三度体磁异常的不定积分变换法研究     

韩波  张维冈  裴建新 《中国海洋大学学报(自然科学版)》2005,35(4):603-607

为发现和圈定干扰覆盖下的不明显异常，作者从三度磁性体的磁异常公式出发，推导磁异常的不定积分变换结果并由参量图方程绘得不定积分变换的磁异常参量图。本文针对2种规则形态磁性体推导其特征点规律，并进而用不同的方法求取磁性体的深度和磁性参数。在不同的空间几何参数条件下，讨论不定积分变换后参量图的曲线变化规律并总结其异常特征。提取判断产状的要素。该方法能简单有效地发现一些重要的地质信息，所得到的空间参数与变换异常间的特征点关系将有助于磁异常的分析。  相似文献   

射阳沿海的旅游资源及开发,利用构想     

杜渺 《海岸工程》1999,18(2):119-125

射阳地处苏北沿海,成陆年代不长,有着广袤的滩涂和多条横绩全境的人海河道,蕴茂着国特色的旅游资源和自然景观,有许多革命纪念地,还流传着不少神话传说人文景观别具一格。本文提出了开发,建设射阳沿海滩涂旅游经济带和是河风光旅游带的总体规划,应遵循的原则和措施。  相似文献   

济南某地区裂隙岩溶地下水硝酸盐污染现状及溯源浅析   总被引：1，自引：0，他引：1  

卢兆群  成世才  宋永芬  张强 《化工矿产地质》2016,(4):226-231

通过对历史资料的对比,揭示了济南某地裂隙岩溶地下水中硝酸根污染现状,并通过三线图法对硝酸根进行溯源分析,显示研究区地下水硝酸根含量受人类活动影响明显,并有进一步发展的趋势。相关性分析法分析结果显示地下水硝酸根含量与Cl相关,说明其与工业废水联系密切,而土壤剖面中硝酸根含量显示,土壤中硝酸根含量的顺序为:禽畜粪便污染类污水排放污染类垃圾堆放污染类。分析认为,研究区裂隙盐溶承压水硝酸根污染的来源主要为补给区及径流区强烈渗漏携带牲畜粪便及氮肥和农家肥的施用、生活污水、工业废水及浅层水混入。  相似文献   

巴彦塔拉油田南屯组、铜钵庙组岩性识别方法研究     

闫伟林  张剑风  王德平 《上海国土资源》2008,(2):63-66

巴彦塔拉油田南屯组、铜钵庙组地层属白垩系,岩性复杂,具有放射性的凝灰质对自然伽马值影响较大,难以用自然伽马来识别含泥地层,针对储层这一特点,提出了利用RLLD—AC交会图识别凝灰质的新途径;依据该区9口井测井、岩心和薄片分析资料,利用一套分步识别该区岩性的交会图方法,对该区巴X2和巴1两井取心井段进行岩性识别,符合率达91．7％,对研究区储层评价及与该区有类似地质特征的油田岩性识别有一定的指导意义。  相似文献   

Examining the distribution and dynamics of impervious surface in different function zones in Beijing     

Kun Qiao  Wenquan Zhu  Deyong Hu  Ming Hao  Shanshan Chen  Shisong Cao 《地理学报(英文版)》2018,28(5):669-684

Impervious surface (IS) is often recognized as the indicator of urban environmental changes. Numerous research efforts have been devoted to studying its spatio-temporal dynamics and ecological effects, especially for the IS in Beijing metropolitan region. However, most previous studies primarily considered the Beijing metropolitan region as a whole without considering the differences and heterogeneity among the function zones. In this study, the subpixel impervious surface results in Beijing within a time series (1991, 2001, 2005, 2011 and 2015) were extracted by means of the classification and regression tree (CART) model combined with change detection models. Then based on the method of standard deviation ellipse, Lorenz curve, contribution index (CI) and landscape metrics, the spatio-temporal dynamics and variations of IS (1991, 2001, 2011 and 2015) in different function zones and districts were analyzed. It is found that the total area of impervious surface in Beijing increased dramatically during the study period, increasing about 144.18%. The deflection angle of major axis of standard deviation ellipse decreased from 47.15° to 38.82°, indicating the major development axis in Beijing gradually moved from northeast-southwest to north-south. Moreover, the heterogeneity of impervious surface’s distribution among 16 districts weakened gradually, but the CI values and landscape metrics in four function zones differed greatly. The urban function extended zone (UFEZ), the main source of the growth of IS in Beijing, had the highest CI values. Its lowest CI value was 1.79 that is still much higher than the highest CI value in other function zones. The core function zone (CFZ), the traditional aggregation zone of impervious surface, had the highest contagion index (CONTAG) values, but it contributed less than UFEZ due to its small area. The CI value of the new urban developed zone (NUDZ) increased rapidly, and it increased from negative to positive and multiplied, becoming an important contributor to the rise of urban impervious surface. However, the ecological conservation zone (ECZ) had a constant negative contribution all the time, and its CI value decreased gradually. Moreover, the landscape metrics and centroids of impervious surface in different density classes differed greatly. The high-density impervious surface had a more compact configuration and a greater impact on the eco-environment.  相似文献   

