1977—2021年博斯腾湖大湖区湖岸线动态变化

湖泊岸线的动态变化可以表征湖泊的变化。以博斯腾湖大湖区为研究区,基于1977—2021年的Landsat遥感影像数据和实测水位资料,利用MNDWI法提取水体信息,运用岸线发育系数与岸线强度,分析研究区岸线动态变化,探讨影响研究区岸线动态变化的主要因素。研究结果表明：1977—2021年研究区岸线变化最明显的区域主要是研究区北岸。1977—1989年北岸岸线向南迁移的最大距离为0.93 km;1989—2003年北岸岸线向北迁移的最大距离为5.12 km;2003—2013年北岸岸线向南迁移的最大距离为5.46 km;2013—2021年北岸岸线向北迁移的最大距离为5.11 km。1977—1989年研究区岸线长度以1.55 km/a的速率逐渐缩短;1989—2002年岸线以16.34 km/a的速率持续增长;2002—2012年岸线以22.67 km/a的速率明显缩短;2012—2021年岸线以14.36 km/a的速率快速增长。年降水量、年均气温以及开都河径流量等自然要素是研究区岸线、水位和水面面积变化的主要自然因素。研究区岸线长度和曲折性受水位和水面面积的影响较为明显,1977—2021年研究区水位、水面面积和岸线长度的变化趋势基本一致。     

基于多源遥感数据的乌伦古湖面积动态变化分析

为精准研究乌伦古湖面积变化趋势,利用研究区1989～2017年高分辨率Landsat遥感影像,在分析不同水体提取方法优劣的基础上,利用改进的归一化差异水体指数法提取乌伦古湖水体面积,识别乌伦古湖面积的时空变化特征.结果表明:乌伦古湖水体面积2002年最大(1045.33 km2),2006年最小(1010.03 km2...     

云南省九大高原湖泊水体面积时空变化研究

基于Google Earth Engine(GEE)云平台和长时序的Landsat遥感影像,研究了近30 a云南省九大高原湖泊水体面积的时空变化趋势,并在此基础上分析了湖泊水体面积变化的驱动因素。研究结果表明:(1)云南省九大高原湖泊表面水体面积由1988年的1 024.91 km~2减少至2018年的1 000.98 km~2,总体呈"先增加后减少"的趋势,总面积减少了23.93 km~2。(2)大部分高原湖泊的水体面积保持稳定,但从2008年以后,杞麓湖和异龙湖的水体面积明显缩小。(3)影响因素分析结果表明:九大高原湖泊水体总面积的变化在2013～2017年和降水的变化呈显著正相关(R=0.9,p=0.08),在1988～2018年与气温呈负相关性(R=-0.63,p=0.001);影响九大高原湖泊水体面积变化的主要人为因素包括湖泊流域的土地利用变化以及政府的经济发展和湖泊保护政策。区域气候变化和人类活动共同影响了云南省九大高原湖泊水体的面积变化。     

1956—2011年青海湖变化特征及原因分析

基于卫星影像数据,从湖水位、水面面积、湖岸线三个方面分析了1956—2011年青海湖的变化特征,结果表明:56 a间水位累计下降3.28 m;2005年是青海湖由萎缩转为扩张的转折年份,2005—2011年湖水位累计涨幅1.01 m;水面面积与湖水位有很好的正相关关系,1956—2004年萎缩了397.5 km2,2005—2011年扩张了80.4 km2;1995年以来沙岛湖一直与大湖水体分离,湖岸线变化不均匀;水位变化的主要影响因素是降水径流的变化,气温、蒸发、冰川融水、人类活动等其他原因并非主导因素。     

