长江中游城市群水资源承载力时空格局及耦合协调性

长江中游城市群是实施生态优先绿色发展战略的重点区域,从水资源承载系统内的水资源、社会、经济、生态环境4个子系统中选取24项指标构建水资源承载力评价体系,综合运用改进熵权TOPSIS模型、空间自相关分析和耦合协调发展模型定量评价2012-2018年长江中游城市群水资源承载力时空变化过程及子系统间的耦合协调性.结果表明,（1）长江中游城市群整体水资源承载力水平表现为：缓慢上升（2012-2015年）、下降（2015-2017年）、再上升的趋势（2017-2018年）;（2）水资源承载力的空间差异不明显（仅2016年差异显著）,武汉城市圈水资源承载力的空间差异相对较大且呈现低值包围高值的空间分布特征;（3）各城市生态环境子系统承载力得分较为均衡,但其他子系统的承载力均差异较大;（4）影响水资源承载力的主要因素依次为城市污水处理厂日处理能力、人均GDP、城镇化率、第三产业比重和人均水资源量;（5）长江中游城市群水资源承载系统的耦合协调度总体处于中等水平,且水资源承载力与耦合协调度有极强的正相关关系.研究结果可为长江中游城市群水资源承载力改善及水资源优化配置提供依据.     

1999年台湾集集地震震源破裂过程

使用GPS同震位移资料和远场P波记录,研究了1999年台湾集集地震震源破裂过程．根据地质构造和余震分布引入了一个由弯曲断层面构造的三段“铲状”断层模型．在使用静态GPS位移资料反演集集地震的断层破裂滑动分布时,由于集集地震断层北部近地表破裂的复杂性,在位错模型中考虑拉张分量对地表同震位移的贡献,可更好地同时拟合GPS观测资料的水平和垂向分量．而纯剪切位错弹性半空间模型和分层地壳模型都无法同时拟合水平和垂向GPS观测资料．在此基础上,同时使用静力学同震位移资料和远场地震波形记录,反演集集地震的震源破裂过程．结果表明,一种垂直于断层面的“挤压性”(负)拉张分量几乎集中分布于地震断层的浅部和北部转折处,而这一带地表破裂远较没有(负)拉张分量出现的南部断层复杂．“冒起构造”的数字模拟表明,这种在集集地震破裂转折处及北部断裂带广为出现的典型破裂造成的地表位移可以用具有负拉张分量(挤压)的逆冲断层更好地模拟．而这种负拉张分量(挤压)的分布正是地震破裂性质和几何复杂性的综合反映,震源破裂过程也显示北部转折处破裂在空间和时间上的复杂性.高滑区域与余震分布表现为负相关.     

基于系统动力学的巢湖流域水资源承载力动态预测与调控

湖泊流域水资源承载能力动态预测与调控是维护湖泊生态安全、保障社会经济健康持续发展的重要基础和手段.本文以巢湖流域为研究对象,提出基于系统动力学的湖泊流域水资源承载力动态预测技术和试验优化调控方法.首先以县(市)为基本单元构建水资源承载力系统动力学模拟与动态预测模型;再从空间上将各县(市)耦合为流域系统整体模型,并通过敏感性分析筛选量质要素调控指标;最后采用正交试验设计确定流域水资源承载力优化调控方案.结果表明:由于流域内产业规模的扩大以及城镇化率的提升,20172050年巢湖流域水资源承载状态值整体呈恶化趋势,并于2030年以后将长期处于超载状态,通过对影响要素针对性优化调控后,20172050年流域水资源承载状态均达到临界或可载.研究表明本文提出的方法对于促进区域社会经济环境协调发展和改善流域水资源承载力具有较好的实际应用价值.     

小波域叠前地震资料衰减参数定性估计方法

叠前地震资料中,高频分量和低频分量随传播距离的衰减特性不同.本文给出了一种在小波域定性估计叠前地震资料衰减参数的方法.该方法利用连续小波变换提取共反射点道集的高、低频分量,以低频分量和高频分量之差定性反映地震波的衰减.通过累加不同偏移距的衰减,提高了估计的稳定性;采用幅度归一化方法,降低了信号幅值对衰减参数估计的影响.将本文提出方法与常用的基于叠后地震资料衰减估计方法用于某油田的地震资料处理,结果表明,本文方法得到的衰减估计结果能够更好地反映油气的空间展布.     

