Dynamic Scaling of the Generalized Complementary Relationship Improves Long-term Tendency Estimates in Land Evaporation     

Jozsef SZILAGYI  Richard CRAGO  Ning MA 《大气科学进展》2020,37(9):975-986

Most large-scale evapotranspiration(ET) estimation methods require detailed information of land use, land cover,and/or soil type on top of various atmospheric measurements. The complementary relationship of evaporation(CR) takes advantage of the inherent dynamic feedback mechanisms found in the soil-vegetation-atmosphere interface for its estimation of ET rates without the need of such biogeophysical data. ET estimates over the conterminous United States by a new, globally calibrated, static scaling(GCR-stat) of the generalized complementary relationship(GCR) of evaporation were compared to similar estimates of an existing, calibration-free version(GCR-dyn) of the GCR that employs a temporally varying dynamic scaling. Simplified annual water balances of 327 medium and 18 large watersheds served as ground-truth ET values. With long-term monthly mean forcing, GCR-stat(also utilizing precipitation measurements)outperforms GCR-dyn as the latter cannot fully take advantage of its dynamic scaling with such data of reduced temporal variability. However, in a continuous monthly simulation, GCR-dyn is on a par with GCR-stat, and especially excels in reproducing long-term tendencies in annual catchment ET rates even though it does not require precipitation information.The same GCR-dyn estimates were also compared to similar estimates of eight other popular ET products and they generally outperform all of them. For this reason, a dynamic scaling of the GCR is recommended over a static one for modeling long-term behavior of terrestrial ET.  相似文献   

青藏高原天然气水合物形成的空间耦合关系探讨   总被引：2，自引：0，他引：2  

周强  李万伦  陈伟涛  王永江 《冰川冻土》2011,33(5):1139-1145

通过对青藏高原地质、地理资料的收集和综合归纳,分析了青藏高原油气地质演化、高原隆升、冻土生成、冰川推移与天然气水合物成生的关系,探讨了青藏高原油气地质与天然气水合物在时空上的耦合关系.初步认为,青藏高原分布的大面积的海相中生界烃源岩为冻土天然气水合物的形成提供了丰富的物源基础;尤其是碳酸盐岩和泥（页）岩,为主力烃源岩,...  相似文献   

东北亚地区晚侏罗—白垩纪构造格架主体特点   总被引：4，自引：0，他引：4  

张允平 《吉林大学学报(地球科学版)》2011,41(5):1267-1284

将东北地区主体构造特征置于东北亚大地构造背景中进行分析,可将东北亚地区晚中生代—古近纪的构造演化划分为3个时段:1)中—晚侏罗世,特提斯洋扩张及古北美大陆板块与古欧亚大陆之间的碰撞,致使蒙古—鄂霍茨克湾闭合,形成大规模深层次逆冲构造;并在南蒙古和华北地块北缘产生远距离的构造叠加效应。2)晚侏罗—早白垩世,特提斯洋板块、古太平洋构造域(包括古太平洋和伊泽纳奇板块)与古欧亚大陆之间的联合作用,导致亚洲东部大陆地壳向东蠕散、伸展和断块活动,伴随发育小型断陷盆地和变质核杂岩。3)早白垩世末(阿尔布晚期)—新近纪(中新世),特提斯洋板块(后期包括印度大陆)、太平洋构造域与欧亚大陆间的联合作用,导致古太平洋(或伊泽纳奇板块)消失及鄂霍茨克海微板块与欧亚大陆之间的碰撞,在大陆边缘叠加形成火山-深成岩带和坳陷盆地。在100～40Ma期间,太平洋构造域与欧亚大陆之间的相互作用,对欧亚大陆东部边缘产生重大影响,在导致大陆岩石圈-地壳减薄、地幔类型转变和强烈深成构造-岩浆活动的同时,也产生一系列与大陆边缘断块活动有关的浅层效应。  相似文献   

应用稳定碳氮同位素分析法研究广东流沙湾海域白腹小沙丁鱼的营养级     

杨国欢  侯秀琼  孙省利  陈春亮 《台湾海峡》2011,30(4):467-472

对2008年5—11月采集的广东流沙湾海域白腹小沙丁鱼（Sardinellaclupeoides）进行稳定碳、氮同位素比值的测定,分析比较了5个不同体长组的差异,并以此为基础推算其营养级．结果表明,流沙湾白腹小沙丁鱼的δ^13C值变化范围为一17．61％。一15．99％。,平均值为一16．59‰,与浮游动物的δ^13C均值（一17．27％0）较为相近．其6”N值变化范围为12．73％。～15．26％0,平均值为14．03％0,比浮游动物的6”N均值（10．56％0）高出3．47％0．5个体长组的8¨c、8”N平均值没有随着体长的增大而增大．由δ15N值推算出广东流沙湾海域白腹小沙丁鱼的营养级范围为2．24～3．25,平均值为2．76,符合其主要摄食浮游动物的食性．  相似文献   