基于Landsat及ICESat和Hydroweb的太湖容积变化监测

为得到太湖长期动态变化过程,利用1975—2015年Landsat数据,基于归一化差异水体指数法(NDWI)和改进型归一化差异水体指数法(MNDWI)提取湖泊面积数据,并基于ICESat和Hydroweb数据提取太湖水位数据。将两者相结合,得到了太湖容积变化和水量平衡数据。据此,分析了太湖水位、面积和容积变化的规律和趋势,并对其影响因素进行了研究。结果表明,太湖面积和容积变化近40年来呈缓慢增长趋势,分别从1975年的2 320.07 km~2和-0.047 0 km~3增长到了2015年的2 341.06 km~2和0.275 9 km3,增长趋势不明显;太湖水位总体上呈波动变化趋势,水位从1975年的0.982 6 m变为2015年的1.135 9 m。因此,太湖水位与面积相关性中等(R2≈0.65),容积变化与面积和水位变化的相关性较高(R~20.85)。太湖水量平衡为正平衡且变化不大,为0.009 2 km~3。入湖水量的增加、年降雨量和年蒸发量的变化及政府"退地还湖"政策是导致太湖发生变化的主要原因。     

阿牙克库木湖动态变化及其对冰川消融的响应

基于Landsat TM卫星遥感数据,应用水体指数法,对新疆祁漫塔格地区阿牙克库木湖的面积变化进行了研究,并分析其影响因素。结果表明:1989—2010年,湖泊面积呈明显增加趋势,增加量为294.9 km2,总体增长率为48.7%,其中2000—2006年湖泊面积增大最快;阿牙克库木湖的面积变化与气象因素密切相关,研究区气温和降水量在22 a间均呈上升趋势;湖泊变化还与冰川消融有关,祁漫塔格地区1989—2006年冰川面积退缩率为20.0%,2006—2011年冰川面积退缩率为7.2%,而1989—2006年、2006—2011年冰储量的减少率分别为26.0%和9.5%,与湖泊面积的增长趋势相吻合。     

近40年可鲁克湖-托素湖面积变化及影响因素分析

以位于青海省德令哈市境内的可鲁克湖-托素湖为研究对象,利用美国地质调查局自1973年-2013年的多年遥感影像,运用目视解译和改进的归一化差异水体指数方法提取可鲁克湖和托素湖的面积值,分析其变化特征,结合德令哈市的降水、气温、蒸发、径流、农业灌溉耗水资料,对影响湖泊面积变化的因素进行初步探讨。结果表明,可鲁克湖的面积大致保持不变,托素湖的面积自1973年以来呈现先减小又增大的趋势,降水量呈增加趋势,可以认为湖泊面积变化受降水的影响较小,可鲁克湖的面积主要受蒸发、气温和上游巴音河径流量的影响,但其影响存在明显的滞后性。上游农业耗水量是间接影响托素湖面积变化的主要因素,气温的变化通过影响蒸发量和上游冰雪融水间接影响托素湖的面积。     

博斯腾湖流域气候水文变化及对湖泊水位的影响研究

随着气候环境变化和人类活动影响加剧,博斯腾湖水位发生了明显改变。基于最近观测的气候水文数据,分析了1961—2019年博斯腾湖流域水文气候要素和湖泊的变化特征,探讨了湖泊水文变化的可能影响因素。结果表明:博斯腾湖水位(面积)发生了明显的阶段性变化,其中1961—1987年有下降(萎缩)趋势,1988—2002年迅速上升(扩张),在2003—2012年大幅下降(萎缩),但在2013年之后有明显上升(扩张)。这种阶段性变化受区域气候转型和人类干扰共同影响,其中区域气候增暖增湿引起了1987年之后湖泊水位上升;但从2003年开始,农业灌溉用水增加使得博斯腾湖入湖径流有所减少,流域生态输水工程增加了博斯腾湖的出湖水量,而降水减少导致的干旱频率增加,这些因素共同作用下使得湖泊水位大幅下降;而2013年以来湖泊水位上升主要与山区降水增加和增温加剧引起的冰雪融水补给增加有关。此外,工农业排放废水导致水质退化,进而改变了博斯腾湖自然水循环系统。因此,在气候变化背景下,博斯腾湖未来的水安全很大程度上依赖于人类活动的影响。     

