陕西柞水地区金盆梁金矿区水系沉积物地球化学特征与找矿方向

对陕西柞水地区金盆梁金矿区1∶50 000水系沉积物样品中微量元素含量,元素分布、分配、共生组合特征以及主要元素地球化学异常特征进行综合研究,进一步确定该区找矿方向。结果表明:Au是金盆梁金矿区内主要的成矿元素,Ag为主要伴生元素,As、Sb为远程指示元素;泥盆系上统桐峪寺组第五岩性段上亚段是金矿富集的有利层位;石炭系下统二峪河组下亚组下段、泥盆系上统第四岩性段上亚段、泥盆系上统桐峪寺组第五岩性段上亚段为金成矿有利岩性段;矿区经历了至少两期热液活动,金矿体的形成受低级区域变质作用的影响,与岩浆热液活动有关;以Au为主成矿元素圈定的4个综合异常区与地层展布方向一致。位于玄檀沟附近的综合异常区处在金矿富集有利层位,次级构造发育,指示元素异常套合较好,浓集中心明显,Au异常强度高且规模大,并在异常内发现金矿体,因此,位于玄檀沟附近的综合异常区具有很好的找矿前景。     

基于汇水盆地的化探异常识别与评价: 以东昆仑乌拉斯太地区1∶5万水系沉积物地球化学测量为例

水系沉积物地球化学测量是卓有成效的找矿技术方法, 基于汇水盆地的水系沉积物地球化学异常提取有助于追溯异常源头、指明找矿方向。基于SCB法提出了汇水盆地法, 该方法以自然汇水盆地为预测单元, 将各样品点的地球化学属性特征赋予各自所在区域, 预测结果较为符合地形地貌特征, 且对于采样密度较高的1∶5万水系沉积物地球化学测量数据有较好的应用效果。以东昆仑乌拉斯太地区为研究区, 使用高精度DEM划分汇水盆地, 利用该方法对1∶5万水系沉积物Au、Ag、Pb因子得分进行了异常信息提取, 在提取过程中利用多种地貌参数(干流坡度、地形起伏比、汇水盆地面积)作为泥沙输移比进行残差校正计算, 并在此基础上, 利用C-A分形法分离了地球化学背景与异常。异常提取结果表明, 汇水盆地面积参数最适合用作乌拉斯太地区的泥沙输移比参与顺流衰减校正, 使用汇水盆地法可以有效识别和提取该地区地球化学异常信息。使用汇水盆地法提取的化探异常范围与矿床空间位置吻合度高, 可以为进一步找矿工作提供有利的信息。      

青海省石灰沟地区水系沉积物测量地球化学特征及找矿预测

通过在青海省都兰县石灰沟地区开展的1:50 000水系沉积物测量工作，运用元素的变化系数、元素富集离散特征、叠加系数对石灰沟地区水系沉积物测量的10种微量元素进行地球化学统计分析，论述了10种微量元素的成矿潜力，得出Au、Cu、Pb、Zn这4种微量元素具有较大的成矿潜力，并通过相关分析、因子分析确立了测区内元素组合特征，共划分了3组成矿元素组合（Ag-Cu-Pb-Zn，Au-As-Sb，W-Bi-Hg）。通过衬值异常法圈定组合异常显示:研究区组合异常明显，异常套合较好。最后，根据组合衬值异常套合结果，在研究区优选了3处金铜铅锌多金属找矿靶区（A，B，C）。      

IMPACT EVALUATION OF HAIZUKA DAM ON ITS UP STREAM： A CASE STUDY IN HIROSHIMA PREFECTURE, JAPAN

Japan ranks fifth in the world for the number of large dams. Environmental impacts of large dams are known, such as enormous losses of water or disruption of fish spawning, however, impacts of the dams on their up streams are functions of topography of the up stream. Haizuka Dam is located in Hiroshima Prefecture, Japan and its implementation will start in 2006. This large dam influences its up stream through dam making activities, which occurs in order and with different spatial presences that were categorized into chronological and spatial impacts. In this case study, spatial impacts were further divided into horizontal and vertical ones. The horizontal impacts were identified as new roads, diversion tunnel, dam lake, and submerged cultivated land, while vertical impacts were recognized as submerged historical monuments, slope protections, dam body, and deforested area in the reservoir. There were convergences of spatial and temporal impacts, however, the extent of the impacts was limited to the lake boundary.     

