河湖水华预测方法研究

以水华预测研究方法的发展为主线,着重从机理生态建模和智能方法建模两方面对水华预测方法进行总结。通过对国内外常用预测模型的建立思路和应用实例进行分析和描述,比较了机理模型和智能模型的优缺点和使用范围。最后,针对目前水华预测存在的问题进行了分析,指出机理建模和智能方法的有机结合将为准确预测水华提供有效的途径。     

贵州铜仁卜口—松桃地区铅锌矿找矿方向分析

铜仁卜口—松桃地区地处湘—黔铅锌成矿带南段铜仁境内,大地构造位于上扬子地台南部被动边缘雪峰基底逆冲过渡带。区内铅锌矿床(点)分布受区域上大断裂铜仁—保靖深大断裂带与江口—松桃—花垣(湘)断裂所夹持,矿床(点)均沿早寒武世龙王庙期碳酸盐台地边缘相藻灰岩丘体分布。根据该区内1∶20万化探Pb、Zn异常,铅矿物重砂异常,含矿地层分布及沉积相等成矿指示标志,将研究区划分为3个找矿远景区,分别为嗅脑铅锌找矿远景区、牛郎铅锌找矿远景区、卜口场铅锌找矿远景区。     

九龙江流域气候变化特征及对藻华暴发的影响

针对气候变化对藻华暴发所起到的推动作用,在分析1954~2011年近58年九龙江流域气候变化特征的基础上,定性分析了气候因子波动对九龙江藻华暴发的影响。结果表明,九龙江流域年、季气温均呈增加趋势,且未来气温仍将持续升高;龙岩、漳州站年、冬季降水未来呈减少趋势;风速和日照时数都明显下降。这均对九龙江藻华暴发起到了一定的推动作用,未来有必要采取一定措施应对气候变化和藻华暴发。     

雷达遥感在环境保护工作中的应用

雷达遥感具有穿透力和全天候作业的优势,在环境保护领域中应用需求广泛。面对国家日益严峻的环保形势和最新发射的环境雷达卫星,急需系统介绍雷达遥感技术在环保领域中的应用。文章通过全面分析合成孔径雷达（SAR）在溢油、水华、土壤湿度、植被长势、生物量以及应急监测等环境保护中的应用,为已经发射的环境一号雷达卫星提供明确的应用目标,并为构建全天候、全天时的环境天地一体化监测体系提供重要的技术参考。     

ECO-HYDRAULICS TECHNIQUES FOR CONTROLLING EUTROPHICATION OF SMALL SCENERY LAKES-A CASE STUDY OF LUDAO LAKE IN SHANGHAI

The Ludao Lake with an area of 0.86 km2 and 50% water surface ratio, was taken as an example to study the eco-hydraulics techniques for preventing lake eutrophication. Besides external water inflow and outflow, the term related to internal local flow circulation was added in the continuity equation of two-dimensional horizontal hydrodynamic model, and further the hydrodynamic model was calibrated by the scenario of no water exchange. The velocity of 0.2 m/s was suggested to be the critical velocity of controlling algal bloom. To achieve the critical velocity in the whole lake, three factors were analyzed, which are wind, artificial external inflow augmentation and internal local flow disturbance by pump circulation. It is found that the role of wind can be disregarded. For the eco-hydraulics technique of external lake water inflow augmentation, the water flowing route should be firstly optimized, further, the lake inflow has a critical value under specified water level due to the narrow inlets, so the whole lake is difficult to reach the critical velocity to prevent algal bloom, and a combination of external inflow augmentation and internal local flowing disturbance should be considered. Simulation results show that the combination of external water inflow augmentation and internal local flow disturbance requires less eco-flow to achieve the global critical velocity than the sole internal local flow disturbance, for the Ludao Lake, the former requires total eco-flow of 25 m3/s, which reduces by 50% than the latter requiring total eco-flow of 52 m3/s.     

汉江中下游河流生态需水量探讨

在借鉴国内外河流生态需水量研究的基础上,对汉江中下游河流生态需水量计算进行了分析,重点分析了维护汉江中下游河流生态所需要的最小水量,探讨了河流自净需水量和防止水华发生的生态需水量,并初步探讨了三峡工程和南水北调中线工程建成后对汉江中下游生态需水量的影响。     

Multimodal microscopy by digital image processing

A matching algorithm is proposed for aligning microscope images obtained using different modalities, making use of cross-correlations of outputs from Prewitt's edge filter. Brightfield, phase contrast and differential interference contrast microscope images of algal and bacterial cells from an experimental, high-rate algal pond are used for illustration. The information content of multimodal images is explored using principal components analysis and colour displays, and an image which represents optical thickness is constructed digitally.     

Effect of algicides on urea fertilizer efficiency in transplanted rice

The effects of the algicides terbutryn and copper sulfate on the potential for reducing the gaseous loss of NH₃ from urea applied to rice were examined in experiments with 2 methods of N fertilizer management, 2 or 3 N rates, and 3 algicide treatments. The experiments were conducted during the 1986 dry and wet seasons in an experimental field at Pila, Laguna, Philippines.Copper sulfate had little effect as an algicide at the rate used, but terbutryn immediately reduced algal growth. The populations of species resistant to terbutryn probably increased, but terbutryn had no long-term effect on the total number of colony-forming units of algae. There was some evidence that terbutryn reduced photodependent N₂ fixation as estimated by acetylene reduction assay.Terbutryn, when applied with urea 10 days after transplanting, reduced the maximum floodwater pH by 0.9 units or more for 7 d in the DS and by about 0.5 units for 8 d in the WS. Terbutryn increased the ammoniacal-N (AN) concentration in the floodwater 100% or more in the DS and 60% in the WS. The combined effect of terbutryn on the floodwater pH and AN concentration was reduced photodependent NH₃ partial pressure (NH₃), about 25% in the DS and 38% in the WS. deceased     

Microcystin-LR toxicity on dominant copepods Eurytemora affinis and Pseudodiaptomus forbesi of the upper San Francisco Estuary

This study investigates the toxicity and post-exposure effects of dissolved microcystin (MC-LR) on the dominant copepods of the upper San Francisco Estuary (SFE), where blooms of the toxic cyanobacteria Microcystis aeruginosa coincide with record low levels in the abundance of pelagic organisms including phytoplankton, zooplankton, and fish. The potential negative impact of Microcystis on the copepods Eurytemora affinis and Pseudodiaptomus forbesi has raised concern for further depletion of high quality fish food. Response of copepods to MC-LR (MC) was determined using a 48-h standard static renewal method for acute toxicity testing. Following exposure, a life table test was performed to quantify any post-exposure impacts on survival and reproduction. The 48-h LC-50 and LC-10 values for MC were 1.55 and 0.14 mg/L for E. affinis; and 0.52 and 0.21 mg/L for P. forbesi. Copepod populations recovered once dissolved MC was removed and cultures returned to optimal conditions, suggesting no post-exposure effects of MC on copepod populations. Dissolved microcystin above 0.14 mg/L proved likely to have chronic effects on the survival of copepods in the SFE. Since such high concentrations are unlikely, toxicity from dissolved microcystin is not a direct threat to zooplankton of the SFE, and other mechanisms such as dietary exposure to Microcystis constitute a more severe risk.