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1.
TRMM3B42降雨数据在渭河流域的应用分析   总被引:3,自引:0,他引:3  
运用渭河流域24个气象站点日降雨数据对2001~2012年热带测雨卫星(TRMM)3B42数据在不同子流域、不同降雨强度以及不同时间尺度的精度进行了对比验证,并对比分析了基于TRMM和站点数据的渭河流域降雨时空分布特征。结果显示:在不同子流域的日TRMM数据比站点观测数据对低值降雨更为敏感,而在极大值降雨数据观测上两者差距较大,月尺度TRMM站点观测数据确定性系数在0.89到0.96之间;两种数据在流域降雨的时空分布上表现一致性,在年内6月中旬~10月初为湿润多雨期,其余月份降雨较少,空间分布呈东南部大,西北部小的格局。  相似文献   
2.
通过对研究区内广泛发育的二叠系哲斯组和林西组砂岩进行岩相学及主量元素地球化学研究,探讨其物源区及其古构造环境。岩相学研究结果表明:二叠系哲斯组和林西组砂岩成分成熟度较低,表现为源区相对不稳定、快速剥蚀、快速搬运的特征。A-CN-K三角图解显示砂岩母岩中斜长石含量要高于钾长石含量,指示两组砂岩物源区母岩应以具英云闪长岩和花岗闪长岩等岛弧性质的岩浆岩系列为主。主量元素判别图解揭示了物源区主要具活动大陆边缘和大陆岛弧型并含有少量被动大陆边缘物源区特点,且总体呈现出由活动大陆边缘向大陆岛弧型物源区过渡的趋势。结合前人的研究成果,推测二叠纪砂岩的物源区主要为区域内广泛分布的大石寨组火山岩及研究区北侧及北西侧的苏尼特左旗—锡林浩特—西乌旗南岩浆弧物质并含有少量来自华北板块基底的物源供给。  相似文献   
3.
The objective of this study is to quantitatively evaluate Tropical Rainfall Measuring Mission(TRMM) data with rain gauge data and further to use this TRMM data to drive a Distributed Time-Variant Gain Model(DTVGM) to perform hydrological simulations in the semi-humid Weihe River catchment in China.Before the simulations,a comparison with a10-year(2001-2010)daily rain gauge data set reveals that,at daily time step,TRMM rainfall data are better at capturing rain occurrence and mean values than rainfall extremes.On a monthly time scale,good linear relationships between TRMM and rain gauge rainfall data are found,with determination coefficients R~2 varying between 0.78 and 0.89 for the individual stations.Subsequent simulation results of seven years(2001-2007)of data on daily hydrological processes confirm that the DTVGM when calibrated by rain gauge data performs better than when calibrated by TRMM data,but the performance of the simulation driven by TRMM data is better than that driven by gauge data on a monthly time scale.The results thus suggest that TRMM rainfall data are more suitable for monthly streamflow simulation in the study area,and that,when the effects of recalibration and the results for water balance components are also taken into account,the TRMM 3B42-V7 product has the potential to perform well in similar basins.  相似文献   
4.
In areas with topographic heterogeneity, land use change is spatially variable and influenced by climate, soil properties, and topography. To better understand this variability in the high-sediment region of the Loess Plateau in which soil loss is most severe and sediment diameter is larger than in other regions of the plateau, this study builds some indicators to identify the characteristics of land use change and then analyze the spatial variability as it is affected by climate, soil property, and topography. We build two indicators, a land use change intensity index and a vegetation change index, to characterize the intensity of land use change, and the degree of vegetation restoration, respectively. Based on a subsection mean method, the two indicators are then used to assess the spatial variability of land use change affected by climatic, edaphic, and topographic elements. The results indicate that: 1) Land use changed significantly in the period 1998–2010. The total area experiencing land use change was 42,302 km2, accounting for 22.57%of the study area. High-coverage grassland, other woodland, and forest increased significantly, while low-coverage grassland and farmland decreased in 2010 compared with 1998. 2) Land use change occurred primarily west of the Yellow River, between 35 and 38 degrees north latitude. The four transformation types, including(a) low-coverage grassland to medium-coverage grassland,(b) medium-coverage grassland to high-coverage grassland,(c) farmland to other woodland, and(d) farmland to medium-coverage grassland, were the primary types of land use change, together constituting 60% of the area experiencing land use change. 3) The spatial variability of land use change was significantly affected by properties of dryness/wetness, soil conditions and slope gradient. In general, land use changed dramatically in semi-arid regions, remained relativelystable in arid regions, changed significantly in clay-rich soil, remained relatively stable in clay-poor soil, changed dramatically in steeper slopes, and remained relatively stable in tablelands and low-lying regions. The increase in vegetation coincided with increasing changes in land use for each physical element. These findings allow for an evaluation of the effect of the Grain to Green Program, and are applicable to the design of soil and water conservation projects on the Loess Plateau of China.  相似文献   
5.
