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Fractal characterization of sediment particle-size distribution in the water-level fluctuation zone of the Three Gorges Reservoir, China 被引量:7
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作者 LI Jin-lin BAO Yu-hai +3 位作者 WEI Jie HE Xiu-bin TANG Qiang Jean de Dieu NAMBAJIMANA 《Journal of Mountain Science》 SCIE CSCD 2019年第9期2028-2038,共11页
The combined effect of periodic water impoundment and seasonal natural flood events has created a 30 m high water-level fluctuation zone(WLFZ) around the Three Gorges Reservoir(TGR), China, forming a unique eco-landsc... The combined effect of periodic water impoundment and seasonal natural flood events has created a 30 m high water-level fluctuation zone(WLFZ) around the Three Gorges Reservoir(TGR), China, forming a unique eco-landscape. Siltation, eutrophication, enrichment of heavy metals, and methane emissions in the WLFZ have been widely associated with sediment and soil particles generated from the upstream catchment or upland slopes. However, little attention has been paid to the complexity of sediment particle-size distributions in the WLFZ. In the present study, core samples(from a 345 cm thick sediment core from the base of the WLFZ), slope transect surface samples(across/up a WLFZ slope), and along-river/longitudinal surface samples(from the reservoir reaches) were collected. Laser granulometry and a volume-based fractal model were used to reveal the characteristics of sediment particle-size distributions. Results indicate that the alternation of coarse and fine particles in the sedimentary core profile is represented as a fluctuation of low and high values of fractal dimension(D), ranging from 2.59 to 2.77. On the WLFZ slope transect, surface sediment particles coarsen with increasing elevation, sand content increases from 3.3% to 78.5%, and D decreases from 2.76 to 2.53. Longitudinally, surface sediments demonstrate a downstream-fining trend, and D increases gradually downstream. D is significantly positively correlated with the fine particle content. We conclude that D is a useful measure for evaluating sediment particle-size distribution. 展开更多
关键词 Spatial DIFFERENTIATION SEDIMENT particle FRACTAL dimension water-level fluctuation zone three gorges reservoir
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Protection and Ecological Restoration of Water Level Fluctuation Zone in the Three Gorges Reservoir 被引量:1
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作者 PAN Xiaojie WAN Chengyan +1 位作者 ZHANG Zhiyong ZHENG Zhiwei 《Journal of Landscape Research》 2017年第1期44-50,共7页
Water level fluctuation zone(hereinafter referred to as "WLFZ") is a transitional ecosystem between terrestrial ecosystem and aquatic ecosystem,and also a key area to control its neighboring terrestrial and ... Water level fluctuation zone(hereinafter referred to as "WLFZ") is a transitional ecosystem between terrestrial ecosystem and aquatic ecosystem,and also a key area to control its neighboring terrestrial and aquatic ecosystem. After the Three Gorges Reservoir was put into use,ecological environment of its WLFZ has aroused wide concern from domestic and foreign experts. On the basis of introducing characteristics of WLFZ of the Three Gorges Reservoir,current ecological environment and main problems of this area were analyzed,plant selection and configuration was elaborated as well as the implementation effect of many WLFZ protection and ecological restoration modes. In view of the actual conditions,pertinent suggestions were proposed for WLFZ of the Three Gorges Reservoir,namely classified protection and ecological restoration,enhancing monitoring and assessment of current situation and change tendency,carrying out technical researches and demonstration of WLFZ wetland ecological restoration. 展开更多
关键词 three gorges reservoir water level fluctuation zone(WLFZ) Ecological restoration Classified protection
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Centrifugal model test on a riverine landslide in the Three Gorges Reservoir induced by rainfall and water level fluctuation 被引量:8
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作者 Fasheng Miao Yiping Wu +2 位作者 Ákos Török Linwei Li Yang Xue 《Geoscience Frontiers》 SCIE CAS CSCD 2022年第3期196-209,共14页
Frequent soil landslide events are recorded in the Three Gorges Reservoir area,China,making it necessary to investigate the failure mode of such riverside landslides.Geotechnical centrifugal test is considered to be t... Frequent soil landslide events are recorded in the Three Gorges Reservoir area,China,making it necessary to investigate the failure mode of such riverside landslides.Geotechnical centrifugal test is considered to be the most realistic laboratory model,which can reconstruct the required geo-stress.In this study,the Liangshuijing landslide in the Three Gorgers Reservoir area is selected for a scaled centrifugal model experiment,and a water pump system is employed to retain the rainfall condition.Using the techniques of digital photography and pore water pressure transducers,water level fluctuation is controlled,and multi-physical data are thus obtained,including the pore water pressure,earth pressure,surface displacement and deep displacement.The analysis results indicate that:Three stages were set in the test(waterflooding