Hydrodynamic effects of reconnecting lake group with Yangtze River in China

The hydrodynamic effects of reconnecting a lake group with the Yangtze River were simulated using a three-dimensional hydrodynamic model. The model was calibrated and validated using the measured water temperature and total phosphorous. The circulation patterns, water temperature, and water exchange conditions between sub-lakes were simulated under two conditions: (1) the present condition, in which the lake group is isolated from the Yangtze River; and (2) the future condition, with a proposed improvement ...     

磷在富营养化湖泊沉积物-水界面的循环

沉积物中部分固定的磷可通过分解或溶解作用而释放磷酸盐到沉积物间隙水中;再生的磷可能释放到上覆水体中,或在沉积物中作为一种自生相而再沉淀,或被沉积物的其它组分所吸附。本文描述了磷在沉积物-水界面的迁移过程,并对影响磷循环的因子及其磷自沉积物释放的机制作一简要概述。     

基于Landsat-TM影像的鄱阳湖典型湿地动态变化研究

利用分层分类法,通过对鄱阳湖典型湿地(蚌湖与赣江中支口三角洲)长序列秋季Landsat-TM影像进行解译分析,探讨了1991年~2008年间鄱阳湖典型湿地动态变化特征。结果表明分层分类方法能够有效地应用于Landsat-TM遥感影像的解译;从1991年到2008年蚌湖和赣江中支口三角洲湿地的植被面积分别增加18.56km2和6.01km2,其中赣江主支三角洲洲滩植被分布呈向湖体扩展态势。植被分布受水情影响比较大,蚌湖湿地的苔草面积与同时期水面积呈负相关性,而赣江主支三角洲湿地植被类型结构变化受水位影响也比较明显,苔草面积变化与秋季湖口水位表现为负相关,芦苇分布面积变化则与湖口水位变化趋势较为一致。     

Assessment of water quality in Lake Garda (Italy) using Hyperion

For testing the integration of the remote sensing related technologies into the water quality monitoring programs of Lake Garda (the largest Italian lake), the spatial and spectral resolutions of Hyperion and the capability of physics-based approaches were considered highly suitable. Hyperion data were acquired on 22nd July 2003 and water quality was assessed (i) defining a bio-optical model, (ii) converting the Hyperion at-sensor radiances into subsurface irradiance reflectances, and (iii) adopting a bio-optical model inversion technique. The bio-optical model was parameterised using specific inherent optical properties of the lake and light field variables derived from a radiative transfer numerical model. A MODTRAN-based atmospheric correction code, complemented with an air/water interface correction was used to convert Hyperion at-sensor radiances into subsurface irradiance reflectance values. These reflectance values were comparable to in situ reflectance spectra measured during the Hyperion overpass, except at longer wavelengths (beyond 700 nm), where reflectance values were contaminated by severe atmospheric adjacency effects. Chlorophyll-a and tripton concentrations were retrieved by inverting two Hyperion bands selected using a sensitivity analysis applied to the bio-optical model. The sensitivity analysis indicated that the assessment of coloured dissolved organic matter was not achievable in this study due to the limited coloured dissolved organic matter concentration range of the lake, resulting in reflectance differences below the environmental measurement noise of Hyperion. The chlorophyll-a and tripton image-products were compared to in situ data collected during the Hyperion overpass, both by traditional sampling techniques (8 points) and by continuous flow-through systems (32 km). For chlorophyll-a the correlation coefficient between in situ point stations and Hyperion-inferred concentrations was 0.77 (data range from 1.30 to 2.16 mg m^− 3). The Hyperion-derived chlorophyll-a concentrations also match most of the flow-through transect data. For tripton, the validation was constrained by variable re-suspension phenomena. The correlation coefficient between in situ point stations and Hyperion-derived concentrations increased from 0.48 to 0.75 (data range from 0.95 to 2.13 g m^− 3) if the sampling data from the re-suspension zone was avoided. The comparison of Hyperion-derived tripton concentrations and flow-through transect data exhibited a similar mismatch. The results of this research suggest further studies to address compatibilities of validation methods for water body features with a high rate of change, and to reduce the contamination by atmospheric adjacency effects on Hyperion data at longer wavelengths in Alpine environment. The transferability of the presented method to other sensors and the ability to assess water quality independent from in situ water quality data, suggest that management relevant applications for Lake Garda (and other subalpine lakes) could be supported by remote sensing.     

