地表水地下水耦合模型在大型山丘平原交错区的研发与应用

大型山丘平原交错区复杂的自然地理和人类活动特征增加了水文循环研究和水资源评价、管理的难度,地表水地下水耦合模型作为流域/区域水文循环模拟的重要工具,为解决这类大型区域诸多水文水资源问题提供了便利.针对目前地表水地下水耦合模型难以兼顾精度和效率的问题,论文提出了一种新型半松散耦合机制,将三维有限差分地下水流数值模型嵌入半...     

长江三角洲碳排放与植被覆盖耦合协调时空格局及影响因素分析

通过构建评价指标体系和分析框架,利用综合指数法、耦合协调度模型和灰色关联度模型分析2005―2017年长江三角洲（长三角）碳排放与植被固碳耦合协调时空变化特征及驱动因素,并模拟政府决策优先级对耦合协调度趋势的影响。结果表明：长三角碳排放空间集聚特征显著,基本形成了以长江沿线和长三角东南沿海区域为核心的沿江沿海高排放带;长三角碳排放与植被固碳耦合协调度具有明显的空间分异特征,呈现出南京-上海沿线一般失调区域为核心的圈层结构特征;植被覆盖综合评价值高于碳排放综合评价值的地区耦合协调度普遍较高,人口的集聚和变化、城市建设和能源消耗对耦合协调度影响最大;同时,政府决策的优先级会显著影响耦合协调趋势。     

人地系统耦合下生态系统服务与人类福祉关系研究进展与展望

21世纪以来生态系统服务退化与人类需求提升间的矛盾愈发激烈,如何有效推进生态系统服务与人类福祉的协调平衡成为当前可持续发展的核心主题.论文通过梳理生态系统服务与人类福祉关系研究的阶段演进发现,现有研究主要从服务对福祉的影响与福祉对服务的反馈切人,逐步聚焦到供需关系与空间流动、权衡/协同的利益博弈、文化服务的价值化、生态...     

Seismic motion in urban sites consisting of blocks in welded contact with a soft layer overlying a hard half-space

We address the problem of the response to a seismic wave of an urban site consisting of   N _b   blocks overlying a soft layer underlain by a hard substratum. The results of a theoretical analysis, appealing to a space–frequency mode-matching (MM) technique, are compared to those obtained by a space–time finite-element (FE) technique. The two methods are shown to give rise to the same prediction of the seismic response for   N _b = 1  , 2 and 40 blocks. The mechanism of the interaction between blocks and the ground, as well as that of the mutual interaction between blocks, are studied. It is shown, in the first part of this paper, that the presence of a small number of blocks modifies the seismic disturbance in a manner which evokes qualitatively, but not quantitatively, what was observed during the 1985 Michoacan earthquake in Mexico City. Anomalous earthquake response at a much greater level, in terms of duration, peak and cumulative amplitude of motion, is shown, by a theoretical and numerical analysis in the second part of this paper, to be induced by the presence of a large (≥10) number of identical equi-spaced blocks that are present in certain districts of many cities.