四川省河流岸线开发利用与保护区划研究——以沱江流域为例

岸线作为一种战略资源,需得到有效保护与合理利用,对沿线经济和社会发展均具有重要意义。以岸线管理要求为目标,结合国家和地方法规文件,以岸线陆域延伸宽度为研究对象,对四川省河流岸线开发利用与保护区划进行了研究,并以沱江流域为例进行了岸线的具体划分。结果表明:①外缘控制线与护堤地之间的区域作为陆域岸线宽度,根据岸线利用情况和主体功能,可分别划分为20,50 m和200 m等不同宽度的岸线。②对沱江流域简阳-资阳段岸线,按功能区划可划分为10个,其中保护区2个,总长度为31.24 km,面积约为0.64 km~2;保留区4个,总长度为73.71 km,面积约为1.47 km~2;控制利用区3个,总长度为28.29 km,面积约为0.85 km~2;开发利用区1个,总长度为7.68 km,面积约为0.16 km~2。     

丹江口水库水域面积动态变化研究

以LANDSAT的TM/ETM＋多时相遥感影像为数据,采用NDWI和MNDWI两种模型定量研究丹江口库区1999年-2006年水域面积动态变化。研究表明,从1991年到2006年期间,丹江口水库的水域面积稳定在300km2至385km2之间。NDWI和MNDWI都能准确提取丹江口水库水域面积,MNDWI模型更适合该地区水体信息定量提取研究。     

Overlap in Offshore Habitat Use by Double-crested Cormorants and Boaters in Western Lake Erie

Double-crested cormorants (Phalacrocorax auritus) and boats of 2 length classes (≤ 8 m and > 8 m) were counted from a boat along 31 established strip transects in western Lake Erie from 24 April to 1 September 2000. Each transect included only one of the following habitats: (1) offshore of a breeding island or roosting/loafing area for cormorants (“refuge”), (2) reefs or shoals, (3) open water, or (4) offshore of an island shoreline that had evidence of development by humans. Foraging cormorants were recorded most often offshore of refuges and least often on open water. There was no difference between the numbers of foraging cormorants/km² recorded offshore of developed shorelines and on reefs and shoals. More than half of all boats recorded were on transects that were within 1 km of developed shorelines. Among those transects > 1 km from developed shorelines, there were no differences among the habitats for the number of boats of either length class. The respective ranks of the 31 transect means of the numbers of cormorants/km² and the numbers of boats/km² in either length class were uncorrelated. The results suggest that (1) cormorants select foraging habitats based mainly on shoreline type, distance from shoreline, and depth, and (2) the amount of boat traffic is influenced by proximity to port and trip objectives, including sport angling and recreational boating. Although there is overlap in habitat use by cormorants and humans, this overlap is not complete. The perception of cormorants as a threat to fish populations may in part be due to this overlap.     

Ground-penetrating radar stratigraphy and depositional model for evolving Late Holocene aeolian dunes on the Lake Huron coast,Ontario

One of the largest (36 km²) Late Holocene systems anywhere in Ontario lies in Pinery Provincial Park on the southeast coast of Lake Huron and postdates a 12‐km‐long beach barrier system left by Lake Nipissing some 5000 years ago. Dunes lie parallel to the lake shoreline, oblique to the dominant west–northwest wind. Linear dunes in the north of the field regardless of age are stable and of moderate height (< 10 m) having grown in situ from foredunes on emergent beach ridges. Southwards however, the same dunes evolve into wider, higher (up to 20 m) parabolic forms with large blow outs. This change in form from north to south appears to have been a persistent evolutionary trend over the past 5000 years. Some 5 km of high resolution radar profiles identifies the changing internal stratigraphy of dunes as they evolve in shape. Linear dunes are composed of a ‘vertical aggradation sequence’ (VAS) that records initial formation of a foredune on top of shore-parallel beach ridges, and upwards growth of the dune by sand trapped by vegetation. Southwards over some 12 km, dunes grow in height and assume a parabolic form expressed on radar profiles by a lowermost VAS overlain by cross-bedded sand comprising a landward accretion sequence (LAS) recording landward migration. A depositional model relates the change in dune shape and stratigraphy to southward increasing sand supply within a large persistent littoral cell in Lake Huron.     

