地貌特征对约旦南部阿尔阿加河(WadiAl-Arja)流域产沙影响分析(英文)

This study addresses the morphometric variables that determine the sediment yield in Wadi Al-Arja through the analysis of the impact of different morphometric characteristics along the course of the valley on its sediment yield, as well as the analysis of spatial and formal dimensions and morphologies of the basin and its relationship to the sediment yield. The study also addresses the size of variation in the volume of sediment yield of the river tributaries that make up the water network of the valley under the differences of its morphometric and hydrological characteristics. The study found several results, most notably: The classification of Wadi Al-Arja basin according to the hypsometric integral value(72.1%) within an uneven topography, which increases the force of the erosive activity and the size of the sediment yield if the basin was exposed to moist climatic periods. The study also showed the presence of convergence in the intra-spaces between the river tributaries in the water network. This increases the volume of water flows when these tributaries meet with each other and thus increasing their erosive ability and sediment yield. The study also showed the presence of marked variation in the sediment yield of the river tributaries depending on the differences in its morphometric characteristics. The results of the step-wise regression analysis confirmed the importance of the morphometric and hydrological variables, and plant coverage in interpreting the variation in the size of the sediment yield of the river tributaries of different stream order in Wadi Al-Arja basin, where these variables interpreted 43% of the total variation, with statistical significance less than 0.05.     

燕山山区潮白河河道特性

密云水库以上的潮白河分为白河和潮河两支,分别穿行于燕山山区。两河的上段为顺直河型或游荡河型,下段为典型的深切曲流。河势及河型受地质构造的深刻影响。潮白两河的纵比降大,来水、来沙在时间和空间上的分配不均匀,对不同河型的形成有影响,这也表明密云水库以上的潮白河具有山地河流的特点。     

黄河中游流域地貌形态对流域产沙量的影响

在黄河中游地区 ,选择了 5 0多个面积约 5 0 0～ 2 5 0 0平方公里的水文测站流域 ,分别代表 6种不同自然地理类型 ,在流域沟壑密度、沟间地坡度小于 15°面积百分比等地貌形态指标量计的基础上 ,进行了流域产沙量与地貌形态指标相关分析。结果表明 ,对于不同类型流域 ,流域产沙量随流域地貌的变化遵循不同的响应规律 ,而且视流域其它下垫面环境条件的均一程度 ,其相关程度和响应速率各不相同。受地面物质、植被、地貌发育阶段等流域其它下垫面环境条件的制约 ,除沟壑密度外 ,流域产沙量与流域地貌形态的关系都没有人们以前所预期的好。     

疏勒河流域泥沙分布规律及水沙关系研究

泥沙是影响河流健康和水环境的重要因素之一,受气候变化和人类活动的影响,流域水文要素和下垫面条件发生了较大变化,尤其是实施大规模的水土保持措施后,部分河流的泥沙含量大幅减少,但在河西内陆河流域发源于祁连山西端的疏勒河流域,受降水条件和人类活动的影响,河流泥沙呈增加趋势。本文应用疏勒河流域实测长系列水文资料,采用水文统计法、差积曲线法、趋势检验法、突变检验法、非线性复相关模型法等方法,分析了流域泥沙时空分布规律及水沙关系,结果表明：疏勒河干流昌马堡站年输沙量为333.5×104 t,至下游潘家庄站减少到223.5×104 t;党河党城湾站年输沙量为76.56×104 t,至下游沙枣园站增加到121.3×104 t;疏勒河干流输沙量主要集中在汛期7～8月,占全年的81.9 %～84.0 %,党河流域输沙量主要集中在4-8月,占全年的92.3 %;流域泥沙变化总体呈增加趋势,突变点1998年以后,年输沙量增加了86.3 %～148.2 %。建立了潘家庄站降水～泥沙、径流～泥沙以及年输沙量～年径流量～年最大洪峰流量关系模型,相关关系较好,相关系数达到0.717～0.858。流域出山口以上对泥沙的影响因素主要是降水,出山口以下主要是修建水库、水电站、引水工程、河道采砂等人类活动影响。随着国家对内陆河流域祁连山和河西走廊的日益关注,以及全国河长制的推行,河流生态健康已经提上日程,研究疏勒河流域泥沙分布规律及水沙关系,对国家实施西部生态安全战略、区域生态环境修复治理、水资源可持续利用等具有重要意义。     

