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1.
耦合魔方——一个分析人地系统耦合机理的多维框架 总被引：1，自引：1，他引：1
Understanding the interactions between humans and nature in the Anthropocene is central to the quest for both human wellbeing and global sustainability.However,the time-space compression,long range interactions,and reconstruction of socio-economic structures at the global scale all pose great challenges to the traditional analytical frameworks of human-nature systems.In this paper,we extend the connotation of coupled human and natural systems(CHANS)and their four dimensions—space,time,appearance,and organization,and propose a novel framework:“Coupled Human and Natural Cube”(CHNC)to explain the coupling mechanism between humans and the natural environment.Our proposition is inspired by theories based on the human-earth areal system,telecoupling framework,planetary urbanization,and perspectives from complexity science.We systematically introduce the concept,connotation,evolution rules,and analytical dimensions of the CHNC.Notably there exist various“coupling lines”in the CHNC,connecting different systems and elements at multiple scales and forming a large,nested,interconnected,organic system.The rotation of the CHNC represents spatiotemporal nonlinear fluctuations in CHANS in different regions.As a system continually exchanges energy with the environment,a critical phase transition occurs when fluctuations reach a certain threshold,leading to emergent behavior of the system.The CHNC has four dimensions—pericoupling and telecoupling,syncoupling and lagcoupling,apparent coupling and hidden coupling,and intra-organization coupling and inter-organizational coupling.We mainly focus on the theoretical connotation,research methods,and typical cases of telecoupling,lagcoupling,hidden coupling,and inter-organizational coupling,and put forward a human-nature coupling matrix to integrate multiple dimensions.In summary,the CHNC provides a more comprehensive and systematic research paradigm for understanding the evolution and coupling mechanism of the human-nature system,which expands the analytical dimension of CHANS.The CHNC also provides a theoretical support for formulating regional,sustainable development policies for human wellbeing. 相似文献
2.
By statistically analyzing the storm data from the Joint Typhoon Warning Center(JTWC) over the Bengal Bay during the period 1945-2006,it is found that the yearly averaged tropical cyclone(TC) number over the Bay of Bengal is 8.12,which takes place in any month of the whole year;February and March have the fewest TC numbers.The TC numbers begin to increase starting in April and arrive at a peak in October.Differing from TC over the Bay of Bengal,the tropical storms(TS) over the Bay of Bengal has two peak periods,appear in May and in October or November,respectively.With regard to TS intensity,the super severe storm of H4 criterion appeared only one time during the period 1971-1986,but appeared eight times during the period 1987-2006.The monthly change of the original position,the averaged maintaining time,and the longest maintaining time of TS also have two peak values:They appear in April or May and in October or November,respectively.The peak value of the original position in October or November is bigger than that in April or May.The peak value of the average maintaining time and the longest main-taining time of the TS in April or May is bigger than that in October or November.TC landfall path is mostly moving toward northwest or west and accounts for 56.7 percent.The landfall path of the TS differs from that of TC in some respects.The main difference is that the numbers of the northwestern path and un-landfall of TS are less than those for TC,and the numbers of the western path and northeastern path of TS are greater than for TC.Because of the landfall TS in the north-east path has a peak,it and the beginning of the rainy season in Yunnan Province are closely related;it is on Yunnan Province’s early summer precipita-tion that they have a great impact. 相似文献
3.
The Three Gorges Reservoir Area(TGRA)is typical of an ecologically vulnerable area,comprised of rural and mountainous areas,and with high immigration.Because of its economic and ecologic importance,studying the traditional agroecosystem changes in the TGRA is key to rural development and revitalization.In this study,we apply a framework of theoretical analysis,empirical study,and trend prediction to the Caotangxi River watershed within the TGRA.Using QuickBird high-resolution remote sensing images from 2012 to 2017 to evaluate natural resources and farmers’behavior,we analyze the transition and trends in the traditional agroecosystem in mountainous areas of the TGRA at spatial scale of the man-land relationship.We find that the agroecosystem in the TGRA can be divided into four modes using 100 m interval buffer rings:high-low-low,high-low-high,low-high-low and low-low-high mode where the different modes represent the agricultural development stages in the TGRA.Furthermore,the traditional agroecosystem in TGRA,represented by system elements such as farmers and sloping farmland,is transforming to accommodate the diversification of farmer livelihoods.For example,sloping farmland,which was dominated by a production function,now has equal emphasis on ecological and economic functions.Spatially,the range of the agroecosystem transition has migrated beyond high mountain areas to flat valley areas.Generally,this study provides an overview of land use in rural areas,controls on soil and water loss in mountainous areas,and better rural living environments in the TGRA. 相似文献
4.