洞体应变对高频气压波响应的传递函数——以陕西宁强台为例

自2011年观测以来,陕西宁强台洞体应变的高频气压效应甚为显著,但其频率依存性至今尚不明晰。为此,本文尝试采用相干函数和传递函数等方法,对该台2019年1月1日—4月2日的洞体应变和气压数据进行了系统诊断。结果表明,在8～40cpd频段内,洞体应变对气压具有较强的频率依赖性,即气压系数和相移均会随频率的变化而呈现非线性变化,其中,最大气压系数为7.80×10^-9/hPa,相位超前可达108.27°,且NS和EW分量的气压响应有所差异。上述结果将有助于该台高频噪声的物理溯源,同时还能为高频气压效应的分频段改正等提供量化依据。     

基于CSP道集的速度分析与建模

对于低信噪比地震资料,现行的叠前偏移方法应用效果欠佳的一个重要原因就是,目前的各种速度分析方法在信噪比太低时都不能建立准确的速度模型.共散射点(CSP)道集聚集了所有可能的散射能量,具有更高的覆盖次数和更大的偏移距范围.因此,对于低信噪比资料,基于CSP道集的速度分析具有一定的优越性.本文首先简单介绍了CSP道集的形成过程和基于CSP道集的速度分析方法的基本原理,提出了一种从CMP道集到CSP道集的快速映射方法,并用一个加权系数消除了映射噪音,最后用模型和实际资料验证了基于CSP道集的速度分析与建模方法的可行性和实用性.     

降雨对大柏舍地电台地电阻率观测的影响

选取大柏舍地电台2011—2019年地电阻率观测数据和降雨量资料,分析降雨对地电阻率观测的影响,利用影响系数理论,对结果进行分析探讨。结果表明,由于大柏舍地电台表层介质影响系数较小且为负值,小幅降雨对该台地电阻率短期影响不明显,仅自然电位差受到干扰;大范围强降雨时,地电阻率和自然电位差均受到影响;因ZD8B仪地电阻率观测系统架空线路漏电,导致EW向分量呈阶降变化,且比用于背景场观测的ZD8M仪变化幅度大。     

四川四分量钻孔应变观测数据精度评价

利用邱泽华等给出的观测数据和回归分析方法,计算钻孔应变仪四分量元件的相对标定系数,并根据偏差计算自检内精度等指标,对观测数据进行质量评价。选取2017年四川四分量钻孔应变观测台网记录资料,结合四分量钻孔应变仪观测特点,计算并分析应变观测仪相对标定自检内精度,客观评价观测数据精度,结果发现,2017年仁和台四分量钻孔应变数据各月及全年相对标定系数K_i最大,偏差s最小,自检内精度数值最小,表明该台钻孔应变观测数据精度最高。分析认为,相对标定自检内精度可如实反映台站记录资料的可信度,可以更好、更客观地评价台站四分量钻孔应变观测资料质量。     

云南地区震前舒曼谐振异常初步分析

舒曼谐振异常现象与地震活动性有较好的相关性,舒曼谐振异常现象可能与地震电离层扰动有关,是岩石层-大气层-电离层耦合的重要体现之一.本文详细介绍了云南舒曼谐振地震前兆观测台的系统结构和仪器参数,以及统计分析和震例分析的结果.永胜台观测数据显示2011年3月10日云南盈江M5.8级地震震前3天By分量出现舒曼异常,2011年1月23日临沧东部M4.0级地震震前2天By分量出现舒曼异常;通海台观测的By分量频谱分析结果显示,2011年5月22日红河州M4.2级地震当日前3阶谐振频率对应谱密度出现强烈扰动.研究表明,舒曼谐振地震前兆监测是一种可行的监测手段.     

锈蚀作用下钢筋混凝土梁承载力退化规律研究

为了掌握锈蚀对钢筋混凝土梁正截面承载力的影响规律,采用电加速锈蚀试验与理论分析相结合的方法,对不同锈蚀等级下钢筋混凝土梁的承载力退化进行了研究。结果表明,钢筋从未锈蚀到严重锈蚀过程中,梁从典型的适筋梁破坏逐渐转化成典型的少筋梁破坏。随着腐蚀程度的增加,梁的极限承载力下降、延性降低、刚度减小。腐蚀量小于1%的情况下,梁的极限承载力略有提高。当腐蚀量增加至24%时,由于严重的局部腐蚀以及锈胀裂纹的存在及扩展都使得梁的极限承载力较经验模型出现较大降低。在钢筋锈蚀率小于24%的情况下,采用协同系数或基于规范的计算模型,能够较准确地计算钢筋混凝土梁正截面受弯极限承载力的影响。     

从经济损失中评估水资源的价值

This paper has calculated the economic losses resulted from water pollution within the district of south Jiangsu Province of Taihu Lake water system in industry, agriculture, drinking, fishery and tourism. It has also evaluated the value of the water resources in the district by a value-function loss model. A new method of natural resources evaluation has been put forward in the paper and a new way in which natural resources can be priced reasonably has been discussed as well.     

