基于Landsat-8数据的博斯腾湖透明度反演

透明度是湖泊水体重要的物理参数之一,是水体光学组分的综合反映,对研究湖泊生态环境具有重要科学意义。目前,利用遥感技术手段对博斯腾湖进行大范围、连续的水透明度监测研究相对较少。基于湖泊透明度实测值、对应点的光谱数据和Landsat-8遥感影像,分析透明度敏感波段及其组合,建立博斯腾湖水体透明度遥感反演模型。实测光谱分析结果显示波段比值运算和和差组合运算的敏感性较高,相关系数可达0.8以上;Landsat-8 OLI遥感数据分析结果得到波段比值(近红外波段和蓝色波段的比值)的敏感性较高,相关系数可达0.7;基于OLI近红外波段B5和蓝色波段B1比值的线性模型反演效果最好,精度较高,且稳定性较好。博斯腾湖透明度在200 cm左右,透明度由西向东先升高再降低,呈带状分布。     

LandSat TM/OLI遥感影像在玛多县近30年小型湖泊面积监测中的应用

气候变化会引起一系列的生态问题,其中湖泊面积变化是其问题之一.采集1990～2018年近30年间的LandSat TM/OLI遥感影像,以玛多县小型湖泊星星海、阿涌吾儿马错、龙日阿错、阿涌该马错为研究区,利用改进后的归一化水体指数对玛多县小型湖泊进行水体的提取.借助湖泊变化幅度以及湖泊演变强度等指数,综合分析了玛多县小...     

基于Landsat8数据的东道海子叶绿素a的遥感反演和监测研究

水质监测是水质评价与水污染防治的主要依据,而叶绿素a是进行水质监测最重要的参数之一。为了研究东道海子叶绿素a的多光谱波段分析技术,形成具有可操作性的中低分辨率多光谱水质遥感监测方法和技术,本文以Landsat8 OLI为数据源,研究叶绿素a的光谱特征,确定叶绿素a遥感定量监测的最佳波段,并结合地面实测数据,建立叶绿素a的遥感估测模型,同时对模型进行精度评价和应用;采用Carlson营养状态指数(TSI)方法,以叶绿素a浓度为指标,进行湖泊水体营养状况评价。结果表明:Landsat8 OLI数据的700 nm~800 nm波段适合用来监测内陆水体中叶绿素a浓度,尤其是叶绿素a浓度较高的水体;Landsat8数据11个波段中,前5个波段适合用来反演水体中的叶绿素a浓度,得到最佳的回归模型;从叶绿素a浓度及富营养化空间分布上看,东道海子中游区域的分布均明显大于上游和下游区域,总体上由南向北逐渐减小;从时间上看,东道海子水质呈好转趋势,中下游区域好转尤为明显。该研究结果对内陆湖泊水质持久监测提供有效手段。     

水面实测遥感光谱数据的叶绿素a反演模型构建—以太湖为例

叶绿素a遥感反演的关键是建立遥感数据和叶绿素含量的定量关系。本文根据2007年11月在太湖实测的水体反射光谱及实验室分析得到的叶绿素浓度数据,对太湖水体反射光谱特征与叶绿素浓度之间的关系进行分析和建模。研究结果表明：687nm附近反射峰位置对叶绿素浓度有很好的指示作用,在太湖水体叶绿素浓度的估测模型中,反射峰位置的指数模型要优于线性模型;叶绿素a浓度与684nm和633nm附近的一阶微分有很好的相关性,利用R’684和R’633所建叶绿素a浓度反演模型的估算精度R2分别达到0.89和0.91。     

湖泊水环境预测及污染的综合治理措施

湖泊水环境污染问题是世界性的环境问题，本文根据湖泊水的特点及水污染的现状，主要论述了湖泊水体的污染评价方法，及水环境预测方法在湖泊水体治理中的重要作用，并综合分析了富营养化的湖泊水治理措施。     

太白山自然保护区湖泊水质状况及季节差异

通过对太白山山顶大爷海、二爷海、三爷海与玉皇池等4个湖泊解冻期与冰冻期水体17项常规指标监测,分别利用单项污染指数与综合污染指数对太白山山顶湖泊水质现状进行评价,并对不同时期水质差异进行分析。结果表明太白山山顶湖泊总氮超标严重,总磷、氨氮与汞含量也出现超标现象,其他指标均符合我国地表水环境质量Ⅰ类标准。综合污染指数显示4个湖泊均属于清洁水体,清洁度排序为玉皇池三爷海二爷海大爷海。冰冻期湖泊水质优于解冻期。     