洞庭湖湖区最低生态水位的确定

为确定洞庭湖湖区最低生态水位,针对洞庭湖湖区复杂、不同湖区差异较大的问题,基于城陵矶、鹿角、南嘴、小河嘴和杨柳潭5个水文站1953—2013年的水文资料,采用天然水位资料法、年保证率法、最低年平均水位法、生态水位法、湖泊形态分析法及最小空间需求法,分别对东洞庭湖、南洞庭湖和西洞庭湖的最低生态水位进行了计算,并与前人关于洞庭湖生态水位的研究成果进行了对比分析。结果表明:东洞庭湖、南洞庭湖和西洞庭湖的最低生态水位分别为22.62 m、27.19 m和28.11 m,相应的湖面面积分别为373.85 km~2、406.88 km~2和142.19 km~2,从保护洞庭湖自然保护区的角度看,确定的最低水位是合理的。     

Investigation of Aksehir and Eber Lakes (SW Turkey) Coastline Change with Multitemporal Satellite Images

Detection and analyses of coastline changes are an important task in environmental monitoring. Several factors such as geology, hydrology, climate impact, environmental problems etc. play an important role in this change. The main objective of this study is to determine coastline change in the Aksehir and Eber lakes (SW, Turkey) by using different remote sensing methods on the multitemporal satellite images. In present study, Landsat MSS (1975), Landsat TM (1987), Landsat ETM+ (2000) and ASTER (2006–2008) satellite images were used. In order to explain reasons of coastline change, geological, hydrogeological and hydrological investigations were carried out. Also, surface area and volume calculations were performed with the aid of bathymetric map which was digitized by using the Arc GIS 9 version software program. The obtained data show that precipitation, evaporation and surface flow are effective in the Aksehir and Eber coastline change. The Eber Lake was evaluated with level measurements due to aquatic plants covered surface of the lake. The coastline change of the Eber Lake is related to hydraulic factors. The Aksehir Lake volume and surface area have decreased 1.11 km³ and 257.95 km², respectively from 1975 to 2006 years. Furthermore, the Lake Akşehir was dried up completely in 2008.     

水系连通工程下博斯腾湖矿化度时空变化及其驱动因素研究

分析了开都河－黄水沟－大湖区－小湖区连通工程实施后博斯腾湖矿化度的时空变化及其驱动因素,以期为进一步改善博斯腾湖水环境提供科学指导。结果表明：空间变化上,水系连通工程促进了博斯腾湖大、小湖区水循环,改善了博斯腾湖矿化度,使黄水沟河道（南大闸）矿化度降低了0.5~1.0 g/L、大湖区西北角和东南部矿化度降低了0.3~0.5 g/L、小湖区东部矿化度降低了0~1.5 g/L;时间变化上,博斯腾湖黄水沟区、西岸区、大湖区和小湖区矿化度变化具有较高的同步性;水系连通工程的实施对改善博斯腾湖矿化度空间分布作用显著;高矿化度水体的扩散和湖水水位,尤其是水温等因素共同驱动了矿化度随时间的变化。在水系连通工程实施下,科学调控年内入湖、出湖水量并严格阻止污水入河、入湖是改善博斯腾湖矿化度的关键。     

青海湖湖滨湿地演变与驱动因素分析

为了更好地应对气候变化的影响,对暖湿化气候下青海湖湖滨湿地的演变现状及其驱动因子进行研究。通过遥感影像解译和水文分析计算结合实地调查,发现21世纪气候暖湿化进程下,青海湖水位升高2.1 m,入湖水量显著增加。2003—2016年的年均径流量比1956—2002年的年均径流量增加了6.0亿m3,湖面降水增加了3.8亿m3,从最低水位到现状水位的湖滨淹没区面积为222 km2。湖滨区的地下水位抬升,地势较低的河谷区沼泽草甸面积扩大11.7 km2,溢出泉恢复,间歇性河流增加了近30条,间歇性湖泊(泡沼)恢复到1980年初的水平。同时,湖水位上升淹没了约23 km2的湖滨沼泽和鸟岛部分区域,植被腐殖质、食物碎屑和鸟类沉积粪便进入湖泊,加之畜牧业和旅游业的发展,牲畜粪便和垃圾流入青海湖,导致水深和光照适宜的湖滨区爆发刚毛藻水华。     

