Effects of historical land cover changes on climate

In order to explore the influence of anthropogenic land use on the climate system during the last mil- lennium, a set of experiments is performed with an Earth system model of intermediate complexity—— the McGill Paleoclimate Model (MPM-2). The present paper mainly focuses on biogeophysical effects of historical land cover changes. A dynamic scenario of deforestation is described based on changes in cropland fraction (RF99). The model simulates a decrease in global mean annual temperature in the range of 0.09-0.16℃, especially 0.14-0.22℃ in Northern Hemisphere during the last 300 years. The responses of climate system to GHGs concentration changes are also calculated for comparisons. Now, afforestation is becoming an important choice for the enhancement of terrestrial carbon sequestration and adjustment of regional climate. The results indicate that biogeophysical effects of land cover changes cannot be neglected in the assessments of climate change.     

Using 137Cs tracing technique to estimate wind erosion rates in the typical steppe region,northern Mongolian Plateau

Wind erosion is one of the major factors of land degradation in the typical steppe region, northern Mongolian Plateau. Using ^137Cs tracing technique, we estimated the wind erosion rates of different pastures and abandoned farmland at Bayannur and Karakorum in Mongolia. The pastures and cutting grassland at Bayannur were slightly eroded by wind, with the rates of 64.58-169.07 t·km^-2.a^-1. The abandoned farmland in Karakorum, however, was strongly eroded by wind, with annual surface soil loss of 4.05 mm. a^-1, and wind erosion rates up to 6723.06 t· km^-2. a^-1. The total loss of surface soil due to wind erosion has been 17.4 cm since the cultivation of the steppe land in the 1960s. The wind ero- sion rate at the abandoned farmland was much higher than that at the typical steppe sites, showing that the cultivation led to serious wind erosion in the typical steppe region, northern Mongolian Plateau. By contrast, traditional livestock grazing resulted in less disturbance to the surface soil, and did not induce to devastating wind erosion, which plays an important role in maintaining the stability of the steppe ecosystem in the northern Mongolian Plateau.     

Interaction of Land Demand and Supply Effects in Intensive Land Use: a Simulation Study for Chengdu,China

Intensive land use( ILU) policies affect the demand and supply of land. These policies promote efficient land use, and demands for land must therefore be evaluated in terms of the level of land-use intensity. If the demand is considered excessive, ILU policies act like a "valve"to restrict the land supply. Drawing on data from Chengdu,China,where developable land is scarce,we construct a model using system dynamics( SD) to simulate two scenarios: ILU development and non-ILU development. The results show that when ILU leads to positive land-use efficiency,land supply will exceed demand,resulting in an appropriate level of real demand for the current population level and GDP. Thus,artificial demand( inflated by investors) is reduced. By contrast,when non-ILU leads to negative land-use efficiency,land demand will exceed supply. In this scenario,artificial demand is higher than real demand.     

Spatiotemporal vegetation cover variations in the Qinghai-Tibet Plateau under global climate change

Empirical Orthogonal Function （EOF） analysis and the related Principal Components （PC） analysis are used to extract valuable vegetation cover derived information from the National Oceanic and Atmos-pheric Administration （NOAA-AVHRR）＇s Leaf Area Index （LAI） satellite images. Results suggest that from 1982 to 2000 global climate change has contributed to an increase in vegetation cover in the Qinghai-Tibet Plateau. The correlation between rainfall and LAI EOF PC1 and PC2 indicates that rainfall is the major climatic factor influencing interannual variations of average vegetation cover throughout the entire Plateau. However, annual mean vegetation cover trends in the Qinghai-Tibet Plateau are mainly out of phase with air temperature increasing, which is primarily responsible for nonsynchro-nous changes of vegetation cover. In the southern ridge of the Qinghai-Tibet Plateau, recent warming trends contribute to humid weather and favorable conditions for vegetation growth. By contrast, higher temperatures have led to arid conditions and insufficient rainfall in the northern part of the Plateau, leading to drought and other climatic conditions which are not conducive to increased vegetation cover.     

