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sand mining impact on Poyang Lake: a case study based on high-resolution bathymetry and sub-bottom data

Journal of Oceanology and Limnology 2022年第4期40卷 1404-1416页

作者： Shuwei ZHENG Heqin CHENG Ming TANG Wei XU Enfeng LIU Shu GAO Jim BEST Yuehua JIANG Quanping ZHOU College of Geography and Environment Shandong Normal UniversityJinan 250358China State Key Lab of Estuarine&Coastal Research East China Normal UniversityShanghai 200062China Departments of Geology Geography and GISMechanical Science and Engineering and Ven Te Chow Hydrosystems LaboratoryUniversity of Illinois at Urbana-ChampaignUrbana IL 61801USA Nanjing Geological Survey Center China Geological SurveyNanjing 210016China

Poyang Lake in the Changjiang(Yangtze)River catchment has undergone frequent spring drought since 2003,and some researchers attributed this phenomenon to sand mining and the lakebed deformation in the outlet channel linking the lake with Changjiang River main channel.However,there is still a lack of high-resolution subaqueous geomorphological evidence of how sand mining led to lakebed deformation in the outlet channel.We examined the bed morphology and sub-bottom sedimentary structure of the outlet channel,using a multibeam echo sounder and sub-bottom profi ler in Poyang Lake.We found that:(1)the subaqueous micro-topography types of the outlet channel are characterized by sand mining disturbance,natural erosional topography,and fl at bed and dunes,accounting for 44.9%,21.4%,28.6%,and 5.1%of the channel area,respectively;and(2)sand mining activity aff ects the local bed topography extensively and signifi cantly.The depth of sandpits caused by sand mining varied from 1.4 m to 12 m deeper than the surrounding bed surface,with 4.41 m of depth increase on average.Hence,the large-scale high-intensity sand mining activities and their signifi cant geomorphic eff ects demand for an improved assessment for future management and longer-term sustainability.Because of the large-scale and ongoing high-intensity sand mining activities in the Poyang Lake outlet channel,these eff ects should raise caution in the future and contribute to monitoring eff orts that are essential to implement sustainable management solutions.The present study and techniques implemented can serve as a scientifi c reference for dam construction and sand mining within the Poyang Lake basin.

关键词： lakebed deformation sand mining multibeam echo sounder Poyang Lake

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Regeneration and anti-migration of sand waves associated with sand mining in the Taiwan Shoal

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Acta Oceanologica Sinica 2023年第9期42卷 71-78页

作者： Jingjing Bao Feng Cai Chengqiang Wu Huiquan Lu Yongling Zheng Yufeng Li Li Sun Chungeng Liu Yongbao Li Laboratory of Ocean and Coast Geology Third Institute of OceanographyMinistry of Natural ResourcesXiamen 361005China Fujian Provincial Key Laboratory of Marine Physical and Geological Processes Xiamen 361005China Fujian Provincial Key Laboratory of Marine Ecological Protection and Restoration Xiamen 361005China Xiamen Ocean Engineering Exploration and Design Institute Co.Ltd. Xiamen 361005China School of Environment and Resource Southwest University of Science and TechnologyMianyang 621010China

sand waves in the Taiwan Shoal are characterized by two distinct spatial scales. Giant sand waves have a length of2 kilometers with height between 5 m and 25 m, whilst small sand waves is less than 100-m long with height less than 5 m between giant sand wave peaks(crests). A series of five high-resolution multi-beam echo-sounding surveys between 2012 and 2020 in the middle of Taiwan Shoal indicated that artificial dredging on the giant sand waves had caused sand wave reform and evolution. Overall, the removal of giant sand waves significantly affected the migration of small sand waves adjacent to the dredging site, with the latter on both sides of the former appear to migrate towards the dredging pit. Moreover, in the dredging area, new sand waves emerged with wavelength much smaller than the original giant sand waves, while the convergent pattern of the small sand waves tends to store and form the giant sand waves, which might spread far beyond the survey period.

