Cladoceran and diatom evidence of lake-level fluctuations from a Finnish lake and the effect of acquatic-moss layers on microfossil assemblages

We studied Holocene lake-level fluctuations from a small lake, Iso Lehmälampi, southern Finland, utilizing cladoceran and diatom analyses. We report data from a sediment core (A) taken from the deepest part of the lake (8.1 m) where two layers of moss, mixed with gyttja, were found. These layers were formed in situ during the early Holocene (1. ca. 8100-7900, 2. ca. 7300 BP). Lake-level fluctuations were inferred also from another core C, which did not have moss layers. According to the ratio of planktonic/littoral Cladocera, the water level was high around 9000 BP and started to fall before 8000 BP. The lowering continued until 7000 BP and the moss layers were formed during this lowering. Water level was high again ca. 6000 BP and lowered towards ca. 4000 BP. The late Holocene is characterized by several rapid fluctuations of lake-level. The ratio of planktonic/littoral Cladocera and the diatom species composition in core A showed drastic changes between the moss layers and the non-moss gyttja sections of the core. We suggest that they reflect changes in sedimentary facies between the local moss environment and the pelagic bottom. Thus, cores which contain moss layers may lead to erroneous interpretations of lake-level fluctuations.     

城市地面沉降与地下水位变化关系的数学模拟

根据滨海平原多个城市多年城市地表沉降及城市地下水位监测资料，系统地分析了地下水位变化与城市地衾沉降的关系，并利用计算机模拟的方法，给出了该类城市地表沉降的数学模型。     

New approaches to integrated quality assessment of lakeshores

The EU Water Framework Directive (WFD) requires the ecological assessment of water bodies. Since the littoral zones and the lakeshores are part of lakes as water bodies as defined by the WFD, a new scheme for ecological quality assessment of lakeshores should be established. It is proposed that this scheme should go beyond the formal requirements of the WFD, as it includes aspects of nature conservancy, landscape protection, and regional planning and development. Some of these aspects are subject to other EU legislation (e.g. Habitats Directive) and some are subject to national legislation. Ten general Quality Elements (QEs) are proposed, which can be refined and reified through several levels of detail, depending on the specific aims of a study. A list of eleven topics, which should be discussed in the establishment of the lakeshore quality assessment scheme, is given. The more complex ones are the implementation of other EU legislation, the definition of lakeshore types and reference conditions, the stipulation of best aggregation procedures, and a better understanding of the significance of hydrological and morphological impacts on the biota.     

滨海城市环境工程地质问题发育特点分析

本文分析了我国滨海城市环境工程地质问题的主要类型,研究了环境工程地质问题的发育特点。     

A preliminary study on the distribution and genesis of underground brine in the littoral plain of Laizhou Bay in the Bohai Sea

Quaternary underground brine in the littoral plain region of the Bohai coast is new type littoral facies evaporation ore deposit in liquid state . This model of " littorally- forming brine " is based on study of the distribution, depositional environment, forming / storing process, and genesis of underground brine in the coast of Laizhou Bay . Essential conditions for genesis of brine are arid and semiarid climate , abundant sources of ancient seawater, and geological and geomorphological environment of wide tidal beach along a coast. The process of underground brine genesis may be : seawater/tidal beach-evaporation and concentration-seeping and accumulation- brine/tidal beach - burial (evolution of the sea- land )- underground brine .Underground brine is characterized by high content of chemical elements, shallow burial depth and easy exploitation . The process of extracting salt from underground brine present in the tidal flat is incomparably superior to that of producing salt from seawater, and has b     

东南沿海地区震级与震中烈度的统计关系

从文献中按一定原则挑选出64例地震资料,通过回归分析,统计出了我国东南沿海地区震级与震中烈度之间的经验公式。通过与其它经验公式的比较,该经验公式对于东南沿海地区具有更好的适用性,并应用该公式得到了福建省泉州市余震的抗震设防烈度。为考虑主余震共同影响下的震害预测方法的研究提供了依据。     

海湾围填海对滩涂湿地生态服务累积影响研究——以福建兴化湾为例

以福建兴化湾为例,选用1959年海图、1986年和2000年遥感影像数据及围填海相关规划等为基本信息源,将研究区划分为农田、养殖池、盐田、草林地、裸地、岛屿及滩涂7种生态系统类型.采用GIS技术分析兴化湾不同时期由于围填海所造成的各生态系统类型面积变化,并借鉴Costanza等研究的生态服务功能单位价值系数,评估围填海对滩涂湿地生态服务造成的累积影响.在1959-2000年,兴化湾滩涂面积减少了21.35%,生态服务的年总价值由1959年的5.31×109元降至2000年的4.45×109元,损失达8.63×109元,损失幅度为16.35%;2000-2020年,围填海相关规划的实施将导致兴化湾滩涂面积急剧下降,生态服务的年总价值由2000年的4.45×109元降至 2020年的3.48×109元,损失达9.68×108元,损失幅度为21.77%,其损失量和损失幅度均高于1959-2000年40余年的损失.     

豫西济源地区中三叠世油房庄组遗迹组构及其环境解释

河南济源地区中三叠世油房庄组发育了一套滨浅湖相的砂泥岩沉积，在该组上段紫红色与黄绿色砂泥岩沉积中发现了大量的遗迹化石。其中高能砂质滨湖沉积中识别出6种遗迹组构:斑状生物扰动组构、Skolithos isp.-Planolites montanus组构、Skolithos verticalis组构、Planolites beverleyensis组构、Skolithos isp.组构和Palaeophycus annulatus 遗迹组构，它们可归入陆相Skolithos遗迹相；极浅湖泥岩夹粉砂岩沉积中识别出3种遗迹组构: Skolithos linearis遗迹组构、Taenidium barretti遗迹组构和植物根迹组构，它们可归入陆相Scoyenia遗迹相。     

Wetland-DNDC模型模拟密云水库消落带甲烷排放（英文）

淡水生态系统消落带是甲烷排放研究的热点区域,但相关数据的积累十分薄弱。本研究利用静态箱法和过程模型(Wetland-DNDC),研究了密云水库消落带CH_4排放通量。在消落带的三个水位梯度:即永久淹水深水区、永久淹水浅水区和季节性淹没区,选取九种典型植被进行CH_4排放通量的野外监测和模型模拟。结果表明:在三个水位梯度上,Wetland-DNDC模拟值与实测值拟合度分别为0.89、0.81和0.49(p0.001)。Wetland-DNDC模型抓住了水位波动、土壤温度和土壤有机质含量等因子对消落带CH_4排放的影响规律,成功地在时间、空间和数量级上对消落带CH_4排放通量进行了模拟,为评估水库温室气体排放提供了新方法。在密云水库生长季模拟的消落带CH_4总排放量为15.1 g CH4·m~(-2),在数量级上,与国内其他类型湿地消落带CH_4排放具有可比性。据此推算Wetland-DNDC模型适用于水库或湖泊消落带区域甲烷排放的模拟,对植被模块进行改进可以进一步提高模型模拟的准确性。