网络版摘要

白洋淀夏季叶绿素a与环境因子的相关性研究 白洋淀 草型湖泊 叶绿素a 环境因子 相关性 采用回归统计方法分析白洋淀水产养殖区水质监测数据,研究白洋淀浅水草型湖泊夏季水体叶绿素a与环境因子的相关性,建立相应的回归方程。研究表明,白洋淀浅水草型湖泊水体叶绿素a含量与水温、pH、DO、COD、高锰酸盐指数呈显著正相关;叶绿素a与NH4^＋-N、NO3^-／-N呈负相关,与NO2／-N无明显相关,与TN无显著正相关;而叶绿素a与TP呈一定的正相关,白洋淀浅水草型湖泊可能是磷限制性湖泊。     

水体富营养化

水体富营养化是指氮、磷等植物营养物质含量过多所引起的水质污染现象。当过量营养进入湖泊、水库、河口、海湾等缓流水体后,水生生物特别是藻类将大量繁殖,使水中溶解氧含量急剧下降,以致影响到鱼类等的生存。在自然条件下,湖泊从贫营养湖→营养湖→沼泽→陆地的演变过程极为缓慢;人类的活动将大量工业废水和生活污水以及农田径流中的植物营养物质排入湖泊等水体后,将大大加速水体的富营养化进程。水体富营养化后,由于浮游生物大量繁殖,往往呈现蓝色、红色、棕色、乳白色等。这种现象在江河湖泊中称为水华,在海中则叫做赤潮。     

青藏高原湖泊变化监测研究

文章采用多源多时相遥感影像为数据源,以Arc GIS、Erdas、Envi等遥感地信软件为信息提取处理平台,对青海可可西里国家级自然保护区高原湖泊进行遥感监测分析。结果显示:1该区土地利用/覆盖类型主要为草地、水域湿地、人工用地和未利用土地,其中草地为主要类型,占区域总面积的68.04%;2调查区以中、小湖为主,共占全区湖泊总数量的91.46%,其中小湖泊占71.95%,面积大于1km2的湖泊总面积3 018.85km2;32006~2013年间,区域内湖泊数量总体上呈增加趋势,其中较大湖泊保持不变、大湖泊增加1个、中湖泊减少2个、小湖泊增加3个。西北部的勒斜武担湖和东北部的库赛湖变化较为显著。     

盐碱地养鱼的水质改良

报道了盐碱地池塘、水库、湖泊养鱼中的水质改良技术。池塘水质改良措施主要为加注淡水、施用有机肥、注水与施肥相结合、改造盐碱土质、控制生石灰用量及合理注排水 ;水库、湖泊等大水面水质改良的主要措施是引淡水和增施肥料 (有机肥和化肥 )。     

Longitudinal‐Vertical Hydrodynamic and Turbidity Simulations for Prediction of Dam Reconstruction Effects in Asian Monsoon Area1

Abstract: This research investigates possible impacts of enlarged water body according to dam reconstruction on the hydrodynamics and water quality of the reservoir using a laterally averaged, two‐dimensional hydrodynamic and transport model, CE‐QUAL‐W2. The lake was formed by the artificial dam in 1983 for agricultural water supply and is currently under consideration of reconstruction so as to expand the volume of reservoir for flood control as well as water supply in downstream areas. To calibrate and validate the model, field‐collected data were compared with model predictions for water level fluctuations and water temperature during the years of 2001 (from January to December) and 2003 (from March to November). The model results showed a good agreement with field measurements both in calibration and verification. Utilizing the model, impacts of dam reconstruction on the thermal hydrodynamics and turbid current were predicted. From the model results, dam reconstruction limited the depth of thermal stratification below 10 meter and formed steep temperature gradient between epilimnion and hypolimnion. The restricted thermal stratification persisted up to the end of September. This result indicated that thermal stratification would become stronger during summer and stay longer after dam reconstruction. In addition, the restricted thermal stratification caused vertical circulation of water mixing lower than 10 meter and isolated the upper water layer from the lower water layer which increased the volume of hypolimnetic water with low temperature. The vertical circulation near the surface also mitigated propagation of density plume within the depth of 10 m which would remain the hypolimnetic water clean.     

