共查询到20条相似文献，搜索用时 421 毫秒
1.
黄河源区不同地貌环境下的河网发育模式、平面形态等具有显著差异,存在羽状、矩形状、对称羽状和树状4种典型的河网类型。选取黄河源区83个典型子流域,计算了河网平面特征参数,探讨了河网参数与地形和气候因子的关系及河网类型的分布规律。结果表明,4类河网平面特征差异性通过流域宽长比、河网密度和流域内河流流向最大频数得到了较好的体现。流域坡度和降雨量对河网密度及流向的影响显著,且能较好解释河网密度及流向最大频数的变化;降雨对流域宽长比的影响显著。羽状主要分布在源区上游北部边缘地带,气候干旱,地表裸露,流域坡度均值为4.5°,流域高差均值为730 m。矩形状集中分布在若尔盖地区,气候相对湿润,且有大量的沼泽湿地,流域坡度和流域高差均值分别为2.3°和177 m。对称羽状处于高山峡谷地带,流域坡度和流域高差均值分别为16.9°和1167 m,降雨量变化范围大。树状分布在黄河源中游山区及中下游的冲积地貌,流域坡度和流域高差均值分别为15.4°和968 m,植被覆盖较好。结合4类河网的空间分布特征及河网参数与环境因子的多元回归分析结果分析,认为地形是决定河网平面形态分异的主要原因;当地形限制减小,气候条件和植被覆盖情况对河网的发展起了重要作用。 相似文献
2.
黄河上游气候变化对地表水的影响 总被引：29，自引：2，他引：27
利用1961~2002年黄河上游唐乃亥水文站水文资料及同期该流域气象资料,研究黄河上游流域气候变化及其对地表水资源的影响,结果表明: 黄河上游年流量呈现出逐年减少趋势,20世纪90年代以来减少趋势更为明显;黄河上游流域气候变化表现出气温升高、降水减少和蒸发增大的干旱化趋势,这一变化趋势在90年代以来尤为突出;气温升高、降水量减少和蒸发量增大是导致黄河上游流量减少的气候原因,其中降水量是影响流量的主要气候因子,降水量的减少特别是夏季降水量的减少直接导致了黄河上游流量的减少。 相似文献
3.
Wu Shengguang Yang Dayuan Department of Geography Nanjing University Nanjing People''s Republic of ChinaWang Yunfei Nanjing Institute of Geography Limnology Academia Sini Nanjing People''s Republic of China 《地理学报(英文版)》1997,(2)
Ｉ.ＴｈｅＴｅｒｒａｃｅｓｏｆｔｈｅＵｐｐｅｒＹｅｌｌｏｗＲｉｖｅｒＴｈｅｔｅｒｒａｃｅｓｏｆｔｈｅｕｐｐｅｒＹｅｌｌｏｗＲｉｖｅｒａｒｅｍｏｓｔｌｙｄｉｓｐｅｒｓｅｄａｌｏｎｇｔｈｅｗｉｄｅｒｃｏｕｒｓｅｓｉｎｓｅｖｅｒａｌＭｅｓｏｚｏｉｃＣｅｎｏｚｏｉｃｂａｓｉｎｓ(Ｆｉｇｕｒｅ1).1.ＴｅｒｒａｃｅｓｂｅｔｗｅｅｎＮｇｏｒｉｎｇＬａｋｅａｎｄＧｙａｒｉｎｇＬａｋｅＴｈｅｓｕｒｆａｃｅｌａｙｅｒｓｏｆｔｈｅｓｅｄｉｍｅｎｔｉｎｔｈｅｗｉｄｅａｎｄｓｈａｌｌｏｗｂａｓｉｎｓｗｈｅｒｅｔｈｅＹｅｌｌ… 相似文献
4.
甘宁蒙陕农牧交错区的水资源及节水研究 总被引：2，自引：1，他引：1
甘宁蒙陕农牧交错区干旱缺水,黄河是惟一的过境河流和水源,但河水资源在该区已开发,利用过度,已造成了断流灾害和一系列重大环境问题。"南水北调"西域工程调入黄河的水量,主要是保证黄河流域社会经济结构调整和生态环境保护重建的需水,水源分配也基本上未考虑农业用水(兰州-河口镇段只安排了2亿m3农业用水)。显而易见,该区水资源的利用,主要是节水。尤其在甘宁蒙陕农牧交错区建成的几处扬黄灌区,普遍存在重开源轻节流,重骨干工程轻田间配套工程建设,重工程轻管理的思想,起点低工程不配套,水资源浪费损失严重,利用率低。 相似文献
5.
