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“西部”生态足迹模型及其在宁夏生态足迹测算中的应用 被引量:4
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作者 董宏林 杜慧莹 《干旱地区农业研究》 CSCD 北大核心 2011年第5期219-223,241,共6页
为了更准确评估和比较西部各地区发展的可持续性,"西部"生态足迹模型引入热值概念,克服了不同属性的生物产品不能直接加总的难题。计算"西部"生态足迹模型的核心参数,并尝试性的将该模型用于宁夏生态足迹核算。结... 为了更准确评估和比较西部各地区发展的可持续性,"西部"生态足迹模型引入热值概念,克服了不同属性的生物产品不能直接加总的难题。计算"西部"生态足迹模型的核心参数,并尝试性的将该模型用于宁夏生态足迹核算。结果显示,2009年宁夏人均生态赤字达0.749 whm2,生态剩余人口占总人口的33%。认为,宁夏的发展已经不可持续,同时提出了改善性建议。"西部"生态足迹模型适用于西部地区间生态足迹分析,其思路也可为其它中小区域的生态足迹研究提供参考。 展开更多
关键词 西部”生态足迹模型 核心参数计算 宁夏生态足迹测算
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西部开发:一个东西合作模型
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作者 田素华 陈晖 陈联明 《世界经济文汇》 CSSCI 北大核心 2000年第3期53-58,47,共7页
一、引言 我国西部经济发展长期落后于东部沿海地区。有关中国各地区家庭人均收入相对水平的统计显示,1995年与1985年相比,东部省份除辽宁外,收入相对水平均有大幅度提高,其中,上海上升了77.9%,北京上升了48.9%,广东上升了42.1%;西... 一、引言 我国西部经济发展长期落后于东部沿海地区。有关中国各地区家庭人均收入相对水平的统计显示,1995年与1985年相比,东部省份除辽宁外,收入相对水平均有大幅度提高,其中,上海上升了77.9%,北京上升了48.9%,广东上升了42.1%;西部省份则相对下降,西部个别省份最大降幅达到23.1%(魏后凯等,1997)。 东西部差距形成了典型的刘易斯二元经济结构,大大影响了中国经济可持续增长,而且随着东西部收入差距拉大,会对中国社会稳定构成严重威胁。随着我国对外开方程度加深,国内地区之间经济不发展平衡也会削弱我国对外整体竞争实力。为此,国家提出了开发大西部战略,吹响了向西部进军号角。 如何开发西部呢?有些学者(比如华民,2000)认为,根据要素禀赋和专业分工理论,考虑到我国劳动力等生产要素流动受到一定程度的限制,因此,东部应重点发展资本密集型产业,西部地区发展资源密集型产业或者劳动密集型产业,然后东西部开展贸易。根据李嘉图等古曲经济学家的自由贸易理论。 展开更多
关键词 西部大开发 刘易斯二元经济结构 西部合作模型
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内蒙古分区地壳速度模型的建立及应用分析 被引量:5
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作者 赵艳红 舒雷 +2 位作者 刘永梅 张珂 尹占军 《中国地震》 北大核心 2018年第4期731-744,共14页
内蒙古测震台网自"十五"数字化网络建成以来,一直使用华南速度模型。多年的大震速报和地震编目结果显示,华南速度模型不符合内蒙古地区的地质构造特征; 2016年开始使用的内蒙古2015速度模型也不能完全满足内蒙古各区域地震定... 内蒙古测震台网自"十五"数字化网络建成以来,一直使用华南速度模型。多年的大震速报和地震编目结果显示,华南速度模型不符合内蒙古地区的地质构造特征; 2016年开始使用的内蒙古2015速度模型也不能完全满足内蒙古各区域地震定位的需求。本文对内蒙古地区2009~2016年记录的所有M_L≥3.0地震震相数据利用速度拟合和折合走时方法,反演适合内蒙古西部、东部、中部各区域的分区地壳速度结构模型,并对西部速度模型、东部速度模型、中部速度模型进行应用对比分析。各分区的地壳速度模型定位误差较小,可靠性和稳定性优势明显。 展开更多
关键词 华南模型 内蒙古2015速度模型 西部模型 东部模型 中部模型
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内蒙古西部一维两层地壳速度结构研究
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作者 赵艳红 《中国科技期刊数据库 科研》 2016年第9期45-48,共4页
华南模型与内蒙古地区区域地质构造存在一定的差异,需要修定、完善。内蒙古地形狭长,地质构造复杂,2015内蒙古最优均匀模型不能满足内蒙古各区域地震定位要求。基于内蒙古地震台网2009年—2016年4月产出的地震观测报告,采用地震震相的... 华南模型与内蒙古地区区域地质构造存在一定的差异,需要修定、完善。内蒙古地形狭长,地质构造复杂,2015内蒙古最优均匀模型不能满足内蒙古各区域地震定位要求。基于内蒙古地震台网2009年—2016年4月产出的地震观测报告,采用地震震相的线性拟合和折合走时曲线得到初始模型。对发生在内蒙古西部区域的225次地震Hyposat批处理结果进行搜索,确定西部模型为:V1=6.06km/s;Vpb=6.61km/s;Vn=8.12km/s;H1=30m,莫霍面深度H=44km。新模型和参照模型检验结果对比显示,新模型定位残差及震中差均值有明显降低。 展开更多
关键词 内蒙古地区 华南模型 2015最优模型 西部模型
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西部可持续能源开发利用模型 被引量:8
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作者 李华林 陈文颖 +1 位作者 吴宗鑫 吴欧密 《清华大学学报(自然科学版)》 EI CAS CSCD 北大核心 2006年第9期1615-1619,共5页
为了研究中国西部可持续的能源开发利用战略,建立了西部可持续能源开发利用模型。该模型以能源系统优化模型——MARKAL模型为内核,耦合了能源服务需求预测模块、水资源需求模块、污染物排放模块、经济分析模块和内生技术学习模块。应用... 为了研究中国西部可持续的能源开发利用战略,建立了西部可持续能源开发利用模型。该模型以能源系统优化模型——MARKAL模型为内核,耦合了能源服务需求预测模块、水资源需求模块、污染物排放模块、经济分析模块和内生技术学习模块。应用该模型研究了2000—2050年间西部地区终端能源需求、一次能源供应、电力消费及构成、水资源需求以及污染物排放等。并分析了“能源东送”方案对西部能源系统的影响。结果显示,2050年中国西部终端能源消费量将达到12.43亿t,一次能源消费量将达到14.67亿t。预计“能源东送”方案实施后,一次能源消费、电力需求、水资源需求和污染物排放均会有较大幅度增加。 展开更多
关键词 可持续发展 “能源东送”方案 中国西部MARKAL模型
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Direct Climatic Effect of Aerosols and Interdecadal Variations over East Asia Investigated by a Regional Coupled Climate-Chemistry/Aerosol Model 被引量:5
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作者 HAN Zhi-Wei XIONG Zhe LI Jia-Wei 《Atmospheric and Oceanic Science Letters》 2011年第6期299-303,共5页
The direct climatic effect of aerosols for the 1980-2000 period over East Asia was numerically investigated by a regional scale coupled climate-chemistry/ aerosol model, which includes major anthropogenic aerosols (s... The direct climatic effect of aerosols for the 1980-2000 period over East Asia was numerically investigated by a regional scale coupled climate-chemistry/ aerosol model, which includes major anthropogenic aerosols (sulfate, black carbon, and organic carbon) and natural aerosols (soil dust and sea salt). Anthropogenic emissions used in model simulation are from a global emission inventory prepared for the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC AR5), whereas natural aerosols are calculated online in the model. The simulated 20-year average direct solar radiative effect due to aerosols at the surface was estimated