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1.
1 INTRODUCTION The Ussuri / Wusuli River watershed is located in the southeast part of Heilongjiang Province of China, which joins remote regions of Russia. The watershed consists of approximately 26 000 000 ha, which is about two thirds of the watershed ecosystem in Russia, one  third in China. The Ussuri River forms part of the border between Russia and China, the shared border stretches more than 1100 km. Khanka/Xingkai Lake lies within both China and Russia. Its total area …  相似文献   

2.
TheSonghuaRiver,oneofthemajorriversinNortheastChina,hastwosources:thenorthsourceistheNenjiangRiverandthesouthsourceistheSecondSonghuaRiver.ThetrunkstreamoftheNenjiangRiver,risingatthesouthernfootoftheYilehuliMountain,is1370kmlonganditswatershedareais…  相似文献   

3.
Dynamic variation of nitrogen content in the Second Songhua River   总被引:1,自引:0,他引:1  
ThewaterpollutionintheSecondSonghuaRiverhasbeenpaidmuchattentiontoforalongtime.Manyenvironmentalscientistshavedonealotofresearchworkonit,butmostofresearchcontentsweretofocusonheavymetalpollutionandorganicpollutioninwater,andlittleaboutnitrogen(Fuet…  相似文献   

4.
Satellite-based products with high spatial and temporal resolution provide useful precipitation information for data-sparse or ungauged large-scale watersheds. In the Lower Lancang-Mekong River Basin, rainfall stations are sparse and unevenly distributed, and the transboundary characteristic makes the collection of precipitation data more difficult, which has restricted hydrological processes simulation. In this study, daily precipitation data from four datasets(gauge observations, inverse distance weighted(IDW) data, Tropical Rainfall Measuring Mission(TRMM) estimates, and Climate Hazards Group InfraRed Precipitation with Stations(CHIRPS) estimates), were applied to drive the Soil and Water Assessment Tool(SWAT) model, and then their capability for hydrological simulation in the Lower Lancang-Mekong River Basin were examined. TRMM and CHIRPS data showed good performances on precipitation estimation in the Lower Lancang-Mekong River Basin, with the better performance for TRMM product. The Nash-Sutcliffe efficiency(NSE) values of gauge, IDW, TRMM, and CHIRPS simulations during the calibration period were 0.87, 0.86, 0.95, and 0.93 for monthly flow, respectively, and those for daily flow were 0.75, 0.77, 0.86, and 0.84, respectively. TRMM and CHIRPS data were superior to rain gauge and IDW data for driving the hydrological model, and TRMM data produced the best simulation performance. Satellite-based precipitation estimates could be suitable data sources when simulating hydrological processes for large data-poor or ungauged watersheds, especially in international river basins for which precipitation observations are difficult to collect. CHIRPS data provide long precipitation time series from 1981 to near present and thus could be used as an alternative precipitation input for hydrological simulation, especially for the period without TRMM data. For satellite-based precipitation products, the differences in the occurrence frequencies and amounts of precipitation with different intensities would affect simulation results of water balance components, which should be comprehensively considered in water resources estimation and planning.  相似文献   

5.
The upper Huanghe(Yellow) River basin is situated in the northeast of the Qinghai-Xizang(Tibet)Plateau of China.The melt-water from the snow-cover is main water supply for the rivers in the region during springtime and other arid regions of the northwestern China, and the hydrological conditions of the rivers are directly controlled by the snowmelt water in spring .So snowmelt runoff forecast has importance for hydropower,flood prevention and water resources utilize-tion.The application of remote sensing and Geographic Information System(GIS) techniques in snow cover monitoring and snowmelt runoff calculation in the upper Huanghe River basin are introduced amply in this paper.The key parame-ter-snow cover area can be computed by satellite images from multi-platform,multi-templral and multi-spectral.A clus-ter of snow-cover data can be yielded by means of the classification filter method.Meanwhile GIS will provide relevant information for obtaining the parameters and also for zoning .According to the typical samples extracting snow covered moun-tained in detail also.The runoff snowmelt models based on the snow-cover data from NOAA images and observation data of runoff,precipitation and air temperature have been satisfactorily used for predicting the inflow to the Longyangxia Reser-voir,which is located at lower end of snow cover region and is one of the largest reservoirs on the upper Huanghe River, during late March to early June.The result shows that remote sensing techniques combined with the ground meteorological and hydrological observation is of great potential in snowmelt runoff forecasting for a large river basin.With the develop-ment of remote sensing technique and the progress of the interpretation method,the forecast accuracy of snowmelt runoff will be improved in the near future .Large scale extent and few stations are two objective reality situations in Chian,so they should be considered in simulation and forecast.Apart from dividing ,the derivation of snow cover area from satellite images would decide the results of calculating runoff.Field investigation for selection of the learning samples of different snow patterns is basis for the classification.  相似文献   