stage,rainfall stage and drainage stage).Seven transverse cracks with wide of 1–5 mm appeared during the model test,of which 3 cracks at the toe landslide were caused by reservoir water fluctuation,and the cracks at the middle and rear part were caused by rainfall.During rainfall process,the maximum displacement of landslide model reaches 3 cm.And the maximum deformation of the model exceeds 12 cm at the drainage stage.The failure process of the slope model can be divided into four stages:microcracks appearance and propagation stage,thrust-type failure stage,retrogressive failure stage,and holistic failure stage.When the thrust-type zone caused by rainfall was connected or even overlapped with the retrogressive failure zone caused by the drainage,the landslide would start,which displayed a typical composite failure pattern.The failure mode and deformation mechanism under the coupling actions of water level fluctuation and rainfall are revealed in the model test,which could appropriately guide for the analysis and evaluation of riverside landslides. 展开更多
关键词 Riverine landslide The three gorges reservoir Centrifugal model test RAinFALL fluctuation of water level
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Analysis of the relationship between water level fluctuation and seismicity in the Three Gorges Reservoir(China) 被引量:5
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作者 Lifen Zhang Jinggang Li +3 位作者 Guichun Wei Wulin Liao Qiuliang Wang Chuanfang Xiang 《Geodesy and Geodynamics》 2017年第2期96-102,共7页
The Three Gorges Reservoir is a good site for the further researches on reservoir induced seismicity due to decades' seismic monitoring. After the first water impounding in 2003, seismic activity becomes more frequen... The Three Gorges Reservoir is a good site for the further researches on reservoir induced seismicity due to decades' seismic monitoring. After the first water impounding in 2003, seismic activity becomes more frequent than that before water impoundment. In order to quantitatively study, the relationship between the water level fluctuation and earthquakes in TGR, we introduced statistical methods to attain the goal. First of all, we relocated the earthquakes in TGR region with double difference method and divided the earthquakes into 5 clusters with clustering analysis method. Secondly, to examine the impacts of water level fluctuation in different water filling stages on the seismic activity in the 5 clusters, a series of statistical analyses are applied. Pearson correlation results show that only the 175 m water level fluc- tuation has significantly positive impacts on the seismic activity in clusters I, II, III and V with correlation coefficients of 0.44, 0.38, 0.66 and 0.63. Cross-correlation analysis demonstrates that 0, ], 0 and 0 month time delay separately for the clusters I, II, III and V exists. It illustrated the influences of the water loading and pore pressure diffusion on induced earthquakes. Cointegration tests and impulse response analysis denoted that the 175 m water level only had long term and significant effects just on the seismic events in the intersection region of the Fairy Mount Fault and Nine-brook Fault. One standard deviation shock to 175 m water level increased the seismic activity in cluster V for the first 3 months, and then the negative influence was shown. After 7 months, the negative impulse response becomes stable. The long-term effect of the 175 m water impoundment also proved the important role of pore pressure diffusion in RIS with time. 展开更多
关键词 three gorges reservoir reservoir-induced seismicity water level fluctuation Cross correlation Impulse response Pore pressure diffusion
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Soil anti-scourability enhanced by herbaceous species roots in a reservoir water level fluctuation zone 被引量:3
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作者 XU Wen-xiu YANG Ling +2 位作者 BAO Yu-hai LI Jin-lin WEI Jie 《Journal of Mountain Science》 SCIE CSCD 2021年第2期392-406,共15页
Revegetation is one of the successful approaches to soil consolidation and streambank protection in reservoir water level fluctuation zones(WLFZs).However,little research has been conducted to explore the impact of he... Revegetation is one of the successful approaches to soil consolidation and streambank protection in reservoir water level fluctuation zones(WLFZs).However,little research has been conducted to explore the impact of herbaceous species roots on soil anti-scourability during different growth stages and under different degrees of inundation in this zone.This study sampled two typical grasslands(Hemarthria compressa grassland and Xanthium sibiricum grassland)at two elevations(172 and 165 m a.s.l.)in the water level fluctuation zone(WLFZ)in the Three Gorges Reservoir(TGR)of China to quantify the changes in soil and root properties and their effects on soil anti-scourability.A simulated scouring experiment was conducted to test the soil anti-scourability in April and August of 2018.The results showed that the discrepancy in inundation duration and predominant herbaceous species was associated with a difference in root biomass between the two grasslands.The root weight density(RWD)values in the topsoil(0-10 cm)ranged from 7.31 to 13 mg cm^(-3) for the Hemarthria compressa grassland,while smaller values