Northward-shift of temperature zones in China’s eco-geographical study under future climate scenario     

WU Shaohong  ZHENG Du  YIN Yunhe  LIN Erda  XU Yinlong 《地理学报》2010,20(5):643-651

Despite the well-documented effects of global climate change on terrestrial species’ ranges, eco-geographical regions as the regional scale of ecosystems have been poorly studied especially in China with diverse climate and ecosystems. Here we analyse the shift of temperature zones in eco-geographical study over China using projected future climate scenario. Projected climate data with high resolution during 1961–2080 were simulated using regional climate model of PRECIS. The number of days with mean daily temperature above 10℃ and the mean temperature of January are usually regarded as the principal criteria to indicate temperature zones, which are sensitive to climate change. Shifts due to future climate change were calculated by comparing the latitude of grid cells for the future borderline of one temperature zone with that for baseline period (1961–1990). Results indicated that the ranges of Tropical, Subtropical, Warm Temperate and Plateau Temperate Zones would be enlarged and the ranges of Cold Temperate, Temperate and Plateau Sub-cold Zones would be reduced. Cold Temperate Zone would probably disappear at late this century. North borderlines of temperature zones would shift northward under projected future climate change, especially in East China. Farthest shifts of the north boundaries of Plateau Temperate, Subtropical and Warm Temperate Zones would be 3.1°, 5.3° and 6.6° latitude respectively. Moreover, northward shift would be more notably in northern China as future temperature increased.  相似文献   

江浙典型茶园土壤有机质空间异质性分析   总被引：1，自引：0，他引：1  

徐云鹤  方斌 《地球信息科学学报》2015,17(5):622-630

茶园土壤有机质分布有明显的空间性,如何凭借有限的采样点数据预测研究区的有机质分布,对了解茶叶种植区土壤状况、指导茶园经营管理、提高茶叶品质和产量有重要意义。本文对江浙4种名茶种植区,利用描述性统计,以及地统计学中的半方差函数模型、空间插值等方法对比分析了茶园土壤有机质的空间异质性。研究结果表明:(1)4个研究区的土壤有机质平均水平均较高,适合茶叶生长,且浙江省2个茶叶种植区的有机质平均水平高于江苏省2个茶叶种植区的有机质水平;(2)半方差函数模型拟合表明,溪龙乡种植区有机质含量表现出中等空间相关性,而其他3个种植区表现出强烈的空间相关性;(3)各种植区土壤有机质的空间分布以结构性因子(土壤理化性质、地形地貌)为基础,受人类活动、经营模式、茶园管理等随机性因子影响,整体趋势上表现出局部变异的特征。  相似文献   

RLS-BP人工神经网络算法在降水预报中的应用   总被引：2，自引：0，他引：2       下载免费PDF全文

余运河  胡邦辉  孔玉寿  谭言科  许云海 《气象科学》2004,24(3):333-341

RLS—BP是一种新发展起来、自动设置网络主要参数和具有快速收敛能力的人工神经网络模型，用预报对象动态消空处理加以改进，应用于大连地区短中期降水MOS预报，实施了其预报效果与普通BP网络对比的试验。结果表明，改进后的新模型既提高了降水的预报精度，又有良好的计算稳定性．并且适合推广应用于气温、能见度等诸多气象要素的预报和预测问题。  相似文献   

Climatic trends over the Tibetan Plateau during 1971-2000     

WU Shaohong  YIN Yunhe  ZHENG Du  YANG Qinye 《地理学报》2007,17(2):141-151

Trends of annual and monthly temperature, precipitation, potential evapotranspi-ration and aridity index were analyzed to understand climate change during the period 1971–2000 over the Tibetan Plateau which is one of the most special regions sensitive to global climate change. FAO56–Penmen–Monteith model was modified to calculate potential evapotranspiration which integrated many climatic elements including maximum and mini-mum temperatures, solar radiation, relative humidity and wind speed. Results indicate gen-erally warming trends of the annual averaged and monthly temperatures, increasing trends of precipitation except in April and September, decreasing trends of annual and monthly poten-tial evapotranspiration, and increasing aridity index except in September. It is not the isolated climatic elements that are important to moisture conditions, but their integrated and simulta-neous effect. Moreover, potential evapotranspiration often changes the effect of precipitation on moisture conditions. The climate trends suggest an important warm and humid tendency averaged over the southern plateau in annual period and in August. Moisture conditions would probably get drier at large area in the headwater region of the three rivers in annual average and months from April to November, and the northeast of the plateau from July to September. Complicated climatic trends over the Tibetan Plateau reveal that climatic factors have nonlinear relationships, and resulte in much uncertainty together with the scarcity of observation data. The results would enhance our understanding of the potential impact of climate change on environment in the Tibetan Plateau. Further research of the sensitivity and attribution of climate change to moisture conditions on the plateau is necessary.  相似文献   

