基于空间协同共享技术的规划用地监测平台研究

基于空间共享的空间库平台多源数据,设计开发了规划用地监测平台,对现状用地情况、规划用地情况、规划审批情况、土地存量情况、集体用地情况、棚户区情况等进行动态监测,为规划管理和规划研究工作提供及时有效的数据支撑。     

A non-hydrostatic model for the numerical study of landslide-generated waves

This paper proposes and demonstrates a two-layer depth-averaged model with non-hydrostatic pressure correction to simulate landslide-generated waves. Landslide (lower layer) and water (upper layer) motions are governed by the general shallow water equations derived from mass and momentum conservation laws. The landslide motion and wave generation/propagation are separately formulated, but they form a coupled system. Our model combines some features of the landslide analysis model DAN3D and the tsunami analysis model COMCOT and adds a non-hydrostatic pressure correction. We use the new model to simulate a 2007 rock avalanche-generated wave event at Chehalis Lake, British Columbia, Canada. The model results match both the observed distribution of the rock avalanche deposit in the lake and the wave run-up trimline along the shoreline. Sensitivity analyses demonstrate the importance of accounting for the non-hydrostatic dynamic pressure at the landslide-water interface, as well as the influence of the internal strength of the landslide on the size of the generated waves. Finally, we compare the numerical results of landslide-generated waves simulated with frictional and Voellmy rheologies. Similar maximum wave run-ups can be obtained using the two different rheologies, but the frictional model better reproduces the known limit of the rock avalanche deposit and is thus considered to yield the best overall results in this particular case.     

Carbonate formation mechanism in paleosol sediments of the Bohai Sea coastal zone,China

The Bohai Sea coastal zone of China consists of the Pacific Ocean to the east and Eurasia to the west; hence, this region is influenced by both the ocean and continental landmasses. The carbonate formation mechanism of eolian sediment within this area is poorly understood. The loess-paleosol sediments of the Miaodao stratigraphical section (MDS) contain a record of carbonate changes in this region during the last interglacial period. New insights into regional carbonate formation mechanisms since the last interglacial period were obtained by analyzing the ages of various sedimentary facies in combination with proxy paleoclimatic indices (including average grain size, standard deviation, CaCO₃ content, and clay minerals), as well as via foraminiferal analysis. The results led to three principal findings: (1) The carbonate content change in the MDS was neither controlled by grain size nor affected by minerals. The carbonate change controlled by precipitate leaching in the Loess Plateau region cannot explain the eolian sediments within the Bohai Sea coastal zone. (2) Various subsections contain obvious carbonate content changes caused by foraminiferal deposits atop the eolian sediments, which were deposited by storm surges during a high sea-level period. This increased the carbonate content in the eolian sediments and restricted the carbonate content in the Bohai Sea coastal zone. (3) Newly detected foraminifera of the last interglacial period on the eolian sediment of the MDS were the main source of carbonate content, providing a new understanding of the carbonate formation mechanism in eolian sediments different from that of the Loess Plateau.     

内蒙古冬季极端多雪气候事件环流演变特征及季节预测信号

文章研究关注了内蒙古冬季极端多雪气候事件的季节预测问题,在对大量降水观测资料、海温及大气环流场资料进行统计、分析、研究的基础上,确定了历史上58a(1960—2017年)内蒙古冬季极端多雪和少雪气候事件样本,通过对大气环流场的对比分析发现极端多雪或少雪冬季环流场特征显著不同,分析后确定了影响内蒙古冬季降雪的主要环流系统,包括西太平洋副热带高压、极涡、东亚大槽、环流E型及南方涛动等系统。同时,探索了对这些主要环流系统具有预测意义的来自海洋和大气场的预测信号,对预测信号关键区做了标准化定量提取,确定了预测信号综合指数分段判别阈值,给出了预测概念模型,取得了较好预测效果。     

How changes of groundwater level affect the desert riparian forest ecosystem in the Ejina Oasis,Northwest China

Groundwater is a key factor controlling the growth of vegetation in desert riparian systems. It is important to recognise how groundwater changes affect the riparian forest ecosystem. This information will not only help us to understand the ecological and hydrological process of the riparian forest but also provide support for ecological recovery of riparian forests and water-resources management of arid inland river basins. This study aims to estimate the suitability of the Water Vegetation Energy and Solute Modelling(WAVES) model to simulate the Ejina Desert riparian forest ecosystem changes,China, to assess effects of groundwater-depth change on the canopy leaf area index(LAI) and water budgets, and to ascertain the suitable groundwater depth for preserving the stability and structure of desert riparian forest. Results demonstrated that the WAVES model can simulate changes to ecological and hydrological processes. The annual mean water consumption of a Tamarix chinensis riparian forest was less than that of a Populus euphratica riparian forest, and the canopy LAI of the desert riparian forest should increase as groundwater depth decreases. Groundwater changes could significantly influence water budgets for T. chinensis and P. euphratica riparian forests and show the positive and negative effects on vegetation growth and water budgets of riparian forests. Maintaining the annual mean groundwater depth at around 1.7-2.7 m is critical for healthy riparian forest growth. This study highlights the importance of considering groundwater-change impacts on desert riparian vegetation and water-balance applications in ecological restoration and efficient water-resource management in the Heihe River Basin.     

