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Tempo-spatial variations of sediment-associated nutrients and contaminants in the Ruxi tributary of the Three Gorges Reservoir, China 被引量:2
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作者 SHI Zhong-lin WANG Yong-yan +2 位作者 WEN An-bang YAN Dong-chun CHEN Jia-cun 《Journal of Mountain Science》 SCIE CSCD 2018年第2期319-326,共8页
Ruxi River is a tributary of the Three Gorges Reservoir. This study examined the temporal and spatial dynamics in particle size characteristics and the associated nutrients and contaminants of the fluvial suspended an... Ruxi River is a tributary of the Three Gorges Reservoir. This study examined the temporal and spatial dynamics in particle size characteristics and the associated nutrients and contaminants of the fluvial suspended and deposited sediments along the Ruxi River. Temporal variations in the particle size distribution of the suspended sediment are controlled mainly by differences in sediment source during different seasons. Total organic carbon (TOC), total nitrogen (TN) and total phosphorous (TP) in the 〈 62 μm fraction of the suspended sediment exhibit considerably higher concentrations in spring, indicating high probability of algal blooms in the backwater areas. Downstream trends in the nutrient contents of 〈 62 pm deposited sediments imply the greatest potential for eutrophication in the backwater ends, where highest nutrient concentrations were detected. Assessment of metal contamination shows that the sediments deposited in the water-level fluctuation zone were moderately to strongly contaminated by Cadmium (Cd), with a considerably high potential ecological risk. The findings reported have emphasized the impacts of reservoir impoundment on aquatic and/or terrestrial environment in this region. More information on physical, chemical and biological processes of sediment and sediment-associated materials are needed for developing ecologically sound policies management. environmentally and of water and sediment 展开更多
关键词 SEDIMENTS NUTRIENTS Trace metals Water-level fluctuation zone Ruxi tributary threegorges reservoir
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Microplastics in sediment of the Three Gorges Reservoir:abundance and characteristics under different environmental conditions
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作者 Wang LI Bo ZU +2 位作者 Yiwei LIU Juncheng GUO Jiawen LI 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第1期101-112,共12页
Freshwater microplastic pollution is an urgent issue of global concern,and research on the distribution in reservoirs is lacking.We investigated the microplastic pollution levels in wet sediments collected from the Th... Freshwater microplastic pollution is an urgent issue of global concern,and research on the distribution in reservoirs is lacking.We investigated the microplastic pollution levels in wet sediments collected from the Three Gorges Reservoir,the largest reservoir of China.Results show that microplastics were ubiquitous in the sediments of the Three Gorges Reservoir,and their abundance ranged from 59 to 276 pp/kg(plastic particles per kg,dry weight).Economic development and total population were important factors affecting the spatial heterogeneity of microplastic abundance,and the contribution of large cities along the reservoir to microplastic pollution should be paid with more attention.Fibrous microplastics were the most abundant type of microplastic particles in reservoir sediments,whereas polystyrene,polypropylene,and polyamide were the main types of polymers.The apparent spatial heterogeneity in morphology and color of microplastics is attributed to different anthropogenic or landbased pollution sources.Moreover,the accumulation of microplastics near the inlet of tributaries reflects the role of potential contributors of tributaries.More importantly,multiple bisphenols(BPs)and heavy metals detected at the microplastic surfaces indicate that microplastics can act as carriers of these pollutants in the environment in the same way as sediments did,which may alter the environmental fate and toxicity of these pollutants.Therefore,we conclude that the Three Gorges Reservoir had been contaminated with microplastics,which posed a stress risk for organisms who ingest them along with their associated pollutants(BPs,heavy metals). 展开更多
关键词 microplastics three gorges reservoir SEDIMENT BISPHENOL heavy metal
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Characteristics and influencing mechanisms of production-living-ecological space dynamics in the Three Gorges Reservoir Area(TGRA),Chongqing,China