ranging from 0.48 to 8.61 mg cm^(-3) were observed for the Xanthium sibiricum grassland.In addition,the root biomass of the two herbs was significantly greater at 172 m a.s.l.than that at 165 m a.s.l.in the early recovery growth period(April).Both herbs can effectively improve the soil properties;the organic matter contents of the grasslands were 128.06%to 191.99%higher than that in the bare land(CK),while the increase in the water-stable aggregate ranged from 8.21%to 18.56%.Similarly,the topsoil antiscourability indices in both the herbaceous grasslands were larger than those in the CK.The correlation coefficients between the root length density(RLD),root surface area density(RSAD)and root volume density(RVD)of fine roots and the soil antiscourability index were 0.501,0.776 and 0.936,respectively.Moreover,the change in the soil antiscourability index was more sensitive to alternations in the RLD with diameters less than 0.5 mm.Overall,the present study showed that the perennial herbaceous(H.compressa)has great potential as a countermeasure to reduce or mitigate the impact of erosion in the WLFZ of the Three Gorges Reservoir. 展开更多
关键词 Herbaceous species root system Soil anti-scourability water level fluctuation zone three gorges reservoir
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Soil nutrients in relation to vertical roots distribution in the riparian zone of Three Gorges Reservoir,China 被引量:3
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作者 ZHONG Rong-hua HU Jin-ming +2 位作者 BAO Yu-hai Wang Fei HE Xiu-bin 《Journal of Mountain Science》 SCIE CSCD 2018年第7期1498-1509,共12页
Since the impoundment of the Three Gorges Reservoir(TGR), the riparian zone has been subjected to numerous environmental changes. This study was conducted to recognize the distribution of grass roots and its impacts o... Since the impoundment of the Three Gorges Reservoir(TGR), the riparian zone has been subjected to numerous environmental changes. This study was conducted to recognize the distribution of grass roots and its impacts on soil nutrients in the water level fluctuation zone of TGR. Roots of four predominant herbaceous plants in the study area, specifically, Cynodon dactylon, Hemarthria altissima, Hemarthria compressa, and Paspalum paspaloides, and their corresponding relation with soil nutrient contents were investigated. Root surface area density was determined with Win RHIZO, and the relationships of root distribution with soil depths and soil nutrient contents were studied. The results indicates that most roots are distributed in the top soil layer of 0-10 cm. Estimated root surface area density for the selected grass species ranges from 0.16 to 13.44 cm^2/cm^3, and decreases exponentially with an increase in soil depth. Soil organic matter and total nitrogen contents are significantly lower on bare control area than the corresponding values on the grasslands. Total nutrient contents on grasslands of C. dactylon and H. compressa are higher than those of other grass areas. Root length density and root surface area density are significantly correlated with soil organic matter and total nitrogen content for the four grasslands. The present results suggests that plant roots have significant effects on the distribution of soil nutrients in soil profiles in the riparian zone along the TGR. Nevertheless, additional investigations are needed to reveal the specific interactions between plant roots distribution, soil nutrients and water level fluctuations. 展开更多
关键词 Roots distribution Soil nutrients water level fluctuations Riparian zone Root surface area density Root length density
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Application of Vegetation Geosynthetic Technique to Slope Stability in the Three Gorges Reservoir
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作者 YuFei WangYuanhan 《Journal of China University of Geosciences》 SCIE CSCD 2005年第1期51-57,共7页
The vegetation geosynthetic reinforced slope is one of the new composite structures in civil engineering. It has a series of characteristics, such as low cost, convenient construction, optimal land utilization and... The vegetation geosynthetic reinforced slope is one of the new composite structures in civil engineering. It has a series of characteristics, such as low cost, convenient construction, optimal land utilization and flexible structure, and it has been widely used in hydraulic engineering, road, railway and harbor construction. The Three Gorges reservoir bank protection system is a challenging work. As the background, the interaction mechanism of soil and reinforced material has been studied. The test engineering is simulated by the numerical methods. The failure mechanism of the reinforced slope in the process is studied through analyzing the variation of the displacement, stress, plastic failure fields and factor of safety in the changing process of the water level. The reasonable evaluation of the protecting effect and bank slope stability is carried out. The research results could be used in the protective design and construction in the high slope in the Three Gorges reservoir region, and it also could provide reference to other protective engineerings in the littoral area. 展开更多
关键词 the three gorges reservoir reinforced slope water level fluctuation interactivity reinforced mechanism slope stability.
