运城盐湖藻类植物资源研究进展

盐湖是湖泊的一种极端类型,含有特殊的生物资源。文章论述了运城盐湖藻类植物资源的研究进展及目前面临的问题和今后研究的发展方向。     

人工湿地系统改善滇池入湖水水质

在代表性高原湖泊-云南省滇池湖区进水口附近构建人工湿地,考察了不同植物（紫叶美人蕉（Canna indica L.）、水葱（Scirpus tabernaemontanl Gmel.）、水葫芦（Eichornia crassipes（Mart.）Solms.）、水芹菜（Oenanthe ja vania（Bl.）DC.）、菖蒲（Acorus calamus L.）、芦苇（Phragmitas communis Trin.））的表流人工湿地与潜流人工湿地的处理效果,试验水力负荷为12 cm/d,水力停留时间（HRT）为3 d。结果表明：紫叶美人蕉潜流湿地、水葱潜流湿地对TP和TN的去除效果运行稳定,前者对TN、TP的去除率分别为70.60%、88.27%,后者为73.33%、83.87%;水芹菜湿地对TP去除效果波动大,均值为84.35%;菖蒲潜流湿地和芦苇潜流湿地对TN的去除率均值分别为71.73%和74.33%,对TP去除效果波动较大。水葫芦、芦苇湿地处理效果（温度较高的夏、秋季节）优于其余植物类型湿地。随着植物进入休眠期,两类人工湿地对TP、TN的去除效率均降低。各植物两种类型人工湿地对COD均有较好的去除效果,数值均在78%以上,出水浓度低于57 mg/L。     

洞庭湖区间径流模拟

洞庭湖对长江中游洪水有着重要的调蓄作用,其调蓄能力不仅受到湖区面积和容积的限制,还受到其上游四水来水和区间洪水的影响。四水来水可通过水文控制站实测,但是区间洪水难以估计。在洞庭湖洪水模拟中通常忽略区间洪水或做简单概化处理,从而影响了洪水模拟精度。本研究以洞庭湖区间洪水模拟为目标,根据洞庭湖区间流域的特点,将洞庭湖区间划分为山丘区与堤垸区,根据其不同的产汇流特点,分别采用分布式水文模型GBHM和基于栅格的新安江模型进行模拟,并利用洞庭湖水量平衡对模拟结果进行间接验证,结果显示区间洪水模型具有较高的模拟精度。     

洞庭湖植被对降水的响应

We analyzed the Normalized Difference Vegetation Index (NDVI) from satellite images and precipitation data from meteorological stations from 1998 to 2007 in the Dongting Lake wetland watershed to better understand the eco-hydrological effect of atmospheric precipitation and its relationship with vegetation. First, we analyzed its general spatio-temporal distribution using its mean, standard deviation and linear trend. Then, we used the Empirical Orthogonal Functions (EOF) method to decompose the NDVl and precipitation data into spatial and temporal modes. We selected four leading modes based on North and Scree test rules and analyzed the synchronous seasonal and inter-annual variability between the vegetation index and precipitation, distinguishing time-lagged correlations between EOF modes with the correlative degree analysis method. According to our detailed analyses, the vegetation index and precipitation exhibit a prominent correlation in spatial distribution and seasonal variation. At the 90% confidence level, the time lag is around 110 to 140 days,which matches well with the seasonal variation.     

以区域统筹为核心,推进环淀山湖地区合作发展

推进长三角地区的合作发展,是《环淀山湖地区概念规划》的出发点。在研究处于沪苏两地的淀山湖地区的发展现状基础上,从区域统筹的角度,探讨如何在功能、产业、布局等规划中推进地区合作,为长三角地区合作发展积累经验,推进区域共融。     

Determination of major and trace elements in sediments of lake Eğridir,Turkey

Some major and trace element contents of sediment samples from four sampling stations in Lake E?ridir have been analysed by flame atomic absorbtion spectrometry. The mean levels (μg.g^‐1) of Ca, Mg, Cu, Mn, Pb, Fe, Zn, Ni, Cd for each station and the mean level of each metal for the four sampling stations together with the statistical evaluation of data are listed. The results indicate that, although the amounts of these metals fall within the range of unpolluted sediments, the fact that the samples from the second and third stations contained higher metal levels indicate the effect of some pollution in these areas.     

