艾比湖湖区土壤质地测定及其分析

艾比湖是一个典型的干旱区湖泊,近年来由于湖面的萎缩,干涸湖底的面积随之增加[1]。此外,该地区常年受到阿拉山口大风的影响,地表抗风蚀能力弱,致使沙尘天气时有发生。文章通过对湖区不同类型土壤质地测定及分析,得出该区域土壤质地的分布规律。     

Water balance estimates of ten greatest lakes in China using ICESat and Landsat data

Lake level and area variations are sensitive to regional climate changes and can be used to indirectly estimate water balances of lakes. In this study, 10 of the largest lakes in China, ～1000 km² or larger, are examined to determine changes in lake level and area derived respectively from ICESat and Landsat data recorded between 2003 and 2009. The time series of lake level and area of Selin Co, Nam Co, and Qinghai Lake in the Tibetan Plateau (TP) and Xingkai Lake in northeastern China exhibit an increasing trend, with Selin Co showing the fastest rise in lake level (0.69 m/a), area (32.59 km²/a), and volume (1.25 km³/a) among the 10 examined lakes. Bosten and Hulun lakes in the arid and semiarid region of northern China show a decline in both lake level and area, with Bosten Lake showing the largest decrease in lake level (?0.43 m/a) and Hulun Lake showing the largest area shrinkage (?35.56 km²/a). However, Dongting, Poyang, Taihu, and Hongze lakes in the mid-lower reaches of the Yangtze River basin present seasonal variability without any apparent tendencies. The lake level and area show strong correlations for Selin Co, Nam Co, Qinghai, Poyang, Hulun, and Bosten lakes (R ² >0.80) and for Taihu, Hongze, and Xingkai lakes (～0.70) and weak correlation for East Dongting Lake (0.37). The lake level changes and water volume changes are in very good agreement for all lakes (R ² > 0.98). Water balances of the 10 lakes are derived on the basis of both lake level and area changes, with Selin Co, Nam Co, Qinghai, and Xingkai lakes showing positive water budgets of 9.08, 4.07, 2.88, and 1.09 km³, respectively. Bosten and Hulun lakes show negative budgets of ?3.01 and ?4.73 km³, respectively, and the four lakes along the Yangtze River show no obvious variations. Possible explanations for the lake level and area changes in these four lakes are also discussed. This study suggests that satellite remote sensing could serve as a fast and effective tool for estimating lake water balance.     

鄱阳湖最小生态需水研究

基于鄱阳湖水文特征,建立鄱阳湖最小生态需水计算模型。研究将频率95%对应的水位为湖泊最低生态水位,根据鄱阳湖水位-面积关系曲线,得到对应的鄱阳湖湖区面积为1 503.9 km~2。通过折算将水面蒸发转换成湖面蒸发,得到湖面净蒸发量为483.09 mm,湖区年最小生态耗水为7.3亿m~3。采用计算河道内生态需水的方法计算出湖生态需水,运用最小月平均流量法、逐月最小流量法、Tennant法、90%保证率最枯月平均流量法和90%保证率逐月流量法等,对出湖河道生态需水进行计算,并用Tennant法对结果进行评价,通过分析比较得出90%保证率逐月流量法更适合确定鄱阳湖出湖最小生态流量,得到出湖最小生态需水为777.1亿m~3,最终得到鄱阳湖最小生态需水为784.4亿m~3。研究结果对鄱阳湖流域生态保育、水生态与水环境保护及水资源管理,提供重要科学依据。     

基于"3S"技术的艾比湖地区荒漠化现状分析

选取荒漠化问题突出的艾比湖地区作为研究区,采用2004年遥感TM影像,通过ERDAS软件处理,再运用GIS分析手段,综合土地利用图、地形图和其他资料形成艾比湖地区的荒漠化现状图.结果显示,艾比湖地区荒漠化土地类型的比例为未荒漠化占12.39%,微度荒漠化占12.56%,轻度荒漠化占24.87%,中度荒漠化占27.95%,重度荒漠化占22.23%.由于治理有方及降水有所增加,最近荒漠化速度有所放缓,但任务还很繁重.总之,荒漠化发展的原因是自然因素与人为因素共同作用的结果.     