国家尺度社会经济数据格网化原理和方法   总被引：2，自引：0，他引：2  

胡云锋  王倩倩  刘越  李军  任旺兵 《地球信息科学学报》2011,13(5):573-578

空间信息获取和处理技术,可将传统关系型社会经济数据转变为空间化的矢量或者格网数据.首先,分析了传统关系型社会经济数据库的不足,并对社会经济数据格网化理论研究及格网数据库建设的历史做了回顾;在明确社会经济数据格网化基本概念的基础上,提出了社会经济数据格网化的3个基本要求,即时间可比、空间一致和逻辑自洽;同时提出了一个包括...  相似文献   

Relationships between two Pseudoalteromonas from the Canada Basin and the Southern polyphasic approach strains Ocean isolated using a     

Zeng YinXin  Zheng TianLing 《极地研究(英文版)》2011,(1):25-34

  相似文献   

Priestley-Taylor公式的改进及其在互补蒸散模型中的应用   总被引：3，自引：0，他引：3  

赵玲玲  王中根  夏军  陈喜  秦年秀 《地理科学进展》2011,30(7):805-810

Priestley-Taylor公式是无平流的假设条件下提出的,而实际情况很难满足。为了消除基本假设所带来的计算误差,原公式中引入修正系数α。但大量研究表明,修正系数α具有很大的时空变异性,取值具有很大的不确定性。本文尝试直接引入平流项的方法来反映平流的影响作用。通过在乌江鸭池河流域进行实例验证分析,结果表明该方法具有一定的合理性,能够为冬季蒸散发的计算提供最小能量保证。相比原有的修正系数法,蒸散发的计算精度得到有效提高。特别是原有公式计算出现的冬季偏小、夏季偏大的情况得到了有效的改善。  相似文献   

Structure Analysis of the Complete Mitochondrial Genome in Cultivation Variety 'Rongfu'     

ZHANG Jing  LI Ning  ZHANG Zhifeng  LIU Tao 《中国海洋大学学报(英文版)》2011,10(4)

In this report,complete mitochondrial genome sequences of Laminaria cultivation variety 'Rongfu' were obtained.The results showed the length of circular molecule of mtDNA was 37 638 bp(64.7% A+T),encoding three rRNAs(23S,16S and 5S),25 tRNAs,35 known mitochondrial proteins and 3 ORFs.Sequence alignment indicated its mtDNA genome was very similar to that of Laminaria japonica.Phylogenetic trees inferred from concatenated 30 mitochondrial genes showed that 'Rongfu',Laminaria japon-ica,Laminaria longipedalis,L...  相似文献   

Testing a conceptual hillslope recession model based on the storage–discharge relationship with the Richards equation     

Do‐Hun Lee 《水文研究》2007,21(23):3155-3161

The conceptual recession model based on the storage–discharge relationship was proposed to account for the unsaturated–saturated water storage interaction. The recession model was formulated by combining the constitutive storage–discharge relationship with the integral balance equation for unsaturated and saturated water storage. The functional form of the constitutive storage–discharge relationship was determined from the spatial integration of the Richards equation. The performance of the recession model was tested by comparing with the solution of the Richards equation for different simulation geometric shapes and soil types. The conceptual recession model incorporating the unsaturated–saturated water storage interaction was in good agreement with the recession response of the Richards equation. However, the recession model that neglected the unsaturated–saturated water storage interaction was comparable to the Richards equation only for soils with the weak interaction between unsaturated water storage and saturated water storage. This result suggests the important role of the unsaturated–saturated water storage interaction in the formulation of the recession process when the derivative of the functional relationship between the unsaturated water storage and saturated water storage becomes significant. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Geophysical surveys for identifying saline groundwater in the semi‐arid region of the central Altiplano,Bolivia     

Roger Gurin  Marc Descloitres  Anne Coudrain  Amal Talbi  Robert Gallaire 《水文研究》2001,15(17):3287-3301

In the central part of the Bolivian Altiplano, the shallow groundwater presents electrical conductivities ranging from 0·1 to 20 mS/cm. In order to study the origin of this salinity pattern, a good knowledge is required of the geometry of the aquifer at depth. In this study, geophysics has been used to complement the sparse data available from drill holes. One hundred time‐domain electromagnetic (TDEM) soundings were carried out over an area of 1750 km². About 20 geological logs were available close to some of the TDEM soundings. Three intermediate results were obtained from the combined data: (i) the relationship between the electrical conductivity of the groundwater and the formation resistivity, (ii) geoelectrical cross‐sections and (iii) geoelectrical maps at various depths. The limited data set shows a relationship between resistivity and the nature of the rock. From the cross‐sections, a conductive substratum with a resistivity of less than 1 Ω·m was identified at most of the sites at depths ranging from 50 to 350 m. This substratum could be a clay‐rich formation containing brines. Using derived relationships, maps of the nature of the formation (sandy, intermediate and clayey sediments) were established at depths of 10 and 50 m. Discrimination between sand and clays was impossible where groundwater conductivity is high (>3 mS/cm). In the central part of the area, where the groundwater conductivity is low, sandy sediments are likely to be present from the surface to a depth of more than 200 m. Clayey sediments are more likely to be present in the south‐east and probably constitute a hydraulic barrier to groundwater flow. In conclusion, the study demonstrates the efficiency of the TDEM sounding method to map conductive zones. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献