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Water level fluctuations influence microbial communities and mercury methylation in soils in the Three Gorges Reservoir,China 被引量:2
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作者 Yuping Xiang Yongmin Wang +2 位作者 Cheng Zhang Hong Shen Dingyong Wang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2018年第6期206-217,共12页
Reservoirs tend to have enhanced methylmercury(MeHg) concentrations compared to natural lakes and rivers, and water level fluctuations can promote MeHg production. Until now, little research has been conducted on th... Reservoirs tend to have enhanced methylmercury(MeHg) concentrations compared to natural lakes and rivers, and water level fluctuations can promote MeHg production. Until now, little research has been conducted on the effects of microorganisms in soils for the formation of MeHg during different drying and flooding alternating conditions in the Three Gorges Reservoir(TGR). This study aimed to understand how water level fluctuations affect soil microbial composition and mercury concentrations, and if such microbial variations are related to Hg methylation. The results showed that MeHg concentrations and the ratios of MeHg to THg(MeHg%) in soils were higher in the seasonally drying and flooding alternating areas(DFAs, 175–155 m) than those in the non-inundated(NIAs, 〉 175 m) and inundated areas(IAs, 〈 145 m). However, MeHg% in all samples was less than 1%, indicating that the Hg methylation activity in the soils of the TGR was under a low level. 454 highthroughput sequencing of 16 S rRNA gene amplicons showed that soil bacterial abundance and diversity were relatively higher in DFA compared to those in NIA and IA, and microbial community composition varied in these three areas. At the family level, those groups in Deltaproteobacteria and Methanomicrobia that might have many Hg methylators were also showed a higher relative abundance in DFA, which might be the reason for the higher MeHg production in these areas. Overall, our results suggested that seasonally water level fluctuations can enhance the microbial abundance and diversity, as well as MeHg production in the TGR. 展开更多
关键词 water level fluctuation zone three gorges reservoir SOIL Microbial communities METHYLMERCURY Methylators
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Evaluation of the treatment effect of rear slope cutting on hydrodynamic pressure landslides:A case study
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作者 WANG Li HUANG Jun-jie +4 位作者 CHEN Yong WANG Shi-mei FAN Zhi-hong GUO Fei LI Xiao-wei 《Journal of Mountain Science》 SCIE CSCD 2023年第7期1968-1983,共16页