Root distribution of three co-occurring desert shrubs and their physiological response to precipitation 总被引：1，自引：0，他引：1
Root distribution of three desert shrubs,Tamarix ramosissima Ledeb.,Haloxylon ammodendron(C.A.Mey.) Bunge and Reaumuria soongorica(Pall.) Maxim.was investigated under co-occurring conditions using a method for excavating the whole root system.Assimilation shoot water potential and transpiration rates were monitored during the wet-dry cycle.Leaf-specific apparent hydraulic conductance and the index of water stress impact for the three species were calculated from shoot water potential and transpiration rate.The results showed that,along the soil profile,the root system of T.ramosissima mainly distributed at 50 to 310 cm interval,with an average total absorbing root-surface area of 30,249.2 cm2 per plant;the root system of H.ammodendraom distributed at 0 to 250 cm interval with an average total absorbing root-surface area of 12,847.3 cm2 per plant;the root system of R.soongorica distributed at 0-80 cm interval,with an average total absorbing root-surface area of 361.8 cm2.The root distribution shows the following:T.ramosissima uses groundwater as its main water source;H.ammodendraom uses both groundwater and rainwater;and R.soongorica uses rainwater only.During the wet-dry cycle,the hydraulic parameters of T.ramosissima showed no responses to precipitation.R.soongorica responded most significantly,and the responses of H.ammodendraom were intermediate.In conclusion,the plant response to rain events is closely related to their root distribution and plant water-use strategy. 相似文献
5.
地理双语教学要求师生同时具备对地理学科的汉语思维和英语思维的能力。如在介绍美国工业部门及分布时，学生对其理解都比较抽象，怎样让他们快速掌握城市和工业的分布呢?可以先请对NBA感兴趣的同学介绍几支球队情况，要求学生从这些球队的名称上来理解课文的内容。(如The Detroit Pistons底特律活塞队：The name“Pistons”refers to a key part of an automobile engine活塞一词是指汽车发动机的关键部件；The Houston Rockets休斯顿火箭队：The NASA Mission Control Centeris located in Houston美国宇航局控制中心位于休斯顿。) 相似文献
6.
长江上游退耕还林工程的农业生产和水环境效益评价——以四川省为例 总被引：1，自引：0，他引：1
退耕还林工程是我国大规模的土地利用方式的改变.以四川省为例,基于退耕还林工程实施后粮食产量、粮食作物播种面积、化肥用量以及水质和水土流失状况变化的分析,讨论了退耕还林工程对环境保护的贡献和可能存在的问题.退耕还林工程导致粮食作物播种面积、粮食产量和化肥用量的减少,在退耕还林工程实施前,这三者之间有很好的相关性,但自工程实施后,这三者的下降幅度与退耕还林面积的增加幅度有较大的差异.几种原因可能造成这种不一致性,值得进一步研究.退耕还林工程实施后河流径流量、泥沙含量以及输沙量的下降充分证实了退耕还林工程对长江上游水土保持的重要贡献,同时进一步证实长江上游的泥沙主要来源于坡耕地的耕作. 相似文献
7.
8.
Extreme weather is an important noise factor in affecting dynamic access to river morphology information.The response characteristics of river channel on climate disturbances draw us to develop a method to investigate the dynamic evolution of bankfull channel geometries(including the hydraulic geometry variables and bankfull discharges)with stochastic differential equations in this study.Three different forms of random inputs,including single Gaussian white noise and compound Gaussian/Fractional white noise plus Poisson noise,are explored respectively on the basis of the classical deterministic models.The model parameters are consistently estimated by applying a composite nonparametric maximum likelihood estimation(MLE)method.Results of the model application in the Lower Yellow River reveal the potential responses of bankfull channel geometries to climate disturbances in a probabilistic way,and,the calculated average trends mainly run to synchronize with the measured values.Comparisons among the three models confirm the advantage of Fractional jump-diffusion model,and through further discussion,stream power based on such a model is concluded as a better systematic measure of river dynamics.The proposed method helps to offer an effective tool for analyzing fluvial relationships and improves the ability of crisis management of river system under varying environment conditions. 相似文献
9.
