The sedimentary and tectonic evolution of the Amur River and North Sakhalin Basin: new evidence from seismic stratigraphy and Neogene–Recent sediment budgets

The North Sakhalin Basin in the western Sea of Okhotsk has been the main site of sedimentation from the Amur River since the Early Miocene. In this article, we present regional seismic reflection data and a Neogene–Recent sediment budget to constrain the evolution of the basin and its sedimentary fill, and consider the implications for sediment flux from the Amur River, in particular testing models of continental‐scale Neogene drainage capture. The Amur‐derived basin‐fill history can be divided into five distinct stages: the first Amur‐derived sediments (>21–16.5 Ma) were deposited during a period of transtension along the Sakhalin‐Hokkaido Shear Zone, with moderately high sediment flux to the basin (71 Mt year^?1). The second stage sequence (16.5–10.4 Ma) was deposited following the cessation of transtension, and was characterised by a significant reduction in sediment flux (24 Mt year^?1) and widespread retrogradation of deltaic sediments. The third (10.4–5.3 Ma) and fourth (5.3–2.5 Ma) stages were characterised by progradation of deltaic sediments and an associated increase in sediment flux (48–60 Mt year^?1) to the basin. Significant uplift associated with regional transpression started during this time in southeastern Sakhalin, but the north‐eastward propagating strain did not reach the NE shelf of Sakhalin until the Pleistocene (<2.5 Ma). This uplift event, still ongoing today, resulted in recycling of older deltaic sediments from the island of Sakhalin, and contributed to a substantially increased total sediment flux to the adjacent basinal areas (165 Mt year^?1). Adjusted rates to discount these local erosional products (117 Mt year^?1) imply an Amur catchment‐wide increase in denudation rates during the Late Pliocene–Pleistocene; however, this was likely a result of global climatic and eustatic effects, combined with tectonic processes within the Amur catchment and possibly a smaller drainage capture event by the Sungari tributary, rather than continental‐scale drainage capture involving the entire upper Amur catchment.     

Channel processes on the spawning Kerbi and Nimelen rivers (Lower-Amur Region)

We examine the morphology and dynamics features of the river channels within the basin of the lower reaches of the Amur river on spawning grounds. We report evidence that the spawning grounds tend to occur at definite elements of the river channel as well as data on particle-size composition of alluvial deposits in autumn chum salmon (keta) spawning stretches. Factors having a negative influence on the preservation of spawning grounds have been identified.     

Water exchange in lacustrine areas along the valley of the lower Amur (as deduced from data of expedition-based investigations)

It is shown that at the time of a flood decline the areas along the valley of the Amur in its lower reaches, including the lakes near the floodplain impounded during a high flood, can ensure a total of about 15% of the current value of the main river’s discharge. Under the conditions of the lowest-water level on the Amur as well as of the river backwater at the passage of the flood wave, the volume of discharge (water flow rate) increases only slightly, not going beyond the limit of water flow rate measurement accuracy.     

Cartographic study of the soil-geographical regularities within the Amur basin

We have generated the “Dominant Soils” geoinformation layer (digital coverage), the base for the general-purpose soil map for the Amur river basin encompassing the trans-boundary territories of Russia, China and Mongolia. It relies on the principle of maximum possible retention of information from the source soil maps, and on unification of soil-cartographic material. We demonstrate the geographical regularities of soil occurrence within the entire basin, and the specific character of its separate regions.     

Characteristics of extreme precipitation events within the Amur river basin in summer 2013

We investigated the precipitation characteristics for the summer period of 2013 on the basis of analyzing the daily precipitation amounts according to observational data from the Russian and Chinese meteostations on the territory of the Amur river basin. An analysis is made of the synchronism in the fluctuations of long-term series of precipitation amounts for two summer months (July and August) by using a modified algorithm for a classification of the fields of hydrometeorological characteristics, such as cluster analysis. The study revealed a poor correlation of precipitation amounts in different parts of the basin. We analyzed the interannual fluctuations in absolute maxima of the consecutive precipitation amounts for different periods of time (from 1 to 30 days). It is shown that precipitation over the summer period of 2013 that caused a disastrous flood in the lower reaches of the Amur were extreme primarily as regards the territory encompassed and the flood duration, which was due to a combination of synoptic processes of a different genesis. It was found that the precipitation amounts for periods shorter than 19 days in 2013 were not extreme in terms of intensity. A comparison was made with the year 1984 when there also occurred a flood on the Amur but not as violent. Parameters of the probability curves for 2013 and 1984 are presented for long-term series of maximum precipitation amounts for the summation period of 7 and 30 days. It is concluded that for calculating the maximum possible precipitation amounts which are necessary for assessing the maximum possible floods, it is appropriate to consider synoptic situations with long-lasting precipitation rather than separate short-lasting storm rains.     