A study of coral reef resilience and implications of adaptive management and rehabilitation in Khanh Hoa Province, Vietnam

The Province of Khanh Hoa, Vietnam, is located in the western South China Sea and boasts a shoreline of 385 km and many islands. Previous studies have indicated the extreme diversity and abundance of coral reefs in its waters as compared with other coastal provinces of Vietnam. A study on the resilience of coral reefs against increased surface water temperature and anthropogenic impact is conducted at 19 reef sites in 2015. At each site, a series of parameters (e.g., coral covers, genus diversity, and coral recruitment, substratum heterogeneity, depth, water exchange level, and sediment deposit and water temperature) are measured quantitatively or semi-quantitatively. The measured data are rated based on the relationship between the parameter values and coral susceptibility; the consideration that reef health reflects the biological capability to adapt to environmental changes and the recruitment potential if bleached; and positive or negative influences of physical factors in the mitigation of thermal stress and protecting corals from bleaching. A cumulative analysis enables researchers to divide the studied reefs into four categories based on varying levels of reef health to support resilience, recovery, and vulnerability in the case of increased water temperature. Relevant management interventions for each category and other supporting activities are suggested to enhance management effectiveness and to plan the rehabilitation of coral reefs for biodiversity conservation and touristic development, taking into account the involvement of related stakeholders.     

城市倾斜摄影实景三维模型数据质量检查方法研究与实践

基于倾斜摄影可以快速获得高精度的城市实景三维模型,分析了实景三维模型数据的特点,探讨了实景三维模型数据质量检查的重点内容和质量元素,结合北京市大规模倾斜摄影实景三维数据质量检查实例,对实景三维数据质检问题与内容进行了总结,最后提出了实景三维模型数据的质量检查方法。     

贵州凤冈南北向隔槽式褶皱变形区滑坡孕灾地质条件研究

贵州凤冈南北向隔槽式褶皱变形区独特的地质构造形成了典型的侏罗山式褶皱组合区,其与滑坡的孕育具有较强的关联性。本研究基于实地调查与数据分析,通过地质构造、地形地貌、地层岩性及河流分布等因素与滑坡发育的关系,探讨研究区滑坡孕灾地质条件。结果表明,研究区滑坡主要发育于构造相互截接严重的区域;在地形上主要发育于高差100300 m、坡度25°35°的顺向坡和斜向坡,地貌类型以侵蚀—溶蚀沟谷地貌为主;滑坡孕育地层具有倾向性,主要为志留系兰多维列统韩家店组(S1h)的泥岩、页岩及奥陶系中下统湄潭组(O1-2m)的页岩、砂质页岩;研究区河流对斜坡的影响范围平均为900 m,影响区内距河流越远,滑坡发育数量越少。     

Quality influencing factors of dispersion curves from short period dense arrays based on a convolutional neural network across the north section of the Xiaojiang fault area

The number of dispersion curves increases significantly when the scale of a short-period dense array increases. Owing to a substantial increase in data volume, it is important to quickly evaluate dispersion curve quality as well as select the available dispersion curve. Accordingly, this study quantitatively evaluated dispersion curve quality by training a convolutional neural network model for ambient noise tomography using a short-period dense array. The model can select high-quality dispersio...     

Clinoform growth and sediment flux into late Cenozoic Qiongdongnan shelf margin,South China Sea

The South China Sea continental margin in the Qiongdongnan Basin (QDNB) area has incrementally prograded since 10.5 Ma generating a margin sediment prism more than 4km-thick and 150–200 km wide above the well-dated T40 stratigraphic surface. Core and well log data, as well as clinoform morphology and growth patterns along 28 2D seismic reflection lines, illustrate the evolving architecture and margin morphology; through five main seismic-stratigraphic surfaces (T40, T30, T27, T20 and T0) frame 15 clinothems in the southwest that reduce over some 200 km to 8 clinoforms in the northeast. The overall margin geometry shows a remarkable change from sigmoidal, strongly progradational and aggradational in the west to weakly progradational in the east. Vertical sediment accumulation rate increased significantly across the entire margin after 2.4 Ma, with a marked increase in mud content in the succession. Furthermore, an estimate of sediment flux across successive clinoforms on each of the three selected seismic cross sections indicate an overall decrease in sediment discharge west to east, away from the Red River depocenter, as well as a decrease in the percentage of total discharge crossing the shelf break in this same direction. The QDNB Late Cenozoic continental margin growth, with its overall increased sediment flux, responded to the climate-induced, gradual cooling and falling global sea level during this icehouse period.