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1.
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.  相似文献   

2.
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.  相似文献   

3.
Presented are the results from experimental investigations into the influence of large tributaries (the Zeya, Bureya and Sungari rivers) on the water quality formation in the Amur river during the transformation of organic matter in bottom sediments. A spectral method and biochemical indication were used to show that toxic heavy metals (mercury, lead, and cadmium) accumulate in river sections of sedimentation of suspended load forming along the right bank from the mouth of the Sungari river to the city of Komsomolsk-on-Amur, and to substantiate the risk of emergence of hydrogen sulfide zones on the lower Amur.  相似文献   

4.
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.  相似文献   

5.
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.  相似文献   

6.
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.  相似文献   

7.
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.  相似文献   

8.
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.  相似文献   

9.
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.  相似文献   

10.
The spatial and temporal dynamics of monsoon in the Holocene has been reconstructed for the Lower Amur area. Four stages of cooling are determined (10300–10800, 8000–8300, 4200–4600 and 2500 yrs. ago). During these periods the intensity of the summer monsoon was weakest. The conventional northern boundary of monsoon influence moved from 54 to 48o N. Two retrospective scenarios of the interaction versions of interaction of seasonal atmospheric centers are suggested, which had influence on the dynamics of the cyclone process over the southern part of the Far East in the Holocene. The cyclones attenuated as a result of frequently recurring long-lasting periods of an increase in pressure in the region of the summer Far-Eastern and Asian depressions, and a decrease in pressure over the Sea of Okhotsk as well as the displacement of the center of the Okhotsk anticyclone toward southern latitudes, which was often in a quasi-stationary state blocking the passage of cyclones to the southern coast of the Sea of Okhotsk. In either case, the cyclones were forced away to lower latitudes and intensified over northern and eastern regions of China. The two scenarios could work both synchronously and metachronously.  相似文献   

11.
李飞  张克  董锁成  李泽红 《地理研究》2021,40(11):3063-3072
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。  相似文献   

12.
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。  相似文献   

13.
We examine the natural-environment development dynamics within the Amur basin during the Neoglacial. The study revealed the opposing directedness in climate humidity changes for different parts of the basin. In the maritime and inland parts, a cooling was accompanied by an increase and decrease in humidity, respectively. It is established that a cooling in the maritime part of the basin led to a shift of the boundaries of vegetation zones, an enhancement in waterlogging of bog systems, and to a change of biogeocenoses. In the inland part of the basin, an enhancement in aridization was conducive to a retrogression of the lakes’ level, and to an intensification of aeolian processes.  相似文献   

14.
Quantitative studies on river channel lateral erosion/accretion area changes over time can reveal the characteristics of channel evolution. Taking the 213-km-long Linhe reach braided channel of the Yellow River as an example, area changes in channel bank erosion/accretion in four sub-reaches (S1, S2, S3 and S4) over 19 different periods were evaluated on the basis of remote sensing images captured since 1977. Mean channel shrinkage rate for the whole river reach was also obtained. Results show that the left and right banks of the Linhe reach were dominated by lateral net accretion between 1977 and 2014. The channel area of this section of the Yellow River was characterized by reduction between 1977 and 2001, while periods of alternate erosion and accretion occurred subsequent to 2001. Mean channel shrinkage rate in the Linhe reach braided channel was 6.15 km2/yr between 1977 and 2014, while the most remarkable changes in channel planform occurred in the 1990s. Compared to 1995, channel length and sinuosity increased by 5.8% and 6.6% by 2000, while channel area and mean width decreased by 39.4% and 42.8%, respectively. Significant changes in channel planform and shrinkage of the Linhe reach occurred in the 1990s, mainly as a result of the joint-operation of the Longyangxia and Liujiaxia reservoirs since 1986, which caused substantial reductions in runoff and sediment flux during the annual flooding season. In addition, bank erosion/accretion in the four sub-reaches was affected by the physical properties of local banks, engineering emplaced to protect channel banks, and hydrodynamic differences. However, since the implementation of integrated river management measures from 2000 onwards, these changes have been significantly mitigated and the health of the Linhe reach braided channel of the Yellow River has been restored.  相似文献   