无定河流域不同地貌区水沙过程对比

为了查明人为影响程度较低时期无定河流域内不同地貌区的水沙过程及其变化规律,选取1970年以前一段时期该流域内风沙区和黄土丘陵沟壑区河流的有关水文站的水文泥沙实测数据进行对比分析。结果表明,风沙区河流的流量变率较黄土丘陵沟壑区的小;风沙区河流的含沙量远小于黄土丘陵沟壑区河流的含沙量。黄土丘陵沟壑区河流具有极高的输沙率,而风沙区河流的输沙率微不足道。风沙区和黄土丘陵沟壑区河流的产流模数基本相近,但产沙模数非常悬殊,前者的产沙模数很小,为118.58~725.38t /km² · a,而后者的达到1879.36~25112.15t /km² · a。显然,无定河流域黄土丘陵沟壑区的河流是侵蚀产沙的主要来源区,因而是水土保持工作的重点区域。     

气候变化对渭河上游径流量和输沙量的影响

利用渭河上游北道水文站的径流量和输沙量资料和渭河上游流域16个气象站的气象资料,分析了1951—2000年期间气候变化对渭河上游径流量和输沙量的影响。结果表明:渭河上游径流量变化总体呈下降趋势,跃变点发生在1967年,20世纪60年代径流量最大,90年代以后径流量最小。径流量的变化主要取决于流域降水量的变化。葫芦河支流流域的降水量对径流量变化的影响最为敏感,其次是榜沙河支流流域的降水量。输沙量的多少主要取决于上游降水量的多少和大雨的次数,其次是风速大小和大风次数的多少。     

基于氢氧稳定同位素和水化学的青藏高原高寒内陆流域水文过程示踪研究

氢氧稳定同位素和水化学已成为研究水文循环过程的良好示踪剂,两者的结合能很好地揭示流域或者区域(特别是缺少水文观测数据的高寒内陆地区)的水文循环过程.青藏高原地表环境较恶劣,缺乏流域尺度的水文观测资料,不利于对流域尺度水文循环过程的综合理解和认识,成为水资源高效综合利用的瓶颈.为此,本文以青海湖沙柳河流域为研究对象,通过...     

汉江上游郧县段全新世古洪水滞流沉积物特征

对汉江上游郧县段一级阶地上典型古洪水滞流沉积物、古土壤和黄土3 种不同沉积物的宏观特征、粒度成分、理化性质、微观形态及地球化学元素进行了综合分析对比.结果表明,研究剖面中的古洪水滞流沉积物呈灰黄色(2.5YR7/2),与上下相邻地层往往呈突变关系且界线清晰;粒度组成总体较粗,粉砂质细砂土,分选较好;磁化率稍高于马兰黄土,但显著低于古土壤;烧失量平均值低于黄土和古土壤;石英颗粒表面分布有水下环境机械相撞形成的V形坑;元素的含量及UCC标准化曲线均与黄土和古土壤差异明显.与渭河谷地相比,汉江上游谷地古洪水滞流沉积物具有粒度组成偏粗、分选性稍差的特点.该研究成果对汉江上游谷地古洪水滞流沉积物的鉴别和古洪水水文参数的重建具有重要意义.     