to be in a range of-9- -33 W m-2 over most areas of China, with maxima over the Gobi desert of West China, and-12 W m-2 to -24 W m-2 over the Sichuan Basin, the middle and lower reaches of the Yellow River and the Yangtze River. Aerosols caused surface cooling in most areas of East Asia, with maxima of-0.8℃ to -1.6℃ over the deserts of West China, the Sichuan Basin, portions of central China, and the middle reaches of the Yangtze River. Aerosols induced a precipitation decrease over almost the entire East China, with maxima of-90 mm/year to -150 mm/year over the Sichuan Basin, the middle reaches of the Yangtze River and the lower reaches of the Yellow River. Interdecadal variation of the climate response to the aerosol direct radiative effect is evident, indicating larger decrease in surface air temperature and stronger per- turbation to precipitation in the 1990s than that in the 1980s, which could be due to the interdecadal variation of anthropogenic emissions. 展开更多
关键词 AEROSOLS direct radiative effect climatic response interdecadal variation model simulation
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A dynamic model for exploring water-resource management scenarios in an inland arid area: Shanshan County, Northwestern China 被引量:2
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作者 CHEN Chao AHMAD Sajjad +1 位作者 KALRA Ajay XU Zhi-xia 《Journal of Mountain Science》 SCIE CSCD 2017年第6期1039-1057,共19页
Water scarcity is a challenge in many arid and semi-arid regions; this may lead to a series of environmental problems and could be stressed even further by the effects from climate change. This study focused on the wa... Water scarcity is a challenge in many arid and semi-arid regions; this may lead to a series of environmental problems and could be stressed even further by the effects from climate change. This study focused on the water resource management in Shanshan County, an inland arid region located in northwestern China with a long history of groundwater overexploitation. A model of the supply and demand system in the study area from 2006 to2030, including effects from global climate change,was developed using a system dynamics(SD)modeling tool. This SD model was used to 1) explore the best water-resource management options by testing system responses under various scenarios and2) identify the principal factors affecting the responses, aiming for a balance of the groundwater system and sustainable socio-economic development.Three causes were identified as primarily responsible for water issues in Shanshan: low water-use efficiency low water reuse, and increase in industrial waterdemand. To address these causes, a combined scenario was designed and simulated, which was able to keep the water deficiency under 5% by 2030. The model provided some insights into the dynamic interrelations that generate system behavior and the key factors in the system that govern water demand and supply. The model as well as the study results may be useful in water resources management in Shanshan and may be applied, with appropriate modifications, to other regions facing similar water management challenges. 展开更多
关键词 System dynamics Water resources management Northwestern China Water scarcity
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Effect of Land Use Change on Runoff and Sediment Yield in Da River Basin of Hoa Binh province, Northwest Vietnam 被引量:6
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作者 NGO Thanh Son NGUYEN Duy Binh Rajendra Prasad SHRESTHA 《Journal of Mountain Science》 SCIE CSCD 2015年第4期1051-1064,共14页
The objective of this study was to assess runoff discharge and sediment yield from Da River Basin in the Northwest of Vietnam using Soil and Water Assessment Tools(SWAT) model.The SWAT model was calibrated and validat... The objective of this study was to assess runoff discharge and sediment yield from Da River Basin in the Northwest of Vietnam using Soil and Water Assessment Tools(SWAT) model.The SWAT model was calibrated and validated using the observed monthly stream flows and sediment yield at selected gauging stations.The results indicated that SWAT generally performs well in simulating runoff and sediment yield according to Nash-Sutcliffe efficiency(NSE), Observation's standard deviation ratio(RSR), and percent bias(PBIAS) values.For runoff, the values of NSE, RSR, and