地貌格局与流域侵蚀产沙过程关系定量分析——以黄河中游河龙区间为例

以河龙区间42个流域为对象,在流域地貌格局信息提取和侵蚀产沙过程特征指标计算及其相互关系分析的基础上,探讨地貌格局对流域侵蚀产沙过程的影响。结果表明:①在河道系统水平,河流数量、长度等几何特征指标和河流分叉率(Rb₁₂)、分级率(Rd₃₂)、相邻级别间的河流长度比等形状特征指标与流域侵蚀模数显著相关;②在流域系统水平,坡度粗糙度、相对高差、圆度比、高长比是影响流域侵蚀产沙过程的主要指标,其中坡度粗糙度是最根本的解释变量;③各地貌格局因子间相互作用复杂,且对侵蚀过程的影响要强于泥沙输移过程,其通径分析模型对流域侵蚀模数、输沙模数和泥沙输移比变化的解释度分别为65%、33%和20%。这对正确认识影响流域侵蚀产沙过程的格局因素和建立准确的过程模型,具有重要参考价值。     

黄土丘陵沟壑区流域系统侵蚀与产沙关系

从长期来看流域系统的侵蚀与产沙基本可以达到平衡,泥沙输移比约等于１。但次降雨或分年度泥沙输移比有相当大的变幅,在短期内会经常存在泥沙的滞留和滞留的泥沙被重新锓蚀搬运,而出现泥沙输移比小于１和大于１的情况。这主要与降雨的空间分布和洪峰增减幅度及径流深度增减幅度密切相关。流域系统次降雨泥沙输移比及各级沟道含沙水流的挟沙能力变化可用单位面积上洪峰增减幅度变化时暴雨洪水的剪切力的转化机制来描述。     

塔克拉玛干沙漠简单线形沙丘形态动力学过程研究

采样分析、风沙观测以及计算结果表明,在不同风向作用以及沙丘形态参数改变等因素的控制下,简单线形沙丘表面起动剪切速度有明显的差异。表面的气流强度随风向的改变而有所不同。气流与沙丘正交时迎风一侧的输沙率远大于背风一侧同地貌部位的输沙率,但当气流与沙丘走向斜交时,沙丘两侧同地貌部位的输沙率差异不是太大,这是线形沙丘在动力学过程中能保持其形态的最主要原因之一。风向的多变以及沙丘形态的变化使风沙流内边界层内随高度的风速与所观测的输沙率虽也表现为幂函数关系,但相关性较低。沙丘表面被输移的沙物质的粒度分布与下垫面物质组成有一定的差异,在中低强度的起沙风范围内,被输移的沙物质的平均粒径小于下垫面沙物质的平均粒径,且随风速或输沙率的增大,粒度组成也趋于统一。总体上,地表沙物质的输移仍是一随机过程。     

中国河流地貌研究进展——纪念沈玉昌先生100年诞辰

2016年是中国现代河流地貌研究的开拓者和奠基人沈玉昌先生100年诞辰,本文对中国河流地貌研究进展进行综述,以资纪念。研究涉及4个方面：① 水系发育与河谷地貌演变,包括大江大河水系历史发育和山区河流地貌;② 侵蚀与产沙过程,包括有物理成因基础的侵蚀产沙模型、侵蚀产沙过程的尺度效应、植被对侵蚀的影响及临界现象、坡面细沟发育过程模拟等;③ 河床过程与河型,包括河道冲淤过程、河床演变、河型成因与演变等;④ 河流地貌系统研究,包括流域系统不同子系统的耦合关系、河流地貌系统中的高含沙水流和多营力地貌过程、河流地貌系统对于自然因素变化和人类活动的响应、河流地貌系统中的泥沙灾害和河流地貌系统的实验研究等。50年前沈玉昌先生与钱宁先生提出在地貌学与河流动力学相结合的基础上发展中国河流学科。文中对此方面的进展进行了综述,并提出了需要深化和解决的问题。     

基于GIS的小流域土壤侵蚀与产沙的简化模拟

将泥沙输移能力公式与USLE公式相结合,建立了一个简化的分布式小流域产沙模型,并将其应用于川中丘陵区小流域的土壤侵蚀与泥沙输移的空间分布模拟。得到的主要结论:1.该模型适用于川中丘陵区小流域产沙的模拟;2.魏城河流域1980—1987年8 a平均土壤侵蚀量为16.8×104t,侵蚀模数为675.8 t/(km2.a),模拟得到的输沙模数为238.6 t/(km2.a),泥沙输移比为0.35;3.魏城河流域主要以微度侵蚀为主,占到全流域总面积的68%,强度侵蚀占流域面积的1%,主要分布在坡度较陡的流域边缘地带;4.相对其他因子,降雨与坡度对该流域侵蚀产沙的影响更为突出。     