风蚀水蚀共同作用下沙漠河流泥沙级配特征

以水蚀风蚀区内蒙古河段重要入黄支流西柳沟为研究对象,通过对西柳沟流域产沙地层及河流水文站悬移质泥沙采样分析和激光粒度仪测定,对研究区河道纵向、横向断面沉积的泥沙级配特征进行了分析,揭示了流域沉积泥沙粒径分布变化规律。结果表明：西柳沟流域沉积泥沙的中数粒径从上游丘陵沟壑区到下游农田区逐渐减小;河流右岸泥沙粒径较大,左岸泥沙粒径相对较小,河床泥沙粒径介于二者之间;流域沉积泥沙粒径主要分布在0.125~0.5 mm,而流域出口水文站悬移质泥沙粒径72.5%在0.025 mm以下,说明西柳沟进入黄河干流的泥沙主要为细泥沙。     

三峡水库不同类型支流河口泥沙淤积成因及趋势

为揭示三峡水库库区不同类型支流河口泥沙淤积的内在机理和变化趋势,本文充分利用水文、泥沙、固定断面和河道地形等原型观测资料,从支流水沙输移规律和河口局部水沙分布特征出发,研究了不同类型支流河口段泥沙淤积规律及主要影响因素的作用机理,探讨其淤积趋势及形成拦门沙的风险。结果表明:三峡水库蓄水后,库区不同类型支流河口普遍淤积,淤积范围及河道形态的变化各有特点;水库蓄水造成水动力条件减弱是河口泥沙淤积的根本原因,淤积幅度和范围主要取决于干支流来沙量和局部河势。在干支流来沙均明显减少的情况下,三峡水库库区支流河口泥沙淤积速度显著下降,形成拦门沙坎的可能性较小。     

人类活动对长江上游近期输沙变化的影响

利用1956-2007年径流—输沙序列,分期定量研究了长江上游近期主要干支流输沙变化及其原因,结果显示:①长江上游1994-2002年输沙量减少1.43亿t/a,人为减沙占91.2%,主要来自嘉陵江措施减沙;2003-2007年减沙4.50亿t/a,径流减沙占14.1%,前期持续的人类活动减沙占39.8%,三峡水库蓄水拦沙、金沙江措施减沙等新增人为减沙占46.2%。②金沙江1983-2000年输沙量增加0.48亿t/a,人为增沙占74.7%,主要是工程增沙;2001-2007年输沙量减小1.183亿t/a,全部为人为减沙,包括二滩等各型水库拦沙、水保减沙和工程增沙减少。③嘉陵江1985-1993年输沙减少0.827亿t/a,人为减沙占81.4%,主要人为减沙包括农村社会经济因素变化导致的土壤减蚀和水库拦沙;1994-2007年输沙量减少1.285亿t/a,其中自然径流减沙占29.6%,前期持续人类活动减沙占42.1%,宝珠寺等新增水库拦沙和水保减沙占23.4%,另有4.9%的人为减水减沙。     

陕西神府矿区束鸡沟流域风蚀水蚀交互作用特征研究

以神府矿区束鸡沟为典型小流域,讨论了风蚀水蚀交互作用的时空分布及其特征。风蚀水蚀交互作用在沙质坡面,坡面切沟和沙质沟道区表现最为突出,并形成了风蚀水蚀交互作用特有的侵蚀形态。     

长江流域侵蚀产沙尺度效应的区域分异

以长江流域水文站点的观测数据为依据,基于一定的分区原则,将整个长江流域分成了8个区域,对所有分区产沙模数的尺度效应进行了深入分析.研究表明,所有分区产沙模数的尺度效应可以概括为三类:产沙模数随流域面积的增大而减小,或先减小后基本保持不变的,主要包括长江中下游干流沿岸区域,岷江主体区域,洞庭湖流域和鄱阳湖流域;产沙模数随流域面积的增大基本保持不变的,包括嘉陵江主体区域和汉江流域;产沙模数随流域面积增大而增大,或先增大后基本保持不变的,包括长江上游干流沿岸的非泥石流区域和乌江流域.不同流域尺度效应的差异主要与流域土地利用方式有关.基于各分区校正方程,将所有站点进行了标准面积为100 km2,1 000 km2,10 000 km2的尺度校正,结果表明,当校正面积为100 km2,侵蚀最强烈的区域主要是岷江流域,其次是鄱阳湖和洞庭湖流域,校正面积为1 000 km2和10 000 km2,产沙模数图变化不显著,但明显区别于校正面积为100km2下的产沙模数图.侵蚀最强烈的区域主要是嘉陵江流域,其次是长江上游干流沿岸的部分区域和汉江流域的部分区域.不同校正面积下产沙模数图的变化,显示了不同流域侵蚀来源的差异.     