大黑山条垒南段,靠近佳-伊断裂西侧发育有一构造变形带,构造带内西部远离佳-伊断裂的岩石表现为韧性变形,东部靠近佳-伊断裂的岩石表现为脆性变形,岩石的变形特征自西向东呈现出由韧性到脆性渐变的规律,这主要是由大黑山条垒的差异隆升造成的.本文认为大黑山条垒的隆升始于早白垩世泉头组地层沉积之后,自晚白垩世之后一直处于隆升状态,遭受剥蚀,缺失晚白垩世以来的地层沉积.  相似文献   
6.
为阐明碎屑岩储层孔隙结构差异性及其对储层质量的影响,以南堡凹陷南部4号和2号构造带东二段碎屑岩储层为例,采用常规物性、铸体薄片、扫描电镜、压汞、粒度分析、X衍射等手段,在储层基本特征研究的基础上,对储层孔隙结构差异及其对储层质量的影响进行了研究。结果表明,4号构造带东二段以岩屑质长石砂岩为主,碎屑含量平均为Q40.6F30.1R29.3,平均成分成熟度0.69,2号构造带东二段则主要以长石质岩屑砂岩为主,碎屑含量平均为Q32.9F26.8R40.2,平均成分成熟度为0.49;4号构造带东二段主要以低渗砂岩储层为主,而2号构造带则以致密储层(渗透率小于1 m D)为主;4号构造带东二段砂岩储集空间主要以原生剩余粒间孔为主,且孔喉间的连通性相对较好,2号构造带砂岩储集空间则以粒间溶孔等次生孔隙为主,孔喉间的连通性较差;4号构造带东二段孔喉大小分布主要呈现单峰式,进汞增量主要集中在大于1μm的喉道半径范围,2号构造带东二段储层的孔喉分布也主要为单峰式,但进汞增量主要集中在小于1μm的喉道半径范围。整体上,造成南堡凹陷4号与2号构造带东二段储层差异的原因主要是微观孔隙结构的差异,而微观孔隙结构存在差异的原因是两个构造带东二段储层的沉积和成岩作用后期改造的不同。  相似文献   
7.
采集都柳江上游沿岸喀斯特地区62个土壤样品,利用地累积指数法、潜在生态风险指数法、克里金插值方法综合研究Sb、Cd、As、Cr和Pb五种重金属元素累积污染特征和潜在生态风险。结果表明,研究区土壤中Sb和Cd元素平均含量分别超过贵州省土壤环境背景值4.085倍和1.876倍。空间分布上,Sb元素严重污染面积占研究区总面积37.87%,主要受区内赋矿层位望城坡组、尧梭组和鸡窝寨组的影响。而Cd元素轻度累积污染面积为59.76%,其与碳酸盐岩分布密切相关。研究区土壤重金属污染潜在生态风险属于低风险等级,但是Cd和Sb元素单项污染潜在生态风险概率较大,Cd污染最高概率风险地层主要是石牛栏组和邦寨组,而Sb污染最高概率风险地层为邦寨组、鸡窝寨组和独山组。因此,研究区应重点防控石牛栏组、邦寨组、鸡窝寨组和独山组土壤Cd与Sb污染的潜在生态风险。   相似文献   
8.
黄河中游多沙粗沙区(渭河段)土地利用对植被盖度的影响   总被引:3,自引:0,他引:3  
针对黄河中游多沙粗沙区植被变化及其影响因素研究薄弱环节,利用MSS、TM和环境星CCD等多源遥感数据,运用相邻图幅递进回归分析消除时相差异后反演植被盖度,人机交互式解译土地利用,研究黄河中游多沙粗沙区(渭河段)1978-2010年间3个时期土地利用对植被盖度的影响。结果表明:(1)研究区内植被盖度已显著恢复,植被变化有较强的波动性和异质性;(2)土地利用已发生明显变化,土地利用变化有较强的时空分异特征;(3)土地利用转型和渐变均有利于促进植被盖度恢复,但土地利用转型对植被恢复的贡献更突出;(4)土地利用对植被盖度的影响有一定的复杂性和差异性,区域植被持续恢复迫切需要有针对性的土地利用转型与生态系统优化策略。  相似文献   
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10.
研究区位于西拉木伦河缝合带北侧,地理位置位于内蒙古东部草原区、大兴安岭南段,构造部位介于苏尼特左旗—锡林浩特—西乌珠穆沁旗南缝合线和西拉木伦河缝合带之间,是讨论华北地块北缘与其北侧地块拼贴过程的关键地区.通过对西拉木伦河缝合带北侧克什克腾旗(简称克旗)和林西地区二叠纪砂岩进行碎屑锆石LA-ICP-MS U-Pb年代学研...  相似文献   
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