After the impoundment of the Three Gorges Reservoir,some huge ancient landslides were reactivated and deformed,showing typical hydrodynamic pressure landslide characteristics.The Baishuihe landslide was a typical hydr... After the impoundment of the Three Gorges Reservoir,some huge ancient landslides were reactivated and deformed,showing typical hydrodynamic pressure landslide characteristics.The Baishuihe landslide was a typical hydrodynamic pressure landslide.The management department conducted slope cutting treatments from 2018 to 2019.To evaluate the treatment effect of rear slope cutting,this study analyzed the data of the surface deformation survey and field monitoring over the past 20 years and the characteristics of the reservoir water-triggered Baishuihe landslide deformation,and calculated the seepage field,displacement field,and stability coefficient before and after landslide treatment.The results showed that the deformation of the Baishuihe landslide was primarily related to a decrease in the reservoir water level.Owing to the poor permeability of the landslide soil,the decrease in the reservoir water level produced a seepage force pointing to the outside of the landslide body,leading to the step deformation of the landslide displacement.The landslide was treated by rear slope cutting,and the“step”deformation of the landslide disappeared after treatment.The hydrodynamic pressure caused by the change in reservoir water after cutting the slope did not disappear.However,as the slope cutting greatly reduced the overall sliding force of the landslide,its stability was greatly improved.Notably,high stability can still be ensured under extreme rainfall after treatment.Slope cutting is effective for treating hydrodynamic pressure landslides.This study can provide effective technical support for the treatment of reservoir landslides. 展开更多
关键词 Hydrodynamic pressure landslide three gorges reservoir Slope cutting Load reduction Landslide monitoring Ancient landslides reservoir water level fluctuation
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三峡水库小江回水区水华暴发期浮游植物群落结构及其与环境因子的关系
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作者 胡莲 郑志伟 +4 位作者 杨志 杨晴 邹曦 万成炎 张云昌 《湖泊科学》 EI CAS CSCD 北大核心 2024年第4期1025-1035,I0003-I0005,共14页
三峡水库蓄水以来,支流水华频发,尤以小江情况最为严重,给三峡库区的生态安全带来较大隐患。为探究支流水华暴发特征和主控因素,于20142021年小江水华暴发期间在小江高阳江段进行浮游植物及环境因子调查,并使用单因素方差分析、聚类分... 三峡水库蓄水以来,支流水华频发,尤以小江情况最为严重,给三峡库区的生态安全带来较大隐患。为探究支流水华暴发特征和主控因素,于20142021年小江水华暴发期间在小江高阳江段进行浮游植物及环境因子调查,并使用单因素方差分析、聚类分析、百分比相似性分析以及基于距离的线性模型等方法,对小江水华暴发期间浮游植物和环境因子在不同年份不同水层间的差异以及二者的关系进行研究。结果表明:小江水华暴发期内,浮游植物的种类数在43~70种之间,其中2015年蓝藻种类数明显减少,2018年以后硅藻种类数明显减少;采样期间浮游植物平均细胞密度在0.66×10^(6)~61.28×10^(6)cells/L之间,同期表层细胞密度明显高于中层和底层;各层水体间水华微囊藻、铜绿微囊藻、不定微囊藻等10种藻的密度存在明显差异,是主要差异种;显著影响表层、中层和底层浮游植物群落结构变动的环境因子是水位的日平均变幅;水位的日平均变幅与藻类优势种拟合关系显示,当日水位下降幅度在0.5 m以上时,浮游植物平均密度会呈指数级减少。研究结果可为三峡库区支流水华的防控提供数据支持。 展开更多
