Analog simulation of urban construction land supply and demand in Chang-Zhu-Tan Urban Agglomeration based on land intensive use     

Xiong  Ying  Chen  Yun  Peng  Fen  Li  Jingzhi  Yan  Xiaojing 《地理学报(英文版)》2019,29(8):1346-1362

Journal of Geographical Sciences - Urban land intensive use is an important indicator in harmonizing the relationship between land supply and demand. The system dynamics (SD) can be used to...  相似文献   

基于国家海洋治理和全球气候变化的我国海洋灾害防治          下载免费PDF全文

齐庆华 《海洋开发与管理》2019,36(2):17-23

为建立和完善现代化的海洋灾害防治体系,提高我国海洋治理和应对全球气候变化的能力,文章以全球治理和国家治理为背景,在明确致灾因子、承灾体、灾害以及灾害风险和管理等基本概念及其内涵的基础上,分析全球气候变化背景下我国海洋灾害及其风险的特征以及海洋灾害防治的关键性和基础性科学问题,并提出我国构建海洋灾害防治体系的建议。研究结果表明:在全球气候变化的影响下,我国沿海地区的海洋灾害风险复杂多变且有所提升;提出以群-环-域为主体的体系架构,研究全球气候变化与区域海洋的响应和反馈、全球气候变化背景下海洋灾害与风险的特征和规律以及综合海洋灾害风险评估和海洋灾害防治等问题;在我国构建海洋灾害防治体系的过程中,应加强科学研究以及技术和信息支撑、促进区域和全球联动联防以及提高全社会对海洋灾害的认知和防范水平。  相似文献   

Relationship Between Electrical Properties and Sedimentary Environment of the Longmaxi Formation Shale, Southern Sichuan     

YANG Kai  ZHANG Bing  WANG Xuben  HE Lanfang  YANG Hongyu  WANG Pengwan  TANG Jialin  DENG Jixin  ZHANG Cong 《《地质学报》英文版》2020,94(5):1531-1546

The Lower Silurian Longmaxi Formation in the south of Sichuan is a key player in the exploration and development of shale gas in China. Due to a highly complex topographic area, electromagnetic methods (EM) become important exploration means in this area. Many studies have been conducted on the shale mineral composition and electrical properties of shale, however, the correlation between sedimentary environments and the electrical properties of shale remain poorly understood. The electrical properties and sedimentary environment of the organic-rich shale of the Longmaxi Formation have been studied by means of X-ray diffraction, organic geochemistry, scanning electron microscopy and complex resistivity measurements. The discovered high quartz content of the Longmaxi Formation shale results in low resistivity. Deep-water shelf biogenic quartz contributes lower resistivity more than that of shallow-water terrigenous quartz. The deep-water anoxic and organic sedimentary environment led to major enrichment of pyrite, leading to a high polarization effect in shale. We present the correlation between the lithofacies types and electrical properties of Longmaxi Formation. The mixed siliceous shale lithofacies is the most favorable among the three lithofacies, which is characterized by high total organic carbon (TOC) content, high brittleness mineral content, high polarization and low resistivity (“three high and one low”). This feature is an effective identification of shale gas reservoirs by electromagnetic prospecting. Our study can provide constraints on electrical parameters of rocks for electromagnetic “sweet spot” exploration of shale gas, and so this has important geological significance to shale gas exploration and development.  相似文献   

中国人海经济系统环境适应性演化及预警     

李博  史钊源  田闯  苏飞  彭飞 《地理科学》2019,39(4):533-540

基于敏感性-稳定性-响应3维要素构建指标体系,运用熵值法和ARIMA-BP组合预测模型研究中国人海经济系统环境适应性的演化及预警。结果表明：① 2001~2016年中国人海经济系统环境适应性呈稳定上升态势,总体集中于中警状态,期间经历了“人海环境系统比较优势阶段→耦合协调阶段→人海经济系统比较优势阶段”的双螺旋适应过程,预计2017~2020年再次进入相互契合的轻警状态;② 16 a间中国人海经济系统环境适应性波动存在上升期短-衰退期长现象,预计未来4 a人海经济系统环境适应性在经济下行和生态约束背景下的速率不容乐观;③ 权衡人海经济系统和人海环境系统的关系,追求总体效益最大化,延长适应性周期波动中扩张期活动,差别化和灵活性的适应行为是未来主要排警对策。  相似文献   