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作者 ZHU Xinyi GAO Jinlong 《Regional Sustainability》 2024年第2期49-62,共14页
The Three Gorges Reservoir Area(TGRA)is an important ecological barrier in the Yangtze River Basin,China.Therefore,it is of great importance to understand the spatio-temporal variation and the driving factors of produ... The Three Gorges Reservoir Area(TGRA)is an important ecological barrier in the Yangtze River Basin,China.Therefore,it is of great importance to understand the spatio-temporal variation and the driving factors of production-living-ecological spaces for sustainable and high-quality development in the TGRA.This study investigated the dynamic variation of production-living-ecological spaces in the TGRA by employing land use data in 2000,2005,2010,2015,and 2018,and detected the influencing factors by using the Geographic detector(GeoDetector).Results implied that the structure and dynamic trajectories of production-living-ecological spaces in the TGRA varied in both horizontal and vertical directions,and the study area was dominated by ecological space.A spatial orientation towards the northeast was detected in the evolution of production-living-ecological spaces during 2000-2018.In terms of quantity,the transition from ecological space(grassland and woodland)to agriculture land accounted for the largest proportion from 2000 to 2018.However,the reverse transition from agriculture land to ecological space has increased since 2000 with the efforts of“Grain for Green”.In terms of temporal scale,there was a fluctuating trend in production space with the continuous expansion of living space,while ecological space showed an inverted U-shaped trend during 2000-2018.The dynamic pattern of production-living-ecological spaces in the TGRA was influenced by both physical and socio-economic variables as basic determinants and dominant driving factors,respectively.Finally,the harmonization and protection of production-living-ecological spaces still require policy-makers’efforts.This work may have potential in advancing our understanding about land use conflicts,and provide a reference for rational layout of spatial functions and the realization of sustainable development in the TGRA. 展开更多
关键词 Production-living-ecological spaces Functional transition three gorges reservoir Area(TGRA) Physical and socio-economic variables Yangtze River
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Projecting Spring Consecutive Rainfall Events in the Three Gorges Reservoir Based on Triple-Nested Dynamical Downscaling 被引量:2
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作者 Yanxin ZHENG Shuanglin LI +2 位作者 Noel KEENLYSIDE Shengping HE Lingling SUO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第8期1539-1558,共20页
Spring consecutive rainfall events(CREs) are key triggers of geological hazards in the Three Gorges Reservoir area(TGR), China. However, previous projections of CREs based on the direct outputs of global climate model... Spring consecutive rainfall events(CREs) are key triggers of geological hazards in the Three Gorges Reservoir area(TGR), China. However, previous projections of CREs based on the direct outputs of global climate models(GCMs) are subject to considerable uncertainties, largely caused by their coarse resolution. This study applies a triple-nested WRF(Weather Research and Forecasting) model dynamical downscaling, driven by a GCM, MIROC6(Model for Interdisciplinary Research on Climate, version 6), to improve the historical simulation and reduce the uncertainties in the future projection of CREs in the TGR. Results indicate that WRF has better performances in reproducing the observed rainfall in terms of the daily probability distribution, monthly evolution and duration of rainfall events, demonstrating the ability of WRF in simulating CREs. Thus, the triple-nested WRF is applied to project the future changes of CREs under the middle-of-the-road and fossil-fueled development scenarios. It is indicated that light and moderate rainfall and the duration of continuous rainfall spells will decrease in the TGR, leading to a decrease in the frequency of CREs. Meanwhile, the duration, rainfall amount, and intensity of CREs is projected to regional increase in the central-west TGR. These results are inconsistent with the raw projection of MIROC6. Observational diagnosis implies that CREs are mainly contributed by the vertical moisture advection. Such a synoptic contribution is captured well by WRF, which is not the case in MIROC6,indicating larger uncertainties in the CREs projected by MIROC6. 展开更多
关键词 triple-nested downscaling three gorges reservoir area consecutive rainfall events geological hazards PROJECTION