Selection of Preferred Floodplains for the Renaturalization of Hydrologic Functions: A Case Study of the Paraíba do Sul River Basin,Brazil

The primary goal of this study is to identify floodplains that are in large river basins and could potentially undergo renaturalization of their hydrologic functions. The study area is the Paraíba do Sul River Basin (55,400 km²), which is located in southeastern Brazil. The field work included the application of geoprocessing techniques (ArcGIS 10 and ENVI 4.7) for the delineation and individualization of the floodplain, and the following characteristics were surveyed: area, perimeter, circularity index and urbanization index. Discriminant and cluster analyses (SPSS 15) were performed, and 77 floodplains were found that exhibited a wide variation in area (0.13 to 1,540 km²) and perimeter (1.8 to 4,200 km), low circularity indices (<0.52), and a low average urbanization index (18.9 %). The floodplains were grouped according to how well the renaturalization of their hydrologic functions could be managed and categorized as follows: a) low management potential (9 units); b) medium management potential (15 units); and c) high management potential (52 units). The discriminant analysis correctly classified 100 % of the cases, which indicates that the model has a high predictive ability and can accurately classify the management potential of floodplains.     

基于卫星测高和实测数据的博斯腾湖水位变化分析

湖泊水位是湖泊水文观测必不可缺的要素,直接关系到湖泊物质交换和能量平衡,对研究湖泊运动和区域气候环境变化至关重要。为了掌握内陆湖泊水位的变化过程和空间特征,以新疆博斯腾湖为例,综合Jason-1&2、ENVISat&ERS、ICESat-1、ICESat-2等卫星测高资料,提取博斯腾湖湖泊水域瞬时水位和日均水位,并根据Hydroweb水位记录和1975-2020年博斯腾湖湖泊水位观测及水域面积数据,检验Jason-1&2、ENVISat&ERS、ICESat-1、ICESat-2测高数据的估计精度。借助趋势面分析方法,分析博斯腾湖水域水位变化的空间差异和特征。结果表明：Hydroweb水位记录、Jason-1&2、ENVISat&ERS、ICESat-1、ICESat-2卫星资料估计湖泊日均水位的绝对误差分别为0.24、0.34、0.28、0.18、0.08 m; 2020年博斯腾湖年均水位为1 048.10±0.12 m,与1975年年均水位相比增加了0.70±0.15 m;湖泊瞬时水位在空间尺度上存在一定水位差,ICESat-2测高数...     

Variations in water level,area and volume of Hongze Lake,China from 2003 to 2018

Lake changes have great impacts on local and regional ecosystems and socioeconomic activities. To determine the recent changes in Hongze Lake, radar altimeter and Landsat data were used to examine the water level and area and estimate the water volume changes from 2003 to 2018. Generally, the annual water level results from radar altimeter data showed good agreement with in situ measurements (r² = 0.62, bias = −0.02 m, mean absolute error = 0.10 m and root mean square error = 0.12 m). Although the results show that the water level and water volume of Hongze Lake had no trends during the 16 years, the water area decreased significantly at a rate of 19.76 km² per year. Despite great fluctuations throughout 16 years, two shifts occurred in approximately 2007 and 2013. The water level, area and volume of Hongze Lake decreased from 2007 to 2012, but they all showed increasing trends after 2013. The interannual changes in the water level and volume of Hongze Lake were consistent with the changes in annual precipitation, while the change in area was mainly affected by human activities, especially land reclamation and aquaculture activities along the lakeshore. In addition, the intra-annual change in the water level was greatly affected by artificial activities such as irrigation and flood prevention.