关键词 三峡水库 小江 水华暴发 浮游植物 群落结构 水位变动
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周期性水位波动对三峡水库消落带土壤有机碳含量和密度的影响
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作者 王鹏 冉义国 +3 位作者 梅渝 马茂华 黄平 吴胜军 《土壤》 CAS CSCD 北大核心 2024年第3期672-680,共9页
为探究水位波动对三峡水库消落带土壤有机碳的影响,在三峡水库消落带采集和测定了受不同水淹强度影响的石灰土、紫色土、黄壤及其植物样品,并运用Kruskal-Wallis非参数检验和基于冗余分析的典范分析等方法进行了研究。结果表明:周期性... 为探究水位波动对三峡水库消落带土壤有机碳的影响,在三峡水库消落带采集和测定了受不同水淹强度影响的石灰土、紫色土、黄壤及其植物样品,并运用Kruskal-Wallis非参数检验和基于冗余分析的典范分析等方法进行了研究。结果表明:周期性水淹增加了石灰土和紫色土的有机碳含量和密度,但降低了黄壤的有机碳含量和密度。此外,石灰土的有机碳分布还受地上生物量、土壤pH和土层深度的影响,紫色土的有机碳分布还受土层深度和地上生物量的影响,而黄壤的有机碳含量和密度则与地上生物量、土层深度和地下生物量有关。总之,周期性水位波动对消落带土壤有机碳影响深刻,但土壤类型分异了有机碳对水位波动的响应。 展开更多
关键词 三峡水库 消落带 土壤有机碳 有机碳密度
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三峡库区黑石板滑坡的变形特征和涌浪预测
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作者 尚敏 袁朔 +3 位作者 王殿鹏 宋云鹏 张欣艺 郑子良 《水利学报》 EI CSCD 北大核心 2024年第10期1236-1247,共12页
三峡库区水位波动易于导致库岸滑坡失稳进而形成涌浪灾害。以三峡库区黑石板滑坡为研究对象,基于近5年的监测数据分析:三峡库区黑石板滑坡为动水压力型滑坡,降雨只在库水位下降时和低水位波动期对滑坡的变形有一定的助推作用,其他时间... 三峡库区水位波动易于导致库岸滑坡失稳进而形成涌浪灾害。以三峡库区黑石板滑坡为研究对象,基于近5年的监测数据分析:三峡库区黑石板滑坡为动水压力型滑坡,降雨只在库水位下降时和低水位波动期对滑坡的变形有一定的助推作用,其他时间对滑坡变形影响并不大。通过分析累积位移曲线中的6次阶跃变形,确定了库水位下降至165 m时为滑坡阶跃变形的启动阈值,并以此作为滑坡最危险情况下所对应的库水位高度,将其设置为数值模拟的初始水位高度。运用FLOW-3D软件进行了涌浪计算及预测:在165 m水位时,滑坡入水的最大速度为19.4 m/s,涌浪产生的最大波高为24.9 m,最大爬高为42.21 m。预测结果表明,黑石板滑坡破坏后引发的涌浪将会淹没水田坝乡沿岸部分区域,毁坏入乡主干道,这将严重影响后续对水田坝乡的救援工作。该研究为三峡库区库岸滑坡涌浪的风险管理提供科学依据,具有一定的工程实践意义。 展开更多
关键词 三峡库区 库水位升降 启动阈值 数值模拟 涌浪预测
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三峡水库消落带土壤反硝化及DOM的影响 被引量:1
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作者 朱砚涛 苏培兴 +3 位作者 张代钧 袁淑培 张峻通 刘寅飞 《中国环境科学》 EI CAS CSCD 北大核心 2024年第6期3270-3279,共10页
在重庆主城与涪陵选取了3个典型点位采集土壤样品,并对土壤的理化性质、原位反硝化速率、溶解性有机质(DOM)驱动的反硝化以及库区土壤的微生物进行了考察与分析.结果显示在海拔145~155m区间,淹水期镇安镇、涪陵区和鱼嘴镇最高氨氮(NH_(4... 在重庆主城与涪陵选取了3个典型点位采集土壤样品,并对土壤的理化性质、原位反硝化速率、溶解性有机质(DOM)驱动的反硝化以及库区土壤的微生物进行了考察与分析.结果显示在海拔145~155m区间,淹水期镇安镇、涪陵区和鱼嘴镇最高氨氮(NH_(4)^(+)-N)平均浓度分别为31.32,28.63和19.23mg/kg,均高于落干期.在淹水期,与高海拔区域土壤中硝酸盐氮(NO_(3)^(-)-N)平均浓度相比,低海拔土壤中NO_(3)^(-)-N平均浓度分别增大了46.91%(镇安镇)、37.89%(涪陵区)和29.69%(鱼嘴镇).在淹水期,土壤有机质(SOM)平均浓度随着海拔高程的降低而降低,镇安镇、涪陵区和鱼嘴镇分别从109.16,80.93和82.61mg/kg降至65.63,64.53,53.41mg/kg.土壤中NH_(4)^(+)-N和NO_(3)^(-)-N的含量与现场反硝化速率呈显著正相关(P<0.05),在提供充足的碳(C)和氮(N)营养元素后,土壤潜在反硝化速率表现出较大的时间和空间差异性.在由DOM驱动的反硝化实验中,DOM降解符合一级动力学模型(R^(2)>0.93),N2O累积量符合Logistic模型(R^(2)>0.97).在三峡水库消落带土壤中,反硝化功能微生物主要是Bacillus和Comamonadaceae,其丰度变化与土壤潜在反硝化速率呈现显著的正相关性(P<0.05). 展开更多
关键词 三峡水库消落带 土壤反硝化 溶解性有机质 微生物群落
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消落区沉积物落干期氮磷形态分析——以碧流河水库为例