中蒙俄经济走廊耕地资源格局与合作战略研究

中蒙俄经济走廊耕地资源战略合作对于“一带一路”共建、加强中俄新时代全面战略协作伙伴关系意义重大。本研究综合运用遥感影像解析、野外实地考察、统计分析等方法,揭示了中蒙俄经济走廊耕地资源分布格局,剖析了耕地资源开发利用的主要制约因素;研究了中国对外耕地合作开发的主要问题,探索提出了中蒙俄经济走廊耕地资源合作对策建议。中蒙俄经济走廊耕地资源丰富,主要集中在俄罗斯欧洲部分莫斯科河和伏尔加河流域,以及鄂毕河流域、叶尼塞河流域、阿穆尔河流域与贝加尔湖流域等地。中蒙俄经济走廊俄罗斯部分耕地面积和高产耕地面积分别占经济走廊的60%和74%左右;而经济走廊俄罗斯部分未利用耕地面积占俄罗斯未利用耕地面积的近50%,占中蒙俄经济走廊未利用耕地面积的95%左右。今后应高度重视中蒙俄经济走廊耕地资源合作开发,推动中蒙俄耕地与农业合作自由化发展,可探索在阿穆尔州、犹太自治州等地率先开展中俄毗邻重点耕地国际合作创新示范区建设和农业自贸区建设,扩展延伸经济走廊耕地产业链和价值链,共建多元稳定的中蒙俄经济走廊农产品物流贸易通道。     

Flood Hazard on the Rivers of the Baikal Region

A comprehensive characterization of the flood hazard on the rivers of the Baikal region is presented, which was obtained by investigating the streams within the basins of the Angara, Upper Lena (with the Vitim and Olekma), Lower Tunguska (headwaters), Upper Amur and Lake Baikal (including the entire Selenga basin). The main flood indicators for the period 1985–2017 are estimated: the genesis, recurrence, duration, flooded area and the force of impact. The influence of changes in the river runoff characteristics on the flood risk is shown by results of correlation analysis and analysis of integro-differential curves. An assessment is made of the changes in the flood frequency at gauging stations during the period of pronounced climatic changes (from 1981 to 2014), compared with the earlier period. The flood hazard within the spatial context for municipalities in the rank of administrative districts is determined on the basis of the dual (socio-economic and natural) nature of floods. It has been confirmed that the most dangerous in the Baikal region are rainfall floods in the southern areas of Irkutsk oblast, the Republic of Buryatia and Zabaikalskii krai. They have the highest frequency, and the largest flooding areas and force of impact and are characterized by the greatest damage and by the largest number of victims and evacuated people. At the same time, the frequency of floods at gauging stations in recent years has decreased compared to the earlier period against the background of the observed low-water period, which is most pronounced on the rivers of South Baikal and in the Selenga river basin.     

Water use in the transboundary basin of the Amur river

This paper summarizes the problems and consequences associated with water use in the Russian and Chinese parts of the Amur river basin. Taking into consideration the set of indicators involving the water withdrawal, the utilization of source water, the volumes of recirculated and repeated-consecutive water supply, the volumes of waste waters, the capacity of pollution control facilities, etc., an outline is given of the present status of water use in the national parts of the basin. The future amounts of water consumption are forecasted, and it is shown how it will increase in the Russian as well as the Chinese parts. An analysis of the spatiotemporal dynamics of water-use indicators revealed the differently directed tendencies in the water-use pattern in the Russian and Chinese parts of the Amur river basin, and the existence of quantitative disproportions caused by a different degree of development and a different intensity of economic growth. In the Russian part of the basin, the amounts of water used have stabilized in recent years after a decrease, whereas they are increasing steadily in the Chinese and Russian parts where the highest proportion of water is used to meet agricultural and production needs, respectively. It is shown that water use, the density of the water-economy structure and the discharges of pollutants in the Chinese part of the basin are larger by factors of several tens than those in the Russian part. The manufacture of water-intensive industrial products and the load of agriculture on water resources also differ by factors of several tens. The indicator of population size is used to characterize the degree of development of the basin’s territory. For the Russian part of the basin the study revealed a dependence of water consumption on the population size and on the volumes of water-intensive products in the production facilities with a low coefficient of recirculated water use. This dependence can also be extended to the Chinese part where circulated water supplies are being used only moderately.     