6.
基于2004~2021年GRACE/GRACE-FO重力卫星数据反演黄河流域陆地水储量时空变化,并构建干旱指数模型和洪水因子模型,对黄河流域的极端气候现象进行分析研究。结果表明,2004~2021年黄河流域的陆地水储量以0.56 cm/a的速度减少,具有明显的季节周期性特征,在夏季和秋季呈盈余状态,春季和冬季呈亏损状态;干旱指数模型监测到期间黄河流域发生极度干旱事件22次、重度干旱事件37次,干旱事件范围涵盖整个黄河流域;洪水因子模型探测到黄河流域共发生洪水事件118次,多出现在夏季和秋季雨水较为丰沛的时候,期间黄河流域陆地水储量能力较弱,降雨量增大。利用GRACE/GRACE-FO重力卫星数据构建的干旱指数模型和洪水因子模型探测的气象结果与实际观测结果较为符合,能真实反映黄河流域发生的极端气候,可为极端气候研究提供有利工具。  相似文献   

7.
以研究区3030个流域水文数据为基础,利用数字高程模型(DEM)并运用非线性拟合法分析中小流域集水面积阈值与河源密度的相关关系,分析集水面积阈值与河源密度的幂函数关系可得,幂指数a近似为-1,拟合公式常系数k具有区域分布特征,反映了不同地区的河网发育程度,k值越大,河源密度越大,河网越密集,河网发育程度越高。对河源密度随集水面积阈值的变化趋势进行分析,发现2个具有统计意义的阈值临界点,分别为河源从坡面到沟道及从沟道到河道的集水面积分界点,在研究区内选择不同k值区间的贡曲流域、辰清河流域和藤条江流域作为样本流域,利用样本流域数字正射影像(DOM)手工提取其沟谷河网及主河道河网的图形信息和水文信息,并与分界点处阈值提取的河网作对比,将分析得出的河网密度相对误差率作为检验标准,对临界点的物理意义进行检验。  相似文献   

8.
1INTRODUCTION Physiognomycharacteristicofawatershedisasymbolof ground erosion and incision, and it has been one of the most important factors influencing soil erosion and sedi- ment in the drainage area. Therefore physiognomy char- acteristic of the watershed and its influences on hydro- logical bed load have been one important focus in the watershed research both domestic and abroad (SCHUMM, 1977; QIAN et al., 1987) since the classical study by Horton in 1942 (HORTON, 1954). In rec…  相似文献   

9.
黑龙江(又称为阿穆尔河)是中国和俄罗斯之间的国际界河,近年来洪水事件频发,给流域内中俄两国带来巨大的人口伤亡和经济损失,加强该流域的洪水监测是两国面临的共同紧迫需求。传统的光学遥感影像受制于洪水期间多云多雨的天气状况,难以及时获得无云影像。本文充分利用全天候雷达数据的优势,提出了一种基于哨兵1号(Sentinel-1)合成孔径雷达数据监测大面积区域洪水的方法。通过Gamma分布和高斯分布拟合SAR影像后向散射系数的概率密度分布,迭代后验概率差值,自动获得全局阈值来分割初始的水体,基于辅助数据细化去除了初始水体中与水体相似的误分类型,并由形态学操作后处理提高了提取的洪水的均匀性。结果表明:① 与传统的分割算法相比,本文提出的方法基于SAR影像后向散射系数的分布规律进行概率密度函数分段拟合,将全局统计划分为局部关系,显著地改善了常规分割算法在水体和非水体像素量级相差过大而表现不佳的情况;② 研究获得了2017—2020年逐年的洪水分布,结果总体精度在87.78%~94.89%之间,Kappa系数在0.76~0.89之间;③ 特别是对于大面积半干旱地区,本文结合了后向散射特性、地形和其他辅助信息的关系,使得能够有效地保留水体并去除与水体后向散射系数相似的地物;④ 结果显示黑龙江(阿穆尔河)中下游沿岸城市哈巴罗夫斯克、阿穆尔斯克等地区为经常性泛洪区域,洪水面积整体呈增加趋势。研究表明,基于雷达数据对洪水空间范围进行时间序列监测,可以为中俄黑龙江流域洪水发展动态监测提供科学支撑。  相似文献   