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Environmental heterogeneity and productivity drive the assemblage of benthic diatom:a case study of the Three Gorges Reservoir
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作者 Songqi YANG Tian OUYANG +4 位作者 Shaojun XU Lu ZHAO Lulu JI Junqiong SHI Zhongxing WU 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第3期991-1006,共16页
Dam construction has a critical effect on river ecosystems in the world,resulting in a rapid decline in biodiversity and ecosystem health.However,the effect of dam construction on the assemblage pattern of benthic dia... Dam construction has a critical effect on river ecosystems in the world,resulting in a rapid decline in biodiversity and ecosystem health.However,the effect of dam construction on the assemblage pattern of benthic diatoms remains unclear.The benthic diatoms assemblages in the tributary backwater area of the Three Gorges Reservoir(TGR)were investigated under low water level(LWL)and high water level(HWL)conditions.Results show that Discostella stelligera,Nitzschia palea,and Craticula subminuscula were dominant species in LWL,while Achnanthidium minutissimum and Nitzschia dissipata were dominant in HWL.Furthermore,environmental variables,productivity parameters,diversity indices,and community similarity were found significantly different between LWL and HWL periods.The Mantel test indicated that both environmental and spatial factors had significant effects on diatom communities in backwater area,while productivity was also a key driving force in LWL.The variation partitioning analysis(VPA)further demonstrated that environment factors could explain the largest variance of diatom assemblages in HWL(9%)and LWL(11%),followed by spatial factors.The relative importance of productivity to diatom community was significantly enhanced in LWL,but only a slight effect was found in HWL.These results indicate that the diatom assemblages were shaped by both environmental filtering and spatial factors.The relative importance of spatial factors depended on the degree of productivity.Therefore,the homogenization of diatom communities due to environmental disturbance,e.g.eutrophication and dam building,is the underlying mechanism in assembling the benthic diatoms. 展开更多
关键词 three gorges reservoir benthic diatom ASSEMBLAGE environmental heterogeneity PRODUCTIVITY
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Seasonal variation of nitrogen and phosphorus in Xiaojiang River-A tributary of the Three Gorges Reservoir 被引量:8
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作者 Zhe LI Jinsong GUO +3 位作者 Man LONG Fang FANG Jinping SHENG Hong ZHOU 《Frontiers of Environmental Science & Engineering》 SCIE EI CSCD 2009年第3期334-340,共7页
A yearlong monitoring program in the backwater area of Xiaojiang River(XBA)was launched in order to investigate the eutrophication of backwater areas in tributaries of the Yangtze River in the Three Gorges Reservoir(T... A yearlong monitoring program in the backwater area of Xiaojiang River(XBA)was launched in order to investigate the eutrophication of backwater areas in tributaries of the Yangtze River in the Three Gorges Reservoir(TGR)in China,starting after the impoundment water level of the TGR reached 156 m.From March 2007 to March 2008,the average concentration of total nitrogen(TN)and total phosphorus(TP)were(1553484)μg·L^(–1)and(6231)μg·L^(–1),respectively.The mean value of chlorophyll was(9.070.91)μg·L^(–1).The trophic level of XBA was meso-eutrophic,while the general nutrient limitation was phosphorus.The results indicated that XBA has a strong ability to purify itself and has non-point source pollution from terrestrial runoff.The variation of TN/TP ratio was caused by a variation in TN rather than in TP when TN/TP<22.N-fixation from cyanobacteria occurred and became an important process in overcoming the nitrogen deficit under a low TN/TP ratio.When TN/TP≥22,the variation of TP affected the TN/TP ratio more significantly than TN.The increase of TP in XBA was caused mainly by particulate phosphorus,which could originate from a non-point source as adsorptive inorganic forms after heavy rainfall and surface runoff.An increase in the river’s flow could also contribute to an unstable environment for the growth of phytoplankton. 展开更多
关键词 three gorges reservoir EUTROPHICATION NITROGEN PHOSPHORUS seasonal variation CHLOROPHYLL
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Strategies for Safe Land Use of the Three Gorges Reservoir Area (Chongqing Section)——With the Restoration of Degraded Forest Landscapes as a Study Case
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作者 牟萍 《Journal of Landscape Research》 2010年第8期51-55,共5页