Spatial-temporal variability of snow cover over the Amur River Basin inferred from MODIS daily snow products in recent decades

MODIS snow products MOD10A1\MYD10A1 provided us a unique chance to investigate snow cover as well as its spatial-temporal variability in response to global changes from regional and global perspectives. By means of MODIS snow products MOD10A1\MYD10A1 derived from an extensive area of the Amur River Basin, mainly located in the Northeast part of China, some part in far east area of the former USSR and a minor part in Republic of Mongolia, the reproduced snow datasets after removal of cloud effects covering the whole watershed of the Amur River Basin were generated by using 6 different cloud-effect-removing algorithms. The accuracy of the reproduced snow products was evaluated with the time series of snow depth data observed from 2002 to 2010 within the Chinese part of the basin, and the results suggested that the accuracies for the reproduced monthly mean snow depth datasets derived from 6 different cloud-effect-removing algorithms varied from 82% to 96%, the snow classification accuracies (the harmonic mean of Recall and Precision) was higher than 80%, close to the accuracy of the original snow product under clear sky conditions when snow cover was stably accumulated. By using the reproduced snow product dataset with the best validated cloud-effect-removing algorithm newly proposed, spatial-temporal variability of snow coverage fraction (SCF), the date when snow cover started to accumulate (SCS) as well as the date when being melted off (SCM) in the Amur River Basin from 2002 to 2016 were investigated. The results indicated that the SCF characterized the significant spatial heterogeneity tended to be higher towards East and North but lower toward West and South over the Amur River Basin. The inter-annual variations of SCF showed an insignificant increase in general with slight fluctuations in majority part of the basin. Both SCS and SCM tended to be slightly linear varied and the inter-annual differences were obvious. In addition, a clear decreasing trend in snow cover is observed in the region. Trend analysis (at 10% significance level) showed that 71% of areas between 2,000 and 2,380 m a.s.l. experienced a reduction in duration and coverage of annual snow cover. Moreover, a severe snow cover reduction during recent years with sharp fluctuations was investigated. Overall spatial-temporal variability of Both SCS and SCM tended to coincide with that of SCF over the basin in general.     

Channel activity of trunk rivers of the Amurskaya region in conditions of current economic management

Based on analyzing the recent research data on the Middle and Upper Amur, it is shown that the flow regulation of the Zeya and asymmetric engineering development of the Amur riversides modify the character, intensity and, in some places, the rearrangement direction of separate channel forms as well as of the channel as a whole. In the Amurskaya region, not only do the technogenic effects on the drainage area manifest themselves in the activity of low-order water streams, but they have influence on the operation of large rivers.     

Natural-resource potential of the trans-boundary territory of Russia and the PRC within the Upper and Middle Amur basin

The specific natural-geographical system of the Upper and Middle Amur basin, including the right-bank area (PRC) is investigated. The system is characterized by a single-type landscape and geological structure, and by mineral resources similar in composition. An analysis is made of the natural-resource potential, and the strategic directions of its economic utilization with due regard for the trans-boundary factor are predicted.     

