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Palaeoclimate simulation of Little Ice Age

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Progress in Natural Science:Materials International 2004年第8期 68-76页

作者： LIU Jian 1, CHEN Xing 2, WANG Sumin 1 and ZHENG Yiqun 1 (1. nanjing Institute of geography and limnology, {3., nanjing 210008, china 2. Department of Atmospheric Science, nanjing University, nanjing 210093. china) nanjing Institute of geography and limnology Chinese Academy of Sciences Nanjing 210008 China Department of Atmospheric Science Nanjing University Nanjing 210093 China

Little Ice Age (LIA) is a typical cold climate period in global scope with a profound impact upon human society. In this study, a coupled global atmospheric circulation model including the land processes (AGCM + SSiB) is used to perform the simulation of LIA climate. Under the control of solar radiation reduction mechanism, the decrease of temperature is more obvious in summer than in winter; meanwhile, there is regional difference in the change of winter temperature. But the temperature decrease is the main characteristic of the annual mean temperature. Volcanic dust has an evident effect on the winter temperature decrease, but to a less extent than the solar radiation. The synchronous function caused by the reduction of solar radiation and the increase of optic depth of volcanic dust has a superposed strengthening effect on the temperature decrease in large regions. Promotion of the vegetation cover rate profits the increase of temperature, and vise versa. Certain decrease of solar radiation will favor the increase of summer monsoon precipitation in East Asia. The increase of optic depth of volcanic dust does not have a significant effect on the annual precipitation in most parts of Eurasian continent. The composite effect of the decrease of solar radiation and the increase of volcanic dust makes the summer monsoon precipitation in East china increase, and that in South Asia decrease. Together with vegetation change, the result shows that precipitation increases with the increase of vegetation coverage (e.g. East Asia), and when the vegetation coverage reduces (e.g. North Africa) the precipitation will decrease, too.

关键词： Little Ice Age model simulation East Asia.

Improvement of modelling accuracy by using high resolution soil data in a coupled surface-subsurface water flow model

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Improvement of modelling accuracy by using high resolution s...

Cambrian- Ordovician Deep - Water Deposits in Southwest Jiangxi, china

2011 World Congress on Engineering and Technology(CET 2011)

作者： Qi Zhang State Key Laboratory of Lake Science and Environment nanjing Institute of geography and limnology {3. nanjing 210008 china Jinling Yang Institute of Soil Science {3. nanjing 210008 china

This paper tested the effects of refined soil property on the hydrological modelling results, exemplified in the surface runoff-groundwater coupled model for Xitiaoxi catchment, Lake Taihu basin, by extending the previous study where a relatively coarse soil map was used. This study finds that the refined soil property, associated with a finer model grid size significantly improves the accuracy in modelling the stream flow for dry seasons, when the groundwater base flow （groundwater discharged to rivers） dominates the stream flow. Since the groundwater base flow is highly dependent on the soil water percolation processes, the accurate simulation of base flow requires an accurate representation of the soil property and soil water processes. This finding implies that the soil resolution may affect the partitioning of surface and subsurface water flow, and should be appropriately considered in coupled simulation of surface and subsurface water flow, especially for the cases that stream flow simulations for dry seasons demand for a high accuracy.

关键词： Soil resolution surface-subsurface water flow modelling accuracy dry seasons WATLAC Xitiaoxi catchment

来源： cnki会议评论

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Acta Geologica Sinica(English Edition) 1994年第4期68卷 435-449,471-472页

作者： Ji Leinanjing Institute of geography and limnology, Academia Sinica, nanjing Jiang Minxi nanjing Institute of geography and limnology Academia Sinica Nanjing

The Cambrian-Ordovician rocks in southwestern Jiangxi are mainly composed of deep-water deposits, in which 5 facies have been recognized: sandstone facies, sandstone-mudstone facies, siltstone-mudstone facies, mudstone (slate)facies, and chert facies. They are of turbidity current origin and are related to pelagic and hemipelagic deposits. In the light of facies distribution, the Cambrian-Ordovician deposits can be classified into 3.facies associations formed in middle fan, outer fan and deep-sea plain environments respectively. The 3.different orders of vertical cycles in the stratigraphic sequence are considered to be controlled by factors such as sea-level fluctuation, basin subsidence and submarine fan progradation. The tectonic setting of the sedimentary basin is interpreted as passive continental margin based on the chemical composition analysis of the sandstone.