Microstructure and structural color in wing scales of butterfly Thaumantis diores

The butterfly Thaumantis diores is a species in the Northeast of China. There are two kinds of scales on its wings, which overlap like roof tiles and completely cover the membrane. The SEM results showed that only Type-I scales play a key role in forming the blue structural color. Type-II scales have black chemical color. The cross section micro-configuration of scales is achieved by using the transmission electron microscopy (TEM). The brilliant blue generated through the multilayer microstructure is explained by the photonic crystal reason. The multilayer microstructure of the ridges is optimized to 1D Bragg stack for simulation. The reflectivity of the wing is measured by a spectrometer, and the experimental graph accord with the simulation curves basically. When this species fly, the wing’s color and brightness can change because of the transform between structural color and chemical color. The bionic color-changing design and the significance of this effect in video stealth or other fields are discussed at the end of the paper. Supported by Fok Ying Tong Education Foundation (Grant No. 101020), the Natural Science Foundation of China (Grant No. 30570235, 50635030), National Basic Research of China (Grant No. 2007CB616913) and Key Project of the Ministry of Education (Grant No. 105059)     

Self-organized criticality of power system faults and its application in adaptation to extreme climate

This paper analyzes the statistics of faults in a transmission and distribution networks in central China, unveils long-term autocorrelation and power law distribution of power system faults, which indicates that power system fault has self-organized criticality (SOC) feature. The conclusion is consistent with the power systems data in 2008 with ice storm present. Since power systems cover large areas, climate is the key factor to its safety and stability. In-depth analysis shows that the SOC of atmosphere system contributes much to that of power system faults. Extreme climate will be more intense and frequent with global warming, it will have more and more impact upon power systems. The SOC feature of power system faults is utilized to develop approaches to facilitate power systems adaptation to climate variation in an economical and efficient way. Supported by the National Basic Research Program of China (Grant No. 2009CB219701), National Natural Science Foundation of China (Grant No. 50595414), and Youth Scientific & Technological Innovation Project of CSEE     

The early-warning effects of assimilation of the observations over the large-scale slope of the “World Roof” on its downstream weather forecasting

To improve the numerical simulation of the severe snow storms occurred in the south of China and the middle/lower reaches of Changjiang River during January of 2008, the observations from the automatic weather stations (AWS) over the Qinghai-Xizang Plateau (QXP) and its surrounding areas were assimilated into the Weather Research and Forecasts (WRF) model using multi-cycle 3-dimensional variational data assimilation (3DVAR). Due to the large-scale special topography of the QXP and its surrounding areas which may reach up to the mid-troposphere, the AWS located at different height on the deep slope of the plateau are different to those located on plains and take a role analogous in some extent to that of radio soundings in obtaining the vertical “profile” information of the atmosphere, and have the advantages in the aspects of sampling frequency, location/height fixing, and synchronization. The information captured by these AWS may carry the early-warning “strong signals” in the upstream sensitive area for the downstream weather systems to the east of the plateau and thus the assimilation of these AWS data is expected to lead to significant improvements on the simulation of the severe weather system occurred in its downstream areas through adjusting the 3-dimensional structures of the atmospheric thermal-dynamics for the initial conditions of the model. This study indicates that the assimilated information of moisture, temperature and pressure carried in the observations of AWS over the Qinghai-Xizang Plateau and its surrounding areas is very important and useful in the forecasting of precipitation in its downstream areas. Supported Jointly by National Natural Science Foundation of China (Grant Nos. 90502003 and 40625017), LaSW Project (Grant No. 2008LASWZI04), the Key Project of AMS (Grant No. 2008Z006), the JICA Program and the International Sci-Tech Cooperative Project (Grant No. 2007DFB20210)     

利用CLUE-S模型对四川省未来10年土地利用变化的预测与分析

土地利用配置对生态环境和经济发展有着重要影响,通过研究土地利用配置对人类可持续发展具有重要意义。以我国四川省为研究区,设定了生态效益型、经济效益型和综合效益型3种发展情景,通过CLUE-S模型模拟研究区2030年的土地利用数据,计算了各情景下相应的生态服务价值量和经济效益,分析了3种情景下模拟结果各土地利用类型分布的相同和差异。研究结果表明,生态服务价值量在情景1下达到最大值,为108 405.5亿元;经济效益则在情景2下最大,为78 346.3亿元。从土地利用空间分布上来看,3种情景的变化趋势基本一致:生态用地中林地和水域的增加主要分布在攀西地区;建设用地的增加主要分布在攀西地区和四川盆地。研究结果可对四川省未来的土地规划管理提供参考。     

Ecosystem vulnerability of China under B2 climate scenario in the 21st century

This paper applies climate change scenarios in China based on the SRES assumptions with the help of RCMs projections by PRECIS （providing regional climates for impacts studies） system introduced to China from.the Hadley Centre for Climate Prediction and Research at a high-resolution （50 kmx50 km） over China. This research focuses on B2 scenario of SRES. A biogeochemical model ＂Atmosphere Vegetation Integrated Model （AVIM2）＂ was applied to simulating ecosystem status in the 21st century. Then vulnerability of ecosystems was assessed based on a set of index of mainly net primary production （NPP） of vegetation. Results show that climate change would affect ecosystem of China severely and there would be a worse trend with the lapse of time. The regions where having vulnerable ecological background would have heavier impacts while some regions with better ecological background would also receive serious impacts. Extreme climate even would bring about worse impact on the ecosystems. Open shrub and desert steppe would be the two most affected types. When the extreme events happen, vulnerable ecosystem would extend to part of defoliate broad-leaved forest, woody grassland and evergreen conifer forest. Climate change would not always be negative. It could be of some benefit to cold region during the near-term. However, in view of mid-term to long-term negative impact on ecosystem vulnerability would be enormously.     

