After the bursting of Huiten Nor in Hoh Xil Region in September, 2011, the topic on whether the water overflowed from the Salt Lake would enter into the Chumaer River and become the northernmost source of the Yangtze ...After the bursting of Huiten Nor in Hoh Xil Region in September, 2011, the topic on whether the water overflowed from the Salt Lake would enter into the Chumaer River and become the northernmost source of the Yangtze River has aroused wide concern from public and academic field. Based on Landsat TM/ETM+/OLI remote sensing images during 2010–2015, SRTM 1 arc-second data, Google Earth elevation data and the observation data from the Wudaoliang meteorological station, the study initially analyzed the variations of the Salt Lake and its overflowing condition and probability. The results showed that the area of the Salt Lake expanded sharply from October 2011 to April 2013, and then it stepped into a stable expansion period. On October 27, 2015, the area of the Salt Lake had arrived at 151.38 km^2, which was about 3.35 times the area of the lake on March 3, 2010. The Salt Lake will overflow when its area reaches the range from 218.90 km^2 to 220.63 km^2. Due to the differences between SRTM DEM and Google Earth elevation data, the water level of the Salt Lake simulated would be 12 m or 9.6 m higher than the current level when the lake overflowed, and its reservoir capacity would increase by 23.71 km^3 or 17.27 km^3, respectively. Meanwhile, the overflowed water of the Salt Lake would run into the Qingshui River basin from its eastern part. Although the Salt Lake does not overflow in the coming decade, with watershed expansion of the Salt Lake and the projected precipitation increase in Hoh Xil region, the probability of water overflow from the Salt Lake and becoming a tributary of the Yangtze River will exist in the long term.展开更多
This study is a part of a global approach in which, the main purpose is to understand the reasons behind the upsurge of flood events in the peri-urban area of the city of Dakar.</span><span style="font-f...This study is a part of a global approach in which, the main purpose is to understand the reasons behind the upsurge of flood events in the peri-urban area of the city of Dakar.</span><span style="font-family:""> </span><span style="font-family:Verdana;">Hydrological and hydraulics simulations were carried out to assess the risks of overflowing of the Lake Warouwaye after a so-called exceptional rain. Data were collected through field surveys, as well as site observations of dwellings before and after rain episodes. The simulations were performed using EPA’s Storm Water Management Model (SWMM) software with input data obtained from sub-software and supervisory applications such as Google Earth, Excel, and Global Mapper. The simulation results show factors of natural and anthropogenic origin may contribute to dysfunction hydrological elements such as the watershed capacity to drain and store water. In light of the results of this study, institutional governance efforts are to be made and to be sustained in order to reverse the tendency to occupy rainwater natural flow channels. It will also be necessary to involve the first actors who are the potential victims of flooding caused by the recurrent overflow of reservoirs.展开更多
Through high-resolution research of sedimental chronology and the sediment environmental indexes, such as graininess, minerals, magnetic parameters, pigment content, organic carbon and chronology in Ds-co...Through high-resolution research of sedimental chronology and the sediment environmental indexes, such as graininess, minerals, magnetic parameters, pigment content, organic carbon and chronology in Ds-core and Ws-core in Nansihu Lake, the authors analyze the formation cause of the Nansihu Lake and its water environmental changes. Historical documents are also analyzed here in order to reach the conclusion. Researches indicate that the Nansihu Lake came into being about 2500 aBP and its evolution succession can be divided into four stages. In this evolution process, several scattered lakes merge into one large lake in the east of China. This process is distinctively affected by the overflow of the Yellow River, the excavation of the Grand Canal and other human activities.展开更多
水系演化研究是揭示流域地貌—构造—气候演化之间相互作用的重要途径。松花江水系演化研究目前还相对薄弱,尤其是第四纪松花江中上游是否发生流向反转存在争议。自动定量矿物分析系统TIMA(TESCAN Integrated Mineral Analyzer)在源区...水系演化研究是揭示流域地貌—构造—气候演化之间相互作用的重要途径。松花江水系演化研究目前还相对薄弱,尤其是第四纪松花江中上游是否发生流向反转存在争议。自动定量矿物分析系统TIMA(TESCAN Integrated Mineral Analyzer)在源区识别和古地理重建方面有极大的应用潜力。为此,本文利用TIMA技术对位于松花江T2阶地的哈尔滨荒山岩心沉积物进行重矿物及全岩矿物地球化学组成分析。结果表明,以深度62.3 m为界,岩心上、下地层沉积物的重矿物(例如,锆石、磷灰石、金红石、榍石、石榴石、钛铁矿、铁磁矿物和硅铁矿)及全岩矿物地球化学组成均存在明显差异。62.3 m以上地层沉积物的重矿物组合是闪石类+帘石类+榍石+铁磁矿物,硅铁锂钠石在上段地层中出现,全岩矿物地球化学元素较为稳定,波动幅度较小;62.3 m以下地层沉积物的重矿物组合是闪石类+帘石类+钛铁矿+榍石,方解石、铬铁矿、蛇纹石、黄铁矿和磁黄铁矿仅在下段地层中出现,全岩矿物地球化学元素波动幅度较大。TIMA重矿物和全岩矿物地球化学组成反映了岩心沉积物的物源发生明显变化,进而指示了松花江的水系演化。结合在依兰发现的河湖相地层,我们提出了松花江水系演化的新模式。早更新世时期,佳依(佳木斯—依兰)分水岭将松嫩水系和三江平原水系分隔开,作为松花江上游的牡丹江向东流经依兰—通河—哈尔滨,最终注入松嫩古湖。在0.94 Ma B. P.之后,松辽分水岭局部隆升,古松花江发生反转,从西向东流至通河—依兰地区形成古大湖。湖泊水位不断升高致使湖水溢流切穿佳依分水岭,形成现代松花江水系的基本格局。这挑战了以前的向源侵蚀导致佳依分水岭被切穿的水系演化模式。展开更多