黄河中游流域环境要素对水沙变异的影响

目前 ,黄河中游地区流域的水沙变化主要以水文法和水保法研究为主。由于黄河中游具有明显的自然地带性分布特征 ,流域系统的水沙过程受到环境要素的综合影响。本文根据黄河中游河口镇至龙门区间已控一级支流的测站资料 ,采用地理环境要素法分析水沙变异及成因。研究表明 ,河龙区间流域径流量和输沙量与地理环境因子的影响密切相关。 2 0世纪 70年代以来 ,降雨减水减沙作用不断减小 ,随着水土保持措施的提高 ,人类活动减水减沙所占比重不断增大。 70年代与 80年代气候波动和人类活动影响的平均减水减沙作用分别为5 3 4 %、 2 8 6 %和 4 6 6 %、 71 4 %。     

Groundwater control on the suspended sediment load in the Na Borges River, Mallorca, Spain

Groundwater dominance has important effects on the hydrological and geomorphological characteristics of river systems. Low suspended sediment concentrations and high water clarity are expected because significant inputs of sediment-free spring water dilute the suspended sediment generated by storms. However, in many Mediterranean rivers, groundwater dominance is characterised by seasonal alternations of influent and effluent discharge involving significant variability on the sediment transport regimes. Such areas are often subject to soil and water conservation practices over the centuries that have reduced the sediment contribution from agricultural fields and favour subsurface flow to rivers. Moreover, urbanisation during the twentieth century has changed the catchment hydrology and altered basic river processes due to its ‘flashy’ regime. In this context, we monitored suspended sediment fluxes during a two-year period in the Na Borges River, a lowland agricultural catchment (319 km²) on the island of Mallorca (Balearic Islands). The suspended sediment concentration (SSC) was lower when the base flow index (i.e., relative proportion of baseflow compared to stormflow, BFI) was higher. Therefore, strong seasonal contrasts explain the high SSC coefficient of variation, which is clearly related to dilution effects associated with different groundwater and surface water seasonal interactions. A lack of correlation in the Q-SSC rating curves shows that factors other than discharge control sediment transport. As a result, at the event scale, multiple regressions illustrate that groundwater and surface water interactions are involved in the sedimentary response of flood events. In the winter, the stability of baseflow driven by groundwater contributions and agricultural and urban spills causes hydraulic variables (i.e., maximum discharge) to exert the most important control on events, whereas in the summer, it is necessary to accumulate important volumes of rainfall, creating a minimum of wet conditions in the catchment to activate hydrological pathways and deliver sediment to the drainage network. The BFI is also related to sediment delivery processes, as the loads are higher with lower BFI, corroborating the fact that most sediment movement is caused by stormflow and its related factors. Overall, suspended sediment yields were very low (i.e., < 1 t km^− 2 yr^− 1) at all measuring sites. Such values are the consequence of the limited sediment delivery attributable to soil conservation practices, low surface runoff coefficients and specific geomorphic features of groundwater-dominated rivers, such as low drainage density, low gradient, steep valley walls and flat valley floors.     