A runoff capability classification system based on surface features criteria in semi-arid areas of West Africa

An analysis of the factors influencing infiltration and runoff was carried out using data obtained under simulated rainfall conditions on 87 plots in arid and semi-arid areas of West Africa, arranged in a hierarchical sequence. One of the key factors to emerge from this typological classification is the type of surface crust. Together with faunal activity, vegetation cover and surface roughness, this parameter permits the inclusion of a ‘unit surface’ factor in the classification system. Each unit surface is characterized in terms of genetic, morphological and hydrological properties.

At a higher level, the combination of these unit surfaces allows a ‘soil surface features unit’ to be defined, based on an original mapping method. The samples, once defined in this system, were found to correspond to homogeneous criteria both in terms of evolution dynamics and hydrological behaviour. Furthermore, such cartography could be successfully extrapolated through remote sensing image analysis, making possible a classification of the runoff capability of small watersheds based on objective and standardized criteria.     

抚仙湖历史水位反演与未来30年水位变化预测

在极端气候事件频发和人类活动加剧的背景下,抚仙湖水位波动显著,尤其是2009—2012年极端干旱事件的发生,使抚仙湖平均水位（1721.31 m）低于法定最低水位（1721.65 m）,给生态环境安全带来严重威胁.因此,找到合适有效的湖泊水位模拟方法,对气候变化影响下的未来水位进行预测,并做好相应的应对准备,对湖泊生态系统的保护至关重要.本文运用DYRESM水动力模型对抚仙湖1959—2050年水位进行了模拟.因抚仙湖流域尚无长时间序列的历史水文观测数据,故利用模型和水量补偿法对抚仙湖入湖水量进行反推,构建了降水量-入湖水量的回归方程,并通过有效的实测入湖水量和水位数据,对回归方程的精度进行了检验.利用全球气候模式BCC-CSM2-MR中SSP245和SSP585两种情景提供的未来气候预估数据,运用DYRESM预测了抚仙湖2021—2050年水位变化趋势.结果表明：（1）构建的DYRESM水动力模型和降水-入湖水量回归方程精度较高,模型结果能很好地反映抚仙湖水位的年际和年内变化趋势,且能有效捕捉到抚仙湖的水位峰值.（2）在SSP245和SSP585两种情景下,抚仙湖2021—2050年多年平均水位分别为1722.98和1723.93 m,较1959—2017年平均水位1721.77 m分别升高1.21和2.16 m.两种情景下抚仙湖未来水位均有部分时段超过法定最高蓄水位（1723.35 m）,但均高于法定最低水位.因此,未来气候变化对抚仙湖水量的影响有限,并不会导致水位过低,当水位超过法定最高蓄水位时,可通过控制出流闸门将水位调节在合理范围内.     

Soil temperature and soil moisture dynamics in winter and spring under heavy snowfall conditions in North-Eastern Japan

Warm winters and high precipitation in north-eastern Japan generate snow covers of more than three meters depth and densities of up to 0.55 g cm⁻³. Under these conditions, rain/snow ratio and snowmelt have increased significantly in the last decade under increasing warm winters. This study aims at understanding the effect of rain-on-snow and snowmelt on soil moisture under thick snow covers in mid-winter, taking into account that snowmelt in spring is an important source of water for forests and agriculture. The study combines three components of the Hydrosphere (precipitation, snow cover and soil moisture) in order to trace water mobility in winter, since soil temperatures remained positive in winter at nearly 0.3°C. The results showed that soil moisture increased after snowmelt and especially after rain-on-snow events in mid-winter 2018/2019. Rain-on-snow events were firstly buffered by fresh snow, increasing the snow water equivalent (SWE), followed by water soil infiltration once the water storage capacity of the snowpack was reached. The largest increase of soil moisture was 2.35 vol%. Early snowmelt increased soil moisture with rates between 0.02 and 0.035 vol% hr⁻¹ while, rain-on-snow events infiltrated snow and soil faster than snowmelt and resulted in rates of up to 1.06 vol% hr⁻¹. These results showed the strong connection of rain, snow and soil in winter and introduce possible hydrological scenarios in the forest ecosystems of the heavy snowfall regions of north-eastern Japan. Effects of rain-on-snow events and snowmelt on soil moisture were estimated for the period 2012–2018. Rain/snow ratio showed that only 30% of the total precipitation in the winter season 2011/2012 was rain events while it was 50% for the winter 2018/2019. Increasing climate warming and weakening of the Siberian winter monsoons will probably increase rain/snow ratio and the number of rain-on-snow events in the near future.     