Understanding how the transpiration of this vegetation type responds to environmental stress is important for determining the wa-ter-balance dynamics of the riparian ecosystem threatened by groundwater depletion. Transpiration and sap flow were measured using the heat-pulse technique. The results were then projected up to the stand level to investigate the stand’s water-use in relation to climate forcing in the desert riparian forest in an extreme arid region. This study took place from April through October 2003 and from May through October 2004. The experimental site was selected in the Populus euphratica Forest Reserve (101o10’ E, 41o59’ N) in Ejina county, in the lower Heihe River basin, China. The sapwood area was used as a scalar to extrapolate the stand-water consumption from the whole trees’ water consumption measured by the heat-pulse velocity recorder (HPVR). Scale transferring from a series of individual trees to a stand was done according to the existing natural variations between trees under given environmental conditions. The application of the biometric parameters available from individual tree and stand levels was proved suitable for this purpose. A significant correlation between the sapwood area and tree diameter at breast height (DBH) was found. The prediction model is well fitted by the power model. On the basis of the prediction model, the sapwood area can be cal-culated by DBH. The sap-flow density can then be used to extrapolate the stand-water use by means of a series of mathematical models. 相似文献
10.
中国地理学会地貌与第四纪专业委员会 《地理学报》2008,63(1):111-111
2007年全国地貌与第四纪学术研讨会于2007年11月20日-22日在福建师范大学隆重召开.本次会议由中国地理学会地貌与第四纪专业委员会主办,福建师范大学地理科学学院承办.来自全国31个研究所、大学等单位的86位代表参加了这次会议.大会开幕式由中国地理学会地貌与第四纪专业委员会副主任杨小平研究员主持.福建师范大学生态文明所所长廖福霖教授致辞.中国地理学会地貌与第四纪专业委员会主任许炯心研究员做了主题发言. 相似文献
11.
A 332-cm long lacustrine core was drilled in the Nam Co in the central-southern part of the Tibetan Plateau. From the core, 15 species of ostracods (Crustacea: Ostracoda), which belong to 6 genera have been identified. According to the variations of the ostracod assemblages and the ostracods ecological features, which are sensitive to the changing environment, three main stages can be distinguished as follows: Stage I was from 8400 to 6800 a BP, during which the climate was cold-humid, and the lake depth changed from shallow to deep. Stage II was from 6400 to 2500 a BP, during which the climate changed from warm-humid to cold-humid, and then to cold-dry. The lake depth gradually became deep. The shifting of climate, from wet-cold to dry-cold during this period, had constructed the basis of present environment in the Nam Co. Stage III was from 2500 a BP to the present, which showed a trait of lake depth increasing. At the earlier period of this stage, the climate kept as cold-dry as that in the former stage, but the salinity of the lake increased. At the later period of this stage, the degree of cold-dry was enhanced, and the activities of land surface runoff tended to be weakened. Our research also found that the peak values of ostracods with black shell was coherent with the maximum production of the ostracods, and agreed with the increasing sedimentary water dynamics. This indicated that the ostracods with black shell was simultaneous with the high prolificacy of ostracod, and transported from other places. The abundance of Candona juvenile shells reflected the high mortality of that kind of ostracods under an unfavorable condition. This was probably a result of the rapid change of water dynamics of sedimentary environment. 相似文献
12.
8.4 ka 以来纳木错湖芯介形类组合的环境变化意义 总被引：1，自引：1，他引：0
对青藏高原中南部纳木错长332cm的NMLC1孔湖芯研究发现,沉积物的介形类动物群计有6属15种。介形类属种生态特征和组合变化分析表明这些介形类对环境条件具有敏感性,其组合能够很好地反映过去环境变化的特征。结果表明,8．4ka以来具有三个不同的环境变化时期：早期在8400～6800aBP,湖泊由浅向深发展,环境具有相对冷湿的特征：中期在6800～2500aBP,湖泊深度逐渐加大,环境经历了暖湿-冷湿-冷干的变化．其中由冷湿向冷干的转化奠定了纳木错现今环境条件的基础：晚期在2500--9aBP,湖泊深度继续增加,这个时期的较早阶段,继续保持了前一时期的冷干特点,但湖水盐度可能开始增加．较晚阶段的冷干化加剧,陆面流水的活跃性大大降低。研究发现,纳木错NMLC1钻孔介形类黑色壳体的高峰值与介形类的最大生产量相一致,并且与沉积水动力条件增强相适应．指示了这些黑壳的产生与介形类的大量繁殖处于同一阶段．并且主要为异地搬运为主。钻孔中出现大量Candona幼虫壳体．其原因可能与沉积环境的水动力条件迅速改变有关。 相似文献
13.