艾比湖水位变化对湖区生态效益影响的初探

新疆艾比湖是典型的干旱区湖泊,作为一个封闭的内陆湖泊,具有特殊的湿地、干旱生态系统.文章从分析湖泊水位变化入手,阐述了湖泊水位变化原因,讨论了艾比湖水位变化所引发的一系列生态环境问题.指出要遏制湖区生态效益的下降,必须结合流域的实际情况,对艾比湖的最优运行水位加以研究,以确保湖区生态环境的可持续发展.     

基于SMMI的红碱淖湖区面积遥感分析

红碱淖是我国最大的沙漠淡水湖,在当地气候的调节、水资源的平衡及生物多样性的保持等方面发挥着非常重要的作用。以2000~2014年MODIS陆地植被数据产品MOD13Q1为数据源,在提取NIR和Red波段反射率的基础上,利用土壤湿度监测指数(SMMI)提取红碱淖年内和年际面积数据,并对其15 a间变化趋势进行分析。结果表明:红碱淖面积年内变化规律为每年4月开始缓慢增大,至7月~8月间达到最大,而后逐渐减小;红碱淖湖区面积总体呈线性减少趋势(R~2=0.884 7),由2000年的49.63 km~2减小到2014年的31.88 km~2,变化率为36%,平均缩减速度为1.18 km~2/a。相比较气象因子而言,人类活动是影响红碱淖面积变化的主要因素。     

基于GIS和USLE模型的巢湖流域土壤侵蚀评价

土壤侵蚀是全世界都关心的土地资源与环境保护问题。巢湖作为中国第五大淡水湖,近年来由于水体富营养化产生的水华现象引起多方重视,对巢湖流域土壤侵蚀评估对于环境保护战略与土地规划政策具有重要的意义。基于GIS平台,采用通用土壤流失方程(USLE)来评估巢湖流域14县/区2000年到2010年土壤侵蚀空间分布变化趋势。研究表明:(1)巢湖流域土壤侵蚀严重区域主要分布在金安区、舒城县、居巢区以及含山县的丘陵地区,即杭埠河-丰乐河流域、裕溪河流域与柘皋河流域的上游地区;(2)从2000年到2010年,土壤微度侵蚀、强度侵蚀、极强度侵蚀和剧烈侵蚀区域占巢湖流域总面积比例分别减少了0.5%、0.05%、0.21%和0.23%,而轻度侵蚀、中度侵蚀区域所占比例分别增加了0.98%和0.01%,总体呈现土壤强度侵蚀、极强度侵蚀与剧烈侵蚀区域向轻、中度侵蚀转移的趋势。(3)植被覆盖度变化是巢湖流域土壤侵蚀分级发生变化的主要原因,总体上,2000~2010年研究区由于植被覆盖度的波动性增加呈现土壤侵蚀分级波动性降低的趋势。     

Oxygen isotope variation in the water cycle of the Yamzho lake Basin in southern Tibetan Plateau

Given the potential use of stable isotope in the paleoclimate reconstruction from lacustrine records as well as in the local hydrology cycle, it is crucial to understand the processes of stable isotope evolution in catchment in the Tibetan Plateau region. Here we present a detailed study on the water oxygen isotope based on 2 years observation including precipitation, river water and lake water in the Yamzho Lake, south of the Tibetan Plateau. Temporal variation of local precipitation 5180 shows an apparent ＂monsoon cycle＂. In monsoon season, 5180 in waters is lower. In non-monsoon season, δ^18O in precipitation and lake water is higher and higher river δ^18O exists in spring, probably reflecting the effect of land surface evaporation, together with the higher δ^18O values in spring precipitation. It is also found that the surface lake water δ^18O varies seasonally and annually. The lower lake water δ^18O in the late summer is apparently related to the summer monsoon precipitation. The mean δ^18O value of lake water in 2007 is 1.2‰ higher than that in 2004, probably due to the less monsoon precipitation in summer of 2007, as can be confirmed from the precipitation data at the Langkazi meteorological data. It is also found that an obvious shift of vertical lake water δ^18O reflects the fast mixture of lake water. δ^18O values of lake water are over 10‰ higher than those of precipitation and river water in this region due to the evaporation fractionation. The modeled results show that the evaporation process of the lake water is sensitive to relative humidity, and the present lake water δ^18O reflects a relative humidity of 51% in the Yamzho Lake. It shows that the lake will take 30.5 years to reach present lake water δ^18O given a large shift in the input water δ^18O. The modeled results also reveal that surface lake water temperature and inflow δ^18O have slight effect on the isotopic balance process of lake water in the Yamzho Lake.     