PBIAS were 0.98,0.02, and 3.69 during calibration period and 0.99,0.01, and 1.56 during validation period, respectively.For sediment yield, the efficiency was lower than the value of NSE, RSR, and PBIAS during calibration period were 0.81, 0.19, and-4.14 and 0.84, 0.16, and-2.56 during validation period, respectively.The results of the study indicated that the vegetation status has a significant impact on runoff and sediment yield.Changes in land use type between 1995 and2005 from forest to field crop and urban strongly contributed to increasing the average annual runoff from 182.5 to 342.7 mm and sediment yield from101.3 to 148.1 ton-1 ha.Between 2005 and 2010, adecrease of both runoff(from 342.7 to 167.6 mm) and sediment yield(from 148.1 to 74.0 ton-1 ha) was due to the expansion of forested area and application of soil conservation practices.The results of this study are important for developing soil and water conservation programs, extending future SWAT modelling studies and disseminating these results to other regions in Vietnam. 展开更多
关键词 Land use change HYDROLOGY Soil erosion Soil and Water Assessment Tools(SWAT) Da River Basin
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Regimes of Runoff Components on the Debris-covered Koxkar Glacier in Western China 被引量:3
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作者 HAN Hai-dong DING Yong-jian +1 位作者 LIU Shi-yin WANG Jian 《Journal of Mountain Science》 SCIE CSCD 2015年第2期313-329,共17页
By using a degree-day based distributed hydrological model, regimes of glacial runoff from the Koxkar glacier during 2007-2011 are simulated, and variations and characteristics of major hydrological components are dis... By using a degree-day based distributed hydrological model, regimes of glacial runoff from the Koxkar glacier during 2007-2011 are simulated, and variations and characteristics of major hydrological components are discussed. The results show that the meltwater runoff contributes 67.4%, of the proglacial discharge, out of which snowmelt, clean ice melting, buried-ice ablation and ice-cliff backwasting account for 22.4%, 21.9%, 17.9% and 5.3% of the total melt runoff, respectively. Rainfall runoff is significant in mid-latitude glacierized mountain areas like Tianshan and Karakorum. In the Koxkar glacier catchment, about 11.5% of stream water is initiated from liquid precipitation. Spatial distributions for each glacial runoff component reveal the importance of climatic gradients, local topography and morphology on glacial runoff generation, and temporal variations of these components is closely related to the annual cycle of catchment meteorology and glacier storage. Four stages are recognized in the seasonal variations of glacier storage, reflecting changes in meltwater yields, meteorological conditions and drainage systems in the annual hydrological cycle. 展开更多
关键词 Debris cover MELTWATER GLACIER Koxkar RUNOFF
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Model Evaluation and Projection on the Linkage between Hadley Circulation and Atmospheric Background Related to the Tropical Cyclone Frequency over the Western North Pacific
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作者 ZHOU Bo-Tao 《Atmospheric and Oceanic Science Letters》 2012年第6期473-477,共5页
The performance of climate models in simulating the linkage of the spring Hadley circulation (HC) to the vertical zonal wind shear and atmospheric divergence in the lower and upper troposphere, which are related to th... The performance of climate models in simulating the linkage of the spring Hadley circulation (HC) to the vertical zonal wind shear and atmospheric divergence in the lower and upper troposphere, which are related to the tropical cyclone frequency over the western North Pacific (WNPTCF) during June-September (JJAS), is evaluated on the basis of the 20th century climate simulations (20C3M). It is found that four models can simulta-neously reproduce the pattern revealed in the observation, with the spring HC in the Northern Hemisphere being positively correlated to the vertical zonal wind shear in the major tropical cyclone (TC) genesis region and negatively (positively) correlated to the atmospheric diver- gence in the upper (lower) troposphere over the western North Pacific (WNP) in the following JJAS. These four models are further used to project their relationship in the late 21st century under the A1B scenario. The results show that the association of spring HC with the vertical zonal wind shear and the upper-and lower-tropospheric divergence over the WNP will weaken in the late 21st century, thereby resulting in a weak relationship between the spring HC and the JJAS WNPTCF. 展开更多