青藏高原西北部17000年以来的介形类及环境演变 总被引：32，自引：3，他引：32
通过班公错和松西错两钻孔以及红山湖地层剖面的介形类分析，讨论了昆仑山、喀喇昆仑山地区晚更新世晚期以来的主要气候事件和环境变迁。 相似文献
14.
近22 ka以来吉兰泰盐湖的环境变化及成盐过程 总被引：5，自引：3，他引：2
根据研究区及毗邻地区第四纪地层沉积特征资料,运用层序地层学的基本方法,对吉兰泰盐湖22 ka BP以来的环境变化和成盐过程进行初步分析。同时,将其划分为6个阶段:冷干期（22.0~14.0 ka BP）,淡水湖演化阶段;冷湿期（14.0~10.0 ka BP）,仙女木期气候颤动期,湖水开始咸水化;暖湿期（10.0~7.0 ka BP）,咸水湖阶段;暖湿转干期（7.0~6.0 ka BP）,咸水湖阶段,亦是湖泊“成盐事件”的预备阶段;冷干期（6.0~4.7 ka BP）,盐湖阶段气候干湿交替,也是盐湖的成盐发展期;凉干期（4.7 ka BP至今）,是盐湖的成盐旺期,盐湖湖水不断缩减,加之周围沙漠的不断吞噬,盐湖开始由干盐湖向沙下湖发展。吉兰泰地区距今22 ka以来的古环境变化及气候转型,不仅是对全球古气候变化的响应,而且对盐湖矿产资源的成盐事件及区域可持续发展具有重要意义。 相似文献
15.
Studies on playas (known locally as inland sabkhat) are rare and lack a focus on their role as geoarchives for Holocene climate and environmental change. We present characteristic sediments and processes that illustrate the change from relatively humid to hyperarid conditions within the sedimentary record of the playa of Tayma (Saudi Arabia). The shift from the Holocene humid period (10–8 ka BP) to the hyperarid conditions of today left traces in this geoarchive. During the humid period, a perennial lake had formed in the playa depression. The occurrence of biota, especially ostracod valves and foraminifer shells, adapted to salinity fluctuations and physiochemical reactions of ostracods and foraminifers testify environmental changes. Phases of lake contraction and high salinities were responsible for the formation of ‘open water’ evaporites, such as aragonite needles, and ooids. Dilution occurred during rain events and flooding of the playa; it is characterised in the sedimentary infill by clastic layers that were deposited in graded sequences. The smooth surface, the phenomenon of microsomia and sieve pore variations of the ostracod valves provide evidence for changing salinities, which are testimony to short lived changes. These processes and further aridisation resulted in the formation of ‘capillary’ evaporites, which are dominated by sulphate minerals. The precipitates undergo fractionation and re-dissolution, which results in a typical stratification of salts with different solubilities. 相似文献
16.
Jonathan A. Holmes Patrick A. Fothergill F. Alayne Street-Perrott R. Alan Perrott 《Journal of Paleolimnology》1998,20(4):369-380
The ostracod record from Kajemarum Oasis in the Sahel zone of Northeastern Nigeria covers the last c. 4000 cal. years of a 5500 cal. year lake-sediment sequence. The first appearance of ostracods, around 4000 cal. yr BP, reflects the switch from a very dilute lake during the mid-Holocene, to slightly oligosaline conditions that favoured the occurrence and preservation of ostracods. Between 3800 and 3100 cal. yr BP, the lake remained permanent and fresh or slightly oligosaline, with a Ca-Mg-HCO3 composition. A rise in salinity c. 3100 cal. yr BP, accompanied by a change to more variable conditions on a seasonal to interannual timescale, led to the influx of more-euryhaline taxa. Oligosaline conditions continued between 3100 and 1500 cal. yr BP. Around 1500 cal. yr BP, there was a sharp rise in salinity, probably accompanied by a shift to Na-CO3-type water, with marked seasonal and interannual variability. Salinity decreased after 900 cal. yr BP, although short-term variations were marked between 900 cal. yr BP and the top of the sequence, 95 cal. yr BP. Changes in the species assemblages and ostracod abundance were a response to climate-driven variations in the seasonal and interannual stability of the lake, together with changes in its salinity and solute composition, but there is no simple relationship between ostracod faunas and salinity. Within Kajemarum, there is no evidence of ostracod assemblages typical of deep, fresh water, nor of hypersaline Na-Cl waters. The sediments associated with the freshest waters at Kajemarum did not favour ostracod preservation, and the driest climatic conditions were associated with oligosaline to mesosaline water of Na-CO3-type. The species-poor assemblages reflect the short-term instability of the lake, coupled with the limited opportunities for the colonisation of this isolated basin. 相似文献
17.