A new version of the USLE‐MM for predicting bare plot soil loss at the Sparacia (South Italy) experimental site          下载免费PDF全文

Vincenzo Bagarello  Vito Ferro  Vincenzo Pampalone 《水文研究》2015,29(19):4210-4219

Improving empirical prediction of plot soil erosion at the event temporal scale has both scientific and practical importance. In this investigation, 492 runoff and soil loss data from plots of different lengths, λ (11 ≤ λ ≤ 44 m), and steepness, s (14.9 ≤ s ≤ 26.0%), established at the Sparacia experimental station, in Sicily, South Italy, were used to derive a new version of Universal Soil Loss Equation (USLE)‐MM model, by only assuming a value of one for the topographic length, L, and steepness, S, factors for λ = 22 m and s = 9%, respectively. An erosivity index equal to (Q_REI₃₀)^b1, Q_R and EI₃₀ being the runoff coefficient and the event rainfall erosivity index, respectively, with b₁ > 1 was found to be an appropriate choice for the Sparacia area. The specifically developed functions for L and S did not differ appreciably from other, more widely accepted relationships (maximum differences by a factor of 1.22 for L and 1.09 for S). The new version of the USLE‐MM performed particularly well for highly erosive events, because predicted soil loss differed by not more than a factor of 1.19 from the measured soil loss for measured values of more than 100 Mg ha^?1. The choice of the relationships to predict topographic effects on plot soil loss should not represent a point of particular concern in the application of the USLE‐MM in other environments. However, tests of the empirical approach should be carried out in other experimental areas in an attempt to develop analytical tools, usable at the event temporal scale, reasonably simple and of wide validity. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Variation in curve numbers derived from plot runoff data for New South Wales (Australia)     

Hongxia Cao  R. Willem Vervoort  Seth M. Dabney 《水文研究》2011,25(24):3774-3789

The curve number method is a simple one parameter (the curve number) rainfall runoff model. While its theoretical underpinning has been questioned it remains a powerful hydrological tool in the absence of detailed data and is therefore used extensively in hydrological models. This study aims to characterize the variation in maximum retention values (S), which underlie curve numbers, for a range of agricultural treatments across a large spatial area in New South Wales (NSW), Australia. The data used for the analysis spans several decades of rainfall runoff observations. A range of different derivation methods result in variation in mean and variance of S. In particular, methods that emphasize the larger storms result in greater S and thus lower runoff. For larger spatial scales, emphasis on larger storms gives more reliable estimates of S. Systematic variation in S arises from variations in treatment, pre‐runoff soil moisture, rainfall depth, and variations in cover. On the basis of the analysis, a table of curve number values for different land uses found in NSW is presented. The resulting distributions of S and curve numbers provide guidance for rainfall runoff modelling studies in the agricultural important areas of NSW. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

四川盆地东北部二叠系层序发育的动力学分析   总被引：1，自引：1，他引：0  

李凤杰  刘琪  刘殿鹤  刘犟 《地层学杂志》2010,34(1)

运用可容空间分析法,在野外剖面岩性、岩相厚度和旋回变化分析的基础上,对川东北地区宣汉县渡口镇羊鼓洞二叠系剖面的旋回层序进行研究,识别出3种类型5种亚类型的高频旋回层序类型,并将剖面中栖霞组、茅口组以及吴家坪组下部划分为118个高频旋回层序。根据测井曲线的旋回变化,将普光4井的长兴组划分出49个高频旋回层序,据此运用Fischer图解绘制了二叠系可容空间变化曲线。将可容空间变化曲线与相对海平面升降曲线之间进行对比发现,二者之间存在着良好的对应关系。采测井曲线的频谱分析,对研究区长兴组进行了米兰科维奇沉积周期进行研究,结果表明:长兴组中广泛地保存着124,44.89,35.11,21.16和17.72ka的米兰科维奇沉积周期;地层中的沉积旋回主要受古气候变化的控制,偏心率、地轴倾角和岁差周期引起的地层旋回厚度变化范围分别为:12.47—13.74m,3.56—5.21m,1.78—2.41m,其中受偏心率周期的影响最大。在构造活动相对较弱的川东北二叠系中,层序发育的动力学因素主要为相对海平面的变化和气候变化两个方面。相对海平面的变化主要是三级层序的控制因素,而气候变化则是高频层序旋回的主要动力。  相似文献   

Further testing of the integrated hydrology model (InHM): multiple‐species sediment transport     

Qihua Ran  Christopher S. Heppner  Joel E. VanderKwaak  Keith Loague 《水文研究》2007,21(11):1522-1531

  相似文献   

菲律宾宿务岛地区矿化蚀变图像识别与提取分析          下载免费PDF全文

郑纬  朱谷昌  张远飞  石菲菲  王冬寅  李红 《地质找矿论丛》2011,26(2):222-228

文章通过遥感多波段数据的背景端元数M值的估计方法、回归偏度曲线分析和地物光谱反射特征来选择信息提取的特征波段;在综合分析的基础上,选择基于Crosta法的F因子与H因子分析方法,根据不同蚀变信息提取的波段选择,以自行开发的软件对律宾宿务岛地区遥感图像进行矿化蚀变信息检测与提取.提取结果表明,区内已知的矿床(点)和矿化蚀...  相似文献