关键词 Hadley circulation atmospheric circulation tropical cyclone assessment PROJECTION
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A multi-state weather generator for daily precipitation for the Torne River basin, northern Sweden/western Finland
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作者 David RAYNER Christine ACHBERGER Deliang CHEN 《Advances in Climate Change Research》 SCIE CSCD 2016年第1期70-81,共12页
This paper describes a new weather generator e the 10-state empirical model e that combines a 10-state, first-order Markov chain with a non-parametric precipitation amounts model. Using a doubly-stochastic transition-... This paper describes a new weather generator e the 10-state empirical model e that combines a 10-state, first-order Markov chain with a non-parametric precipitation amounts model. Using a doubly-stochastic transition-matrix results in a weather generator for which the overall precipitation distribution(including both wet and dry days) and the temporal-correlation can be modified independently for climate change studies. This paper assesses the ability of the 10-state empirical model to simulate daily area-average precipitation in the Torne River catchment in northern Sweden/western Finland in the context of 3 other models: a 10-state model with a parametric(Gamma) amounts model; a wet/dry chain with the empirical amounts model; and a wet/dry chain with the parametric amounts model. The ability to accurately simulate the distribution of multi-day precipitation in the catchment is the primary consideration.Results showed that the 10-state empirical model represented accumulated 2- to 14-day precipitation most realistically. Further, the distribution of precipitation on wet days in the catchment is related to the placement of a wet day within a wet-spell, and the 10-state models represented this realistically, while the wet/dry models did not. Although all four models accurately reproduced the annual and monthly averages in the training data, all models underestimated inter-annual and inter-seasonal variance. Even so, the 10-state empirical model performed best.We conclude that the multi-state model is a promising candidate for hydrological applications, as it simulates multi-day precipitation well, but that further development is required to improve the simulation of interannual variation. 展开更多
关键词 Weather generator MULTI-STATE Torne River PRECIPITATION
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Numerical Modeling of Shallow Water Table Behavior with Lisse Effect
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作者 ZHANG Jinga GONG Huili +2 位作者 Mark A ROSS LI Xiaojuan ZHOU Demin 《Chinese Geographical Science》 SCIE CSCD 2011年第2期249-256,共8页
Air entrapment is an important consideration in environments with shallow water tables and sandy soil, like the condition of highly conductive sandy soils and flat topography in Florida, USA. It causes water table ris... Air entrapment is an important consideration in environments with shallow water tables and sandy soil, like the condition of highly conductive sandy soils and flat topography in Florida, USA. It causes water table rises in soils, which are significantly faster and higher than those in soils without air entrapment. Two numerical models, Integrated Hydrologic Model (IHM) and HYDRUS-1D (a single-phase, one-dimensional Richards′ equation model) were tested at an area of west central Florida to help further understanding the shallow water table behavior during a long term air entrapment. This investigation employed field data with two modeling approaches to quantify the variation of air pressurization values. It was found that the air pressurization effect was responsible at time up to 40 cm of water table rise being recorded by the observation well for these two models. The values of air pressurization calculated from IHM and HYDRUS-1D match the previously published values. Results also indicated that the two numerical models did not consider air entrapment effect (as the predictive parameters remain uncertain) and thus results of depth to water table from these models did not compare to the observations for these selected periods. Incorporating air entrapment in prediction models is critical to reproduce shallow water table observations. 展开更多