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作者 韩冬凝 许士国 +1 位作者 李维佳 陈小强 《水资源与水工程学报》 CSCD 北大核心 2024年第5期11-19,共9页
水库水位变动致使消落区沉积物经历着频繁的干湿交替,为探讨落干过程对沉积物氮、磷的影响,以碧流河水库为例采集了消落区不同高程下的沉积物样品,并基于现场条件设计落干模拟试验,探讨持续落干条件下消落区沉积物氮、磷的多形态变化特... 水库水位变动致使消落区沉积物经历着频繁的干湿交替,为探讨落干过程对沉积物氮、磷的影响,以碧流河水库为例采集了消落区不同高程下的沉积物样品,并基于现场条件设计落干模拟试验,探讨持续落干条件下消落区沉积物氮、磷的多形态变化特征,为水库内源污染治理提供参考。研究发现:在沉积物干化过程中,受反硝化作用的影响,落干期TN的含量减少了2.99%,但随着水分蒸发反硝化作用易于发生的条件被破坏,TN的含量逐渐稳定;受矿化作用的影响存在有机磷(OP)向无机磷(IP)的形态转化,该转化提高了磷的生物有效性,且干化过程中会出现氮、磷向表层富集的现象。因此,持续的落干作用有利于沉积物中过量氮素的去除,有助于消落区植物生长和初级生产力的提升。 展开更多
关键词 水库 消落区 沉积物 持续落干 理化性质
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三峡水库消落带狗牙根根系对紫色土抗剪性能的影响
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作者 郑晓岚 鲍玉海 +3 位作者 贺秀斌 谢航宇 禹妍彤 王英培 《中国水土保持科学》 CSCD 北大核心 2024年第4期41-50,共10页
植物根系对提高土壤抗侵蚀能力起着最主要的作用。为探究根系对三峡水库消落带土壤抗剪性能的影响,以典型草本植物狗牙根及其根土复合体为研究对象,利用原状土和重塑土、采用直剪试验和三轴试验2种方法,揭示根系形态特征、含根量以及布... 植物根系对提高土壤抗侵蚀能力起着最主要的作用。为探究根系对三峡水库消落带土壤抗剪性能的影响,以典型草本植物狗牙根及其根土复合体为研究对象,利用原状土和重塑土、采用直剪试验和三轴试验2种方法,揭示根系形态特征、含根量以及布根方式对土壤抗剪性能的影响。结果表明:1)内摩擦角、黏聚力与根系形态特征呈对数正相关;各形态指标对土壤抗剪性能的影响程度依次为:根表面积密度>根体积密度>根长密度>根质量密度>根径。2)根系含量与土壤抗剪性能呈正相关。含根量分别为0.9、0.6和0.3 mg/cm^(3)的根土复合体抗剪强度依次比素土提高14.54%~49.56%、9.09%~35.82%和3.80%~17.58%;内摩擦角依次提高13.95%、13.07%和1.98%;黏聚力依次提高29.37%、24.48%和15.34%。3)交叉布根下土壤抗剪性能最强,与垂直布根、水平布根相比,交叉布根的抗剪强度依次提高4.22%~16.95%和11.45%~32.61%;黏聚力依次提高15.61%和16.09%;最大应力值依次提高3.78%~34.18%和36.86%~41.44%。研究结果可为三峡水库消落带固土护岸的物种筛选、水土保持生态建设以及水库岸线管理等提供参考。 展开更多
关键词 植物根系 根土复合体 土壤抗剪性能 消落带 三峡水库
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三峡水库对城陵矶防洪补偿控制水位研究Ⅰ——需求分析与优化条件 被引量:3
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作者 邹强 胡挺 +2 位作者 肖扬帆 饶光辉 何小聪 《人民长江》 北大核心 2024年第1期21-27,共7页
城陵矶地区是长江中下游洪灾最频发的区域之一,是长江水库群防洪的重点保护对象。金沙江下游乌东德、白鹤滩、溪洛渡、向家坝4座梯级水库与三峡水库组成的巨型水库群防洪能力巨大,显著改变了流域防洪调度格局。在概括分析城陵矶地区防... 城陵矶地区是长江中下游洪灾最频发的区域之一,是长江水库群防洪的重点保护对象。金沙江下游乌东德、白鹤滩、溪洛渡、向家坝4座梯级水库与三峡水库组成的巨型水库群防洪能力巨大,显著改变了流域防洪调度格局。在概括分析城陵矶地区防洪需求,回顾三峡水库对城陵矶地区防洪补偿控制水位不同阶段成果的基础上,剖析了优化防洪补偿控制水位的研究要点,研究了金沙江下游梯级防洪库容投入情况,进而明确了提高防洪补偿控制水位的有利条件。研究结果表明:在三峡水库水位达到城陵矶防洪补偿控制水位158.00 m后,金沙江下游梯级水库在预留40.93亿m^(3)防洪库容的基础上,尚有30亿~60亿m^(3)富余防洪库容可配合运用,为进一步提高三峡水库对城陵矶防洪补偿控制水位创造了良好条件。 展开更多
关键词 防洪补偿 控制水位 联合防洪调度 城陵矶地区 金沙江下游梯级水库 三峡水库
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适应水位变化的三峡库区消落带碳汇提升设计及效益评估
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作者 张展菲 袁嘉 +1 位作者 唐婷 陈鸿飞 《风景园林》 北大核心 2024年第6期19-27,共9页
