Spatial and Temporal Patterns of Supply and Demand Balance of Water Supply Services in the Dongjiang Lake Basin and Its Beneficiary Areas

Water-related ecosystem services is a hot topic in ecological research. Water supply services are crucial to regional water cycles and water quantity balance. The Dongjiang Lake basin is a national priority river basin in China where ecological compensation pilot programs concerning water resources and water supply services are top priorities for ecosystem service protection. We analyzed spatial and temporal patterns associated with generation and use of water supply services in the Dongjiang Lake basin using the InVEST model, socio-economic data and water resource data. We found that between 1995 and 2010, water yield in the Dongjiang Lake basin and its beneficiary areas increased before declining, varying 9350-12 400 m³ ha^-1 y^-1; average water yield peaked in 2000. The spatial distribution patterns of water yield during these years are similar, progressively decreasing from upstream to downstream with a remarkable reduction in surrounding areas of city clusters. Average water consumption of the basin and its beneficiary areas ranged from 2900-4450 m³ ha^-1 y^-1 between 1995 and 2010; the spatial distribution patterns of water consumption during these years are similar, dropping gradually from urban construction land to its surroundings with a stronger gradient between urban and rural areas. More water was consumed on both banks and surroundings of the lake. From 1995 to 2010, water supply fell short of demand for urban construction land and its proximity as well as areas along the lake. Water supply services were able to satisfy needs in other regions. The Changsha-Zhuzhou-Xiangtan city cluster suffers from the most strained water supply.     

一种瓦片地图水印算法

首先分析了瓦片地图的特征,并依据这些特征提出了相应的水印算法要求;然后,在此基础上提出了针对瓦片地图特征的水印嵌入和检测算法;最后,对所提出的算法进行了实验验证。结果表明,该算法具有好的不可见性,能够有效抵抗加噪、压缩、拼接和格式转换等的攻击,可有效保护瓦片地图的版权。     

Characterization and source identification of trace elements in PM2.5 from Mira Loma, Southern California

Concentrations of thirty-five trace elements in ambient fine particulate matter (PM_2.5) were measured from September 2001 to January 2002 in Mira Loma, a semi-urban area in southern California. The most abundant species were found to be sulfur (S; 23% of the total trace element concentration), followed by Si, Fe, Ca, and Al (soil-related elements; 51% of the total). In general, total trace element concentrations were found to be significantly higher for the drier months of September and October, compared to December and January. Factor analysis, enrichment factor (EF) analysis, and ratio analysis (Al/Zn) revealed a significant contribution of soil-related sources to the ambient trace elements for PM_2.5 in the study area. Other important contributors to the trace elements in ambient PM_2.5 in Mira Loma included motor vehicle-related emissions (brake pads, lubricant oils, gasoline, and diesel combustion), secondary sulfates, sea salts, and biomass burning. The influence of sea salts on the study area was identified using a backward trajectory analysis.     

2007年7月18日济南大暴雨的β中尺度分析

利用1°×1°的NCEP再分析资料、地面逐小时的观测资料和红外云图,对2007年7月18日的济南大暴雨过程进行了详细的α中尺度分析,揭示了地面β中尺度气旋新生发展的一种物理机制,并重点分析了多尺度的积云并合过程对此次强降水形成的重要作用。研究结果表明:在一个已经发展成热的MαCS的左后侧出现的下沉冷出流在低层向西南方向扩散,与午后不断加强的西南暖湿气流共同作用增强了地面的斜压性,从而使地面辐合线上的气旋性扰动加强,并迅速新生发展出β中尺度气旋。在此次强降水过程中共经历了从γ中尺度对流单体到β中尺度对流云团,再到α中尺度对流云团,最后形成中尺度对流复合系统的4个多尺度积云并合过程,而地面β可尺度气旋在每一个阶段都扮演了非常重要的角色,它们既是β中尺度对流云团的组织者,同时也是α中尺度对流云团的组成者,α中尺度对流云团往往都由一个以上的β中尺度气旋组织而成,当β中尺度气旋出现遭遇、合并之时,对流云团和降水得以强烈发展。在济南强降水发生前的1个多小时内,其西南方边界层内不断出现β中尺度超低空西南急流,它促使这一区域内不断产生回波单体并在向东北方向移动的过程中迅速发展成强回波带,当济南北面的强回波南移与这一强回波带并合后快速发展产生强降水。     

浅谈基层气象局站管理

1基层气象局站状况概述 目前,大部分基层气象局站开展了地面测报、预报服务、气候生态监测、防雷防静电检测、人工影响天气等业务。人员多则十几个,少则八九个。具有业务多,人员少;兼职人员多,专职人员少;业务技能单一的多,综合型人才少,得过且过的多,勇于奉献的少的特点。     