10.
黄河河口湿地景观变化影响丹顶鹤生境的评价分析   总被引:2,自引:0,他引:2  
上世纪90年代以来,在全球气候变化及人类活动的影响下,黄河河口湿地景观发生了显著变化,对河口湿地生态系统及生物多样性保护带来深远影响。本文以景观生态学理论为指导,利用遥感技术和GIS空间分析方法,在对河口湿地景观变化过程分析的基础上,以丹顶鹤为指示物种,重点探讨了湿地景观变化对物种生境的影响,进而为河口退化湿地生态系统恢复和重建,以及湿地生境保护提供理论依据和决策支持。本文研究表明,1992-1999年,黄河三角洲河口湿地干旱化趋势明显,芦苇沼泽和翅碱蓬滩涂萎缩严重,丹顶鹤适宜生境面积大幅度减少,近30%的栖息地生境发生退化,严重退化的生境占11%。1999-2006年,在水量调控及湿地恢复措施的影响下,芦苇沼泽、翅碱蓬滩涂,以及水面湿地面积都有显著增加,占栖息地总面积28.7%的生境,得到一定程度的改善。但受不断加剧的景观破碎化影响,生境得到较好恢复的栖息地面积只占12%。研究认为,对于退化湿地的修复,在改善湿地景观的同时,加强生境管理,减轻人为活动引起的生境破碎化影响,是一重要的措施。  相似文献   

11.
As a major sediment area in the upper Yangtze River, Jialing River basin experienced substantial land-use changes, many water conservancy projects were constructed from the 1980 s onward to promote water and soil conservation. The water and sediment yield at the watershed outlet was strongly affected by these water conservation works, including ponds and reservoirs, which should be considered in the modelling. In this study, based on the observed data of the Weicheng River catchment, the relationships between precipitation, runoff, vegetation, topography and sediment yield were analyzed, a distributed runoff and sediment yield model(WSTD-SED) was developed, and the hydrological processes of different land-use scenarios were simulated by using the model. The main results are summarized as follows: 1) there is an alternating characteristic in river channels and reservoirs in the Jialing River hilly area, with scour occurring in wet years and deposit occurring in dry years. 2) Most of the sediment deposited in river channels and reservoirs is carried off by the largest flood in the year. 3) The model yielded plausible results for runoff and sediment yield dynamics without the need of calibration, and the WSTD-SED model could be usedto obtain qualitative estimates on the effects of land use change scenarios. 4) The modelling results suggest that a 10% increase in cropland(dry land) reforestation results in a 0.7% decrease in runoff and 1.5% decrease in sediment yield.  相似文献   

12.
The results of water sample analyses and investigation in the head area of the Changjiang River reveal that the characteristics of hydrochemistry of the river vary with drainage basins. In the drainage basin of the Tuotuo River, the mineral concentration of water is generally high, ions of Cl and Na are obviously dominant. The water tends to be salty, and the type of hydrochemistry is rather complex. In the drainage basin of the Dam River, the mineral concentration is mainly in a low and middle level, ions of HCO3- and Ca2 are higher than others, and the type of hydrochemistry is relatively simple. The ground water in deep layers plays an important role in recharging surface water, and the stable recharging results in little change in chemical composition of surface water.  相似文献   

13.
随着计算机信息技术在水利学科中应用的深入,以及数字水利、数字流域概念的提出,水利信息化已经成为这一行业领域的主要发展方向,各种流域模型在与地理信息系统平台结合后在数据的收集、存储,提取与处理的基础上都有了很大的发展,在水利工程的规划设计、防洪减灾、水量分配等方面有更为广泛的应用。青岛市大沽河流域内洪水有来势猛、峰高量大和暴涨暴落的特性,为满足防汛管理部门对洪水预测及相关信息快速浏览查询的需求,建立了青岛市大沽河流域防汛信息系统。该系统在MAPX地理信息系统开发软件、数据库存储技术和水流数学模型的支持下,实现了大沽河流域的地理信息、水文信息以及其他信息的综合管理,同时通过水流数学模型对一维和二维洪水进行预测预报,并根据用户的需要完成所需的查询与分析功能,以最直观简洁的方式向用户展示系统的输出结果。系统数据库的开发在满足系统要求的基础上完成了与青岛市雨情水情自动监测系统的对接,保证了水文数据的实时性、完整性和准确性。系统集成了一维非恒定流模型与平面二维非恒定流水流模型,可以根据大沽河流域降雨量计算干流的水位变化以及发生溃堤后洪水的淹没过程。应用表明,该系统界面友好、功能完善、性能良好,具有很强的实用性。  相似文献   

14.
基于DEM的流域水系分维计算与结果分析   总被引:7,自引:0,他引:7  
利用ArcGIS8.3和ArcVIEW3.2中的水文分析模块,根据不同最小河流长度,提取晋江流域河网信息,采用传统的网格法计算提取的不同河网的分维,研究以最小河流长度所提取的不同河网密度与分维的关系,确定晋江流域分维,分析流域地貌的演变。  相似文献   