近50 a来黄河上游水循环要素变化分析 总被引：5，自引：6，他引：5
根据水文、气象台站观测资料,分析了黄河上游有器测资料几十年来降水、温度、径流等水循环素的变化过程与特征。结果显示,温度近几十年来流域各个地方有着不同程度的上升,与全球变暖有着明显的对应关系;而随着气温的上升,蒸发和下渗呈增加的趋势。降水变化的区域性特征十分明显,降水量的增减随地理位置不同而差异较大。受主要产流区域降水减少,气温上升的影响,黄河上游产水量呈持续递减的态势。在上述分析基础上,利用全球气候模式(GCMs)与统计模式对未来流域降水和径流的可能变化进行了预测。结果表明,未来30 a里,随着温度将进一步上升,降水量将比目前有明显增加,黄河上游的径流量将随降水量的增加而进入一个相对丰水的时期。 相似文献
6.
Landscape memory: the imprint of the past on contemporary landscape forms and processes 总被引：1，自引：0，他引：1
Gary John Brierley 《Area》2010,42(1):76-85
The imprint of the past upon contemporary landscape forms and processes is differentiated in terms of geologic, climatic and anthropogenic memory. Geologic memory refers to controls exerted upon relief, erodibility, erosivity and accommodation space (areas in landscapes where sediments are stored and reworked). These factors set the imposed boundary conditions within which contemporary landscape-forming processes operate. Climatic memory refers to the influence of past climatic conditions upon contemporary landscape forms and processes. Climatic controls exert a primary influence upon the nature of geomorphic processes, while the influence of climate upon ground cover affects the effectiveness of these processes. Climate change may induce profound alterations to the flux boundary conditions under which contemporary landscapes operate. This is exemplified by the variable imprint of glacial/interglacial cycles in differing parts of the world. Anthropogenic memory refers to the imprint of past human activities on contemporary landscapes, whereby human disturbance in the past altered landscape forms, processes and associated flow/sediment fluxes in a manner that continues to affect the way the contemporary landscape works. Contrasting examples from a tectonically stable landscape (Australia) and a tectonically uplifting landscape (New Zealand) are used to highlight the variable influence of geologic, climatic and anthropogenic memory upon the persistence and erasure of landscape forms and resulting implications for sediment flux in differing settings. 相似文献
7.
Sedimentation in the lower reaches of the Yellow River is a major problem requiring implementation of large-scale control measures in the upper and middle drainage basin. For maximum benefit, major sediment generation areas must be delimited. For this purpose, the upper and middle drainage basin of the Yellow River has been divided into four major sediment and water source areas. A series of databases of runoff and sediment yields from these source areas and for the corresponding quantities of sedimentation in the lower Yellow River channel have been established. On this basis, a set of multiple-regression equations has been established that define the relationships between sedimentation in the lower Yellow River and the yearly or event-based runoff and sediment yields from the four source areas or subsystems. Based on the regression equations obtained, the contribution of the four major source areas to the sedimentation in the lower Yellow River channel can be estimated. The results obtained indicate that, given other factors, for each ton of sediment reduced from the coarse-sediment producing area (CSA), the sediment deposited in the lower Yellow River would be reduced by 0.455 ton; for each ton of sediment reduced from the fine-sediment producing area (FSA), the sediment deposited in the lower Yellow River would be reduced by 0.154 ton only. Therefore, if limited erosion control measures are applied to the coarse-sediment producing area, the benefits for sedimentation reduction in the lower Yellow River will be much larger than if similar resources are applied to the fine-sediment producing area. 相似文献
8.
黄河流域水循环研究的进展和展望 总被引：7，自引：7，他引：7
总结了黄河流域水循环研究的进展,指出缺乏立足于水循环整体的机理过程的探讨及缺乏较成熟的流域水文模型是已有研究的不足。为能更好地模拟水文过程对各种作用力的响应,今后研究的方向将是建立既考虑垂向水分和能量传输(如降水,蒸发,感热),又考虑水平向的地表水分运动(汇流)和地下水基流过程的黄河流域的分布式水文模型。模型将结合遥感信息与地面资料,建立与区域大气环流模式(GCM)的接口,辅之以野外生态试验小区、径流试验场和室内试验的资料,以深入探索黄河流域水循环动力学机制 相似文献
9.