Comprehensive evaluation of rural courtyard utilization efficiency: A case study in Shandong Province,Eastern China

China is implementing the strategy of Rural Revitalization. Revitalizing idle and inefficient utilization courtyards is an important measure for rural revitalization. The evaluation of courtyard utilization efficiency is the basis of determining the idle and inefficient utilization courtyards in order to revitalizing it. This study provided a reference for the optimal use of rural courtyard utilization and revitalization through the quantitative comprehensive evaluation of courtyard utilization efficiency and the classification of courtyard utilization types. Taking Shandong Province in Eastern China as study area, we selected eight surveyed villages by stratified sampling method. According to the scale of the villages, full survey and sample survey were used, while middleaged men who familiar with the courtyards were selected as the respondents. Through a household questionnaire survey and face-to-face interviews from2017 to 2018, 578 questionnaires of rural courtyardsin eight villages were obtained. Then based on the functions of rural courtyard and land resource conditions, 16 comprehensive factors were formulated,involving land conditions, construction conditions and economic benefits, to build the comprehensive evaluation index system of rural courtyard utilization efficiency. Next the index weight was determined by analytic hierarchy process, and the linear weighted regression model was used to evaluate the utilization efficiency of rural courtyard. Finally, the K-means clustering analysis was used to classify the utilization efficiency of courtyards. The results showed that among the eight villages, the average utilization efficiency of courtyards was moderate(one village was low, five were moderate, and two were high). The proportions of both idle and inefficiently utilized courtyards were high. There were three vital factors leading to the idle and low efficiency of rural courtyards. They were declining rural industries,limited arable land per capita, and more farmer workers. In this case, the utilization efficiency of courtyards should be improved by transferring rural land, developing secondary and tertiary industries,evaluating the development potential of villages,classifying and optimizing courtyard utilization, so as to make full use of idle and inefficient courtyards,increase the income of farmers and collectives and promote the revitalization of rural areas.     

基于t-SNE降维算法的区域化探数据中地质体空间分布信息可视化:以英格兰西南部为例

区域化探数据中包含了丰富的地质信息，提取出蕴含在这些数据中的地质体空间分布信息，对于区域地质研究和找矿勘查具有重要意义。区域化探数据通常包括数十个元素，属于高维数据，隐藏在这些高维数据中的地质体空间分布信息无法直接从数据中观察到。针对这个问题，构建了一个基于t分布随机近邻嵌入(t-distributed stochastic neighbor embedding，简称t-SNE)算法的高维区域化探数据降维可视化模型。t-SNE算法是一种非线性降维方法，特别适用于高维数据集的降维和可视化。选择对岩性鉴定比较稳定的元素，通过t-SNE算法将高维化探数据降维到人眼可观察的一、二、三维，把降维之后的变量表达为栅格图，通过三原色混合等方法进行可视化，从而把隐藏在高维化探数据中的地质体空间分布信息可视化表达出来。以英格兰西南部某地区水系沉积物区域化探数据为例进行研究来检验t-SNE算法在高维化探数据可视化上的实际应用效果。结果显示:①通过t-SNE算法对高维化探数据进行可视化得到的结果能够很好地反映研究区的地质体空间分布情况；②可视化的效果与t-SNE算法的目标维度和复杂度两个参数密切相关。在t-SNE算法中设定要降维到的目标维度越高，所显示的地质体信息越详细。③基于t-SNE算法的化探数据降维可视化效果比基于主成分分析(PCA)的化探数据降维可视化效果更好。本文研究表明基于t-SNE算法的化探数据降维可视化方法能够很好地将地质体空间分布信息可视化表达出来，对于推断地质体的空间分布有一定的指导意义。      