湿地水文过程与植被响应研究进展与案例分析     

徐力刚  赖锡军  万荣荣  王晓龙  李相虎 《地理科学进展》2019,38(8):1171-1181

生态水文学是20世纪90年代兴起的一门研究生态过程和生态格局水文机制的新学科。湖泊湿地作为中国5大类天然湿地类型之一,湖泊湿地生态水文学的研究业已成为生态水文学的研究的一个重要对象和分支,其核心在于研究湖泊湿地生态系统中多时空尺度的水文与生物格局、过程的耦合特征及其相互作用。论文首先概述了湖泊湿地生态水文学的研究进展,包括其基本理论,内涵、外延及其主要研究内容;凝练了湖泊湿地生态水文学研究的方法体系、思路及框架;针对目前湖泊湿地生态水文学研究中存在的问题及薄弱环节,提出了湖泊湿地生态水文学未来研究的发展趋势和亟需加强研究的重点方向。在此基础上,以长江中游的典型通江湖泊湿地——鄱阳湖湿地为例,通过开展的湖泊湿地生态水文过程与模拟研究的典型案例,阐述了鄱阳湖湖泊湿地生态水文过程的变化及其植被响应研究的最新进展和研究成果。论文对于构建涵盖湖泊湿地水资源、湖泊湿地生态景观格局与流域管理、湖泊湿地生物多样性保育以及湿地资源可持续利用与生态管理等方向在内的战略研究体系,完善湿地生态水文研究与流域生态与管理的技术支撑体系具有重要的指导意义和实践价值。  相似文献   

华南上扬子区深部温度估算及其油气地质意义     

李香兰  刘绍文  徐明  李旭东  郝春艳 《地质学报》2020,94(6):1896-1910

盆地热体制及深部温度估算对油气和区域地热能资源评估具有重要意义。南方上扬子区是海相油气勘探的重要区块,近年来更是我国页岩气勘探的主要选区。然而,由于数据不足及研究目标的分散,该区的盆地热体制特征还有待深化。结合前人已有地热数据,并整合新近开展的稳态测温数据,我们揭示了上扬子区现今地温梯度、大地热流分布特征,继而估算了1000～6000m埋深处的深部地层温度和2套主要古生界海相烃源岩底界面处的温度。结果表明,上扬子区具有中-低温的地热状态,其现今地温梯度和大地热流的范围(平均值)分别为10～74℃/km(24℃/km)和27～118mW/m~2(64mW/m~2),整体上从东北向西南方向递增,呈现出"东北低、西南高"的分布趋势。1000～6000m埋深处估算温度的分布格局与地温梯度及热流的分布趋势基本一致。东北部的鄂西-湘北地区为低温区,中部的四川盆地其大部分为中温区,西南的云南地区为高温区。上扬子区现今地热分布格局受区域差异构造和岩浆作用控制。结合储层温度估算并综合其他油气地质资料,提出川东的石柱-涪陵、川南的威远-自贡-泸州和宜宾-长宁等区的下志留统龙马溪组页岩层系是上扬子区油气勘探有利区带。  相似文献   

利用偏光显微镜反射光系统观察黑色生油岩电子探针薄片中的生烃母质特征     

郑庆华  刘行军  刘乔  梁秀玲  张小龙  左琴  杨开艳  马婷  许锋 《岩矿测试》2020,39(3):442-450

鄂尔多斯盆地上三叠统延长组长7油层组的黑色泥岩、油页岩等黑色生油岩薄片中的生烃母质,因黑色石油、沥青等黑色有机质的覆盖或不透明,导致其在偏光显微镜透射光系统下观察常局部或整体呈现为黑色。因此,建立一种黑色生油岩薄片中生烃母质有效观察的方法,对致密油、页岩油的生烃研究具有重要的理论和实际意义。本文提出了一种利用电子探针薄片和偏光显微镜的反射光系统观察黑色生油岩中生烃母质特征的方法。该方法能够克服黑色生油岩薄片中生烃母质因被黑色有机质覆盖或不透明,而在偏光显微镜的透射光系统下局部或整体呈黑色的弊端,能够对生烃母质的大小、形态、结构、分布和物质成分等特征进行整体且清晰的观察。实践表明,本文提出的利用偏光显微镜反射光系统观察黑色生油岩电子探针薄片中生烃母质特征的方法,简单有效,易在致密油、页岩油的生烃研究领域推广使用。  相似文献   