DING Yongjian YANG Jianping LIU Shiyin CHEN Rensheng WANG Genxu SHEN Yongping WANG Jian XIE Changwei ZHANG Shiqing 《地理学报》2003,13(2):172-180
Based on geographical and hydrological extents delimited, four principles are identified, as the bases for delineating the ranges of the source regions of the Yangtze and Yellow rivers in the paper. According to the comprehensive analysis of topographical characteristics, climate conditions, vegetation distribution and hydrological features, the source region ranges for eco-environmental study are defined. The eastern boundary point is Dari hydrological station in the upper reach of the Yellow River. The watershed above Dari hydrological station is the source region of the Yellow River which drains an area of 4.49×104 km2. Natural environment is characterized by the major topographical types of plateau lakes and marshland, gentle landforms, alpine cold semi-arid climate, and steppe and meadow vegetation in the source region of the Yellow River. The eastern boundary point is the convergent site of the Nieqiaqu and the Tongtian River in the upstream of the Yangtze River. The watershed above the convergent site is the source region of the Yangtze River, with a watershed area of 12.24×104 km2. Hills and alpine plain topography, gentle terrain, alpine cold arid and semi-arid climate, and alpine cold grassland and meadow are natural conditions in the source region of the Yangtze River. 相似文献
10.
巩乃斯河流域游憩景观生态评价及持续利用 总被引：21，自引：0，他引：21
流域是重要的景观生态空间和游憩景观建设空间。游憩景观生态适宜性评价与规划是合理利用流域资源,建立流域协调景观体系,促进流域可持续发展的重要环节。以巩乃斯河流域景观空间为依托,以游憩景观生态适宜性评价为核心,通过景观旷奥度和相容度的核心评价和综合评价,研究了巩乃斯河流域游憩景观生态适宜性特征,探讨了巩乃斯河流域游憩景观生态保护、游憩景观资源可持续利用的重点途径。 相似文献
11.
江河源区生态环境范围的探讨 总被引：8，自引：0，他引：8
丁永建 杨建平 刘时银 CHEN Rensheng WANG Genxu SHEN Yongping WANG Jian XIE Changwei ZHANG Shiqing 《地理学报(英文版)》2003,13(2):172-180
The Tibetan Plateau, as the origin of the Yangtze and Yellow rivers, is the region of climate variation and is very sensitive to climate change in China (Feng etal., 1998). The runoff in the upper reaches of the Yellow River has been decreasing at a rate of 9.8 m3/s per decade due to rapid climate warming in the Tibetan Plateau since the mid- and late 1980s (Zhang etal., 2000). Eco-environmental change is also extremely substantial in the source regions of the Yangtze and Yellow rivers. T… 相似文献
12.
13.
黄河水资源量可再生性问题及量化研究 总被引：15，自引：1，他引：14
通过探讨黄河水资源量可再生性的量化问题,对黄河断流的情况、危害和成因进行分析。由于水资源量可再生性问题的复杂性,现行的方法一般都过于简单。目前迫切需要从水文循环更深层次上揭示水资源量可再生性。依据系统理论方法,从河流水循环系统的稳定性和抗干扰能力出发,提出度量和评价河流水体水资源量可再生性的指数。利用该指数,对黄河干流上、中、下游河段不同年代的水资源量可再生能力进行了定量评价,评价结果能够客观地反映实际情况。从维持水资源量可再生性的角度,进行了黄河干流水资源量的调控分析。模拟结果表明,20世纪90年代严重的黄河断流问题主要受人为因素的影响。 相似文献
14.
黄河经济带可持续发展的战略构想 总被引：5，自引：1，他引：4
黄河经济带是我国重要的经济发展战略地带 ,本文在分析黄河经济带资源和环境问题的基础上 ,提出了可持续发展战略是黄河经济带发展的必然选择 ,并且论述了可持续发展的战略思路、原则、措施及对策建议。 相似文献
15.
CHANGXING SHI LUAN ZHANG JIAQIANG XU LIPENG GUO 《Geografiska Annaler: Series A, Physical Geography》2010,92(3):297-309
The Yellow River is one of the largest riverine sediment routing system in the world. Like many other rivers, the sediment load of the Yellow River can not be regarded as constant in its long history due to changes in climate and human activities. This study determined sediment storage on the floodplains of the lower Yellow River in five historical periods after the year 602 bc mainly based on data of 93 boreholes, 182 radiocarbon dates in the Huang‐Huai‐Hai Plain and maps of historical changes of the lower Yellow River channel. Furthermore, the mean annual sediment outputs from the upper and middle reaches of the Yellow River were calculated in the five periods through investigating the sediment delivery ratio of the lower Yellow River under different conditions of artificial levees. Our findings suggest that the sediment output from the upper and middle Yellow River increased slowly before the year around 1128, but was lower than half of the current value on average. It has been in the past about 1000 years that the sediment output from the upper and middle Yellow River escalated. The Loess Plateau is the principal sediment source of the Yellow River. The comparison of historical changes in sediment load of the lower Yellow River with those in the natural conditions and in human activities on the plateau reveals that the changes in sediment yield from the plateau could be attributed mainly to the variations of population, cultivating area, and climate changes on the plateau. 相似文献
16.
17.