贵州山区公路沿线生态系统服务价值变化

为探讨山区公路沿线土地利用变化对生态系统服务价值(ecosystem service value, ESV)的影响,以贵州省麻江县309省道为例,基于1992年、2002年、2012年和2032年土地利用数据和中国陆地生态系统服务单位面积ESV系数,对309省道沿线土地利用变化所引起的ESV变化进行估算。结果表明:①研究期间,耕地和草地持续减少,建设用地不断增加,而不同时期的林地、水域和未利用地或增或减。②1992—2032年间,除情景B外,情景A和C的ESV均不断增加。各地类的ESV变化趋势与各地类面积变化一致。除情景B外,情景A和C的各种ESV均不断增加。越靠近公路的缓冲区(距公路0～500 m区域),ESV变化越剧烈,不同时期各缓冲区ESV变化存在差异。③快速经济发展、退耕还林政策、地形限制等是影响公路沿线ESV变化的主要因素。     

人类活动影响下华北平原水资源可持续利用研究

人类活动对区域水资源可持续利用的影响随着人类社会的发展和进步而不断增大。通过分布式水文模型和系统动力学模型的耦合,设定4大类情景,即现状保持型、农业节水型,南水北调(SNWDP)型和综合发展型(S1~S4),模拟华北平原2009~2028年水资源可持续利用的状况。结果表明:(1)随着社会经济的发展,四种情景下总需水量呈增长趋势,到2028年,S1~S4下华北平原总需水量分别为595.7、543.1、596.9及544.3亿m~3,相应的缺水指数分别为0.509 5、0.429 1、0.251 4及0.177 1;(2)农业节水措施与南水北调工程的结合,才会对华北平原地下水水位的恢复、缺水程度的缓解及水资源的可持续利用产生比较显著的影响;(3)在人类活动影响下,华北平原缺水的问题短期内无法彻底解决,但可以通过采用南水北调与节水措施相结合来缓解缺水问题。     

Elemental composition in surface snow from the ultra-high elevation area of Mt. Qomolangma （Everest）

A total of 14 surface snow （0-10 cm） samples were collected along the climbing route （6500-8844 m a.s.h） on the northern slope of Mt. Qomolangma in May, 2005. Analysis of elemental concentrations in these samples showed that there are no clear trends for element variations with elevation due to redistribution of surface snow by strong winds during spring. In addition, local crustal aerosol inputs also have an influence on elemental composition of surface snow. Comparison between elemental concentration datasets of 2005 and 1997 indicated that data from 2005 were of higher quality. Elemental concentrations （especially for heavy metals） at Mt. Qomolangma are comparable with polar sites, and far lower than large cities. This indicates that anthropogenic activities and heavy metal pollution have little effect on the Mt. Qomolangma atmospheric environment, which can be representative of the background atmospheric environment.     

阿克苏地区土地利用变化情景模拟及其生态安全水平评价

采用CA-MCE-Markov模型设计并模拟了阿克苏地区2030年自然发展、经济发展优先、内涵提升情景下的土地利用变化,运用PSR模型定量评价了3种情景的土地生态安全水平.结果表明：1)面积变化上,内涵提升情景耕地减少了774 km²,城乡建设用地增加了100 km²,实现了集约发展;自然发展情景与经济发展优先情景耕地增加了3 436 km²,城乡建设用地增加了386 km²,呈粗放式发展.2)空间变化上,自然发展情景耕地、林地、水域反演位置不符实际、经济发展优先情景城乡建设用地布局粗放、内涵提升情景用地布局具备合理性.3)顺延历年发展状态,生态安全水平将持续降低;若以经济发展优先为发展导向,安全压力及承载力响应两方面问题依然严峻;相比之下,内涵提升情景生态安全水平大幅提升,为最优模拟方案,生态高度安全.通过评测不同情景土地利用变化差异,为解决实际矛盾、改善生态环境、谋求永续发展提供措施与方法.     