关键词 shallow water table Lisse effect air entrapment Integrated Hydrologic Model (IHM) HYDRUS-1D Florida
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Length of stay in urban areas of circular migrants from the mountainous areas in China
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作者 TAN Ming-hong LI Xiu-bin +2 位作者 YAN Jian-zhong XIN Liang-jie SUN Lai-xiang 《Journal of Mountain Science》 SCIE CSCD 2016年第5期947-956,共10页
Currently, there is limited literature dealing with the length of stay of circular migrants in urban areas (LSCMU), although many studies have discussed the phenomenon of migration and the determinants of migration.... Currently, there is limited literature dealing with the length of stay of circular migrants in urban areas (LSCMU), although many studies have discussed the phenomenon of migration and the determinants of migration. This study attempts to fill that gap using survey data from the mountainous areas of Chongqing, Southwest China. From a comparative perspective, this study divided workers into two groups (a young group aged between 16 and 35 years and an old group aged between 36 and 65 years). The average LSCMU values for the young and old groups were 225 days and ~74 days, respectively. Two multi-regression models were used to estimate the determinants of LSCMU in the two groups. The results showed that LSCMU was closely related to individual factors in both groups, including gender, age and job training. Family and community factors, including household size, arable land per capita and the distance from market, had much weaker effects on the dependent variable, especially in the older group. It was noticeable that job training had significant positive effects on LSCMU in both groups; these findings have special implications for the urbanization process in China. 展开更多
关键词 Circular migrants URBAN Mountain areas China
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Seismotectonic Zonation of the Longmengshan and Chengdu Region
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作者 Kong Jun Shi Bingxin +1 位作者 Zhou Rongjun Wang Shiyuan 《Earthquake Research in China》 CSCD 2016年第4期566-577,共12页
The principle of three-level delineation is adopted in determination of a potential seismic source for the new National Seismic Ground Motion Parameters Zoning Map of China,to embody the inhomogeneity of the spatial d... The principle of three-level delineation is adopted in determination of a potential seismic source for the new National Seismic Ground Motion Parameters Zoning Map of China,to embody the inhomogeneity of the spatial distribution of background seismic activity and induct a uniform seismotectonic model for each seismotectonic region. Based on achievements of determining potential seismic sources in southwestern China,this paper introduces the basic characteristics, historical earthquakes magnitude and frequency distribution,identification of deformation mechanism of main active tectonic structures for the Longmenshan and Chengdu seismotectonic region in the Longmenshan seismic region,establishes the seismogenic model for each seismotectonic region,and identifies the upper limit of background earthquakes. A simple method is also put forward for calculating the spatial distribution function of a background seismic source. 展开更多
关键词 Potential seismic source Seismotectonic region Spatial distribution function
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Study on the coordinated development of the rural infrastructure and the rural economy
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作者 Peng Yi Guo Haifeng Huang Shuqian 《International English Education Research》 2014年第4期45-47,共3页