Main active faults and seismic activity along the Yangtze River Economic Belt: Based on remote sensing geological survey     

《China Geology》2020,3(2):314-338

The Yangtze River Economic Belt (YREB) spans three terrain steps in China and features diverse topography that is characterized by significant differences in geological structure and present-day crustal deformation. Active faults and seismic activity are important geological factors for the planning and development of the YREB. In this paper, the spatial distribution and activity of 165 active faults that exist along the YREB have been compiled from previous findings, using both remote-sensing data and geological survey results. The crustal stability of seven particularly noteworthy typical active fault zones and their potential effects on the crustal stability of the urban agglomerations are analyzed. The main active fault zones in the western YREB, together with the neighboring regional active faults, make up an arc fault block region comprising primarily of Sichuan-Yunnan and a “Sichuan-Yunnan arc rotational-shear active tectonic system” strong deformation region that features rotation, shear and extensional deformation. The active faults in the central-eastern YREB, with seven NE-NNE and seven NW-NWW active faults (the “7-longitudinal, 7-horizontal” pattern), macroscopically make up a “chessboard tectonic system” medium-weak deformation region in the geomechanical tectonic system. They are also the main geological constraints for the crustal stability of the YREB.  相似文献   

Geochemical characteristics and sedimentary environment of the Middle Devonian organic-rich shales in the Northwest of Guizhong Depression,Southwest China     

《China Geology》2020,3(4):567-574

In order to figure out the redox conditions and paleo-sedimentary environment of the Middle Devonian shales in the northwest of Guizhong Depression, the trace element analysis was conducted on the Middle Devonian cores (320.35–938.50 m) of the typical shale gas investigation well (GY-1) at a 1.50 m sampling interval through X-ray fluorescence spectroscopy (XRF) and inductively coupled plasma mass spectrometry (ICP-MS). According to the test result, the average values of V/(V+Ni), V/Cr and Ni/Co in Nabiao formation (Fm.) are larger than 0.67, 4.65 and 7.71 respectively, and Nabiao Fm. is rich in biological assemblages such as tabasheer, ammonite, etc. These evidences indicate the rising sea level rose relatively in the sedimentation period of Nabiao Fm. and a deepwater shelf environment, which was favorable for the preservation of organic matters. The V/(V+Ni), V/Cr and Ni/Co in Luofu Fm. and Tangting Fm. are 0.38–0.65, 0.73–4.10 and 3.70–6.72 respectively, indicating that the sea level dropped relatively in their sedimentation period, during which the water bodies became shallow, and the sedimentary environment was a weak oxidizing shallow water shelf environment. In addition, the variation of TOC has a high correlation with the enrichment degree of Ba element, indicating the favorable conditions for the enrichment and preservation of organic matters under an oxygen-deficient environment. Moreover, according to the identification of trace element indexes, the northwest of Guizhong Depression experienced the sedimentary cycle of relative rise to relative fall of sea level from bottom to top in the Middle Devonian sedimentation period. The relative sea level rose to the highest in the sedimentation period of Nabiao Fm., in which the organic-rich shales with stable thickness and high organic content were deposited. Hence, the Nabiao Fm. could be regarded as the favorable exploration target interval in this area.  相似文献   

Feedback control system for blow-out preventer positioning     

《Applied Ocean Research》2019

During the drilling of ultra-deep-water subsea petroleum wells, a blow-out preventer (BOP), a piece of safety equipment, must be assembled on the wellhead. The BOP is suspended using the drilling riser during the wellhead approach operation, and the riser's top end is connected to the floating platform rig. This article presents a feedback control system for the automatic approach of the BOP to the wellhead. Compared to state-of-the-art controls, ours does not require ancillary thrusters installed alongside the riser nor inclination sensors atop of the drilling riser. Additionally, our proposed control embeds a closed-loop dynamic positioning system, thus retaining the characteristics of the original control system and adding an extra closed-loop. This eases implementation of the BOP approach control to an existing platform. To calculate the optimal gains for the BOP controller, we assume a linear system for the riser, including only the pendulum-shape. The simulation is carried out using nonlinear models for both riser and floating platform. We assume an International Towing Tank Conference standard semi-submersible platform, coupled with a 3000-m free-hanging vertical riser for the time-domain simulation. The results show the BOP tracking to be a step-shaped input signal under current and wave loads. A discussion of the performance of feedback control under different environmental loads is also included.  相似文献