The change characteristics and trends of the regional climate in the source region of the Yellow River, and the response of runoff to climate change, are analyzed based on observational data of air temperature, precipitation, and runoff at 10 main hydrological and weather stations in the region. Our results show that a strong signal of climate shift from warm-dry to warm-humid in the western parts of northwestern China （Xinjiang） and the western Hexi Corridor of Gansu Province occurred in the late 1980s, and a same signal of climate change occurred in the mid-2000s in the source region of the Yellow River located in the eastern part of northwestern China. This climate changeover has led to a rapid increase in rainfall and stream runoff in the latter region. In most of the years since 2004 the average annual precipitation in the source region of the Yellow River has been greater than the long-term average annual value, and after 2007 the runoff measured at all of the hydrologic sections on the main channel of the Yellow River in the source region has also consistently exceeded the long-term average annual because of rainfall increase. It is difficult to determine the prospects of future climate change until additional observations and research are conducted on the rate and temporal and spatial extents of climate change in the region. Nevertheless, we predict that the climate shift from warm-dry to warm-humid in the source region of the Yellow River is very likely to be in the decadal time scale, which means a warming and rainy climate in the source region of the Yellow River will continue in the coming decades. 相似文献
18.
ABSTRACT The tectonic evolution of a collisional hinterland sourcing the Ha?eg Basin, a Late Cretaceous syn‐orogenic sedimentary basin in the South Carpathians (Romania), is revealed through fission track thermochronology of detrital apatite and zircon grains. This basin formed on the upper plate (Getic unit) in response to Late Cretaceous collision with the lower plate (Danubian unit), an allochtonous continental block of the Moesian Platform, upon closure of a narrow oceanic basin (Severin Basin). The fission track results suggest that Turonian to lower Maastrichtian sediments of the Ha?eg Basin have been dominantly derived from pre‐Late Cretaceous sources. The age components they contain relate to pre‐Cretaceous tectonothermal events such as the Variscan orogenic cycle, Jurassic rifting and Severin Basin formation, and to Early Cretaceous compressional tectonics. These results are compatible with the tectonic evolution of the upper plate that is identified as the primary source. From the onset of sedimentation (late Albian) until the early Campanian the Ha?eg Basin resembles a piggy‐back basin formed on the upper plate concomitant with underthrusting and internal stacking of the lower plate. In contrast, important tectonic subsidence during the late Campanian and early Maastrichtian reflects a shift to extensional tectonics causing the unroofing of the collision zone and the exhumation of lower plate rocks back to the surface. Our fission track data place important constraints on the timing of lower plate erosion that must have commenced during the late Maastrichtian, as documented by the completely reset Late Cretaceous age component within upper Maastrichtian sediments (Sînpetru Formation). Late Maastrichtian uplift of the basin and the formation of positive relief at the site of the collision zone is an expression of continuous convergence. The mismatch between the amount of denudation and the amount of sediments trapped in the Ha?eg Basin underlines the importance of concomitant extensional unroofing. 相似文献
19.
准确掌握流域湿地资源的数量和分布, 是流域湿地评价、修复与保护决策的前提。利用“北京一号”小卫星数据对黄河流域2006年湿地格局现状进行了监测, 在GIS技术支持下对流域湿地资源分布的影响控制因素进行了分析, 进而结合不同流域分区水资源条件, 对流域湿地保护策略进行了探讨。研究表明, 2006年黄河流域湿地总面积为25134km2,其中, 河流、湖泊、沼泽、滨海、人工湿地面积分别占该流域湿地总面积的36.2%、8.0%、45.0%、3.9%、6.9%.受气候及水资源支撑条件的影响, 黄河流域重要湿地集中分布在源区高寒沼泽湿地、上游河湖湿地、中下游河道湿地以及河口三角洲湿地。流域天然湿地分布受气候影响显着, 随着气候干燥度的增加, 湿地率呈明显递减趋势。研究认为, 黄河流域大部分地区属于半干旱区, 水资源条件先天不足, 必须充分考虑流域和区域水资源的支撑能力和干扰影响, 在流域层面和河流生态系统的尺度上统筹考虑, 构建科学合理的流域湿地保护框架体系。 相似文献
20.
对中国东北地区侵蚀产沙尺度效应的空间变化进行了探讨。基于气候、下垫面的一致性和流域的完整性,对整个研究区域进行了分区研究。结果表明,尺度效应同时受到地形、坡度、土地利用和地表覆盖物质等因素的影响,不同分区因素因素组合不同,其产沙模数随流域面积的变化趋势亦不相同,可以分为三类:(1) 产沙模数随流域面积增大而增大;(2) 产沙模数随流域面积的增大基本保持不变;(3) 产沙模数随流域面积的增大而减小。基于各分区尺度效应,进行了不同标准面积下产沙模数图的校正,并使用空间插值方法,编制不同标准面积下产沙模数图。 相似文献