Nitrification in modified sewerage stabilisation ponds prior to discharge into the Ugandan side of Lake Victoria

Large volumes of wastewater in the Ugandan capital Kampala have seriously polluted Lake Victoria, from which the city draws its freshwater. Untreated effluent drains directly into this lake. In tropical temperatures, oxidation ponds are used for wastewater treatment, especially for organic matter. This technology should be the focus of work to improve its efficacy, and thus to secure the sustainability of the lake and its freshwater fish which are marketed worldwide. A pilot scale plant was set up comprising an anaerobic tank, a facultative pond and four fibre‐glass maturation tanks. The total nitrification rates in the tanks T₁–T₄ were 5.5, 7.5, 10.1 and 6.4 (±0.4) mg‐N/l/day, respectively. For more efficient wastewater treatment stabilisation pond systems, a modification similar to that in T₃ should be considered. T₃ was constructed with biofilm attachment surfaces in a manner which allowed effluent to be channelled round them, contrary to direct T₁ flow which is currently in use.     

Lake responses following lanthanum-modified bentonite clay (Phoslock) application: An analysis of water column lanthanum data from 16 case study lakes

Phoslock^® is a lanthanum (La) modified bentonite clay that is being increasingly used as a geo-engineering tool for the control of legacy phosphorus (P) release from lake bed sediments to overlying waters. This study investigates the potential for negative ecological impacts from elevated La concentrations associated with the use of Phoslock^® across 16 case study lakes. Impact-recovery trajectories associated with total lanthanum (TLa) and filterable La (FLa) concentrations in surface and bottom waters were quantified over a period of up to 60 months following Phoslock^® application. Both surface and bottom water TLa and FLa concentrations were <0.001 mg L⁻¹ in all lakes prior to the application of Phoslock^®. The effects of Phoslock^® application were evident in the post-application maximum TLa and FLa concentrations reported for surface waters between 0.026 mg L⁻¹–2.30 mg L⁻¹ and 0.002 mg L⁻¹ to 0.14 mg L⁻¹, respectively. Results of generalised additive modelling indicated that recovery trajectories for TLa and FLa in surface and bottom waters in lakes were represented by 2nd order decay relationships, with time, and that recovery reached an end-point between 3 and 12 months post-application. Recovery in bottom water was slower (11–12 months) than surface waters (3–8 months), most probably as a result of variation in physicochemical conditions of the receiving waters and associated effects on product settling rates and processes relating to the disturbance of bed sediments. CHEAQS PRO modelling was also undertaken on 11 of the treated lakes in order to predict concentrations of La³⁺ ions and the potential for negative ecological impacts. This modelling indicated that the concentrations of La³⁺ ions will be very low (<0.0004 mg L⁻¹) in lakes of moderately low to high alkalinity (>0.8 mEq L⁻¹), but higher (up to 0.12 mg L⁻¹) in lakes characterised by very low alkalinity. The effects of elevated La³⁺ concentrations following Phoslock^® applications in lakes of very low alkalinity requires further evaluation. The implications for the use of Phoslock^® in eutrophication management are discussed.     

恢复·重生·延续——成都北湖湿地公园景观修复与再生

湿地公园是一类兼有物种及栖息地保护、生态旅游和生态环境教育功能的湿地景观区域,类似于小型保护区,但又不同于自然保护区和一般意义的公园。湿地公园的建设是推动区域社会经济可持续发展的"催化剂",也是湿地保护和保育理论的实践成果[1]。本文结合成都北湖湿地公园景观修复与再生的案例,深入探讨了如何利用现有或已退化的湿地资源,按照生态学的规律来规划、改造和建设,恢复其生态系统,突出其主题性、自然性和生态性三大特点,将北湖湿地公园建成集生态保育、生态旅游、科普教育、湿地科研等多种功能为一体的生态型主题公园。     

Comparisons of the L- and LH-moments in the selection of the best distribution for regional flood frequency analysis in Lake Urmia Basin

Design flood estimation is an important task that is required in the planning and design of many civil engineering projects. Finding the most suitable distribution to flood samples and selecting the appropriate parameter estimation method are of great importance for flood frequency analysis. In this study, L-moments and LH-moments have been used to characterise the upper part of distributions and larger events in flood data. Three extreme value distributions, that is, generalised extreme value (GEV), generalised logistic (GLO) and generalised Pareto (GPA), through different levels of the LH-moments have been applied to describe the annual maximum flood data obtained from 34 sites in Lake Urmia Basin, northwest Iran. The performances of these distributions have been assessed by evaluating the relative root-mean-square error and the minimum L-kurtosis difference criterion. The result shows that the LH-moments are more efficient for obtaining improved values of flood peaks than the L-moments. For the upper part of distributions, the GEV distribution using the L2-moment is the best, followed by the GLO distribution using the L1-moment and the GPA distribution using the L3-moment. The GLO distribution using the L-moments methods is the best among all distributions for a complete data series.