3D MT anisotropic inversion based on finite-element method with unstructured grids     

Xiaoyue Cao  Changchun Yin  Xin Huang  Yunhe Liu 《《地质学报》英文版》2018,92(Z1):338-339

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湖南平江县仁里超大型伟晶岩型铌钽多金属矿床的发现及其意义   总被引：1，自引：0，他引：1  

刘翔  周芳春  黄志飚  李建康  周厚祥  肖国强  包云河  李鹏  谭黎明  石威科  苏俊男  黄小强  陈虎  汪宣民  林跃  刘晓敏 《大地构造与成矿学》2018,(2):235-243

湖南平江县仁里铌钽多金属矿床是湖南省核工业地质局311大队新发现的高品位超大型伟晶岩型稀有多金属矿床,经过多年的地质勘查,在幕阜山复式花岗岩体西南缘的仁里矿区查明伟晶岩脉140条,发现铌钽矿脉14条。对主要矿脉进行了地表槽探和深部钻探验证,具有北铌钽南锂的特征,铌钽矿体具规模大、矿体形态简单、连续性好,矿化较均匀,品位富、埋藏浅,矿石质量优及资源潜力大等特点。矿区估算(333+334)Ta2O5资源量10791 t,Nb2O5:14057 t,平均品位Ta2O5:0.036%,Nb2O5:0.047%,达到超大型规模。仁里超大型铌钽多金属矿床的发现,突破以往对大岩基难以形成和找到超大型伟晶岩型稀有金属矿床的既往认识,提出幕阜山矿集区定位于构造岩浆隆起带,仁里矿床大型层状构造与燕山期岩浆岩联合控矿、含铌钽矿伟晶岩脉形成于区域后造山构造环境的伸展构造体制的新认识,分析了区域上的找矿方向,丰富和发展了稀有金属成矿理论,为华南地区稀有金属矿产找矿实现了重大突破,使幕阜山地区有望成为我国一个新的重要铌钽等稀有金属资源基地。  相似文献   

3D joint inversion of controlled-source audio-frequency magnetotelluric and magnetotelluric data     

RONG Zhihao  LIU Yunhe 《世界地质(英文版)》2022,25(1):26-33

Different geophysical exploration methods have significant differences in terms of exploration depth,especially in frequency domain electromagnetic(EM)exploration.According to the definition of skin depth,this difference will increase with the effective detection frequency of the method.As a result,when performing three-dimensional inversion on single type of EM data,it is not possible to effectively distinguish the subsurface geoelectric structure at the full scale.Therefore,it is necessary to perform joint inversion on different type of EM data.In this paper we combine the magnetotelluric method(MT)with the controlled-source audio-magnetotelluric method(CSAMT)to study the frequency-domain three-dimensional(3D)joint inversions,and we use the unstructured finite-element method to do the forward modeling for them,so that the numerical simulation accuracies of different electromagnetic methods can be satisfied.By combining the two sets of data,we can obtain the sensitivity of the electrical structure at different depths,and depict the full-scale subsurface geoelectric structures.In actual mineral exploration,the 3D joint inversion is more useful for identifying subsurface veins in the shallow part and blind mines in the deep part.It can delineate the morphological distribution of ore bodies more completely and provide reliable EM interpretations to guide the mining of minerals.  相似文献   