关键词： deep-water deposits turbidite pelagite and hemipelagite submarine fan vertical cycles

Quantitative reconstruction of the paleosalinity at Qinghai Lake in the past 900 years

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chinese Science Bulletin 2004年第7期49卷 730-734页

作者： ZHANG Enlou1,2,SHEN Ji1,WANG Sumin1,YIN Yu1,ZHU Yuxin1 & XIA Weilan1 1.Key Laboratory of Lake Sediment and Environment,nanjing institute of geography and limnology,{3.,Nan-jing 210008,china 2.Graduate School of {3.,Beijing 10003.,china Correspondence should be addressed to Zhang Enlou(e-mail:elzhang@ ***) Key Laboratory of Lake Sediment and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China Graduate School of chinese academy of sciences Beijing 100039 China

Based on the function relationship between the shell length of Limnocythere inopinata and the salinity of its living water in Tibetan Plateau lakes, the paleosalinty of Qinghai Lake in the past 900 years was reconstructed through the measurement of the adult body length of Limno-cythere inopinata. Meanwhile, the paleosalinity sequence of Qinghai Lake during the same period was rebuilt by the Sr/Ca ratio of the shell of Eucypris inflata combined with the Sr/Ca ratio of living ostracod valves from the species of ge-nus Eucypris inflata and the host water. The paleosalinity results obtained by two different methods were compared and assessed in this paper. To check the result, it was also contrasted with other historical climatic sequences of this area including tree ring and ice core. It was shown that the paleosalinity sequence rebuilt by adult ostracod body length had high reliability, and the paleosalinity reconstruction method by trace elements of ostracod shells was not suitable for Qinghai Lake. From the reconstructed paleosalinty se-quence of Qinghai Lake, it can be found that low salinity during 1160—1290 AD showed the humid climate condition on the Mediaeval Warm Period in this area, while the high salinity during 1410—1540 AD, 1610—1670 AD and 1770—1850 AD which was corresponding to the three cold pulses of the Little Ice Age with a dry climate condition. And the high salinity in the latest several decades was consistent with re-cent warm and dry trends of the climate in this area. The good consistency of the reconstructed palaeosalinity sequence and the precipitation sequence in this area rebuilt by tree ring proves the reconstruction of past lake salinity is reliable.

关键词：青海湖数量重建成体特异湖浪介古盐度树轮海底沉积物介形亚纲动物

A general model for estimating actual evaporation from non-saturated surfaces

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Journal of Geographical sciences 2002年第4期12卷 479-484页

作者： QIU Xinfa1,2, ZENG Yan3. LIU Changming3.1. Dept. of Urban && Resource Science, nanjing University, nanjing 210093. china 2. Dept. of {3., nanjing Institute of Meteorology, nanjing 210044, china 3. Inst. of Geographic sciences and Natural Resources Dept. of Urban & Resource Science Nanjing University Nanjing China Dept. of geography Nanjing Institute of Meteorology Nanjing China Inst. of Geographic sciences and Natural Resources Research CAS Beijing China

Based on energy balance equation and mass transfer equation, a general model to estimate actual evaporation from non-saturated surfaces was derived. Making use of two concepts, “relative evaporation” and “relative drying power”, a relationship was established to account for the departure from saturated conditions. Using this model, the actual evaporation (evapotranspiration) can be calculated without the need of potential evaporation estimation. Furthermore, the model requires only a few meteorological parameters that are readily and routinely obtainable at standard weather stations. Based on nearly 3. years data of 43. meteorological stations and 512 hydrological stations in china, in combined with GIS, nine typical river basins were selected. Using the data of the selected river basins, the model was tested. The results show that the actual evaporation rate can be estimated with an error of less than 10% in most areas of china, except few years in the Yellow River Basin.

关键词： potential evaporation actual evaporation

A COUPLING THREE DIMENSIONAL BAROCLINIC MODEL OF BIWA LAKE AIR-WATER SYSTEM

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Journal of Geographical sciences 1996年第3期6卷 76-83页

作者： Zhang Limin Pu Peimin(nanjing Institute of geography & limnology, Academia Sinica, {3.People’s Republic of china)

A numerical model coupling atmosphere with hydrodynamics is set up in this paper, and is applied in the experimental study of Lake Biwa. Some results are obtained as : (1) whatever (SSW) in sunimer or (NNW) in winer, there exists a positive wind-stress curl over a lake; (2) in summer the positive wind-stress curi plays an important role to form circulation in a lake and produces a special temperature field corresponding to circulation, lower in the deep water, higher in the shallow water; (3. in summer, the hypothesis of initial horizontal inhomogeneous water temperature has little effiect on the results of simulation, and (4) in winter,there is no obvious circulation formed in the lake.