地表负载及GPS测站分布对参考框架转换的影响分析

GPS数据处理通常采用Helmert七参数转换将瞬时站坐标转换到指定的框架下,但瞬时站坐标中尚未模型化的季节性地表负载会影响平移参数(地心运动)和尺度参数的估值,进而影响测站坐标;不均匀的测站分布会加剧这一影响.本文利用GRACE重力场系数仿真GPS地表负载的实验表明,基于网平移法采用实际的IGS站至少能够恢复90%的地心运动信号.地表负载及GPS实际测站的不均匀分布可以解释大约30%的GPS尺度的周年变化.相对于IGb08的所有框架站,目前采用91个全球均匀分布的核心站作为框架转换的基准是合理的.采用IGb08的所有框架站进行转换会导致U方向误差增加,特别是对框架站密集的欧洲区域(误差均值约为1mm).因此框架转换时,应尽量选取均匀分布的测站,同时不估计尺度参数.     

Remote Sensing Classification of Marsh Wetland with Different Resolution Images

Successful biological monitoring depends on judicious classification. An attempt has been made to provide an overview of important characteristics of marsh wetland. Classification was used to describe ecosystems and land cover patterns. Different spatial resolution images show different landscape characteristics. Several classification images were used to map and monitor wetland ecosystems of Honghe National Nature Reserve (HNNR) at a plant community scale. HNNR is a typical inland wetland and fresh water ecosystem in the North Temperate Zone. SPOT-5 10 m × 10 m, 20 m × 20 m, and 30 m × 30 m images and Landsat -5 Thematic Mapper (TM) images were used to classify based on maximum likelihood classification (MLC) algorithms. In order to validate the precision of the classifications, this study used aerial photography classification maps as training samples because of their high accuracy. The accuracy of the derived classes was assessed with the discrete multivariate technique called KAPPA accuracy. The results indicate: (1) training samples are important to classification results. (2) Image classification accuracy is always affected by areal fraction and aggregation degree as well as by diversities and patch shape. (3) The core zone area is protected better than buffer zone and experimental zone wetland. The experimental zone degrades fast because of irrational development by humans.     

鲁西南地区中小学生防震减灾科普认知及需求研究

为了解鲁西南地区中小学生对防震减灾科普的认知情况及需求,采用问卷调查等方法对鲁西南地区典型城市菏泽市开展了此次研究。研究发现,该地区中小学生总体上在地震科学常识、地震部门工作内容以及避震救助技能和识别谣言能力方面处于中等偏上水平,但在部分题目上也存在认知度较低的状况。在防震减灾科普的态度和需求偏好方面,97.04%的学生表示愿意参加防震减灾知识培训,大部分学生还是偏好传统媒体的渠道与形式。另外,在示范与非示范学校、城区与乡镇学校、中学与小学的对比中,发现了明显的群体差异性。本次调查对今后开展山东全省公众的防震减灾科普认知及需求状况研究提供了一定的依据和指导。     

钢质埋地管线在不同场地走滑断层下的可靠性研究

断层是造成埋地管线破坏的最重要原因。简化埋地管线小变形段为等效边界弹簧,对管材为三折线本构模型的等效边界弹簧本构方程进行了推导。基于ANSYS软件的有限元概率设计系统,考虑了管线外径、壁厚、内压、埋深及走滑断层位错量等随机输入变量,运用蒙特卡罗方法进行了软土、中等土、硬土3种场地走滑断层位错作用下钢质埋地管线的可靠性分析。研究发现:管线应变和失效概率随场地硬度提高显著增大,而应力增大不明显;三种场地走滑断层位错作用下,对应变的敏感性从高到底依次为走滑断层位错量、壁厚、埋深、内压。研究完善和丰富了该方面理论,为埋地管线抗震设计提供了一些合理且经济的建议。     

基于小波模极大值的地震信号去噪研究

小波分析在时域和频域具有很好的局部化特性,是分析和处理数字信号强有力的工具。文章将基于小波变换的模极大值去噪算法应用到地震信号的去噪研究中。首先依据相关理论验证算法的有效性,并对红山基准台的地震数据进行去噪分析处理。结果表明,去噪后的信号有效去除了大部分毛刺,去噪效果良好,噪声得到很好的抑制。为实现数据处理的界面化及易操作,在基于小波变换模极大值去噪算法比较分析的基础上,设计一个地震信号去噪系统分析界面,从而实现数据去噪的可视化应用。