CARBON DYNAMICS OF WETLAND IN THE SANJIANG PLAIN   总被引：2，自引：0，他引：2  

SONG Chang-chun    WANG Yi-yong  WANG Yue-si  YAN Bai-xing WANG De-xuan  ZHAO Zhi-chun  LOU Yan-jing 《中国地理科学(英文版)》2003,13(3):228-231

1INTRODUCTIONWetlandsplayanimportant roleintheprocessofcar-bonstorage.Thetotalcarbonstoredindifferentkindsofwetlandsisabout15%-35%ofthetotalcarboninthegloballandsoils(POSTetal.,1982;GORHAM,1991).Inaddition,wetlandsaresignificantnaturalsources fortheatmospheric CH4 (MOORE,1994).It isestimatedthatabout110×1012gCH4 originates fromanaerobicdecompositioninthenaturalwetlands,CH4 emission fromthenaturalwetlandsis15%-30%oftheglobalCH4 emission andtheCH4 emission from thepeat land at hi…  相似文献   

Use of multi‐platform,multi‐temporal remote‐sensing data for calibration of a distributed hydrological model: an application in the Arno basin,Italy     

Lorenzo Campo  Francesca Caparrini  Fabio Castelli 《水文研究》2006,20(13):2693-2712

Images from satellite platforms are a valid aid in order to obtain distributed information about hydrological surface states and parameters needed in calibration and validation of the water balance and flood forecasting. Remotely sensed data are easily available on large areas and with a frequency compatible with land cover changes. In this paper, remotely sensed images from different types of sensor have been utilized as a support to the calibration of the distributed hydrological model MOBIDIC, currently used in the experimental system of flood forecasting of the Arno River Basin Authority. Six radar images from ERS‐2 synthetic aperture radar (SAR) sensors (three for summer 2002 and three for spring–summer 2003) have been utilized and a relationship between soil saturation indexes and backscatter coefficient from SAR images has been investigated. Analysis has been performed only on pixels with meagre or no vegetation cover, in order to legitimize the assumption that water content of the soil is the main variable that influences the backscatter coefficient. Such pixels have been obtained by considering vegetation indexes (NDVI) and land cover maps produced by optical sensors (Landsat‐ETM). In order to calibrate the soil moisture model based on information provided by SAR images, an optimization algorithm has been utilized to minimize the regression error between saturation indexes from model and SAR data and error between measured and modelled discharge flows. Utilizing this procedure, model parameters that rule soil moisture fluxes have been calibrated, obtaining not only a good match with remotely sensed data, but also an enhancement of model performance in flow prediction with respect to a previous calibration with river discharge data only. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

胶东“玲珑-焦家式”金矿资源潜力与找矿   总被引：1，自引：1，他引：0  

李士先  王建收 《山东国土资源》2006,22(12):36-41

“玲珑焦家式”金矿的成岩成矿,从新太古代至中生代存在着继承性的成因关系,成矿具有长期性、多源性特点,但中生代燕山早期岩浆活动是主导成矿因素。区域化探成果显示胶东金矿直接矿源岩———郭家岭花岗岩金的丰度比原始矿源岩———早前寒武纪变质沉积岩系及侵入岩系金的丰度低1/2。郭家岭花岗岩面积在2 km2以上岩体定量估计金亏损总量与胶东金矿总量预测的资源量相当,从一个侧面展现了胶东金矿资源的潜力。望儿山金矿的找矿实践展示,焦家式金矿在1 000 m以下尚有巨大潜力,整个胶东金矿产区在3 000 m以上的资源潜力应在5000 t以上。  相似文献   

Size and shape evolution of pores in a viscoplastic matrix under compression     

M. Berli  M. L. Accorsi  D. Or 《国际地质力学数值与分析法杂志》2006,30(12):1259-1281

The frequent use of soils and earth materials for hydraulic capping and for geo‐environmental waste containment motivated our interest in detailed modelling of changes in size and shape of macro‐pores to establish links between soil mechanical behaviour and concurrent changes in hydraulic and transport properties. The objective of this study was to use finite element analysis (FEA) to test and extend previous analytical solutions proposed by the authors describing deformation of a single macro‐pore embedded in linear viscoplastic soil material subjected to anisotropic remote stress. The FEA enables to consider more complex pore geometries and provides a detailed picture of matrix yield behaviour to explain shortcomings of approximate analytical solutions. Finite element and analytical calculations agreed very well for linear viscous as well as for viscoplastic materials, only limited for the case of isotropic remote stress due to the simplifications of the analytical model related to patterns and onset of matrix‐yielding behaviour. FEA calculations were compared with experimental data obtained from a compaction experiment in which pore deformation within a uniform modelling clay sample was monitored using CAT scanning. FEA predictions based on independently measured material properties and initial pore geometry provided an excellent match with experimentally determined evolution of pore size and shape hence lending credence to the potential use of FEA for more complex pore geometries and eventually connect macro‐pore deformation with hydraulic properties. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

STRATEGY OF MAIZE′S CONCENTRATING TO ADVANTAGE AREAS IN JILIN PROVINCE     

JIANG Hui-ming  GU Li-li 《中国地理科学(英文版)》2003,(4)