Identification of the deposited layers in landslides reservoir and investigation of the sediment yields during the later sixteenth century on the Hill Loess Plateau,China

There are many sediment trapping reservoirs in the Hill Loess Plateau. The Huangtuwa small catchment is selected as a research field where samples were collected in a sediment deposit profile with a vertical length of 12.73 m. By the variation of fine particle content and pollen concentration, 54 flood couples were identified. Taking the freeze-thawing disturbed texture as the sign of the latest flood couple in a year, it is ascertained that those 54 floods should happen in 31 years. Using pyramid volume calculation formula, the sediment yields of flood ranged between 716-30376 t· km^-2, The average sediment yield was 7106 t· km^-2, The annual sediment yields varied between 968-55579 t· （km^2· a）^-1, and the average value is 12629 t· （km^2· a）^-1. Compared with the modern annual sediment discharge of the Huaining River, the erosion rate in the Huangtuwa region 450 years ago was similar to the modern erosion rate. In the period from the 27th year to the 31st year, the average annual sediment yield increased sharply to 31309 t· （km^2· a）^-1. It implied that re-reclamation of the abandoned land in the catchment since the landslide disaster, where vegetation had rehabilitated already, caused very severe soil erosion in the catchment.     

广西岩溶区的水土流失特点及其防治

广西岩溶地区水土流失遥感数据和典型地区监测资料显示,广西岩溶地区水土流失有3个显著的特点:土壤侵蚀模数低,以水土漏失为主要过程,坡耕地是重要水土流失区。水土流失的突出危害是导致严重的岩溶内涝灾害和大面积耕地丧失。21世纪以来,国家和广西区政府对于广西岩溶地区水土流失防治工作高度重视,组织实施了一大批水土保持工程,治理水土流失面积14 000km~2,遏制了石漠化,降低了土壤侵蚀模数,形成了高效生态产业,创建了弄拉、龙何等生态与经济协调发展的水土保持模式。但广西岩溶地区水土漏失和内涝灾害防治力度不够,建议进一步加大力度实施广西岩溶地区水土漏失、内涝防治以及耕地资源丧失的水土保持工程。     

艾比湖沿岸地区环境质量演变与生态价值分析

目的借助于遥感资料和GIS方法，研究了近20a来艾比湖沿岸的生态环境质量演变，为研究该地区水土开发与生态环境演变提供了依据。方法在GIS／RS技术支持下获取基础数据，根据研究区的区域特点，将Costanza等人的研究与国内相关研究结合，建立价值模型对艾比湖沿岸的博乐、精河绿洲进行不同历史时段生态系统服务功能价值测评。根据生态系统服务功能价值与生态环境质量之间的正相关关系，从生态系统服务功能价值的角度对博乐、精河绿洲近20a生态环境质量的演变进行了分析。结果研究区生态系统服务功能价值呈下凹曲线变化趋势。结论博乐、精河绿洲近20a的生态环境演变基本上以1991年为界，前期呈现劣变，后期则渐趋好转。(1．西北大学城市与资源学系，陕西西安710069；2．中国科学院新疆生态与地理研究所，新疆乌鲁木齐830011)     

Monitoring lake changes of Qinghai-Tibetan Plateau over the past30 years using satellite remote sensing data