关键词： small sand wave giant sand wave anti-migration regrowing sand mining Taiwan Shoal

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Impacts of the large amount of sand mining on riverbed morphology and tidal dynamics in lower reaches and delta of the Dongjiang River

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Journal of Geographical Sciences 2007年第2期17卷 197-211页

作者： JIA Liangwen LUO Zhangren YANG Qingshu OU Shuying LEI Yaping Coastal Ocean Research Center Sun Yat-sen University Guangzhou 510275 China Institute of Estuarine and Coastal Research Sun Yat-sen University Guangzhou 510275 China

The sand dredging and its impacts on riverbed evolution and tidal dynamic change in the lower reaches and delta of the Dongjiang River are examined in this paper. The large amount of sand, totally 3.32 billion m^3 from 1980 to 2002, was mined from the riverbeds of the lower reaches and delta of the Dongjiang River. Increasing of the channel capacity, lowering of the average riverbed elevation, deepening of the water depth and decreasing of the longitudinal riverbed gradient are the main effects on the riverbed evolution brought by the large amount of sand dredging. Under the strong sand dredging and associated significant riverbed deformation, the notable changes of the tidal dynamic in the lower reaches and delta of the Dongjiang River occurred, including：（1）in the upper reaches of the Dongjiang River delta and lower reaches of the Dongjiang River, tidal level dropped apparently, tidal range widened, flood tidal duration became longer, amplitudes for major tidal components became bigger and tidal dynamics intensified; （2） tidal wave spread faster; and （3） the limits of the tidal level, tidal current and salt water moved upstream.

关键词： Dongjiang River sand mining tide

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Morphologic Response of a River Channel to sand mining in River Tyaa,Kitui County,Kenya

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Journal of Environmental & Earth Sciences 2020年第2期2卷 12-18页

作者： Philip Gathogo Muiruri Joy A.Obando Ishmail O.Mahiri Department of Geography Kenyatta UniversityKenya43844Nairobi

Over 40 billion tons of sand is mined worldwide every year which isestimated to be higher than the natural replacement rates. In Kenya, therate of sand mining is raising concerns over its environmental effects sinceit is not regulated. This paper presents findings on the geomorphic effectsof sand mining in the ephemeral River Tyaa channel in Kitui County. Thestudy adopts the concept of feedback response mechanism of a naturalgeomorphic system. Through purposive sampling River Tyaa was selectedfor the study, where rampant sand mining was reportedly taking place.Random sampling on the five sand mining sites identified came up with arepresentative site namely Kanginga on which systematic sampling wasapplied while collecting data at both the active and control sites. Dataon channel width, depth and slope angles was obtained through physicalmeasurements while data on quantity of sand mined was obtained fromMwingi sand mining Cooperative. Multiple logistic regression analysiswas used to analyse data whereby the model compared active and controlsites. Test results indicated that sand mining had significantly increasedriver channel’s width (O.R. =1.531), depth (O.R. =1.527) and slope angles(O.R. =1.634) at active mining sites compared to control sites as deducedfrom the respective Odds Ratios. It concluded that sand mining had alteredchannel’s morphology resulting to adverse environmental effects such asloss of riparian vegetation and channel incision. It recommended curbingof illegal sand mining through licencing operators and reducing quantity ofsand mined by closing some mines. Furthers, it recommended monitoringthrough regular Environmental Impact Assessment (E.I.A) and Audit (E.A)to inform protection of the river system from degrading.

关键词： Channel incision Ephemeral stream Morphologic response sand mining Sustainable development

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The Influence of Alluvial mining on the Morphology and Ecological Health of the Jhimruk River in Pyuthan, Nepal

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Journal of Geoscience and Environment Protection 2023年第8期11卷 33-48页

作者： Ankit Kandel Kismat Pokhrel Lenin Adhikari Deep Narayan Shah Goldengate International College Tribhuvan University Battisputali Kathmandu Nepal Central Department of Environment Science Tribhuvan University Kirtipur Kathmandu Nepal