Through the construction of the comprehensive evaluation index system and the coordination degree model of the rural in- frastructure and the rural economic development level, the author carries out an empirical analy... Through the construction of the comprehensive evaluation index system and the coordination degree model of the rural in- frastructure and the rural economic development level, the author carries out an empirical analysis on the rural infrastructure and economic coordinated development in the country's 31 regions. Research shows that the gap between the levels of the development of the rural in-frastructure in China is large, presenting the gradually reducing gradient distribution from the east to the west. The rural infrastructure de- velopment level has significant positive correlation with the level of economic development. For those provinces of the high development level of the rural economy, the infrastructure construction level is also relatively high. From the view of the coordination degree, it presents the obvious "dumbbell" shape, and there are more provinces which belong to the high quality coordination and the serious imbalance, with the coordinated degree in the eastern regions obviously higher than that in the central and western regions. 展开更多
关键词 Rural infrastructure rural economy coordinated development principal component analysis
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Analysis of Ground Motion Attenuation Characterization for Moderate Earthquakes in the Sichuan-Yunnan Region 被引量:3
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作者 Yu Tian Cui Jianwen +1 位作者 Li Xiaojun Yang Liwei 《Earthquake Research in China》 CSCD 2015年第2期237-246,共10页
The ground motion attenuation models for PGA,PGV and response spectrum at rock sites and soils sites are derived separately from the digital strong motion records of moderate earthquakes in the Sichuan-Yunnan region a... The ground motion attenuation models for PGA,PGV and response spectrum at rock sites and soils sites are derived separately from the digital strong motion records of moderate earthquakes in the Sichuan-Yunnan region after 2007. By comparison with Yu Yanxiangs attenuation model for rock sites in western China,reliability of the model is verified for moderate earthquake. According to the distribution of strong motion data against magnitude and epicentral distance,the applicability and reliability of the results in this paper are discussed. 展开更多
关键词 Sichuan-Yunnan region Ground motion Attenuation model
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干旱半干旱地区流域水文模型的适用性 被引量:13
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作者 刘松 张利平 +3 位作者 佘敦先 王强 胡辰 夏军 《武汉大学学报(工学版)》 CAS CSCD 北大核心 2019年第5期384-390,共7页
以干旱半干旱地区的辽宁省东白城子和叶柏寿流域为研究实例,通过建立新安江模型、辽宁西部非饱和产流模型和时变增益模型,利用场次洪水观测资料进行模型的率定与验证,比较分析场次洪水在率定期与验证期的模拟预报效果,最后讨论分析了3... 以干旱半干旱地区的辽宁省东白城子和叶柏寿流域为研究实例,通过建立新安江模型、辽宁西部非饱和产流模型和时变增益模型,利用场次洪水观测资料进行模型的率定与验证,比较分析场次洪水在率定期与验证期的模拟预报效果,最后讨论分析了3种水文模型在干旱半干旱地区洪水预报的适用性.结果表明,以蓄满产流为核心的新安江模型不适用于干旱半干旱地区,适用性最差;辽宁西部非饱和产流模型较新安江模型模拟效果有所提高,但仍无法满足洪水预报的精度要求;考虑降雨强度的时变增益模型模拟效果最优,在干旱半干旱地区的适用性最强,具有良好的发展潜力. 展开更多
关键词 干旱半干旱地区 新安江模型 辽宁西部非饱和产流模型 时变增益模型
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A step metallogenetic model for gold deposits in the northwestern Shandong Peninsula, China 被引量:29
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作者 SONG MingChun YI PiHou +5 位作者 XU JunXiang CUI ShuXue SHEN Kun JIANG HongLi YUAN WenHua WANG HuaJiang 《Science China Earth Sciences》 SCIE EI CAS 2012年第6期940-948,共9页
Based on our study of the nature and variation of mineralization-controlling faults in their deep extension and the spatial distribution of gold orebodies in the northwestern Shandong Peninsula (NSP), here we propose ... Based on our study of the nature and variation of mineralization-controlling faults in their deep extension and the spatial distribution of gold orebodies in the northwestern Shandong Peninsula (NSP), here we propose that the gold deposits in the Jiaojia gold belt are controlled by listric faults and the gold deposits in the NSP are controlled by extensional fault system. We also suggest that there is a multiple mineralization space in the deep part of the NSP gold belt. As steps or benches occur along the deep extention of the listric fault where its dipping angle changes from steep to gentle, a number of gold deposits are correspondingly distributed as a steplike pattern, which is named as a step metallogenetic model for gold deposits in the NSP. The gold deposits in Shandong Peninsula were formed in the Cretaceous when the crust in the region experienced extention and thinning following the strong collision between North China Plate and Yangtze Plate during the Triassic. Crust anataxis, fluid remobilization, and extention-detachement of the crust are the leading factors for the gold mineralization. 展开更多