Shadow allometry: Estimating tree structural parameters using hyperspatial image analysis

We present a novel approach to generating regional scale aboveground biomass estimates for tree species of the Lake Tahoe Basin using hyperspatial (< 1 m² ground resolution) remote sensing imagery. Tree crown shadows were identified and delineated as individual polygons. The area of shadowed vegetation for each tree was related to two tree structural parameters, diameter-at-breast height (DBH) and crown area. We found we could detect DBH and crown area with reasonable accuracy (field measured to image derived cross correlation results were 0.67 and 0.77 for DBH and crown area, respectively). Furthermore, the counts of the delineated polygons in a region generated overstory stem densities validated to manually photointerpreted stem densities (photointerpreted vs. image-derived stem densities correlation was 0.87). We demonstrate with accurate classification maps and allometric equations relating DBH or crown area to biomass, that these crown-level parameters can be used to generate regional scale biomass estimates without the signal saturation common to coarse-scale optical and RADAR sensors.     

基于湖心水库的洞庭湖治理新理念

基于"湖心水库"的基本思想,提出"变湖为库、清污分流、蓄洪排污、流水不腐"的洞庭湖全新治湖理念。利用二维水动力模型,分析了西洞庭湖湖心水库建设对行洪、补水、水环境的影响,探讨其运用的可行性。结果表明:湖心水库的分洪蓄水能有效降低西洞庭湖内洪峰水位,缓解湖区的防洪压力;湖心水库的补水在枯水期能有效抬升开湖航道水位,改善通航条件;同时湖心水库的补水增大了开湖航道及湘江尾闾航道内水流流速,加速了水体交换,对洞庭湖水环境有利。     

基于鄱阳湖地域文化特色文创产品“活态化”设计

目的 致力于鄱阳湖地域文化特色产品的“活态化”设计研究,提出具有创新性的鄱阳湖文创产品设计方法,从而提升产品文化内涵,弘扬鄱阳湖地域文化。方法 建立了与鄱阳湖地域文化特色产品对应的设计模型图,并以具体的设计实例进行了展示和验证,使文创产品既拥有优质的视觉效果时又兼具产品的日常使用价值和良好的使用体验感,既具有文化艺术性又注重了“以用为本”的设计理念。着眼于鄱阳湖地域文化特色文创产品“活态化”视角,遵循寻找活态化转换的契合点、注重鄱阳湖地域文化原味的传达、重建文化认同感、树立文化传播观的设计原则,通过案例的结合运用为鄱阳湖文化创意产品的设计提供具体可行的方法策略。结论 以鄱阳湖文化创意产品进行实践论证,为当今文创产品设计提供有参考价值的资料,使鄱阳湖物质文化得以保全,非物质文化得以“活化”,最终实现文化传承与文创产品创新的双赢。     

综合水质指数法对滴水湖水质的评价

正确认识和评价滴水湖水质的变化特征是进行水环境管理的前提。通过监测2006-2009年滴水湖水体溶解氧(DO)、高锰酸盐指数(CODMn)、五日生化需氧量(BOD5)、氨氮(NH3-N)以及总磷(TP)等5种主要污染因子的月度变化,利用综合水质污染指数法进行了比较评价。结果表明2006-2009年间滴水湖湖区整体水质已达到地表水IV类水标准(GB 3838—2002),水质状况有明显好转;有机污染物和总磷是滴水湖水体主要污染因子。     

Start-Up and Optimization of the Ozone Disinfection Process At the Sebago Lake Water Treatment Facility

The purpose of the ozone process at the Sebago Lake Water Treatment Facility (SLWTF) is to meet the disinfection requirements of the Surface Water Treatment Rule with ozone and without filtration. The start-up experience is presented including initial operating strategies to meet disinfection requirements. An ozone system performance test conducted during the first month of plant operation is described and the results are reviewed. The initial and proposed activities of an ozone optimization project are discussed.     

兑卤法生产过程中兑卤比对氯化钾收率的影响

青海察尔汗盐湖是中国最大的可溶性钾镁盐矿床。以相图理论为依据，通过对青海察尔汗盐湖兑卤法生产氯化钾过程进行相图分析，并根据不同兑卤比的条件下计算氯化钾的收率，分析和探讨了兑卤比对氯化钾收率的影响，提出了确定适宜兑卤比应该严格遵循“兑卤结晶、控速分解”的原则，确定了最佳兑卤比（质量比）的范围是1：（1．0—1．3）。