第4期6卷 400-409页

作者： LongShan ZHAO XinLan LIANG FaQi WU College of natural resources and environment Northwest A&F University

As an important parameter in the soil erosion model, soil surface roughness（SSR） is used to quantitatively describe the micro-relief on agricultural land. SSR has been extensively studied both experimentally and theoretically; however, no studies have focused on understanding SSR on the Loess Plateau of China. This study investigated changes in SSR for three different tillage practices on the Loess Plateau of China and the effects of SSR on runoff and erosion yield during simulated rainfall. The tillage practices used were zero tillage（ZT）, shallow hoeing（SH） and contour ploughing（CP）. Two rainfall intensities were applied, and three stages of water erosion processes（splash erosion（I）, sheet erosion（II） and rill erosion（III）） were analyzed for each rainfall intensity. The chain method was used to measure changes in SSR both initially and after each stage of rainfall. A splash board was used to measure the splash erosion at stage I. Runoff and sediment data were collected continuously at 2-min intervals during rainfall erosion stages II and III. We found that SSR of the tilled surfaces ranged from 1.0% to 21.9% under the three tillage practices, and the order of the initial SSR for the three treatments was ZT〈SH〈CP. For the ZT treatment, SSR increased slightly from stage I to III, whereas for the SH and CP treatments, SSR decreased by 44.5% and 61.5% after the three water erosion stages, respectively, and the greatest reduction in SSR occurred in stage I. Regression analysis showed that the changes in SSR with increasing cumulative rainfall could be described by a power function（R2〉0.49） for the ZT, SH and CP treatments. The runoff initiation time was longer in the SH and CP treatments than in the ZT treatment. There were no significant differences in the total runoff yields among the ZT, SH and CP treatments. Sediment loss was significantly smaller（P〈0.05） in the SH and CP treatments than in the ZT treatment.

关键词： tillage practice soil surface roughness overland flow water erosion Loess Plateau

Emission Patterns under Alternative Congestion and Motor Vehicle Pollution Mitigation Policies in Shanghai

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Chinese Journal of Population,resources and environment 2007年第2期5卷 41-48页

作者： Chen Hongfeng1, Li Fen1, Li Xiangling2 1. School of environment and natural resources, Renmin University of China, Beijing 100872, China 2. School of natural resources and environment, Hefei University of Technology, Hefei Anhui 230009, China School of environment and natural resources Renmin University of China School of natural resources and environment Hefei University of Technology

As a megacity with thriving economy, Shanghai is experiencing rapid motorisation and confronted with traffic congestion problems despite its low car ownership. It is of value to look into the policies on emission control of motor vehicle and congestion reduction in such a city to explore how to reconcile mobility enhancement with the environment. Results of a dynamic simulation displayed time paths of emissions from motor vehicles in Shanghai over the period from 2000 to 2020. The simulation results showed that early policies on emission control of motor vehicle could bring about far-reaching effects on emission reduc- tion, and take advantage of available low-polluting technologies and technical innovation over time. Travel demand management would play an important role in curbing congestion and reducing motor vehicle pollution by calming down car ownership rise and deterring inefficient trips as well as reducing fuel waste caused by congestion.

关键词： dynamic simulation motorisation motor vehicle emission traffic congestion travel demand management low-polluting technologies

Spatial Variability of Micronutrients in Rice Grain and Paddy Soil

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Pedosphere 2009年第6期19卷 748-755页

作者： WANG Lin, WU Jia-Ping 2 , LIU Yan-Xuan, HUANG Hui-Qing and FANG Qian-Fang College of environment and natural resources, Zhejiang University, Hangzhou 310029 (China) [a]College of environment and natural resources Zhejiang University Hangzhou 310029 (China)

Consumption of rice is the main source of micronutrients to human in Asia. A paddy field with unknown anthro- pogenic contamination in Deqing County, Zhejiang Province, China was selected to characterize the spatial variability and distribution of micronutrients in rice grain and soil. A total of 96 paired soil and rice grain samples were collected at harvest. The micronutrients in the soil samples were extracted by diethylenetriamine pentaacetic acid （DTPA）. The mean micronutrient concentrations in rice grain were 3.85 μg Cu g^-1, 11.6 μg Fe g^-1, 39.7 μg Mn g^-1 and 26.0 μg Zn g^-1 The mean concentrations were 2.54μg g^-1 for DTPA-Cu, 133.5μg g^-1 for DTPA-Fe, 30.6μg g^-1 for DTPA-Mn, and 0.84μg g^-1 for DTPA-Zn. Semivariograms showed that measured micronutrients in rice grain were moderately dependent, with a range distance of about 110 m. The concentrations of the DTPA-extractable micronutrients all displayed strong spatial dependency, with a range distance of about 60 m. There was some resemblance of spatial structure between soil pH and the grain Cu, Fe, Mn, and Zn. By analogy, similar spatial variation was observed between soil organic matter （SOM） and DTPA-extractable table micronutrients in the soil. Kriging estimated maps of the attributes showed the spatial distributions of the variables in the field, which is beneficial for better understanding the spatial variation of micronutrients and for potentially refining agricultural management practices at a field scale.

关键词： correlation dependency kriging soil properties