As a key for constructing ecologically safe scenery, forest landscape pattern in Chongqing Section of the Three Gorges has shown degradation, fragmentation and revision of varying degrees. To ensure normal and safe op... As a key for constructing ecologically safe scenery, forest landscape pattern in Chongqing Section of the Three Gorges has shown degradation, fragmentation and revision of varying degrees. To ensure normal and safe operation of the Three Gorges, and meet requirements of integrated development strategies for ecological and economic effects in Chongqing City on the ecological security of land use in Chongqing section of the Three Gorges, the following points should be attached more importance in making future strategies for an ecologically safe land use pattern with the restoration of degraded forest landscape as its starting point:a. Ecological effects and economic functions that can be supplied by forest landscape elements in different restoration patterns should be understood to obtain background effect of the ecological security pattern scenario of land use in the reservoir region; b. Relationship between restoration of degraded forest landscapes and serious ecological interference factors such as degradation background, artificial disturbance and engineering stress, should be simulated to figure out the influence of natural or artificial driving factors on landscape pattern, determine the future restoration mode for the degraded forest landscapes in the reservoir region, so as to facilitate the construction of great ecological-economic security pattern of the Three Gorges. The findings will provide scientific basis for the decision-making in building an ecologically safe land use pattern in the Three Gorges reservoir area (Chongqing), when using the degradation of forest landscape restoration as a carrier at present or in the future. Further, they will help realize the development goals of "Livable Chongqing, Expedite Chongqing, Forestry Chongqing, Safe Chongqing and Healthy Chongqing". 展开更多
关键词 LAND use Ecological-economic security Forest LANDSCAPE the three gorges reservoir region
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Effect of nitrogen and phosphorus on the water quality in the Three Gorges Reservoir Area during and after its construction 被引量:10
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作者 LIUHong LIUHui-juan QUJiu-hui 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2004年第3期358-363,共6页
A survey concerning the concentration of the nutrients in the Three Gorges Reservoir Area was carried out. This paper presents the parameters(NO 3 - N, NO 2 - N, Kjeldahl N, non ionic ammonia, P PO 4 and TP)... A survey concerning the concentration of the nutrients in the Three Gorges Reservoir Area was carried out. This paper presents the parameters(NO 3 - N, NO 2 - N, Kjeldahl N, non ionic ammonia, P PO 4 and TP) determined at 16 sampling sites from 1997 to 1999 The dominant soluble nitrogen form was NO 3 - N followed by Kjeldahl N, NO 2 - N and non ionic ammonia. Mean values of NO 3 - N, NO 2 - N, Kjeldahl N and non ionic ammonia ranged from 0 50 to 2 37 mg/L, 0 022 to 0 084 mg/L, 0 33 to 0 99 mg/L and 0 007 to 0 092 mg/L respectively. Mean values of P PO 4 at most sampling sites were higher than 0 1 mg/L for subject to eutrophication. The major factors influencing the concentrations of N and P might be agricultural runoff, municipal and industrial effluents. In addition, 6 kinds of soil were sampled at the area where would inundated after the dam completed. Two approaches were adopted to simulate the N and P release from the inundated soils. The results showed that the soils would release nitrogen and phosphorus to the overlying water when the soils were inundated. The characteristics of soil affected the equilibrium concentrations of N and P between the soil and the overlying water. 展开更多
关键词 three gorges reservoir Area NITROGEN PHOSPHORUS inundated soil
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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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Displacement characteristics and prediction of Baishuihe landslide in the Three Gorges Reservoir 被引量:5
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作者 LI De-ying SUN Yi-qing +3 位作者 YIN Kun-long MIAO Fa-sheng Thomas GLADE Chin LEO 《Journal of Mountain Science》 SCIE CSCD 2019年第9期2203-2214,共12页