WiththedevelopmentofagricultureandChina'sentryintoWTO,thesituationofsupplyanddemandinmaizemarkethaschangedgreatly.Facingtherelativesurplusofmaizeandtheformationofbuyer'smarket,weshouldfullydeveloprelativeadvantages,carryouttheunevenstrategyofsupportingthesuperior inmaizeproduction andcultivateadvantagedareasofmaize.Theabovestrategicmeasurescanrapidlyim-provetheinternationally competitiveabilityandpro-ductivityofmaizeinJilinProvince,getoutofthea-griculturalpredicamentandmaketheagriculturalde-…  相似文献   

SORPTION AND DESORPTION CHARACTERISTICS OF CADMIUM BY FOUR DIFFERENT SOILS IN NORTHEAST CHINA   总被引：3，自引：0，他引：3  

ZHANG Lei SONG Feng-bin 《中国地理科学(英文版)》2005,15(4):343-347

1IN TR O D U C TIO NA s a persistentand toxic pollutant, cadm ium (C d) canresultin m any adverse health effects in a variety oftis-suesand organssuch asthe lung,kidney,urinary,blad-der,pancreas,breast and prostate (SA TA R U G etal.,2003).C adm ium in so…  相似文献   

三峡重庆库区深部地球物理特征与断裂构造   总被引：1，自引：0，他引：1  

胡建平  赵军龙  汪文秉  李娜 《地球科学与环境学报》2005,27(3):49-54

为了深入研究三峡重庆库区岩石圈动力学特征及其对断裂构造活动的控制和影响．并为之提供基础资料，为三峡重庆库区地震、地质灾害的监测与防治提供基础依据，在已有地球物理资料的基础上，从综合地球物理研究角度出发，通过实测地震测线资料的再解释．采用新的处理技术方法，对本区的东西向主剖面和南北向支测线的地震测深资料进行二维射线追踪处理、Pg波成像；选用场分离技术、位移数字成像技术重新处理了重力和航磁资料，通过联合反演来建立深部二维构造剖面，对剖面所揭示的基底构造特征和地壳结构特征、主要断裂构造特征以及莫霍面的起伏特征进行了精细分析和细致研究．从地球物理平面场特征出发建立了岩石圈构造三维框架。研究结果表明，这样的研究思路准确、方法得当．结论可靠；沿该剖面，把可解译的断裂分为Ⅲ级：Ⅰ级为超岩石圈断裂；Ⅱ级为壳断裂；Ⅲ级为盖层断裂。依据地球物理特征，准确揭示了库区的断裂构造特征，达到了预期效果。  相似文献   

甘新蒙北山地区成矿带划分和基本特征对比   总被引：3，自引：1，他引：2  

彭巨贵  张发荣  赵福昌 《地球科学与环境学报》2006,28(3):11-18

在对甘新蒙北山地区成矿地质背景和成矿在时空上的联系性等综合研究分析基础上,运用新理论、新认识,以板块构造单元划分为基础,将本区划分为3个Ⅲ级成矿带、11个Ⅳ级成矿带,并对Ⅲ级成矿带特征进行了阐述,以期为矿产勘查和地质大调查工作部署提供新的思路和依据。进一步就主要矿床(点)、构造单元、矿种、赋矿建造、控矿因素、成矿类型、成矿时代等方面进行了对比,认为各Ⅳ级成矿带在区域上具有相对稳定的展布范围,具有相同的构造环境和成矿条件、类似的矿种和成矿时代,存在一定的相似性、可比性,并且各成矿带具有一定的潜在找矿价值。  相似文献   

山区公路软基病害研究   总被引：2，自引：0，他引：2  

刘雪岭  苏生瑞  周新民 《地球科学与环境学报》2005,27(1):65-69

随着高等级公路建设规模的扩大，山区公路所面临的路基病害特别是软土路基病害问题也逐渐增多。结合对陕南勉(县)一宁(强)高速公路工程实例分析，对山区软土成因及其特性进行了初步分析，认为山区软土属以坡洪积、湖积和冲积为主的软土，也有少量是由坡残积物堆积而形成。山区软土的特殊性表现在成分的复杂性、分布的不均匀性、隐蔽性和物理力学性质的特殊性。根据其特性以及中国山区公路软基普遍存在的病害问题，总结了山区公路软基的主要病害类型为剪切拉裂破坏、浸水沉陷破坏、剥蚀坍塌破坏、推挤滑动破坏。还提出了相应的软基处理方法及建议。  相似文献   

胶辽鲁西徐淮地区新元古代地层多重划分对比          下载免费PDF全文

许克民  王来明  刘桂玲  张增奇  汪又平  胡艳蕾 《山东国土资源》2004,20(5):26-31,36

依据岩性组合、古生物特征及地震事件层研究，对胶辽鲁西徐淮地区新元古代地层可作如下多重划分对比：鲁西黑山官组、二青山组分别与辽东的钓鱼台组，南芬组相当，胶东豹山口组可与南芬组对比，它们同属青白口系。辽东南关岭组下部、鲁西石旺庄组下部、苏皖北部贾园组、淮南九里桥组皆为一套砂灰岩组合，都发育第一期地震事件层，并开始含有后生动物化石，为等时地层单位，与其以上各前寒武岩石地层单位同属灯影峡阶，鲁西的佟家庄组、浮来山组可分别与辽东桥头组、长岭子组、胶东辅子夼组、南庄组、苏皖北部兰陵组一城山组、淮南伍山组一四十里长山组对比，归属《中国区域年代地层(地质年代)表》新划分的陡山陀阶。  相似文献