TEMPERATURE EFFECTS ON GREAT LAKES WATER BALANCE STUDIES1

ABSTRACT. Beginning of month water temperature profiles are estimated for each lake. These water temperature profiles along with surface water temperatures are used to determine the effects of thermal expansion and contraction of water on the net basin supply values obtained from water balance studies using end of month lake levels. It is demonstrated that net basin supply values (equivalent to precipitation on the lake minus the evaporation from the lake plus the runoff into the lake) obtained from water balance studies without accounting for the thermal expansion and contraction of water may be in error by as much as 100 percent during some months for each lake.     

LAKE EVAPORATION STUDIES USING SATELLITE THERMAL INFRARED DATA1

Thermal infrared radiation data were acquired by the Heat Capacity Mapping Mission (HCMM) satellite over the surface area (385 km²) of Utah Lake during periodic overpasses in 1978 and 1979. The thermal infrared data were converted to lake surface temperatures which were subsequently used in correlations with lake evaporation. Correlations between HCMM surface temperature and pan-derived evaporation exceeded r = 0.90 when HCMM night and day/night average temperatures and two-day average evaporation values were tested. Similar regression studies were done using monthly data from a conceptual evaporation model and the evaporation pan versus monthly HCMM temperature data. In this test both the HCMM day and night monthly temperature versus the monthly model or pan evaporation had correlations exceeding r = 0.95. Empirical estimates of both short and long term lake evaporation using satellite thermal infrared data seem feasible. Attempts to use the HCMM thermal information as direct input to a theoretical approach to calculating evaporation were inconclusive; however, a definite potential seems to exist.     

Lake Temperature and Ice Cover Regimes in the Alaskan Subarctic and Arctic: Integrated Monitoring,Remote Sensing,and Modeling1

Arp, C.D., B.M. Jones, M. Whitman, A. Larsen, and F.E. Urban, 2010. Lake Temperature and Ice Cover Regimes in the Alaskan Subarctic and Arctic: Integrated Monitoring, Remote Sensing, and Modeling. Journal of the American Water Resources Association (JAWRA) 46(4): 777-791. DOI: 10.1111/j.1752-1688.2010.00451.x Abstract: Lake surface regimes are fundamental attributes of lake ecosystems and their interaction with the land and atmosphere. High latitudes may be particularly sensitive to climate change, however, adequate baselines for these lakes are often lacking. In this study, we couple monitoring, remote sensing, and modeling techniques to generate baseline datasets of lake surface temperature and ice cover in the Alaskan Subarctic and Arctic. No detectable trends were observed during this study period, but a number of interesting patterns were noted among lakes and between regions. The largest Arctic lake was relatively unresponsive to air temperature, while the largest Subarctic lake was very responsive likely because it is fed by glacial runoff. Mean late summer water temperatures were higher than air temperatures with differences ranging from 1.7 to 5.4°C in Subarctic lakes and from 2.4 to 3.2°C in Arctic lakes. The warmest mean summer water temperature in both regions was in 2004, with the exception of Subarctic glacially fed lake that was highest in 2005. Ice-out timing had high coherence within regions and years, typically occurring in late May in Subarctic and in early-July in Arctic lakes. Ice-on timing was more dependent on lake size and depth, often varying among lakes within a region. Such analyses provide an important baseline of lake surface regimes at a time when there is increasing interest in high-latitude water ecosystems and resources during an uncertain climate future.     

SEMI-INFINITE SOLID MODEL FOR PREDICTION OF TEMPERATURE IN DEEP RESERVOIRS AND LAKES1

ABSTRACT: A lake or reservoir, heated mainly through the air-water interface, is visualized as a solid which is bounded by the interface plane (x = 0) and extends to infinity in the positive x-direction. Analytical expressions give the surface temperature, the temperature profile (with depth) and the position of the thermocline as a function of time (Julian Day). Preliminary model results indicate that the general shape of the temperature profile and the position of the thermocline are influenced primarily by the air-water heat exchange and the time lapse since an isothermal condition existed in the water body.     