Historically, alluvial rivers have been a desirable source of sediment for various industrial purposes. However, the demand for sand is rapidly increasing, leading to environmental concerns associated with its extraction. The extraction of sediment from riverbeds has both visible and invisible effects. This research aims to investigate the dynamics of the Jhimruk River’s morphology and its impacts by evaluating the river’s quality and studying its changing morphology. To assess morphological changes, satellite images from different years were compared using Geographic Information System (GIS). Physical assessments were conducted by calculating a Habitat score based on various parameters. Water quality assessments involved measuring factors such as pH, temperature, nitrate levels, and alkalinity. A water quality map of the river was generated using color coding to indicate different conditions. The Habitat score demonstrated variations in the data collected from all sites, with factors such as instream cover, bottom substrate stability, riparian vegetation, and aesthetic of the river stretch playing crucial roles in influencing the total score. The Water Quality Index value for the disturbed site indicated moderate pollution, falling under class II. Aquatic macroinvertebrates displayed natural responses to increasing levels of stressors across their life stages, as observed through the analysis of the GRS-BIOS/ASPT index. With the exception of the disturbed site, all other sites were classified under water quality class II, while the disturbed site belonged to class III, indicating a moderate to critically polluted state for most of the Jhimruk River. Furthermore, an increase of 180.87 meters in the river width at the disturbed site provided evidence of morphological changes occurring over the specified period. mining activities were identified as a significant contributor to the alteration in river morphology.

关键词： Alluvial mining Physical Assessment Biological Assessment Water Quality Assessment Jhimruk River sand mining

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Dynamic characterization of the migration of a mining pit in an alluvial channel

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International Journal of Sediment Research 2019年第2期34卷 155-165页

作者： Bandita Barman Bimlesh Kumar Arup Kumar Sarma Department of Civil Engineering Indian Institute of Technology Guwahati

Research on in-channel sand mining is imperative as it may have a significant impact on channel morphology.Following this quest to quantitatively comprehend the phenomenon,experimental studies were done to investigate the dynamic characteristics of the migration of a mining pit.The evaluation of the migration rate of a mining pit in a physical scale model has found a rise in the migration rate of the pit’s upstream edge with increasing discharge.A wavelet analysis applied for analyzing scale-dependent migration of the bed profile of a mining pit also revealed similar findings.Additionally,the wavelet analysis examined the length-scale dependent migration of a mining pit and a decrease in the migration rate has been observed with an increase in the length scale.The plan form of a pit(length-to-width ratio)governs the erosion and deposition processes around the pit.Both physical and statistical approaches show an increase in the migration rate with an increase in the length-to-width ratio of the pit.An empirical formulation has been developed for calculating the migration rate of the upstream edge of a mining pit based on pit geometry(length-to-width ratio),average flow velocity,and critical shear stress of the bed material.The results also show a higher bed load transport rate in the channel subjected to mining as compared to a plain bed channel.

关键词： sand mining Migration Wavelet analysis Bed load transport

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RESEARCH ON THE EFFECTS OF sand mining AT RIVER COURSE BY 2D CURVILINEAR FLOW AND SEDIMENT MATHEMATICAL MODEL

RESEARCH ON THE EFFECTS OF SAND MINING AT RIVER COURSE BY 2D...

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第二十届全国水动力学研讨会

作者： XIE~* Zuo-tao~(1,2) (1.Department of Hydraulic Engineering,Tsinghua University,Beijing 100084.China 2.Changjiang institute of survey,planning,design and research,Wuhan,430010,China)

＜正＞Based on the finite volume method,2-D horizontal flow and sediment mathematical model in generalized curvilinear coordinate was presented,and non-staggered grids and SIMPLE algorithm were adopted during the establishment of model.This model was calibrated by field datum of Wuhan reach at the Changjiang River.Then the effects of sand mining at Wuhan reach course,including the variation of water level,velocity and re-silt of sediment,were simulated by the established model.Furthermore,the influences of flood control and river regime induced by sand mining were analyzed in detail,and the results could provide scientific reference for the feasibility of sand mining and the decision-making of mining scale.