15.
Hydropower if scientifically developed is considered to be one of the clean and non-polluted renewable energy sources. But its impacts always exist on physical and social environment of the area. The present study was conducted in the River Satluj basin which is well known for its hydropower potential. The main objective of the study was to understand the vulnerability of the Satluj basin and to develop a strategy for the development of hydropower projects.This basin has been facing many problems relating to construction of haphazard development of hydropower projects. This has led multi-hazards like landslides, floods, earthquakes, etc. Here,vulnerability assessment index was assessed quantitatively and qualitatively. Geographical Information System and people's perception were used to study these aspects in the basin. The parameters considered for vulnerability assessment were slope, slope profile, relative relief, curvature,slope aspect, soil texture, lithology, river morphometry, precipitation, hydroelectric projects,land use and land cover, mass-movement, flood,geological elements and earthquake occurrences. The highest vulnerability was found in the middle zone,and finally on the basis of parameters analyzed; the hydropower's development strategy was developed.  相似文献   

16.
本文在分析山东黄河流域生态基础条件、生态本底状况,识别流域主要生态问题的基础上,提出了流域生态修复基本思路,构建了“两屏两心多廊”的流域生态修复格局,进行了流域生态修复分区;提出了流域生态修复的具体路径,主要是泰山和徂徕山-莲花山区域、黄河和大汶河生态廊道、黄河三角洲和东平湖湿地的生态修复;为实现流域一体化保护修复,从法律、经济、技术等方面构建了流域生态修复协同推进机制。  相似文献   

17.
黄河三角洲南部冲洪积扇区浅层地下水由于长期大量开发利用,早已形成了区域性漏斗群。通过对漏斗区地下水赋存条件和调蓄条件的分析,提出了由新建的引黄主干渠引黄河水,采用河渠、坑塘内施工回灌引渗,以及丰水期大气降水地表径流拦蓄引渗和引黄河水引渗回灌联合调度的方案,并从调蓄资源增量、调蓄可行性和调蓄效益等方面进行了论证。  相似文献   

18.
Based on the isotope analysis result of water samples in the 18 sections of the Yellow River, the variation of δ18Oand δD have been analyzed. From near the source to the entrance to the sea, the Yellow River has a general trend that the ratios of the stable isotope increase progressively; The main factors affecting the isotopes in the river water are mixing of external water bodies, evaporation and others; In the river segment between Lanzhou and Baotou and in lower reaches, the extent of the evaporation effect on the isotope fractionation from the river water surface is limited but the evaporation from the irrigated river water and the return flow is one of the main factors affecting the isotopes in river water.  相似文献   

19.
As a key factor limiting primary productivity in marine ecosystem, dissolved iron(DFe) export from fluvial systems has increased recently. There is particular concern about discharges of DFe during extreme flooding, when they are thought to increase considerably. An extreme flood event that caused inundation of extensive areas of Far Eastern Russia and Northeastern China occurred in the basin of the Amur River during summer and autumn 2013. During this event, water samples were collected in the middle reaches of the Amur River and the lower reaches at Khabarovsk City and analyzed for DFe concentrations and other aquatic parameters. The results show that the average DFe concentrations in the middle reaches of the Amur River(right bank) and at Khabarovsk were 1.11 mg/L and 0.32 mg/L, respectively, during the extreme flood in 2013. The total discharge of DFe during the flood event was 6.25 × 104 t. The high discharge of DFe during the flood reflects the elevated discharge of the river, hydrologically connected riparian wetlands, vast quantities of terrestrial runoff, and flood discharges from the Zeya and Bureya reservoirs. These results show that long-term monitoring is needed to identify and assess the impacts of DFe transport on the downstream reaches, estuarine area, and coastal ecosystems of the Amur River.  相似文献   

20.
This paper presents a paleoflood study to determine the flood frequency of the Changjiang River, based on core cj0702, taken from the Changjiang River subaqueous delta. We identified flood deposits by means of high-resolution grain-size variation, sensitive population, geochemical indexes and magnetic susceptibility. The core covers a time span of 120 years by 210 Pb dating and was sampled at 1–2 cm intervals. Grain size, geochemical elements, and physical parameters were analyzed. The results indicate that the sediment of the core is mainly composed of silt and clay, as well as groups of interbedded silt, clay silt, and clay. Vertically, the grain size pattern was controlled by seasonal variations in water discharge and by the sediment input in winter from the abandoned Huanghe River delta. River flooding caused extreme values in all our measured parameters. We identified more than 20 flood events that occurred since 1887 using the physical parameter analysis method. The environmentally sensitive component of sediment grain size(14.32–96.39 μm) contribution30%, Zr/Rb ratio1.5, and magnetic susceptibility16 were selected as the criteria for flood identification generally. We also found that floods that had taken place in the upstream, midstream, or downstream parts of the river were clearly identified by these indexes while the large-scale floods that covered the whole drainage area did not leave clear indications in the sediment record. This study for identification of flood events is of great significance for understanding hyperpycnal current sedimentation as well as for forecasting of floods.  相似文献   

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