实验流水地貌学研究的回顾与展望

本文简述了地貌实验研究的概况,罗列了我国主要的地貌实验室、站,叙述了我国30多年来,河型造床试验、边界条件及构造运动对河型发育影响实验,应用河流地貌实验、试验理论和技术方面的进展情况,指出实验研究中存在的问题,在回顾基础上,展望了流水地貌实验研究的未来发展趋势。     

地壳构造运动对河型转化影响的实验研究

本文通过室内模拟试验,探讨了由于地壳构造运动以及由此而导致输沙特性变化所引起的不同河型转化和发育的规律。利用试验测量资料进行多元逐步回归分析,分别得到了地壳沉降与地壳抬升时计算河型转化判据的判别函数。应用数量化理论对试验资料进行综合分析,建立了因地壳构造运动影响而形成的五种河型的判别空间,并由此分析了地壳构造运动对河型转化影响的一般规律。     

高含沙型曲流河床形成机理的初步研究

本文描述了在我国黄土高原宽谷中发现的含沙量超过100kg/m^3的曲流河床，并运用高含沙水流的作用对其成因进行了探讨。指出当水流进入高含沙范围时，水流能耗率大幅度降低，挟沙能力大大增加，这是促使河床向弯曲发展的主要原因。由于高含沙水流的稳定输送有赖于边界条件，故边界条件在这种曲流河床的形成中起了重要的作用。文中并讨论了这一地区游荡河型与弯曲河型的判别条件。     

广东省德庆县九竖迳—棠下金矿地质特征——矿床成因及找矿标志

本文通过对德庆县九竖迳—棠下金矿区地层、构造、岩浆岩等矿床地质特征研究,同时结合该矿区近期找矿成果和广东河台金多金属矿国家级整装勘查区成果对矿区矿床成因及找矿标志进行了初步的分析,认为该矿床成因是岩浆热液交代作用形成的构造蚀变岩型(河台式蚀变糜棱岩型)金矿床。     

全新世滦河冲积扇的发育和河型变化

论述全新世中期，滦河冲积扇平原上的古河型是曲流河，晚全新世之后，演变成现在的辫状顺直和微弯曲河型。并探讨它的成因与古环境。     

全新世滦河冲积扇的发育和河型变化

论述全新世中期，滦河冲积扇平原上的古河型是曲流河，晚全新世之后，演变成现在的辫状顺直和微弯曲河型。并探讨它的成因与古环境。     

关于河流分类及成因问题的讨论

河床演变学是一门正在发展中的年轻学科,在很多问题上都存在不同的看法,河型的分类及成因就是其中之一。本文对国外流行的观点作出评价,并提出自己粗浅的看法,以期澄清某些概念,有助于统一认识。文中所讨论的仅限于冲积河流。     

玛纳斯河山麓冲积扇演变遥感研究

基于地质过程,特别是沉积地质过程的理论和方法,通过对航空相片和遥感影像的解译,结合野外考察和地貌与沉积物分析,研究玛纳斯河山麓冲积扇的演变过程,并对其形成和演变原因进行探讨。晚第四纪以来,玛纳斯河山麓冲积扇从第二排山麓到下游冲积平原,可划分为四期规模较大和三期规模较小的冲积扇;玛纳斯河山麓冲积扇的形成演变受气候、构造或气候—构造耦合作用的共同影响,具有多成因性和多层次性。     

弯曲河型与稳定江心洲河型的关系

结合天然河流及室内实验所反映的河型演变过程,本文讨论了弯曲河型与稳定江心洲河型之间的相似性,认为江心洲河型应属于弯曲型河流的范畴。     

游荡性河流演变规律研究进展及其河型归属探讨

游荡性河道在中国广泛分布,其中以黄河下游上段最为典型,但关于游荡性河型的归属问题尚存在很大争议,国际上多将游荡性河流归属为辫状河型。本文以黄河下游游荡性河道为典型案例,系统总结了游荡性河流的演变特征、主要影响因素和形成机理,并从定义、成因、特征及河道形成过程方面,将游荡与辫状河型的异同点进行对比分析。得到以下启示：游荡性河型是一种重要的河道型态,与辫状河型在许多方面存在较明显差异。特别是游荡河型主要发育于能量小于输沙需求的环境,因而形态呈现不稳定特性,但辫状河型不仅出现在能量较多的环境,而且也常在能量较小的环境中出现,因而一部分具有稳定形态,另一部分则表现出不稳定的特性,因此,有必要对游荡性河道和辫状河道给予区分。最后对未来研究进行了展望,提出应重视河型形成的内在机理,对能量理论进行发展及深化,进一步系统性评价游荡性河道与辫状河道的异同性,以解决游荡性河道的河型归属问题。     