黔西北普宜地区富关键金属元素硫铁矿地质、地球化学和S同位素特征及其对成因的约束

探讨黔西北普宜地区富关键金属元素硫铁矿的同位素地球化学特征、元素地球化学特征及成因, 可以为硫铁矿资源开发、伴生有益元素综合利用与评价及理解富关键金属元素硫铁矿聚集机制提供更为丰富的信息。在全面收集已有地质、矿产资料的基础上, 结合野外实地调查, 应用元素地球化学及硫同位素分析等方法, 对该区硫铁矿地球化学特征及成因做了较为深入研究, 并初步建立成矿模式。结果表明: 富关键金属元素硫铁矿主要赋存于中二叠统龙潭组(P₂l)底部的晶屑凝灰岩中, 矿体形态简单, 呈层状分布, 硫铁矿中共(伴)生的稀土, Li, Nb, Zr, Ga等有益元素均可综合利用。w(ΣREE)平均为431.24×10-6, 最大值为1 634.57×10-6, 一般在180×10-6~1 630×10-6之间; w(Ga)平均为32.51×10-6, 一般为25×10-6~120×10-6, 最大为120.00×10-6; w(Nd)平均为103.29×10-6, 一般为40×10-6~380×10-6, 最大为380.00×10-6; w(Li)最大值为1 366.00×10-6; w(Al₂O₃)最大值为42.17%。硫铁矿稀土元素配分模式表现为轻稀土元素富集、重稀土元素相对亏损的右倾型。矿石中成矿元素Ga, Li, Zr, Ti, Se, Cd, Nb, V, Hg等元素相对富集, Ba, Sr, Zn, Te等元素相对贫化。硫铁矿石中黄铁矿硫同位素δ34S变化范围主要在-33.90‰~-18.60‰之间, 平均值-16.04‰, 为轻硫富集型, 富关键金属元素硫铁矿的硫源受生物细菌还原作用影响较大。硫铁矿主要是在沉积阶段通过微生物铁还原、微生物硫酸盐还原和化学铁还原驱动下形成的。初步认为赋存于硫铁矿中的稀土主要以类质同象替代形式赋存于黏土矿物中, 形成过程可分为风化搬运阶段、沉积成矿阶段和成岩后生作用阶段。      

浙江省玄武岩台地稳定性评价:以嵊州市地雅园滑坡为例

玄武岩台地型滑坡是一种特殊的滑坡类型，此前对其稳定性的研究较少。以嵊州市地雅园滑坡为研究对象，采用三维数值模拟的方法进行了稳定性分析评价，首先基于详细的地质资料采用三维模拟软件进行了建模；然后基于P-Ⅲ型分布曲线确定了降雨重现期，分别采用岩土软件MIDAS进行了滑坡稳定性模拟与三维运动模拟平台DAN3D软件进行了滑坡影响范围计算；最后对影响地雅园滑坡稳定性的因子进行了敏感性分析。结果表明:不同降雨强度对地雅园滑坡稳定性的影响不同，最不利工况为百年一遇降雨工况，此时滑坡稳定性系数为0.946，破坏概率为65.25%，影响范围最大增加了36.83%；内摩擦角和降雨是影响地雅园滑坡稳定性的主要因子。分析原因认为玄武岩台地型滑坡稳定性主要与硅藻土滑带、节理裂隙面的发育情况、降雨入渗滞后性有明显的相关性。本研究成果可为同类滑坡稳定性评价提供参考依据。      

INDUSTRIAL LINKAGES AND RURAL INDUSTRIALIZATION: A CASE STUDY OF HENAN PROVINCE, CHINA

The fast growth of rural industry in China has generated regional development of large rural areas. What role does industrial linkages play in Chinese rural industrialization? This is a same question as the relation between industrial linkages and regional development which has been discussed for decades and no final conclusion reached. The paper pursues the discussion and focuses on rural areas in China with special reference to Henan Province. On the basis of data from an investigation on nearly 200 industrial enterprises, this study emphasizes that the linkages play a very important role in spreading development of industry in rural areas. It is recommended that the national policies should prompt industrial linkages to upgrade the technological level of rural industry and to integrate rural industry with urban industry.     