基金National Natural Science Foundation of China,No.41261016,No.41561016Opening Foundation Projection of State Key Laboratory of Cryosphere Sciences,CAS,No.SKLCS-OP-2016-10Youth Scholar Scientific Capability Promoting Project of Northwest Normal University,No.NWNU-LKQN-14-4
文摘After the bursting of Huiten Nor in Hoh Xil Region in September, 2011, the topic on whether the water overflowed from the Salt Lake would enter into the Chumaer River and become the northernmost source of the Yangtze River has aroused wide concern from public and academic field. Based on Landsat TM/ETM+/OLI remote sensing images during 2010–2015, SRTM 1 arc-second data, Google Earth elevation data and the observation data from the Wudaoliang meteorological station, the study initially analyzed the variations of the Salt Lake and its overflowing condition and probability. The results showed that the area of the Salt Lake expanded sharply from October 2011 to April 2013, and then it stepped into a stable expansion period. On October 27, 2015, the area of the Salt Lake had arrived at 151.38 km^2, which was about 3.35 times the area of the lake on March 3, 2010. The Salt Lake will overflow when its area reaches the range from 218.90 km^2 to 220.63 km^2. Due to the differences between SRTM DEM and Google Earth elevation data, the water level of the Salt Lake simulated would be 12 m or 9.6 m higher than the current level when the lake overflowed, and its reservoir capacity would increase by 23.71 km^3 or 17.27 km^3, respectively. Meanwhile, the overflowed water of the Salt Lake would run into the Qingshui River basin from its eastern part. Although the Salt Lake does not overflow in the coming decade, with watershed expansion of the Salt Lake and the projected precipitation increase in Hoh Xil region, the probability of water overflow from the Salt Lake and becoming a tributary of the Yangtze River will exist in the long term.
文摘This study is a part of a global approach in which, the main purpose is to understand the reasons behind the upsurge of flood events in the peri-urban area of the city of Dakar.</span><span style="font-family:""> </span><span style="font-family:Verdana;">Hydrological and hydraulics simulations were carried out to assess the risks of overflowing of the Lake Warouwaye after a so-called exceptional rain. Data were collected through field surveys, as well as site observations of dwellings before and after rain episodes. The simulations were performed using EPA’s Storm Water Management Model (SWMM) software with input data obtained from sub-software and supervisory applications such as Google Earth, Excel, and Global Mapper. The simulation results show factors of natural and anthropogenic origin may contribute to dysfunction hydrological elements such as the watershed capacity to drain and store water. In light of the results of this study, institutional governance efforts are to be made and to be sustained in order to reverse the tendency to occupy rainwater natural flow channels. It will also be necessary to involve the first actors who are the potential victims of flooding caused by the recurrent overflow of reservoirs.
基金Natural Science Foundation of Shandong Province No.Z2000E01
文摘Through high-resolution research of sedimental chronology and the sediment environmental indexes, such as graininess, minerals, magnetic parameters, pigment content, organic carbon and chronology in Ds-core and Ws-core in Nansihu Lake, the authors analyze the formation cause of the Nansihu Lake and its water environmental changes. Historical documents are also analyzed here in order to reach the conclusion. Researches indicate that the Nansihu Lake came into being about 2500 aBP and its evolution succession can be divided into four stages. In this evolution process, several scattered lakes merge into one large lake in the east of China. This process is distinctively affected by the overflow of the Yellow River, the excavation of the Grand Canal and other human activities.
文摘水系演化研究是揭示流域地貌—构造—气候演化之间相互作用的重要途径。松花江水系演化研究目前还相对薄弱,尤其是第四纪松花江中上游是否发生流向反转存在争议。自动定量矿物分析系统TIMA(TESCAN Integrated Mineral Analyzer)在源区识别和古地理重建方面有极大的应用潜力。为此,本文利用TIMA技术对位于松花江T2阶地的哈尔滨荒山岩心沉积物进行重矿物及全岩矿物地球化学组成分析。结果表明,以深度62.3 m为界,岩心上、下地层沉积物的重矿物(例如,锆石、磷灰石、金红石、榍石、石榴石、钛铁矿、铁磁矿物和硅铁矿)及全岩矿物地球化学组成均存在明显差异。62.3 m以上地层沉积物的重矿物组合是闪石类+帘石类+榍石+铁磁矿物,硅铁锂钠石在上段地层中出现,全岩矿物地球化学元素较为稳定,波动幅度较小;62.3 m以下地层沉积物的重矿物组合是闪石类+帘石类+钛铁矿+榍石,方解石、铬铁矿、蛇纹石、黄铁矿和磁黄铁矿仅在下段地层中出现,全岩矿物地球化学元素波动幅度较大。TIMA重矿物和全岩矿物地球化学组成反映了岩心沉积物的物源发生明显变化,进而指示了松花江的水系演化。结合在依兰发现的河湖相地层,我们提出了松花江水系演化的新模式。早更新世时期,佳依(佳木斯—依兰)分水岭将松嫩水系和三江平原水系分隔开,作为松花江上游的牡丹江向东流经依兰—通河—哈尔滨,最终注入松嫩古湖。在0.94 Ma B. P.之后,松辽分水岭局部隆升,古松花江发生反转,从西向东流至通河—依兰地区形成古大湖。湖泊水位不断升高致使湖水溢流切穿佳依分水岭,形成现代松花江水系的基本格局。这挑战了以前的向源侵蚀导致佳依分水岭被切穿的水系演化模式。