Process modeling of fuel cell vehicle power system

Constructed here is a mathematic model of PEM Fuel Cell Vehicle Power System which is composed of fuel supply model, fuel cell stack model and water-heat management model. The model was developed by Matlab/Simulink to evaluate how the major operating variables affect the output performances. It shows that the constructed model can represent characteristics of the power system closely by comparing modeling results with experimental data, and it can be used in the study and design of fuel cell vehicle power system. Supported by the National High Technology Research and Development Program of China (Grant No. 2007AA05Z145), State Key Development Program for Basic Research of China (Grant No. 2007cb209707) and Shanghai Science and Technology Project (Grant Nos. 06SN07115 and 07JC14024)     

基于SD-CA模型的快速城市化地区土地利用空间格局变化预测

利用未来用地模拟(FLUS)模型预测土地利用变化,探讨深圳市在快速城市化进程中土地利用格局的时空演变特征.首先,基于2004-2018年的历史数据,用系统动力学(SD)模型预测未来用地需求.然后,使用元胞自动机(CA)模型,基于2014年土地利用图,预测2025年的耕地、园地、林地、草地、城镇用地、交通用地、水域和其他...     

大城市边缘区土地利用变化模拟研究——以北京市昌平区为例

近年来,土地利用变化模拟模型成为GLP的研究热点.大城市边缘区土地利用因变化剧烈而特殊,一直都是LUCC研究的重点领域.本研究采用国际前沿的土地利用变化及其影响空间建模方法——CLUE-S模型,基于GIS分析和统计分析,以北京市昌平区为例,运用1996年和2004年土地利用数据,构建CLUE-S模型,对2007—2015年不同土地利用政策情景下土地利用变化进行模拟,得到2010年和2015年的土地利用模拟图.结果表明:(1)专门针对中小尺度区域的CLUE-S模型能够对区域内的土地利用变化进行较好的模拟和预测,其中对分布相对集中的林地和建设用地的模拟效果相对较好,而对比较分散的园地、耕地和城市绿地的模拟效果相对较差;(2)在Markov情景下,建设用地的扩张最为明显;粮食安全情景下,山前平原区质量比较好的耕地没有转换为建设用地;而生态安全情景下,林地得到比较好的保护,并且林地的增加在靠近城区和高速公路的两侧最为明显.本研究可为研究区土地利用规划修编和土地可持续性管理提供科学依据.     

Statistical Facts of Clouds, Sunshine Duration, Temperature and Daily Range of Temperature in China During 1950-1988

1. The interannual variation of cloud amount was opposite to that of sunshine duration. The correlation coefficient between them in winter was high and negative. The long term trends of the two terms had different types. The SD obviously decreased during 1950—1988; however, the CA did not increase in the same period. The decreasing of SD in company with the slight decrease of CA could be attributed to the declining sensitivity of sunshine recorders owing to the air pollution. 2. CA and SD had obvious influence on the daytime temperature and then the daily range of temperature. However, they did not affect the nighttime temperature. 3. In southern China, cloud cover plays an important role m the variation of air temperature, but in northern China, perhaps there were some other processes which give more significant influence on the variation of air temperature.     

Coupling and propagating of mesoscale sea level variability between the western Pacific and the South China Sea

The coupling and propagating features of mesoscale sea level variability between the western Pacific (WP) and the South China Sea (SCS) were studied based on time series analyses of satellite altimeter measured, along-track sea surface height anomalies (SSHA) along 21°N and the slope of the northern SCS. The analyses show that mesoscale sea level fluctuations in the WP have rather limited coherent effects on the SCS, and no statistically significant propagation of mesoscale variability through the Luzon Strait was observed except in the 45-day band. Evidence suggests that the 45-day fluctuation is very much likely a character of the Kuroshio originating from its low-latitude beginning. It is also sug- gested that the westward propagating Rossby waves will deform when they encounter the dynamical barrier of the Kuroshio. The Kuroshio will then acts on the SCS in its own way. The SCS is a relatively isolated system in the sense of coupling and propagating of oceanic mesoscale waves.     

重庆市土地利用变化及其生态系统服务价值响应

土地利用变化会引起区域生态环境的一系列响应.以重庆市为研究区,参照国内外的研究成果,根据重庆市2001-2006年的土地利用情况,综合运用景观生态学理论和生态服务价值理论,从土地利用结构变化出发,以生态系统的复杂性和稳定性为前提,测算重庆市近6年来生态服务价值的变化.研究表明重庆市2001-2006年期间生态系统服务功能年度经济价值量变化呈现上升趋势,土地利用结构调整方向总体来说是基本合理的,土地利用生态效益明显.     

Virtual three dimensions reconstruction and isoline analysis of human marks on the surface of animal fossils

Animal fossils in archaeological sites are closely related to human activities. The environment and human activities, such as hunting-selection, cook process, traditional culture and habits can be partly inferred from the variety of fauna, fragmentation of the bones, and the human marks on bones’ sur-faces. So far, researches about marks on fossils are few in China, and are mainly observed directly by eyes. Light Microscopes and Scanning Electron Microscopes are also applied to the observation abroad. These...