The CC1 core, with a length of 216 cm, was drilled in the west part of the Chen Co (Lake) in southern Tibet Plateau. The 210Pb and 137Cs measurement indicated that it was a consecutive sedimentary sequence since ca. 1400 years. The ostracoda and their assemblages under the level of 1 cm samples' cutting interval were finished for this core to reveal the past environmental changes in the lake area. A total of 15 species of ostracods belonging to 7 genera in the core sediments had been identified. According to the ostracod distributions, abundances and preservations in the core, seven ostracod assemblages had been distinguished. The ostracod assemblages and their ecological features, together with the sediments dating decision were used to infer the past ca. 1400 years environmental changes of the Chen Co environmental evolutions in three stages, which had responded to the Medieval Ages Warm-period (MAW), the Little Ice Age (LIA) and modern warm period. The results show that the changes of the Chen Co environment had been mainly influenced by the climatic variations. The trend of the lake level fluctuations had been accorded with that of climatic variation during the past 1400 years. 相似文献
18.
The ostracod assemblages and their environmental significance in the Chen Co area,southern Tibet in recent 1400 years 总被引：1，自引：0，他引：1
The CC1 core, with a length of 216 cm, was drilled in the west part of the Chen Co (Lake) in southern Tibet Plateau. The210Pb and137Cs measurement indicated that it was a consecutive sedimentary sequence since ca. 1400 years. The ostracoda and their assemblages
under the level of 1 cm samples’ cutting interval were finished for this core to reveal the past environmental changes in
the lake area. A total of 15 species of ostracods belonging to 7 genera in the core sediments had been identified. According
to the ostracod distributions, abundances and preservations in the core, seven ostracod assemblages had been distinguished.
The ostracod assemblages and their ecological features, together with the sediments dating decision were used to infer the
past ca. 1400 years environmental changes of the Chen Co environmental evolutions in three stages, which had responded to
the Medieval Ages Warm-period (MAW), the Little Ice Age (LIA) and modern warm period. The results show that the changes of
the Chen Co environment had been mainly influenced by the climatic variations. The trend of the lake level fluctuations had
been accorded with that of climatic variation during the past 1400 years. 相似文献
19.
湖冰物候事件是气候变化的敏感指示器。本文以西藏纳木错湖为研究对象,基于MODIS多光谱反射率产品数据监测了2000-2013年纳木错湖冰冻融日期,并结合多个气象站点的气象数据和实测湖面温度、湖面辐射亮温分析验证了湖冰变化的原因。纳木错湖冰变化较好地响应了区域气候变暖：开始冻结日期延迟和完全消融日期提前使湖冰存在期显著缩短(2.8 d/a)、湖冰冻结期增长、湖冰消融期缩短,其中消融期变化最为明显,平均每年缩短3.1 d。湖冰冻融日期的变化表明：2000年后纳木错湖冰冻结困难,消融加速,稳定性减弱。纳木错湖冰变化主要受湖面温度、湖面辐射亮温和气温变化的影响,它们可以作为气象因子来解释区域气候变化。 相似文献
20.
Jonathan A. Holmes 《Journal of Paleolimnology》1998,19(2):115-128
Two assemblages typify the ostracod fauna of a 9.23 meter core taken from Wallywash Great Pond, a small perennial freshwater marl lake in Jamaica. The first, dominated by Cypretta brevisaepta, lived in deep water, similar to present-day conditions. The second, dominated by Candonopsis sp., reflects the existence of a shallower lake. The core has a basal date of c. 125 kaBP. Four inferred deep-water phases occurred in the period 125–93.5 kaBP with periods of inferred shallower water in between. The lake was dry between 93.5 kaBP and c. 10 kaBP as suggested by the absence of ostracods or fossils of other aquatic organisms. Ostracod faunal evidence indicates that there have been three highstands and two lowstands of the lake during the Holocene, although ostracods are not preserved in the organic mud and lignite that formed under swampy conditions as the basin filled at the start of the Holocene and during part of the two subsequent lowstands of the lake. A major hydrological perturbation, associated with the flooding of the nearby Black River catchment around 1.2 kaBP, caused an increase in the ostracod species diversity of the Great Pond, although this was relatively short lived and the lake attained a faunal composition similar to present around 1 kaBP. Major variations in ostracod assemblages in the core thus represent lake-level changes and accord well with previously-published interpretations of water depth based on lithofacies variation and stable oxygen isotope ratios in authigenic carbonates. 相似文献