During the years 2006–2009,lakes in the Qinghai-Tibetan Plateau(QTP)were investigated using satellite remote sensing strategies.We report the results of this investigation as well as follow-up research and expanded work.For the investigation,we mainly focused on lakes whose areas are more than 1 km2.The remote sensing data that we used included 408 scenes of CBERS CCD images and 5 scenes of Landsat ETM?images in Qinghai Province and Tibet Autonomous Region.All these data were acquired around years 2005–2006.Besides remote sensing images,we also collected 1,259 topographic maps.Numbers and areas of lakes were analyzed statistically,which were then compared with those coming from the first lake investigation(implemented between the1960s and 1980s).According to our investigation,up to and around year 2005–2006,the total number of lakes in the QTP was 1,055(222 in Qinghai and 833 in Tibet),accounting for more than 30%of that of China.Thirty newborn lakes with area[1 km2were found,and 5 dead lakes with initial area[1 km2were also found.Among those 13 big lakes([500 km2),Yamzhog Yumco had seriously shrunk,and it has continued to shrink in recent years;Qinghai Lake had shrunk during the period,but some new researches indicated that it has been expanding since the year 2004;Siling Co,Nam Co,and Chibuzhang Co had expanded in the period.We divided the newborn lakes into six categories according to their forming reasons,including river expansion,wetland conversion,etc.The changes of natural conditions led to the death of four lakes,and human exploitation was the main reason for the death of Dalianhai Lake in Qinghai.We picked out three regions which were sensitive to the change of climate and ecological environment:Nagqu Region,Kekexili Region,and the source area of the Yellow River(SAYR).Lakes in both Nagqu and Kekexili have been expanded;meanwhile,most lakes in the SAYR have obviously been shrunk.These regional patterns of lake changes were highly related to variations of temperature,glacier,precipitation,and evaporation.Our investigation and analysis will provide references for researches related to lake changes in the QTP and the response to climate fluctuations.     

2000～2018年黄土高原沙尘天气遥感监测及尘源分析

利用19年（2000~2018）MODIS L1B数据对黄土高原102次沙尘天气过程进行遥感监测与分析,以探究黄土高原沙尘天气发生的时空规律。结果表明,黄土高原沙尘天气呈减少趋势,沙尘频发季节为春季。黄土高原沙尘源地主要分布在其西北部,位于沙地和沙漠区、农灌区与黄土丘陵沟壑区、黄土高原沟壑区等生态脆弱的原生沙尘暴带。黄土高原典型的沙尘源为活动沙丘及丘间沙地、干涸湖泊河道和农田等,表明沙尘天气频发是由自然因素和人为因素共同导致的。沙尘天气的遥感监测捕捉了黄土高原沙尘活动的时空变化特征,高效地识别了沙尘源地和尘源类型,对黄土高原气候变化、生态环境变化研究和环境修复与评价具有重要指导意义。     

Quantitative reconstruction of the paleosalinity in the Daihai Lake, Inner Mongolia, China

Ostracods are small bivalved aquatic crustaceans. They secrete shells of low-Mg calcite that are often preserved in lake sediments. Recent work has shown that the uptake of trace elements (especially Mg and Sr) into the shell may be a function of the salinity and temperature of the host water. We measured Sr/Ca ratios in living ostracod valves from the species of genus Limnocythere cf. inopinata and Sr²⁺/Ca²⁺ ratios of the host water to calculate distribution coefficient of genus Limnocythere cf. inopinata in the Daihai Lake. A function for Sr²⁺/Ca²⁺ ratio and salinity was established by measuring a series of Sr²⁺/Ca²⁺ ratios and salinities of the lake water in different places of the Daihai Lake. Finally paleosalinities of the lake water were quantitatively reconstructed by the Sr/Ca ratios of ostracod shells of the same species in sediment core of the Daihai Lake.     

鄱阳湖流域近百年生态环境的演变

鄱阳湖流域经过近百年的经济开发,生态环境遭到严重破坏,生态灾害频繁,主要有森林退化,水土流失,水旱灾害,环境污染等类型,并且有相互关联性,潜在性和积累性的特点,该流域的经济发展必须保护生态环境,走可持续发展的道路,应处理好与水利建设,水土保持,水源保护的关系,目前要抓好小流域水土流失及湖区洪灾的综合治理,而造林绿化,保护森林是始终必须重视的工作。     

A study on responses of soil erosion and sediment yield to closing cultivation on sloping land in a small catchment using 137Cs technique in the Rolling Loess Plateau, China