关键词 deep-seated gold deposit step metallogenetic model northwestern Shandong Peninsula Jiaojia gold belt
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Modeling Runoff from Semi-Arid Agricultural Lands in Northwest Iran 被引量:2
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作者 A.R.VAEZI 《Pedosphere》 SCIE CAS CSCD 2014年第5期595-604,共10页
Transformation of rainfall into runoff over an area is a very complex process which exhibits both temporal and spatial variability;runoff in a defined area can be affected by factors such as topography, vegetation, ra... Transformation of rainfall into runoff over an area is a very complex process which exhibits both temporal and spatial variability;runoff in a defined area can be affected by factors such as topography, vegetation, rainfall characteristics and soil properties. This study was conducted to develop an empirical model using the rainfall characteristics and soil properties for predicting runoff from dry-farming lands in a semi-arid agricultural area in Hashtroud, Northwest Iran. Runoff plots(1.83 m × 22.1 m) in triplicate were installed in thirty-six sloped dry-farming lands in the study area. Runoff under natural rainfalls was measured in each plot during a2-year period. The results showed that runoff for 41 runoff-producing rainstorm events with duration longer than 30 min was largely associated with a rainfall index obtained by multiplying the positive square root of rainfall depth(h0.5) by the logarithm of the maximum 30-minute intensity(LogI30)(R2= 0.81). Runoff significantly varied among the plots(P < 0.001), which was considerably related to the effective soil properties(R2= 0.74), i.e., soil permeability(Per) and aggregate stability(AS). A multiple linear regression model was developed between runoff and the rainfall index(h0.5logI30) and the effective soil properties(AS and Per). Evaluation of the model using 34 runoff-producing rainstorm events that occurred during the next two years resulted in high values of the efficiency coefficient and R2(0.88 and 0.91, respectively), which revealed that the model developed in this study could be used in predicting runoff from the dry-farming lands in the semi-arid regions. 展开更多
关键词 aggregate stability dry-farming lands natural rainfall rainfall depth rainfall index rainfall intensity soil permeability
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Parameterizing soil organic carbon's impacts on soil porosity and thermal parameters for Eastern Tibet grasslands 被引量:34
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作者 CHEN YingYing YANG Kun +2 位作者 TANG WenJun QIN Jun ZHAO Long 《Science China Earth Sciences》 SCIE EI CAS 2012年第6期1001-1011,共11页
This study investigates the stratification of soil thermal properties induced by soil organic carbon (SOC) and its impacts on the parameterization of the thermal properties. Soil parameters were measured for alpine gr... This study investigates the stratification of soil thermal properties induced by soil organic carbon (SOC) and its impacts on the parameterization of the thermal properties. Soil parameters were measured for alpine grassland stations and North China flux stations, with a total of 34 stations and 77 soil profiles. Measured data indicate that the topsoils of alpine grasslands contain high SOC contents than underlying soil layers, which leads to higher soil porosity values and lower thermal conductivity and bulk density values in the topsoils. However, this stratification is not evident at the lowland stations due to low SOC contents. Evaluations against measured data show that three thermal conductivity schemes used in land surface models severely overestimate the values for soils with high SOC content (i.e. topsoils of alpine grassland), but they are better for soils with low SOC content. A new parameterization is then developed to take the impacts of SOC into account. The new one can well estimate the soil thermal conductivity values in both low and high SOC content cases, and therefore, it is a potential candidate of thermal conductivity scheme to be used in land surface models. 展开更多
关键词 soil organic carbon soil thermal parameters alpine grassland PARAMETERIZATION
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