无定河流域侵蚀产沙过程对水土保持措施的响应

以黄河中游多沙粗沙区代表性支流无定河为例,研究了降水量变化的背景下水土保持措施对无定河流域侵蚀产沙的影响。从总体上看,年输沙量和年径流量都表现出随时间而减小的趋势,梯田、造林、种草和淤地坝拦沙造地4项水土保持措施面积随时间增大的趋势极其显著。全流域面平均年降水量和汛期 (6~9月) 降水量则略有减少的趋势,但其减少趋势的显著性远低于水土保持措施随时间变化的显著性。产沙模数与梯田、坝地、造林和种草面积的关系,均表现出明显的负相关。对基准期 (1956~1969年) 和措施期 (1970~1996) 进行了比较,结果表明,实施水土保持措施以后,产沙模数、径流系数和汛期径流能够被降水所解释的百分比,分别由69%、80%和77%,下降为26%、31%和54%。说明在后一时期中,水土保持措施起了很大作用,因而降水变化对于产沙模数、径流系数、汛期径流量变化的贡献率大大减小了。以1956~1996年间41年的资料为基础,建立了全沙产沙模数与径流系数、汛期降雨量、最大一日雨量、最大30日累积雨量、梯田林草面积和坝地面积之间的多元回归方程,该方程表明,全沙产沙模数随汛期降雨量、最大一日雨量、最大30日累积雨量的增大而增大,随梯田林草面积和坝地面积的增大而减小, 随径流系数的增大而增大。为了区分人为因素与气候变化对侵蚀产沙变化的影响,采用对数据进行标准化处理之后再进行多元回归分析的方法,来确定相对贡献率。结果表明,降水变化和水土保持措施变化对无定河全沙产沙模数变化的贡献率大致相等,前者占50.3%,后者占49.7%。文中还建立了粗泥沙产沙模数与上述影响因子之间的多元回归方程。     

澜沧江—湄公河流域的水资源及其开发利用现状分析

世界大河澜沧江—湄公河流跨亚洲中国、老挝、泰国、柬埔寨、越南和缅甸６ 国, 是亚洲第一国际大河。流域内有多种气候区和地理环境,其水文特征和水资源分布地域差异极大。文中着重对该区流域内的河川径流特征和水资源时空分布规律进行全面的分析,同时对该区流域内的水资源利用现状及其影响进行初步分析。为国际河流的国际合作开发和流域内水资源的可持续利用提供最基本的依据。     

Analysis of the contribution of multiple factors to the recent decrease in discharge and sediment yield in the Yellow River Basin,China

The Yellow River basin is well known for its high sediment yield. However, this sediment yield has clearly decreased since the 1980s, especially after the year 2000. The annual average sediment yield was 1.2 billion tons before 2000, but has significantly decreased to 0.3 billion tons over the last 10 years. Changes in discharge and sediment yield for the Yellow River have attracted the attention of both the Central Government and local communities. This study aimed to identify the individual contributions of changes in precipitation and human activities (e.g. water conservancy projects, terracing, silt dams, socio-economic and needs, and soil and water conservation measures) to the decrease in discharge and sediment yield of the Yellow River. The study used both improved the hydrological method and the soil and water conservation method. The study focused on discharge analysis for the upper reaches and the investigation of sediments for the middle reaches of the river. The results showed that discharge and sediment yield have both presented significant decreasing trends over the past 50 years. Precipitation showed an insignificant decreasing trend over the same period. The annual average discharge decreased by 5.68 billion m³ above Lanzhou reach of the Yellow River from 2000 to 2012; human activities (e.g. socio-economic water use) contributed 43.4% of the total reduction, whereas natural factors (e.g. evaporation from lakes, wetlands and reservoirs) accounted for 56.6%. The decrease in annual discharge and sediment yield of the section between Hekouzhen station and Tongguan station were 12.4 billion m³ and 1.24 billion tons, respectively. Human activities contributed 76.5% and 72.2% of the total reduction in discharge and sediment yield, respectively, and were therefore the dominant factors in the changes in discharge and sediment yield of the Yellow River.     

黄河中游支流悬移质粒度与含沙量、流量间的复杂关系

本文以黄河中游若干支流为例,研究了宽变幅水沙两相流河流悬移质泥沙的粒度特征。结果表明,宽变幅水沙两相流河流的悬移质泥沙粒度特征与含沙量、流量之间具有复杂的关系。就同一站点而言,随着含沙量和流量的增大,大于0.05mm的粗颗粒泥沙的百分比迅速减小,并达到最小值;当含沙量和流量进一步增大时,其百分比又迅速增大,表现出明显的双值关系。对于小于0.01mm细泥沙而言,情形正好相反。黄河中游不同的支流之间,悬移质泥沙粒度特征与年均含沙量的关系也是复杂的。这些变化图形可以用非高含沙水流与高含沙水流不同的物理力学行为来解释