15.
Joanna Korpak   《Geomorphology》2007,92(3-4):166
The purpose of this paper is to explain the influence of river training on channel changes in mountain rivers. Also considered are the causes of failure of different training schemes. The research was conducted on the regulated Mszanka and Porębianka Rivers, belonging to the Raba River drainage basin in the Polish Flysh Carpathian Mountains. Channel mapping carried out in 2004 drew attention to the contemporary morphology of the channels and the development of their dynamic typology. General changes in channel morphometry and land cover were identified by comparing cartographic sources from various years. Archive material from Cracow's Regional Water Management Authority (RZGW) was used to analyse the detailed channel changes caused by each regulation structure. The material consisted of technical designs of individual training works, as well as plans, longitudinal profiles and cross-sections of trained channel reaches. A series of minimum annual water stages at the Mszana Dolna gauging station was used to determine the tendency of channel bed degradation over 53 years. During the first half of the 20th century, the middle and lower courses of the Mszanka and Porębianka Rivers had braided patterns. The slopes, mostly covered with crops, were an important source of sediment delivery to the river channels. Today, both channels are single-threaded, narrow and sinuous. Downcutting is the leading process transforming the channels. They cut down to bedrock along about 60% of their lengths. The main type of channel is an erosion channel, which occurs also in the middle and lower courses of the rivers. The channel sediment deficit is an important cause for river incision. Sediment supply to the channels was reduced after a replacement of crops on the slopes by meadows or forests. Gravel mining has also caused channel downcutting. The rapid channel changes began after 1959, as systematic training was introduced. Channel regulation seems therefore to be a major factor determining channel adjustment. Debris dams and groynes were built before 1980 and these caused the greatest change of channel pattern, increase of channel gradient and magnitude of river incision. After that date the measures mostly involved drop structures. From then on, the rate of downcutting decreased considerably, but has not ceased. The rivers continued to incise until bedrock was exposed or training structures were destroyed. After that, a tendency to lateral migration and local braiding were observed in the deepened channel. The channels displayed a tendency to return to their morphology and dynamic from before the training. The results demonstrate that river training distorts the equilibrium of channel systems. A channel becomes divided into artificial reaches, which later follow different evolutionary patterns. Most training schemes on mountain channels are ineffective in the long term, as river managers seem to consider a channel at a reach scale only. Individual channel reaches, however, are not independent but rather form a system that must be managed at the entire channel scale.  相似文献   

16.
黄河内蒙河段河床冲淤演变特征及原因   总被引：4，自引：0，他引：4  
利用黄河内蒙段1962-2000年间4期大断面观测资料,计算了各期河床冲淤和河槽形态指标。发现从1962-2000年间前20年、中间9年及后9年,内蒙河段河槽500m2过水面积下河底高程发生了降低-升高-再升高的过程;河槽漫滩过水面积经历了升高-降低-再降低的过程,2000年只有1982年的大约一半;滩地经历了持续淤积过程,平均抬升0.25m;河槽宽深比值经历了变化不显著-增加-减小的过程。分析结果表明:气候变化、引水、水库拦沙和重点产沙支流来沙变化在河床冲淤和河床形态调整中作用较大;水库对径流的年内调节对1982年后河槽淤积贡献较大;来水来沙变化下河流多要素自动调整是造成河槽形态变化过程复杂的原因。  相似文献   