【目的】三峡库区消落带受周期性的水位涨落及冬季长时间深水淹没影响,碳汇能力遭受严重破坏。如何恢复并充分发挥消落带生态系统的碳汇潜力,成为三峡库区生态治理的关键议题。【方法】针对复杂水位变化挑战,提出以林塘模式修复消落带... 【目的】三峡库区消落带受周期性的水位涨落及冬季长时间深水淹没影响,碳汇能力遭受严重破坏。如何恢复并充分发挥消落带生态系统的碳汇潜力,成为三峡库区生态治理的关键议题。【方法】针对复杂水位变化挑战,提出以林塘模式修复消落带生态系统并提升碳汇能力的技术框架,选取位于三峡库区腹心的大浪坝消落带开展实证研究。运用CASA模型测算修复前后大浪坝消落带的净初级生产力(net primary productivity,NPP),基于植被生物量数据计算修复后大浪坝消落带与未修复对照组内不同高程带的碳汇能力,评估林塘碳汇系统的可持续效益。【结果】修复后大浪坝消落带的碳汇能力随时间推移明显提升,NPP由2012年的154.4 g C·m^(2)·a^(-1)增长至2016年的182.5 g C·m^(2)·a^(-1);各高程带的碳汇能力均显著高于对照组,并呈现出随海拔降低而减弱的趋势,170~175 m高程带碳汇能力达到1.827 kg C/m^(2),160~165 m高程带碳汇能力仅为0.830 kg C/m^(2)。林塘系统增强了生态系统的适应性和复原力,形成了适应水位变化的立体固碳模式并有效提升了碳汇效率。【结论】林塘碳汇系统是应对三峡库区复杂水位变化和长时间深水淹没挑战的适应性探索,显示出景观优化、生物多样性、经济效益与碳汇协同耦合的关键特征。研究成果能够为中国大型工程型水库消落带的治理及碳增汇提供科学依据与可复制推广的创新技术模式。 展开更多
关键词 风景园林 生态修复 三峡库区 消落带 碳汇系统设计 碳汇评估
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基于时间序列InSAR的巴东地表形变分析 被引量:4
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作者 娄连惠 刘强 谭玉敏 《长江科学院院报》 CSCD 北大核心 2021年第5期149-152,158,共5页
通过利用2017—2019年间53景Sentinel-1A数据,采用SBAS方法完成了巴东地区长江沿岸区域年平均形变速率图的绘制。结果表明:该区域地表形变速率维持在-5~5 mm/a之间;考虑了水位在时间和空间上的影响,分析了水位变化与江边不同距离区域内... 通过利用2017—2019年间53景Sentinel-1A数据,采用SBAS方法完成了巴东地区长江沿岸区域年平均形变速率图的绘制。结果表明:该区域地表形变速率维持在-5~5 mm/a之间;考虑了水位在时间和空间上的影响,分析了水位变化与江边不同距离区域内时间序列形变间的关联关系,认为该区域形变整体受水位变化影响很小。研究成果为评估三峡库区地表形变状况及对三峡库区沿岸区域地质灾害监测预防、工程建设以及水库安全运行等有重要意义。 展开更多
关键词 地表形变 SBAS Sentinel-1A 形变速率 水位变化 三峡库区 巴东 地质灾害
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基于Markov模型的三峡上游消落带土地利用变化预测
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作者 宋云瑞 王鹏程 +3 位作者 崔鸿侠 胡文杰 姚圣典 贺达 《湖北林业科技》 2024年第1期27-31,共5页
三峡水库蓄水后形成高程差30 m的消落带,以蓄满水位175 m为基准水平外扩150 m得到交错缓冲区。缓冲区土地利用情况较复杂,本研究通过研究库区上游缓冲区近20年土地利用的变化情况,分析前20年上游发展模式。通过马尔可夫函数来预测未来2... 三峡水库蓄水后形成高程差30 m的消落带,以蓄满水位175 m为基准水平外扩150 m得到交错缓冲区。缓冲区土地利用情况较复杂,本研究通过研究库区上游缓冲区近20年土地利用的变化情况,分析前20年上游发展模式。通过马尔可夫函数来预测未来20年的土地利用变化可能,为上游区域未来规划发展方向提出建议。研究表明:(1)上游在发展过程中持续紧抓农业用地,可按目前的模式继续发展;(2)生态方面,森林、灌丛、草地等与生态环境相关的地类占比是有所提高的,目前发展政策是有利生态环境的,但由于水域面积增长导致裸岩增加,水土流失风险增加,需更加重视水土流失的防治;(3)经济发展与城镇化密切相关,城乡建设用地与道路占比不断上升,上游经济形势一片大好。综合来说,可按照2000~2020年的发展模式继续开发建设,但应在此基础上更加重视经济与环境的协同发展,尽量建设森林城市,通过工程护坡、生态护坡等技术来加强两岸土地的水土保持力度。 展开更多
关键词 三峡库区 消落带 3S技术 土地利用 马尔可夫预测
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水位变动对三峡水库消落带典型雌激素效应物质及活性的影响
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作者 周敏 邵迎 +1 位作者 黄思瑜 陈忠礼 《重庆大学学报》 CAS CSCD 北大核心 2024年第4期1-11,共11页
以三峡库区消落带为研究对象,将化学分析与生物测试相结合,研究水位变动对消落带土壤(落干期)和沉积物(淹水期)雌激素效应物质种类和含量及雌激素活性的影响,探讨典型雌激素与雌激素效应的关联程度,以期为水库消落带生态安全和环境健康... 以三峡库区消落带为研究对象,将化学分析与生物测试相结合,研究水位变动对消落带土壤(落干期)和沉积物(淹水期)雌激素效应物质种类和含量及雌激素活性的影响,探讨典型雌激素与雌激素效应的关联程度,以期为水库消落带生态安全和环境健康管理提供重要的数据支撑。借助超高效液相色谱-质谱(UPLC-MS)对8种典型雌激素的赋存与质量浓度进行靶向分析,并使用重组基因酵母筛选(YES)体系检测环境样品雌激素活性,通过相关性分析和浓度加和计算建立化学物质与生物效应间的相关联系。8种典型雌激素仅有雌酮(E1)和乙炔基雌二醇(EE2)被检出,含量在0.025~2.667 ng/g范围内。淹水期的沉积物具有明显的雌激素活性,其雌二醇当量(EEQ)值为0.637~6.987 ng/g。相关性分析结果显示,靶向分析的雌激素效应物质与雌激素效应间无明显相关性,仅能解释29.46%的雌激素活性。水位变动影响消落带雌激素效应物质的种类和质量浓度,淹水提高了沉积物雌激素活性。典型雌激素物质与库区消落带雌激素效应无显著关联。因此,需要开发新的方法与技术,以便更为精确地指导消落带雌激素效应的风险识别与管控。 展开更多
关键词 沉积物 水位变动 三峡水库 雌激素活性 典型雌激素
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