瓯江河口输沙模式与应用研究*

本文从河口塑造与输沙关系、流域泄沙与输移模式,以及口外来沙与潮流输移特征等三方面,探讨河口区的泥沙运移规律和补给来源。并在此基础上,提出粗细不同粒级的造床泥沙按不同方式治理的设想。     

瓯江河口输沙模式与应用研究

本文从河口塑造与输沙关系、流域泄沙与输移模式,以及口外来沙与潮流输移特征等三方面,探讨河口区的泥沙运移规律和补给来源。并在此基础上,提出粗细不同粒级的造床泥沙按不同方式治理的设想。     

流域侵蚀产沙和物质转移*

联系当前全球土壤流失的现状,本文阐明研究侵蚀产沙和物质输移规律的重要性,从侵蚀产沙和物质输移的流域系统概念出发,并结合我国黄土高原的治理,扼要介绍国内外这一领域的研究概况.     

中国三峡库区土壤侵蚀及泥沙控制

三峡库区严重的土壤侵蚀与泥沙输移是三峡库区泥沙重要的来源之一,威胁三峡工程安全。坡耕地是三峡库区泥沙主要源地,占入库泥沙的46%;大规模的库区后靠移民工程引起的土地利用变化与山区开发及三峡工程建设过程的工程扰动加剧了土壤侵蚀与产沙。三峡工程建设及运行后引发的滑坡、泥石流等地质灾害将进一步增加入库泥沙量。为了有效控制三峡库区土壤侵蚀,减少水土流失,保护库区环境,从1989年开始以小流域综合治理为典型模式的水土保持工程在三峡库区广泛开展,有效控制了库区土壤侵蚀与泥沙输移。宜昌市夷陵区太平溪小流域综合治理模式是三峡库区小流域综合治理的成功模式,文章分析了其治理模式与水土保持及泥沙控制效益。应用水保法评价了三峡库区水土保持与小流域综合治理的减沙效益,并把评价结果与遥感监测分析法进行了对比分析,认为两种评价结果均在可接受范围。结果表明经过16年的水土保持与小流域综合治理,截至2005年三峡库区年均减少土壤侵蚀43.75–45.94×106 t ,减少入库泥沙12.25–12.86×106 t 。     

黄河流域土壤侵蚀产沙模型研究进展

土壤侵蚀产沙模型是国土资源动态变化模拟、土地资源环境质量评价、制定水土保持规划措施的重要技术手段,对指导生产实践具有十分重要的意义。黄河流域尤其是黄土高原的土壤侵蚀始终是土壤侵蚀和黄河泥沙研究的热门问题,近年来,结合“数字黄河”、“模型黄土高原”建设,广大地理学、水土保持、水利工程、水文学及水资源科技工作者,围绕黄河流域的土壤侵蚀产沙问题开展了大量卓有成效的工作,配合黄河流域水土保持以及水土资源合理配置和管理,从经验模型到理论模型,不仅提出和开发了许多具有十分重要实用价值的土壤侵蚀产沙模型,而且在引进国外先进技术、先进模型方面也做了大量工作。本文从土壤侵蚀产沙模型的自主开发和现有模型的应用两个方面、经验统计模型与物理模型两个领域简要回顾了90年代中期以后国内学者在黄河流域土壤侵蚀产沙模型方面主要的研究成果,并针对在该地区进行土壤侵蚀模型方面的研究方向提出了作者一些不成熟的看法和建议。     

Relation between the erosion and sedimentation zones in the Yellow River, China

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.     