昌宁-孟连结合带清平地区斜长角闪岩锆石年代学及Sr- Nd- Hf同位素研究   总被引：1，自引：0，他引：1  

彭智敏  付于真  王国芝  关俊雷  耿全如  胡金锋  刘云鹤  张璋 《地质学报》2020,94(2):511-526

昌宁-孟连结合带清平地区发育较为完整的蛇绿岩组合,主要由蚀变橄榄岩、蛇纹岩、枕状玄武岩、斜长角闪岩等构造单元组成。通过对该蛇绿混杂岩中的斜长角闪岩的LA-ICP-MS U-Pb锆石年代学研究,获得~(206)Pb/~(238)U加权平均年龄分别为433.9±2.9Ma,436.7±2.4Ma,说明斜长角闪岩形成为早志留世。对锆石原位微区Hf同位素锆石分析获得ε_(Hf)(t)值为5.5～6.7,均值6.2。SiO_2含量为45.65%～50.71%,平均为48.02%,K_2O/Na_2O比值0.07～0.23,具有富钠贫钾的亚碱性系列岩石。轻稀土富集,重稀土亏损,(La/Yb)_N=1.87～4.35,轻重稀土分馏明显,δEu=0.80～1.26,总体无明显的Eu异常。微量元素大离子亲石元素(Rb、Ba、Sr)相对富集,高场强元素Nb、Ta、Ti和Zr具有不同程度的亏损,反映俯冲带构造的特征,岩石地球化学特征显示具有E-MORB的性质,经构造环境图解判别,样品均落入E-MORB区域,说明在早志留世昌宁-孟连洋存在俯冲消减的作用。(~(87)Sr/~(86)Sr)_t=0.704289～0.704742,(~(143)Nd/~(144)Nd)_t=0.512107～0.512172,ε_(Nd)(t)值在0.54～1.81,均值为0.99。Sr-Nd-Hf同位素组成表明,斜长角闪岩岩浆源区主要来源于富集地幔(EMII),未受到地壳物质的混染,可能受到昌宁-孟连洋俯冲沉积物析出流体的影响。Pb同位素特征显示具有Dupal异常特征,说明在昌宁-孟连结合带双江清平地区在早志留世存在与现今印度洋一致的Dupal异常地幔域,昌宁-孟连结合带在早志留世位于南半球,说明昌宁-孟连早志留世洋盆所处位置属冈瓦纳大陆的一部分。  相似文献   

光因子对离心列海链藻生殖的影响   总被引：4，自引：0，他引：4  

林均民  黄云鹤 《台湾海峡》1997,16(3):255-259

从厦门沿岸分离的离心列海链藻培养体，在光条件下发生在性生殖。实验结果获得，在２０℃温度下诱导该藻雌雄配子形成的最适光强度分别在１１３和３６μＥｉｎ／（ｍ２．ｓ），最适光照时间分别为８和１０ｈ。有性生殖只在３７μｍ宽度以下的细胞中发生，且精囊和卵囊的宽度大小十分相似。  相似文献   

Spatiotemporal characteristics of sea ice transport in the Baffin Bay and its association with atmospheric variability     

Weifu Sun  Haibo Bi  Min Fu  Xi Liang  Yunhe Wang  Yu Liang  Jue Huang  Haijun Huang  Liwen Yan  Qinglong Yu  Shuang Liang 《海洋学报(英文版)》2021,40(3):1-2

Sea ice export through the Baffin Bay plays a vital role in modulating the sea ice cover variability in the Labrador Sea.In this study,satellite-derived sea ice products are used to obtain the sea ice area flux (SIAF) through the three passages in the Baffin Bay (referred to as A,B,and C for the north,middle,and south passages,respectively).The spatial variability of the monthly sea ice drift in the Baffin Bay is presented.The interannual variability and trends in SIAF via the three passages are outlined.The connection to several large-scale atmospheric circulation modes is assessed.Over the period of 1988–2015,the average annual (October to the following September) SIAF amounts to 555×10~3 km~2,642×10~3 km~2,and 551×10~3 km~2 through Passages A,B,and C,respectively.These quantities are less than that observed through the Fram Strait (FS,707×10~3 km~2) of the corresponding period.The positive trends in annual SIAF,on the order of 53.1×10~3 km~2/(10 a) and 43.2×10~3 km~2/(10 a)(significant at the 95%confidence level),are identified at Passages A and B,respectively.The trend of the south passage (C),however,is slightly negative (–13.3×10~3 km~2/(10 a),not statistically significant).The positive trends in annual SIAF through the Passages A and B are primarily attributable to the significant increases after 2000.The connection between the Baffin Bay sea ice export and the North Atlantic Oscillation is not significant over the studied period.By contrast,the association with the cross-gate sea level pressure difference is robust in the Baffin Bay (R equals 0.69 to 0.71,depending on the passages considered),but relatively weaker than that over FS (R=0.74).  相似文献