Straight river: its formation and speciality

Straight river is generally regarded as one of the typical river patterns in conventional classifications in terms of their channel plain landforms. However, very few straight patterns were found to be distributed in wider spatial and temporal spans in the self-adjusted fluvial rivers. Thus, the questions occur such as that is it possible for a channel takes on a stable straight pattern? What are the main factors controlling the processes of the river pattern formation and transformation from a straight to other patterns? Various theories and hypotheses including geomorphic threshold hypothesis, the extreme hypothesis on energy dissipation rate, the stability theory, etc. have been developed to explain the aforementioned questions, but none of them is sound for the explanation to the straight-river formation. From the modern fluvial plain patterns, the straight patterns are not as stable as other typical patterns which occurred in nature; from the historic records of the river sedimentation, no apparent evidence was found to support the stable straight river evolution. Based on the analysis of existing theories, observations, evolvement processes of the channel patterns in the experimental results, this paper concluded that the straight pattern should not be included as one of the typical patterns that are self-formed and developed. This study is of importance to understanding of the river pattern formation and transformation.     

Straight river: its formation and speciality

Straight river is generally regarded as one of the typical river patterns in conventional classifications in terms of their channel plain landforms. However, very few straight patterns were found to be distributed in wider spatial and temporal spans in the self-adjusted fluvial rivers. Thus, the questions occur such as that is it possible for a channel takes on a stable straight pattern? What are the main factors controlling the processes of the river pattern formation and transformation from a straight to other patterns? Various theories and hypotheses including geomorphic threshold hypothesis, the extreme hypothesis on energy dissipation rate, the stability theory, etc. have been developed to explain the aforementioned questions, but none of them is sound for the explanation to the straight-river formation. From the modern fluvial plain patterns, the straight patterns are not as stable as other typical patterns which occurred in nature; from the historic records of the river sedimentation, no apparent evidence was found to support the stable straight river evolution. Based on the analysis of existing theories, observations, evolvement processes of the channel patterns in the experimental results, this paper concluded that the straight pattern should not be included as one of the typical patterns that are self-formed and developed. This study is of importance to understanding of the river pattern formation and transformation.     

基于对Leopold-Wolman关系修正的河床河型判别

在广泛收集中国和世界上冲积河流资料的基础上,以近200条河流的大样本对著名的、国际上沿用40余年的 Leopold-Wolman关系,即用于河型判别的比降-流量关系进行了检验。结果发现,该关系不能用于包括砾石与砂质河床在内的河型判别。这是由于比降-流量关系主要反映砾石河床与砂质河床之间差异,其次才反映分汊与弯曲河型之间的差异。为此,对于Leopold-Wolman关系进行了改进,提出了以比降和河宽来判别河型的新关系。这一关系综合反映了河流在纵向上的能耗、阻力与输沙特性与在横向上的流场与环流分布特性的组合关系,因而具有更好的河型判别效果,可以用于包括砾石与砂质河床在内的河型判别。     

Engineered channel controls limiting spawning habitat rehabilitation success on regulated gravel-bed rivers

In efforts to rehabilitate regulated rivers for ecological benefits, the flow regime has been one of the primary focal points of management strategies. However, channel engineering can impact channel geometry such that hydraulic and geomorphic responses to flow reregulation do not yield the sought for benefits. To illustrate and assess the impacts of structural channel controls and flow reregulation on channel processes and fish habitat quality in multiple life stages, a highly detailed digital elevation model was collected and analyzed for a river reach right below a dam using a suite of hydrologic, hydraulic, geomorphic, and ecological methods. Results showed that, despite flow reregulation to produce a scaled-down natural hydrograph, anthropogenic boundary controls have severely altered geomorphic processes associated with geomorphic self-sustainability and instream habitat availability in the case study. Given the similarity of this stream to many others, we concluded that the potential utility of natural flow regime reinstatement in regulated gravel-bed rivers is conditional on concomitant channel rehabilitation.     

宽变幅水沙两相流的冲淤双临界现象及其地貌学意义

通过黄土高原一些河流资料的分析，发现了宽变幅水沙两相流冲淤过程中的2个临界值，位于非高含水流区域中的临界点，可称之为冲淤下临界；位于高含沙水流区域中的临界点，可称之为冲淤上临界，水沙两相流冲淤的双临界现象，对珩多沙河流河道泥沙的输移有重要意义，随着含沙量的增大，排沙比先减小而后增大，2次与代表排沙比等于1的直线相交，这2个交点即分别对应于挟沙水流冲淤的下临界和上临界，运用所揭示的水沙两相流冲淤过程的双临界现象，可以对冲积河流河型的形成进行新的解释，以我国近百条冲积河流的资料为基础，点绘了年均悬移质输沙率与年均流量的关系，并以不同的符号来区分弯曲河型、游荡河型和高含沙曲流河型。结果表明，上述3种河型可以很好于被代表特征含沙量分别为C=60kg/m^3和C=3.3kg/m^3的2条直线所区分，这2个特征含沙量反映了河道水沙两相流冲淤的上、下临界值。     