Temporally weighted average curve number method for daily runoff simulation

The modified Soil Conservation Service curve number (CN) method is widely used in long‐term continuous models to predict daily surface runoff. However, it has been shown that this method gives poor results in reproducing peak flows in high rainfall periods. This is because there is an inaccuracy stemming from the model algorithm as it adjusts the daily runoff curve number as a function of soil moisture content at the end of the previous day. This paper proposes an alternative daily based curve number technique that can provide better prediction of daily runoff during the high flow season. The proposed method uses the temporally weighted average curve number (TWA‐CN) to estimate daily surface runoff, while considering the effect of rainfall during a given day as well as the antecedent soil moisture condition. To test the applicability of the TWA‐CN method, it was incorporated with the long‐term, continuous simulation watershed models SWAT and SWAT‐G. Simulations were conducted for the Miho River watershed located in the middle of South Korea. The graphical displays and statistics of the determination coefficient (R²) and the Nash–Sutcliffe model efficiency (NSE) of the observed and simulated daily runoff indicated that the modified SWAT with the TWA‐CN method may provide better runoff prediction (R² = 0·837, NSE = 0·833) than the original SWAT (R² = 0·815, NSE = 0·824). Likewise, the determination coefficient (R² = 0·816) and the Nash–Sutcliffe efficiency (NSE = 0·834) for the modified SWAT‐G are also higher than the original version (R² = 0·782, NSE = 0·825). It is expected that the improved capability in predicting surface runoff using the suggested CN estimate method will provide a sound contribution to the accurate simulations of water yield. Copyright © 2008 John Wiley & Sons, Ltd.     

How do we know when we have done enough to protect the environment?

The changing concepts and challenges that the process industry has to face in relation to environmental protection are discussed. The original requirements on industry to reduce emissions of contaminants through the installation of filters and waste water treatment facilities or through process modification and introduction of ‘clean production’ strategies were mainly based on economic and technical considerations rather than on an effort to avoid environmental impacts. The introduction of concepts such as ‘assimilative capacity of the environment’ and ‘critical load’ provided useful instruments for setting effect-related emission standards, resulting in acceptable environmental protection. However, the actual requirement for ‘sustainability’ has forced industry to focus not only on controlling emissions of contaminants and pollutants, but to take a global environmental approach, including the choice of raw materials and energy sources, recycling and re-utilization of wastes and to take responsibility for the fate of their products, during their whole lifecycle.     

3-D Non-linear Travel-time Tomography: Imaging High Contrast Velocity Anomalies

In this paper we present an approach for 3-D travel-time tomography, which works well in reconstructing high contrast velocity anomalies in both location and strength. It uses a revised ‘irregular’ approach to the shortest-path method as the ray tracer and a damped minimum norm, and constrained least-squares CG approach as the inversion solver. In ray tracing, the advantages of the revised ‘irregular’ over the ‘regular’ approach are that the secondary nodes introduced on the cell surfaces significantly improve accuracy of computed travel times, without dramatically increasing the total number of cells and nodes; the tri-linear velocity function defined across the cell guarantees accurate ray tracing in a high velocity contrast medium; and the capacity to calculate a relatively large 3-D model, due to the fast run speed (at least one order of magnitude over the ‘regular’ approach) and less number of total nodes. The introduction of ‘soft’ and ‘hard’ bounds into the inversion process changes the conditioning and makes the solution meaningful in a physical sense. Thus the artifacts caused by noise and high velocity contrasts are substantially suppressed and the image quality is considerably improved, making the solution realistic with noisy or inconsistent travel-time data. Several numerical tests indicate that we can obtain good quality images even for high velocity contrast anomalies (say more than 20%) in the target region. This means the inversion algorithm is an efficient and effective procedure. Meanwhile, the inversion procedure is not very sensitive to the quality of the travel-time data, which is promising for practical usage.     

Assessing morphological degradation in running waters using Blackfly communities (Diptera, Simuliidae): Can habitat quality be predicted from land use?