窟野河流域河岸沙丘地貌格局及变化

风水交互作用是黄土高原北部风蚀水蚀交错带特殊的侵蚀营力,并致该区土壤侵蚀强度加重。以毛乌素沙地窟野河流域作为研究区,基于影像解译及数理统计方法,研究河道与沙丘交互地貌过程。结果表明：（1）窟野河“三河夹沙”区沙地以河流为中心呈现出对称条带状格局分布,距离河流,依次呈现出流动沙丘、固定半固定沙丘、丘陵沟壑区的空间格局;（2）典型河段河道与沙丘空间格局呈现出河道穿越流动沙丘、河道两侧斑块状沙丘镶嵌分布、两河交汇处流动沙丘分布等3种格局;（3）河道弯曲系数与河道两侧沙丘活动性的变化之间呈现出一定的对应关系。     

河流旅游：缘起、内涵及其研究体系——一个本体论的诠释

从旅游及地域系统复杂性的角度探讨河流旅游的概念及其内涵。首先从厘清缘起出发,分析其中的3个传统——审美与寄情的传统、人文主义与后工业化的传统,以及朝觐的传统——及其对当今研究的意义。从本体论的角度,按照旅游主体对河流本体的利用形式及程度,构建了从完全亲近、部分亲近、部分疏离、到完全疏离4个维度的连续概念;从河流客体本身所受的人工干预程度,亦构建起从无干预、弱干预、强干预到完全干预4个维度的连续概念,在此基础上将二者叠合,诠释河流旅游内涵。在此概念体系中,提出在后现代/后工业化的语境下,建立基于主观体验和地域系统耦合的研究体系,旨在探寻基于不同体验类型的河流旅游主体参与方式、分析河流旅游地系统发展演化的“过程-结构-机制”、关注游憩娱乐功能主导下河流利用方式转变及其影响、关注游憩活动在流域综合发展中的地位,并结合系统研究与传统区域研究明确方法论与技术手段。     

近30年来深圳河网变化及其生态效应分析

在地形图、河道普查数据、遥感影像等多源数据支持下, 分析了深圳近30 年河网的时空变化规律及其与城市化水平的关系, 在此基础上通过分析植被盖度、生产有机物质的价值、生态系统服务价值、生态资产等指标的变化规律探讨了深圳观澜河流域河网变化的生态效应。 结果表明: (1) 近30 年深圳市河网结构趋于简单化、主干化, 河流支流发展受到较大限制; 河网总长度减少355.4 km, 总条数减少378 条, 河网密度从0.84 km/km² 降低到0.65 km/km²; 以区/ 街道办驻地为圆心, 半径为1-2 km 的圆环区成为河网萎缩、河网消失的主要 区域; 依据流域城市化水平和河流主干是否直接入海等2 个指标可将深圳市9 大流域/ 水系 分为4 种不同的河网变化类型; (2) 当城市化水平低于30%时, 城镇用地扩展与河网萎缩, 尤其是河网支流的萎缩存在显著相关; 当城市化水平大于30%时, 城镇用地扩展对河网的影响较小; (3) 2000-2005 年观澜河流域生态系统功能显著降低, 以生产有机物质价值降低幅度最 大(41%), 植被盖度次之(24%), 单位面积生态资产从2.79 元/m² 降低到2.34 元/m², 总生态 资产减少3136 万元; (4) 河网变化和城市化成为影响生态系统功能的主要因素, 其中河网变化因素和城市化因素对植被盖度降低的贡献率分别为23.1%和35.8%, 对生产有机物质价值减少的贡献率分别为25.1%和32.7%, 对生态系统服务价值减少的贡献率分别为7.7%和 56.2%, 对生态资产减少的贡献率分别为10.6%和52.2%。     

水系连通变异下荆南三口河系水文干旱识别与特征分析

为揭示水系连通变异下荆南三口河系水文干旱演变特征,运用荆南三口河系五站1956-2016年的月径流量数据,采用游程理论识别该河系水文干旱特征变量,并运用Kolmogorow-Smirnov优度检验法选出干旱历时、干旱强度和峰值的概率分布函数,构建出水文干旱特征联合分布Copula函数,对水系连通变异下该河系水文干旱特征进行深入研究。结果表明：① 1989年为荆南三口河系（1956-2016年）水系连通变异分割点;② 该河系连通性变异前后水文干旱特征均发生显著变化,水文干旱事件发生的次数增多,干旱历时增长,干旱强度增大,峰值增高;③ 各站点的相同单变量重现期下二维联合重现期在水系连通变异前基本上均比水系连通变异后长,二维同现重现期在水系连通变异前均比水系连通变异后短;④ 水系连通变异后,该河系水文干旱历时、干旱强度和峰值呈现增加趋势,且在相同单变量重现期的情况下,干旱历时更长,干旱强度更大,峰值更高;⑤ 水系连通变异后水文干旱特征的变化幅度与变异前存在差异,不同河系其水文干旱特征的变化幅度不同。     