17.
There is a need for improved and up-to-date land use/land cover (LULC) data sets over an intensively changing area in the Amur River Basin (ARB) in support of science and policy applications focused on understanding of the role and response of the LULC to environmental change issues. The main goal of this study was to map LULC in the ARB using MODIS 250-m Normalized Difference Vegetation Index (NDVI), Land Surface Vegetation Index (LSWI), and reflectance time series data for 2001 and 2007. Another goal was to test the consistency of the classification results using relatively coarse resolution MODIS imagery data in order to develop a methodology for rapid production of an up-to-date LULC data set. The results on MODIS land cover were evaluated using existing land use/cover data as derived from Landsat TM data. It was found that the MODIS 250-m NDVI data sets featured sufficient spatial, spectral and temporal resolution to detect unique multi-temporal signatures for the region’s major land cover types. It turned out that MODIS 250 NDVI time series data have high potential for large-basin land use/land cover monitoring and information updating for purposes of environmental basin research and management.  相似文献   

18.
基于DEM的沟谷网络节点水流累积量研究   总被引：4，自引：1，他引：3  
以陕西省境内黄土高原丘陵沟壑区绥德县韭园沟、延川和宜君三个典型地貌区作为实验样区,基于栅格数字高程模型(Digital Elevation Mode,DEM)沟谷网络自动提取技术以及沟谷网络节点及其自动提取技术,得到了各样区沟谷网络节点,从地貌形态学,沟谷成因学以及水文学原理出发,对不同级别沟谷网络节点水流累积属性进行了深入分析,结合数理统计方法获得了同一沟谷系统不同分辨率沟谷网络节点水流累积量均值分级统计规律,不同地貌类型样区沟谷系统相同分辨率节点水流累积量均值分级统计规律。该数理统计结论能够有效解释黄土高原丘陵沟壑区各级沟谷系统的形成机理及其空间分异规律,同时能够合理地说明沟谷系统发育与地表侵蚀、切割强度之间的相互关系。因此,本研究对整个黄土高原丘陵沟壑区地表形态的研究具有重要的参考意义。  相似文献   

19.
Ellen Wohl  David Dust 《Geomorphology》2012,138(1):329-338
Since 1974, flow releases from Long Draw Reservoir have increased annual peak flows on La Poudre Pass Creek, Colorado, from ~ 5.6 m3/s to > 8.4 m3/s. The creek drains 61 km2 and channel morphology varies from step-pool to pool-riffle. Comparison of five channel reaches along the creek to channel reaches along neighboring rivers without flow regulation indicates that channel width has increased by as much as a factor of three along La Poudre Pass Creek. Width-to-depth ratio has also increased, the bed material in step-pool channel reaches has coarsened, and residual pool volumes have increased in pool-riffle channel reaches. Pool-riffle channel reaches have undergone the greatest change in response to flow augmentation. Although discharge has increased consistently for all five channel reaches, morphologic response varies in relation to gradient and channel morphology, making it impractical to precisely predict a priori the magnitude of channel response to flow augmentation.  相似文献   

20.
以俄罗斯远东联邦区的布拉戈维申斯克—符拉迪沃斯托克(布符)沿边铁路为研究对象,在高速铁路情景下,利用可达性指标测度高铁运行前(普铁)后(高铁)沿线节点的可达性动态变化,探讨该线路升级提速后对沿线各个节点的贡献作用与空间效应。研究表明：未来布符高铁的建设运营使其沿线可达性得到大幅提升,时空收敛获益多,8 h交流圈覆盖全线,可达性最优要素由末端城市(符拉迪沃斯托克)向线路中间城市(哈巴罗夫斯克)自南向北、继而向首端城市(布拉戈维申斯克)自东向西扩散,呈布符铁路首末可达性改善幅度大、部分中间线路可达性改善稍弱的空间特征。可达性的变化加速远东的西南沿边地区空间格局的演变与重塑,布符沿边高铁集散场的空间延拓、袭夺态势加剧;铁路轴带的空间极化加深,呈现新的“核心—边缘”格局;跨城流动性突显,加速空间对接与同城空间发展模式。  相似文献   

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