河流地貌系统的过程响应模型实验

本文讨论了河流地貌系统的过程响应模型的基本原理、设计步骤、模型砂料配制以及实验数据的系统分析,并给出了设计实例和某些分析成果。     

Testing links between river patterns and in-channel characteristics using MRPP and ANOVA

This study tests the assumption that the characteristics of channels within multiple channel rivers are different from those of single channel rivers. Some river restoration approaches propose radical transformation of river patterns, from multiple to single channels, based on the link between river patterns and their in-channel characteristics. Determining the links between river patterns and their in-channel characteristics is complicated by differences in geology, history, climate and discharge among rivers. Furthermore, multiple channel rivers are composed of a mosaic of channel types with a range of in-channel characteristics. This study minimizes these problems by analysing a single river containing neighbouring single and multiple channel patterns with little change in discharge downstream, and by analysing all channel types. The study addressed two objectives: to determine the hydraulic geometry, energy, and sediment mobility characteristics of neighbouring single and multiple channel river patterns, and to test for statistical differences in these characteristics between patterns. The Renous River shows a wandering pattern for 11.5 km, with multiple channels around semipermanent islands and abandoned channels in the flood plain. The river displays a single channel river pattern where channels are confined by their valley walls, upstream and downstream of wandering. The analysis was conducted at three scales. First, the confined single channel and wandering multiple channel patterns were compared (pattern scale). Second, the confined channel pattern was compared to single and multiple channel sections within the wandering pattern (section scale). Third, all channel types were compared (channel type scale). Multi response permutation procedure (MRPP) and analysis of variance (ANOVA) were used to analyze differences between channels. Difference tests found no simple discrimination between the single and multiple channel river patterns of the Renous River. Tests between the single confined and multiple wandering channel patterns found few differences in the in-channel variables. The tests did find differences between multiple channel sections within the wandering pattern and confined single channels; however, a greater number of differences were found between multiple channel and single channel sections within the wandering pattern, highlighting the variability within the wandering pattern. Two groups emerged when all channel types were tested for differences: perennial main-channels containing the thalweg, and ephemeral side-channels. Therefore, side-channels define the in-channel characteristics of wandering rivers because few differences were found among main-channels in either pattern. This analysis suggests that all channel types, not just main-channels, should be investigated to obtain a complete picture of a river pattern prior to any restoration efforts. Engineers must exercise caution when applying the link between river patterns and in-channel characteristics to river restoration efforts.     

In-channel geomorphic complexity: The key to the dynamics of organic matter in large dryland rivers?

Large rivers are often considered to retain less organic material than smaller streams primarily because of a decrease in retentive structures. From our observations on the Barwon–Darling River, a semi-arid river in southeastern Australia, we suggest that geomorphic complexity plays a fundamental role in the retention of organic matter. The Barwon–Darling River has a ‘complex’ river channel cross-section with large inset benches being a prominent morphological feature within the channel. The importance of geomorphic complexity for retaining organic material is likely to be significant in dryland rivers. These rivers spend extended periods at low flow with infrequent large floods that inundate the floodplain. They do, however, experience more frequent within channel floods that inundate in-channel ‘bench’ features. In-channel geomorphic complexity and its ability to retain organic material, therefore, means that although the dominant lateral movements of organic material will still occur during large overbank flows, smaller ‘pulse’ inputs will occur with each in-channel rise and fall in water level. In dryland rivers, where large overbank flows may only occur every seven or more years, these small ‘pulse’ inputs of organic material may well be vital for the integrity of the system.This paper describes the contemporary complexity of a channel in a regulated and an unregulated reach of the Barwon–Darling and compares this with cross-sections surveyed in 1886. We show that flow regulation has greatly reduced channel complexity. We estimate the potential organic matter input to each bench level within the channel (using data collected under near natural riparian conditions) and measure the contemporary organic loads within the channel of the regulated and unregulated reach. This modelling suggests that the development of water resources has reduced the complexity of the channel in the regulated reach, resulting in a potential decrease in the retention of organic matter in this region of the river. The importance of this organic matter to the aquatic food web of the Barwon–Darling River is also demonstrated.     

冲积扇-三角洲系统自组织行为与治理对策——以黄河下游及其河口地区为例

从黄河下游河道平面和断面形态特征、河型沿程变化、河槽淤高与外延相互反馈、河口拦门沙消长、及蚀退型三角洲海岸地貌过程诸方面,论述了冲积扇—三角洲系统适应环境功能与自组织行为。指出了这种自组织行为完全是为了将流域来沙均匀地分布在扇三角洲面上和同步地均匀分布在三角洲沿岸。因此,坚持沿线长期计划放淤及河口三角洲流路计划改道是解决黄河下游泥沙问题的根本出路,也是解决黄河下游洪水问题的一种由突变变为均变、化害为利的措施,是使区域走向可持续发展之途的措施。