By comparison of volumes and ¹³⁷Cs contents of the deposited sediments before and after 1993, changes of specific sediment yields and relative sediment contributions from the gully area and from the inter gully area after closing cultivation on the later area on a small catchment of Zhaojia Gully, in the Rolling Loess Plateau, are analyzed in this paper. Closing cultivation in a large scale has not resulted in decrease but increase of specific sediment yield of the catchment, in sharp decrease of the sediment yield and the relative sediment contribution of the inter-gully area, and in increase of the sediment yield and the contribution of the gully area, for a short term. The mean specific sediment yield of 29650 t km⁻² a⁻¹ of 1994–1996 in the catchment was 2.2 times the average value of 13413 t km⁻² a⁻¹ for a long term. The specific sediment yield of the inter-gully area decreased from the 14335 t km⁻² a⁻¹ in 1994 to 7034 t km⁻² a⁻¹ in 1995 and 3517 t km⁻² a⁻¹ in 1996, while the yield of the gully area varied between 44944 and 62136 t km⁻² a⁻¹ during the period of 1994–1996 which was much greater than the value of 21118 t km⁻² a⁻¹ before 1993. The relative sediment contribution from the inter-gully area decreased from 23% in 1994 to 15% in 1995 and 6% in 1996, while the contribution from the gully area increased from 77% in 1994 to 85% in 1995 and 94% in 1996. It is suggested that compacting of ploughed soils resulted in increasing of the erosion resistance but in decreasing of the precipitation infiltration, therefore, the soil erosion reduced but the runoff amount increased on the inter-gully area. Increase of delivering runoff from the inter-gully area to the gully area should result in activeness of gully erosion and mass movements, consequently, in increase of the total sediment yield from the catchment.     

论鄱阳湖区生态安全与生态建设

鄱阳湖是中国最大的淡水湖。鄱阳湖区生态安全具有重要的生态意义、经济意义、社会意义和国际意义。目前,鄱阳湖区生态安全面临着一系列问题和挑战,如水土流失、土地沙化、水旱灾害、耕地锐减、农田鼠害、农田渍害、土壤退化、环境污染、生物入侵、生物多样性衰退等。为确保新世纪鄱阳湖区生态安全,必须加强生态建设,并采取各种有效对策和措施。这包括:提高生态素质、开展植树造林、加强水利建设、实施退田还湖、调整产业结构、实行清洁生产、发展循环经济、增加物质投入、制定生态规划、完善法律法规、重视国际交流与合作。     

基于SRTM3和SWBD的滇池流域特征信息提取

滇池是我国著名的高原淡水湖泊,属国家重点保护水域之一。滇池流域是云南省经济和社会发展水平最高的区域。以滇池流域为研究对象,选用SRTM3和SWDB数据,利用ArcGIS软件集成的Hydrology水文分析模块,对流域进行了特征信息提取工作。通过数据预处理、洼地填充、流向计算、汇流累积量计算、汇流点捕捉等步骤,有效的提取了滇池流域的边界和河流水系,成果具有一定的实际应用价值。     

High lake levels on Alxa Plateau during the Late Quaternary

Field investigations including lake shoreline measurement and ¹⁴C chronology have been carried out on the Alxa Plateau to better understand the formation and evolution of the high lake levels in northwest China during the late Pleistocene. Comprehensive field investigations show that there are at least ten shorelines at different elevations at Juyan Lake, at least four on the northwest side of the Jilantai Salt Lake, and nine shorelines and one terrace on the northeast margin of Zhuye Lake. Stratigraphic correlations and chronological evidence indicate that the paleo-lakes have the highest lake levels in Marine Isotope Stage (MIS) 3. Though the optically stimulated luminescence (OSL) results which have been reported by some scholars do not support this view, the fact that the paleo-lakes have the highest lake levels in MIS 3 can not be denied. Differences between OSL and ¹⁴C results from this work might indicate that high lake levels existed on the Alxa Plateau during two different periods. It also suggests that the high lake levels may exist in both MIS 5 and early MIS 3. This paper also provides the basic hydrological information for further water resources research in this arid region.     

艾比湖流域风沙天气与艾比湖干缩之间的关系初探

本在探讨艾比湖风沙天气形成机制的基础上，对艾比湖流域风沙天气与艾比湖干缩之间的关系作了初步研究，指出由于艾比湖的干缩而导致的风沙天气主要是浮尘天气，浮尘来源主要是干涸湖床所形成的盐尘，但也有因大规模开荒而形成的沙土尘。引起艾比湖风沙天气变化的原因是多方面的，但人为因素是第一位的，其中以河流上游大量截流引水和大规模开荒为主要原因。风沙天气对艾比湖流域(尤其是精河县)的人类生产生活活动的危害是十分严重的，但与其它因素导致的风沙天气相比，因湖泊干缩而产生的风沙天气对精河县的危害相对而言居于次要地位。