Based on benthic macroinvertebrate samples from 57 sites of streams in the European Central Highlands (Ecoregion 9; Illies (1978). Limnofauna Europaea, Stuttgart), the composition and the abundance of Simuliid species were analysed in relation to hydromorphological and land use parameters. Sampling sites were located at two stream types differing in catchment geology, stream morphology and channel width. Land use data were taken from the official German information system for cartography and topography (ATKIS) and the German River Habitat Survey. Land use categories suitable to describe the sampling sites were ‘agricultural land’, ‘urban’ and near-natural areas. Hydromorphological parameters of the sites were recorded using the AQEM site protocol (AQEM Consortium (2002). Manual for the application of the AQEM system. A comprehensive method to assess European streams using benthic macroinvertebrates, developed for the purpose of the Water Framework Directive. EVK1-CT1999-00027, Version 1.0. Available via the Internet from www.aqem.de). Relevant parameters controlling Simuliid distribution in streams were the mineral substrates and the biotic microhabitats. Blackfly larvae and pupae were sampled at each site for 15 min. Statistical analysis was performed by CANOCO^® (Ter Braak & Smilauer (1997). CANOCO Version 4.5. Biometrics Plant Research International, Wageningen, The Netherlands) using redundancy analysis (RDA).

Our results show a stream type-specific composition of the Blackfly fauna. The analyses reveal sensitivity of the Simuliid species to morphological degradation, which is indicated by the shift in the longitudinal zonation of the Simuliid communities. Especially, Prosimulium hirtipes (Fries, 1824) and Simulium argyreatum Meigen, 1838 are typical representatives of headwater streams. While they seem to indicate undisturbed conditions of this stream type and react sensitively to the degradation of stream habitats, Simulium ornatum Meigen, 1818 and Simulium equinum (Linnaeus, 1758) are more tolerant to stream degradation.

On catchment scale, ‘% natural forest’ and ‘% agricultural land use’ illustrate the degree of degradation of the two selected stream types. ‘Average stream depth’ and ‘relation riffles/pools’ account for hydromorphological degradation reflected by Simuliid species on the smaller reach scale. The analysis of habitat quality revealed that ‘% woody debris’ represents an important parameter of morphological degradation reflected by the Blackfly community.     

张掖MS 5.0地震前山丹地震台地电阻率异常分析

通过分析山丹地震台地电阻率资料发现,在2019年9月16日张掖M_S 5.0地震前地电阻率出现了明显的异常变化,即2016年11月开始EW测道观测数据出现年变畸变异常,年变幅度几近消失,该异常持续至2018年年底。采用傅里叶滑动去年变分析发现,同段年变消失,去年变后数值出现超阈值异常;采用矩平处理方法分析发现,2016年11月至2018年10月观测值小于矩平拟合值,出现低值异常。研究表明,该异常可能与2019年9月16日张掖M_S 5.0地震有关。     

Experimental evidence for the exsolution of cratonic peridotite from high-temperature harzburgite

Phase equilibrium experiments were performed on typical ‘oceanic’ and ‘cratonic’ peridotite compositions and a Ca, Al-rich orthopyroxene composition, to test the proposal that garnet lherzolites exsolved from high-temperature harzburgites, and to further our understanding of the origin of ancient cratonic lithospheres. ‘Oceanic’ peridotites crystallize a garnet harzburgite assemblage at pressures above 5 GPa in the temperature range 1450–1600°C, but at 5 GPa and temperatures less than 1450°C, crystallize clinopyroxene to become true lherzolites. ‘Cratonic’ peridotites crystallize a garnet harzburgite assemblage at pressures above 5 GPa in the temperature range 1300–1600°C. Garnet-free harzburgite crystallizes from both ‘cratonic’ and ‘oceanic’ peridotite at temperatures above 1450°C and pressures below 4.5–5 GPa. Phase relations for the high Ca, Al-rich orthopyroxene composition essentially mirror those for ‘oceanic’ peridotite.The complete solution of garnet and clinopyroxene into orthopyroxene observed in all three starting compositions at temperatures near or above the mantle solidus at pressures less than 6 GPa supports the hypothesis that garnet lherzolite could have exsolved from harzburgite. The inferred cooling path for the original high-temperature harzburgite protoliths of garnet lherzolites differs depending on bulk composition. The precursor harzburgite protoliths of garnet lherzolites and harzburgites with ‘cratonic’ bulk compositions apparently experienced simple isobaric cooling from formation temperatures near the peridotite solidus to those at which most of these peridotites were sampled in the mantle (< 1200°C). The cooling histories for harzburgite protoliths of sheared garnet lherzolites with ‘oceanic’ compositional affinity are speculated to have involved convective circulation of mantle material to depths deeper than those at which it was originally formed.Phase equilibria and compositional relationships for orthopyroxenes produced in phase equilibrium experiments on peridotite and komatiite are consistent with an origin for ‘cratonic’ peridotite as a residue of Archean komatiite extraction, which has since cooled and exsolved clinopyroxene and garnet to become the common low-temperature, coarse-grained peridotite thought to comprise the bulk of the mantle lithosphere beneath the Archean Kaapvaal craton.