关键词： sand mining 2-D horizontal flow and sediment model generalized curvilinear coordinate calibrated sediment re-silt

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Effects of the Anthropogenic Activities on the Morphological Evolution of the Modaomen Estuary, Pearl River Delta, China

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China Ocean Engineering 2013年第6期27卷 795-808页

作者：贾良文潘顺琪吴超羽 Coastal Ocean Research Center Sun Yat-sen University School of Engineering Cardiff University

Owing to the intensive human activities, the Modaomen Estuary has been significantly modified since 1950s, which has resulted in considerable changes of hydrodynamics and morphodynamics in the area. In this paper, the effects of the anthropogenic activities on the hydrodynamics and morphological evolution in the estuary at different stages are systematically assessed based on the detailed bathymetric data and field survey. The results show that the human activities have caused the channelization of the enclosed sea area in the Modamen Estuary;fast seaward movement of the mouth bar with high siltation;expansion of the channel volume due to channel deepening. The paper also highlights the main hydrodynamic changes in the estuary, including the rise of the water level;the distinguishing changes of tidal range before and after the 1990s （decrease and increase respectively）; as well as the increase of the divided flow ratio. It is found that reclamation is the main factor promoting the transition of nature of the estuary from runoff dominant to runoff and wave dominant, and sand mining activities are mainly to strengthen the tidal dynamic and to low the water level. The results provide useful guidance for better planning of the future developments in the estuary and further research in the area.

关键词： Modaomen Estuary anthropogenic activities morphological evolution reclamation sand mining

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Time lag between reduction of sediment supply and coastal erosion

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International Journal of Sediment Research 2011年第1期26卷 27-35页

作者： HUANG Guangwei~1 University of Tokyo,Japan, Dr. University of Tokyo Japan

The disruption of sediment supply from river to coast by dam development has been a topic of global concern.In Japan,among the top 30 dams in terms of height,14 dams were constructed prior to 1970 and another 6 dams before 1980.However,the coastline erosion did not surface up as a grievous problem until the 1980s.According to the River Bureau of Japan,the overall erosion rate along the coastline of Japan was 0.72×10~6 m~2/yr prior to 1980,but sharply increased to 1.6×10~6 m~2/yr since 1980.Therefore,there was a time lag between the disruption of sediment supply by dam and beach erosion.This paper presents a case study on what may have delayed the response of beach to the effect of dam construction.

关键词： Erosion Sediment supply Dam sand mining Time lag

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Key drivers of changes in the sediment loads of Chinese rivers discharging to the oceans

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International Journal of Sediment Research 2021年第6期36卷 747-755页

作者： Cheng Liu Yun He Zhongwu Li Jia Chen Zhijing Li China Institute of Water Resources and Hydropower Research International Research and Training Center on Erosion and Sedimentation College of Resources and Environmental Sciences Hunan Normal University Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water Resources University of Chinese Academy of Sciences Changjiang River Scientific Research Institute

The magnitude and variation of the sediment loads transported by rivers have important implications for the functioning of river systems and changes in the sediment loads of rivers are driven by numerous factors. In this paper, the key drivers of changes in the sediment loads of the major rivers of China are identified by reviewing recent studies of changes in their sediment loads. Except for the Songhua River,which presents no clear tendency of change in runoff or sediment load, nearly all the major rivers of China are characterized by an apparent decline in annual sediment load. The total annual sediment load of major Chinese rivers transported to the coast decreased from 2.03 billion t/yr during the period 1955-1968 to 0.50 billion t/yr during the period 1997-2010. The primary drivers of changes in the sediment loads of the rivers are dam construction, implementation of soil and water conservation measures,catchment disturbance, agricultural practices, sand mining and climate change. Examples drawn from Chinese rivers are used to demonstrate the importance of these drivers. Construction of a large number of reservoirs in the Yangtze River basin represents the primary driver for the reduced sediment load of the Yangtze River. The implementation of soil and water conservation programmes is one of the key drivers for the sharp decline in the sediment load of the Yellow River. Catchment disturbance explains why the reduction of the sediment load of the Lancang-Mekong River at the Chiang Saen gauging station was much less than that at the Gajiu gauging station upstream. A reduction in sediment load resulting from the expansion of agricultural production may be the main driver for the reduced sediment load of the Huaihe River. The decrease in the sediment load of the Pearl River has been influenced by sand mining activities. Climate change is one of the key drivers responsible for the greatly reduced sediment load of the rivers in the Haihe River Basin.

关键词： Sediment load Dam construction Soil and water conservation Catchment disturbance sand mining Climate change

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