ESTIMATING EVAPORATION FROM UTAH'S GREAT SALT LAKE USING THERMAL INFRARED SATELLITE IMAGERY1

ABSTRACT: Water surface temperatures can be obtained from satellite thermal remote sensing. Landsat and other satellites sense emitted thermal infrared radiation on a regular basis over much of the earth's surface. Evaporation is accomplished by the net transport of mass from the water surface to the atmosphere. The evaporative transfer predominantly determines the water surface temperature. Hence, there should be good correlations between evaporation and surface temperatures. Previous investigations on Utah Lake with satellite-derived temperatures and pan- and model-derived evaporation values have produced good correlations. However, more study was required with additional satellite data and evaporation measurements for saltwater conditions. The applicability of this method for estimating evaporation on Utah's Great Salt Lake was of particular interest at this time because of the unprecedented rise of this terminal lake. Satellite thermal data and evaporation data from four different years were obtained for the Great Salt Lake and the surrounding region. More than 350 correlation and linear regression analyses were performed on the temperature and evaporation data. The lake salt concentrations were also factored into the analyses in several different ways. The correlation results were generally very good and a methodology for using satellite-derived water surface temperatures along with salt concentrations was developed to estimate evaporation.     

FIELD TESTING OF AN ICE-PRESERVING WINTER LAKE AERATION SYSTEM1

ABSTRACT: Artificial aeration is used to prevent winter fish kills due to oxygen depletion in ice-covered lakes. Conventional aeration by air bubble plumes and other techniques usually mixes the water column and produces hazardous open water in the ice cover. A non-mixing winter lake aeration system which creates a fish refuge was designed and field tested to oxygenate the water and maintain water temperature stratification in a lake such that no open water is created. The system uses a cascade aerator and has a design discharge and dissolved oxygen input rate of 85 1/s and 70 kg/d, respectively. Aerated water is discharged near mid-depth with minimum disturbance of the ambient water through a specially designed diffuser. The system was tested in a shallow 3 m deep lake of 17 ha surface area during two winters and was found to perform as expected. Significant photosynthetic production of dissolved oxygen under the ice-cover was also observed during snow-free periods.     

A FICKIAN ANALYSIS OF LAKE SEDIMENT UPSURGE1

ABSTRACT. The fundamental hypothesis of this paper is that the stratified-mixed states which occur annually in lakes play a dominant role in the movement of nutrient-rich material from the lake bottom upward into the water column. The stratified-mixed history has been used previously to develop a Fourier type, semi-infinite slab energy model to represent the lake surface temperature, thermal profile, and thermocline position with Julian day (Thibodeaux, 1975). The present paper extends the semi-infinite slab idea to include a Fickian type model for the upsurge of nutrients from the sediment-water interface upward. Relations will be developed for the rate of nutrient upwelling into the epilimnion and the photoactive zone of a lake. A lake time constant emerges from the model equations. This constant is thought to be important in predicting the likelihood of a fall algal bloom. Results of model verification attempts on three lakes are presented.     

LAKE HURON SURFACE WATER TEMPERATURE MAY – NOVEMBER, 19661

ABSTRACT. Data from seven vessel cruises from late May to early November permitted definition of the surface water temperature regime of Lake Huron on a monthly basis. Quantitative values are furnished for a portion of the warming, stable, and cooling periods. The lowest temperatures occurred near the center of the lake, southwest of Manitoulin Island, and at De Tour Passage. The highest temperatures occurred at the mouth of Saginaw Bay and in the southernmost portions of the lake. Comparison of the surface water temperatures with temperatures in the 21 - 30 m layer shows the heat storage lag characteristic of large lakes.     

A TEST OF SEVERAL EVAPORATION EQUATIONS FOR WATER TEMPERATURE SIMULATIONS IN LAKES1

ABSTRACT: Evaporative heat loss is an essential component of any heat budget used for the modeling of lake water temperatures. Seven evaporative heat loss equations were tested in a year-round, physically-based temperature and dissolved oxygen model for lakes. Deciding which equation to choose for use in the year-round model was based on the goodness of fit of the simulated vs. measured surface temperatures, which were taken at a depth of 1 m below the water surface. An equation which includes free and forced convection components and which was previously used for cooling ponds gave the best fit between temperature simulations and measurements.