A method for spatial heterogeneity evaluation on landscape pattern of farmland shelterbelt networks: A case study in midwest of Jilin Province,China

On the basis of landscape ecology, combining the Spot 5 high resolution satellite imagery with GIS, a method evaluating the spatial heterogeneity of shelterbelts distribution at landscape scale is put forward in this paper. The distance coefficients of reasonable and existing landscape indexes of farmland shelterbelt networks were computed, and then through the classification of the distance coefficients, and the establishment of evaluation rules, the spatial heterogeneity of farmland shelterbelts was evaluated. The method can improve the evaluating system of previous studies on shelterbelts distribution, resolve the disadvantages of lacking spatiality of overall evaluation, and make the evaluation results have more directive significance for shelterbelt management. Based on this method, spatial heterogeneity of shelterbelt networks was evaluated in the midwest of Jilin Province, China. The results show that the regions with fewer shelterbelts and no closed network account for 34.7% of the total area, but only 4.9% of the area has relative reasonable pattern of shelterbelt networks. Many problems exist in the distribution pattern of shelterbelts, therefore, much attention should be paid to construct farmland shelterbelts in the study area.     

Nodes and Field of Tourist Origins to Ancient Village——A Case Study of Huangcheng Village in Shanxi Province of China

Based on Hagget's theory of spatial structure,researches on the nodes and field of tourist origins to Huang-cheng Village in Shanxi Province of China have been explored.Nodal hierarchy structure of tourist origins is analyzed with cluster analysis and the gravity model.And field of tourist origins is analyzed with attraction radius index(R)and geography concentration index(G).In the field analysis,R and G of Huangcheng Village are compared with Xidi Village that is a world heritage located in Huangshan City of Anhui Province in China.According to comparison of loca-tions of two areas,influential factors for field area of Huangcheng Village are identified.It is concluded that:1)cluster analysis and gravity model can be complementary methods to each other for nodal hierarchy structure analysis of tour-ist origins;and 2)as far as location is concerned,the weak intensity effect of tourism resources in the tourist region is a major cause for explaining why tourist origins to Huangcheng Village are mainly its neighboring areas.Moreover,it is suggested that the regional effect of tourist resources should be regarded as a component of destination attractiveness when applying gravity model.     

Risk-based evaluation on geological environment carrying capacity of mountain city - A case study in Suide County,Shaanxi Province,China

With the rapid development and expansion of the cities in China, the carrying capacity of resource and environment has become a huge concern for local governments. From the perspective of geological environment, geological disasters are the main restraining factor of the development in mountain cities. This study was conducted in Suide County of Shaanxi Province with a risk-based approach as followed: a hazard analysis on geological disasters based on a slope geological survey at a scale of 1:10,000; a consequence analysis based on unmanned aerial vehicle (UAV) aerial survey data; integrating the results of hazard analysis and consequence analysis, a risk zonation and analysis of geological disasters in urban areas were completed considering urban planning, land use planning and the safety of infrastructure and major engineering. Subsequently, taking the acceptable levels of human life and property risks incurred by landslides as the criteria of the evaluation of geological environment carrying capacity, a comprehensive assessment of current and future urban carrying capacity was conducted based on the results of the risk analyses. Accordingly, the prior development zone, the restricted development zone and the prohibited zone were delineated, with corresponding suggestions for future urban development. The technological and methodological system used in the study can be applied to geological environment carrying capacity evaluation of other important mountain cities, which can provide scientific basis for the optimization of land and space.