淮河(安徽段)南岸诸河流水质标识指数评价

2010年夏季,对淮河(安徽段)南岸诸河流水质进行调查,共设置采样点160个,选取总氮、总磷、氨氮和化学需氧量4项水质指标,利用综合水质标识指数评价法(WQI)对淮河(安徽段)南岸诸河流水质进行评价。结果表明,淮河(安徽段)南岸诸河流水质达标率77%,超标的评价因子为氮营养盐和化学需氧量。污染物主要来自农业面源和生产、生活废水;水流流速、沉积物性质和周围环境对水质产生一定影响。     

黄山北麓青弋江发育研究

青弋江位于黄山北麓,为长江下游最长的支流。野外考察发现青弋江泾县盆地段存在溪口剖面和城北剖面等2个天然剖面,共发育了1级洪积扇台地（P）和3级河流阶地（T3、T2和T1）,并相应堆积了4级砾石层。通过对砾石层进行砾组分析,并借助电子自旋共振（ESR）测年和古地磁测年等方法,初步探讨了青弋江发育的年代、过程和成因。研究结论为：① 砾组分析表明青弋江T3阶地是青弋江的最老阶地,并且其砾石层是青弋江的最老砾石层;② 测年结果表明青弋江发育的年代区间为1300~900 ka,其中~1300 ka为青弋江发育的最早年代,而~900 ka则为青弋江发育的最晚年代;③ 青弋江发育于~1377 ka前的洪积扇辫状河,并先后经历了洪积扇及辫状河发育、辫状河下切、青弋江形成等阶段,即所谓的源于洪积扇辫状河的青弋江发育过程;④ 青弋江发育可能是降水增加和构造抬升共同作用的结果。该研究有助于为中国东部地区中小河流发育研究提供参考。     

Scaling in river corridor widths depicts organization in valley morphology

Landscapes have been shown to exhibit numerous scaling laws from Horton's laws to more sophisticated scaling in topography heights, river network topology and power laws in several geomorphic attributes. In this paper, we propose a different way of examining landscape organization by introducing the “river corridor width” (lateral distance from the centerline of the river to the left and right valley walls at a fixed height above the water surface) as one moves downstream. We establish that the river corridor width series, extracted from 1 m LIDAR topography of a mountainous river, exhibit a rich multiscale statistical structure (anomalous scaling) which varies distinctly across physical boundaries, e.g., bedrock versus alluvial valleys. We postulate that such an analysis, in conjunction with field observations and physical modeling, has the potential to quantitatively relate mechanistic laws of valley formation to the statistical signature that underlying processes leave on the landscape. Such relations can be useful in guiding field work (by identifying physically distinct regimes from statistically distinct regimes) and advancing process understanding and hypothesis testing.     

河流阶地形成过程及其驱动机制再研究

河流阶地的形成是在内因(河流内部动力变化)和外因(低频和高频气候变化、构造运动、基准面变化)共同作用下的结果。受单一气候变化制约的河流阶地发育模式可以解释由于沉积物通量和径流量变化引起的河流堆积-侵蚀过程,但它难以解释形成多级阶地的逐步(或间歇性)下切过程。多级阶地的形成可能同时受到构造抬升和周期性气候变化的制约。由于下切过程的滞后效应,侵蚀和冰川均衡抬升、河谷的侧向侵蚀过程等影响,山地的构造抬升与河谷的下切之间并非一种简单的线性关系,应当慎用河谷的下切速率来代表山地的抬升速率。     

新疆塔里木河三源流径流量变化趋势分析

运用非参数检验、R/S分析和小波分析等方法对塔里木河三源流的年径流序列进行了分析。结果表明:阿克苏河与叶儿羌河的突变点在1993年,而和田河在1978年;阿克苏河径流呈显著增加趋势而叶儿羌河增加不显著,结合其Hurst指数可知,在未来阿克苏河仍将保持增加走势而叶尔羌河将转变为减少;和田河径流呈轻微的减少趋势,其Hurst指数接近于0.5,具有随机性,不可做长程预测;阿克苏河在6、18、22 a周期性明显,和田河主周期为9和17 a,而叶尔羌河在3、9、13和17 a处周期性明显。