Channel change at Toudaoguai Station and its responses to the operation of upstream reservoirs in the upper Yellow River

The application of dams built upstream will change the input conditions, including water and sediment, of downstream fluvial system, and destroy previous dynamic quasi-equilibrium reached by channel streamflow, so indispensable adjustments are necessary for downstream channel to adapt to the new water and sediment supply, leading the fluvial system to restore its previous equilibrium or reach a new equilibrium. Using about 50-year-long hydrological, sedimentary and cross-sectional data, temporal response processes of Toudaoguai cross-section located in the upper Yellow River to the operation of reservoirs built upstream are analyzed. The results show that the Toudaoguai cross-section change was influenced strongly by upstream reservoir operation and downstream channel bed armoring thereafter occurred gradually and extended to the reach below Sanhuhekou gauging station. Besides, median diameter of suspended sediment load experienced a three-stage change that is characterized by an increase at first, then a decrease and an increase again finally, which reflects the process of channel bed armoring that began at Qingtongxia reservoir and then gradually developed downstream to the reach below Sanhuhekou cross-section. Since the joint operation strategy of Longyangxia, Liujiaxia and Qingtongxia reservoirs was introduced in 1986, the three-stage change trend has become less evident than that in the time period between 1969 and 1986 when only Qingtongxia and Liujiaxia reservoirs were put into operation alone. In addition, since 1987, the extent of lateral migration and thalweg elevation change at Toudaoguai cross-section has reduced dramatically, cross-sectional profile and location tended to be stable, which is beneficial to the normal living for local people.     

黄河中下游水沙变化趋势

本文论述由于黄河上游清水区水资源的优先开发,中上游地区工农业用水的增长,而黄河中游地区的水土保持和支流治理的减沙作用不甚明显,龙羊峡水库投入运用后,汛期进入河口镇的水量大幅度减少,使汛期进入黄河下游的基流减小含沙量增加,高含沙洪水出现的机会增多.面临水少沙多的不利情况,应加强宽浅河道的改造及利用窄深河道输送高含沙水流的研究.     

黄河上中游产水产沙系统与下游河道沉积系统的耦合关系

本文在黄河为例，动用数理统计方法，研究了河流流域系统中产水产沙子系统与河道沉积子系统之间的关系，得到了描述这种耦合关系的多元回归模型。运用这一模型，可以定量回答来自上中游不同来源区的泥沙，各有多大比例淤在下游河道中的问题。     

黄河近年径流泥沙剧减的多因素贡献率分析（英文）

The Yellow River basin is well known for its high sediment yield. However, this sediment yield has clearly decreased since the 1980 s, 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 %。     

50年代以来黄河下游河道的萎缩及其原因*

根据黄河下游7个控制断面的深泓高程、平均河底高程、滩槽高差及过水断面面积的历年变化,可以看出黄河下游河道的萎缩过程,大型水利工程的运用及引黄灌溉加速了下游河道的淤积和萎缩。     

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.     

唐至北宋黄河下游水患加剧的人文背景分析

作者应用水患频率 5年滑动平均数法 ,分析了唐、五代至北宋 5 10年的黄河下游水患发展过程。认为 :唐初水患较轻 ,但以后逐步加剧 ,至晚唐已相当严重 ;五代、北宋则几乎年年决溢 ,且灾情远较前代为重。作者又分析比较了两汉、唐至北宋黄河中游及河口镇至龙门间农业人口的变迁 ,发现农业人口的增减与下游水患的增减并不同步。而党项等游牧民族在鄂尔多斯及黄土高原北部的传统放牧活动 ,才是土壤荒漠化和下游水患加剧的根本原因     

Chaotic characters of the Yellow River Basin based on the sediment time series: An attempt to integrated research in geography

The sediment content of the Yellow River is resulted from the interactions of natural, economic, and social factors, so it includes some evolutive information of the Yellow River Basin system. Sediment contents from 1952 to 2007 on Toudaoguai, Tongguan, Huayuankou and Lijin sections along the river are chosen as the study time series, and correlation dimensions (D2), Kolmogorov entropies (K2), and Hurst indexes (H) of the time series were calculated. Correlation dimensions on Toudaoguai, Tongguan, Huayuankou, and Lijin sections are 3.24, 5.69, 6.57 and 7.34 respectively, and the Kolmogorov entropies are 0.13, 0.37, 0.40 and 0.38 respectively, which indicates that the systems controlled by different sections along the Yellow River are chaotic systems and the chaotic degrees increase gradually from the upper to lower section. The average predictable period of the sediment contents is 8 years on Toudaoguai section and 3 years on the other sections with the reciprocals of the Kolmogorov entropies. The more obvious the chaotic degree is, the shorter the average predictable period is. Hurst indexes on the sections are above 0.5, with the maximum of 0.86 on Tongguan section and the minimum of 0.68 on Toudaoguai section, which indicates that the time series have persistent trends in the average predictable period. Eight state variables and two control parameters are necessary to construct the dynamic model of the Yellow River Basin system.