关键词： air-water coupling model Lake Biwa numerical simulaton

THE TIDAL FLATS MORPHOLOGICAL DEVELOPMENT AND THE COASTAL LAND RECLAMATION IN SHANGHAI

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Journal of Geographical sciences 1996年第1期6卷 84-91页

作者： Li Jiufa(Institute of Estuanne & Coastal Research, East china Normal Univ., Shanghai 200062People’s Republic of china)Zhang Chen(nanjing Institute of {3. and limnology, CAS, nanjing 210008People’s Republic of china) Inst of Estuarine + Coastal Rsch East China Normal Univ Shanghai 200062 China

More than 904.2 km2 of the flats are above the theorotical datum level with progressive rate of 20-200 m/a to the sea in Shanghai. Since the reclaimed land is vital important to the city, multiple approaches to accelerating siltation are proposed in the paper according to detailed study of dynamics, sedimentary structure and landform evolution based on plentiful in situ data. It is of great significance to utilize tidal flats and reclamation of land in Shanghai.

关键词： Changjiang Estuary Shanghai tidal flat reclamation

CLIMATIC VARIATIONS IN china OVER THE LAST 2000 YEARS

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chinese Geographical Science 2001年第2期11卷 97-103页

作者： YANG Bao1, SHI Ya-feng2, LI Heng-peng2 (1. Cold and Arid Regions Environmental and Engineering Research Institute, the chinese academy of sciences,Lanzhou 73.000, P.R. china 2. Institute of geography and {3., the chinese academy of sciences Cold and Arid Regions Environmental and Engineering Research Institute the Chinese Academy of Sciences Lanzhou P. R. China Institute of geography and limnology the Chinese Academy of Sciences Nanjing P. R. China

A compilation of paleoclimate records from ice core, tree-rings, lake sediments and historical documents provides a view of temperature change in china over the recent 2000 years. For all-china temperature reconstruction, six sub-stages are identified for the last two millennia. Around AD 0－240, AD 800－1100, AD 13.0－1400 and the period from AD 1880 on were warm while around AD 240－800, AD 1100－13.0, AD 1400－1880 were cold. Also, temperature varied from region to region in each of the warm or cold periods. The Eastern Han warm period (0－AD 240), the cold period covering the span of Wei, Jin, and the Southern and Northern Dynasties, the MWP (AD 800－1100) and succeeding LIA occurred in eastern china and the Qilian Mountains. Only the first two climatic events were recorded in Guliya ice core while the so-called MWP and LIA was far weaker. Also, the warming between AD 800 and 1100 didn′t occur in the south of Xizang (Tibet) Plateau. Instead, the southern Xizang Plateau experienced warming in AD 1150－1400. The aggregated china temperature agrees well with North-hemisphere temperature in the past millennia, indicating close relationship of temperature changes between china and North-hemisphere.

关键词： climatic variations the last two millennia china

Soil Erosion Changes over the Past Five Decades in the Red Soil Region of Southern china

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Journal of Mountain Science 2010年第1期7卷 92-99页

作者： LIANG Yin LI Decheng LU Xixi YANG Xuan PAN Xianzhang MU Huan SHI Deming ZHANG Bin Institute oj: Soil Science Chinese Academy of Sciences Nanjing 210008 China Department of geography National University of Singapore Singapore 119260 Key Laboratory of Soil Environment and Pollution Remediation Institute of Soil Science Chinese Academy of Sciences. Nanjing 210008 China

This paper reports the dynamic changes of soil and water loss in the red soil region of Southern china since the 1950s. The red soil region covers eight provinces: Jiangxi, Zhejiang, Fujian, Anhui, Hubei, Hunan, Guangdong and Hainan. From the 1950s to 1986, the annual rate of soil erosion increased by 3.4%. From 1986 to 1996 and from 1996 to 2000, the annual rates of soil erosion decreased by 2.0% and 0.3.%, respectively. Field surveys showed that from 2000 to 2005, the area of soil and water loss decreased annually by 1.2%. This decrease was a result of large-scale erosion control activities across china. Although the eroded soil has been restored, the restoration process is very slow and full restoration will take a long time. Our report suggests that controlling soil and water loss is a challenging task, and additional measures must be taken to effectively control the soil erosion in the red soil region.

关键词： red soil region soil and water loss dynamic change remote sensing field samplingsurvey