In order to reach the designated final water level of 175 m, there were three impoundment stages in the Three Gorges Reservoir, with water levels of 135 m, 156 m and 175 m. Baishuihe landslide in the Reservoir was cho... In order to reach the designated final water level of 175 m, there were three impoundment stages in the Three Gorges Reservoir, with water levels of 135 m, 156 m and 175 m. Baishuihe landslide in the Reservoir was chosen to analyze its displacement characteristics and displacement variability at the different stages. Based on monitoring data, the landslide displacement was mainly influenced by rainfall and drawdown of the reservoir water level. However, the magnitude of the rise and drawdown of the water level after the reservoir water level reached 175 m did not accelerate landslide displacement. The prediction of landslide displacement for active landslides is very important for landslide risk management. The time series of cumulative displacement was divided into a trend term and a periodic term using the Hodrick-Prescott(HP) filter method. The polynomial model was used to predict the trend term. The extreme learning machine(ELM) and least squares support vector machine(LS-SVM) were chosen to predict theperiodic term. In the prediction model for the periodic term, input variables based on the effects of rainfall and reservoir water level in landslide displacement were selected using grey relational analysis. Based on the results, the prediction precision of ELM is better than that of LS-SVM for predicting landslide displacement. The method for predicting landslide displacement could be applied by relevant authorities in making landslide emergency plans in the future. 展开更多
关键词 LANDSLIDE three gorges reservoir IMPOUNDMENT process DISPLACEMENT PREDICTION
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Present Situation and Control of Outbreaks of Algal Blooms in the Three Gorges Reservoir 被引量:3
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作者 Ma Jianhua Hu Mingming Zhu Xi 《Meteorological and Environmental Research》 CAS 2016年第6期33-37,44,共6页
After water storage in the Three Gorges Reservoir Region,there are no outbreaks of algal blooms in the main stream of the reservoir region,but the density of algae increases obviously. Outbreaks of algal blooms mainly... After water storage in the Three Gorges Reservoir Region,there are no outbreaks of algal blooms in the main stream of the reservoir region,but the density of algae increases obviously. Outbreaks of algal blooms mainly appeared in the tributaries of the reservoir region such as the Xiangxi River,Daning River,Shennong River and Xiaojiang River,but they did not occur every year. The reasons for outbreaks of algal blooms in the tributaries are shown as follows: the existence of sources of algae(blue-green algae) in the Three Gorges Reservoir is the root cause,and the sources include sources existing and being produced in the reservoir and sources from upstream main stream and its tributaries and other related lakes and reservoirs,of which the sources are mainly from the Dianchi Lake; slight or moderate eutrophication of water is the basic condition;hydrologic and hydrodynamic conditions and suitable temperature are conducive to proliferation and aggregation of algae(blue-green algae) after the operation of the Three Gorges Reservoir until outbreaks of algal blooms appear. Outbreaks of algal blooms in the tributaries of the Three Gorges Reservoir Region mainly appear in backwater reaches; they mainly occur in the tributaries in the north of the reservoir region and near to the dam;they mainly appear from March to July; the dominant species of algae( blue-green algae) in the Three Gorges Reservoir are Pyrrophyta,Bacillariophyta and Chlorophyta,but they tend to change into blue-green algae and other algae. To control outbreaks of algal blooms in the tributaries of the Three Gorges Reservoir Region,it is needed to prevent water containing blue-green algae collected from the Dianchi Lake and other lakes and reservoirs from being input into the lower reaches,reduce pollution load flowing into the Three Gorges Reservoir,use enclosures to change hydrodynamic conditions of backwater reaches of the tributaries appropriately,and adopt biological measures such as culturing fish and planting plants to improve ecosystem of the tributaries and other measures to inhibit and eliminate algae and decrease eutrophication level. 展开更多
关键词 Outbreaks of ALGAL BLOOMS Control measures TRIBUTARIES the three gorges reservoir REGION China
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Dynamics of Rodent and Rodent-borne Disease during Construction of the Three Gorges Reservoir from 1997 to 2012 被引量:5
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作者 CHANG Zhao Rui LU Liang +7 位作者 MAO De Qiang PAN Hui Ming FENG Lian Gui YANG Xiao Bing LIU Feng Feng HE Yuan Yuan ZHANG Jing YANG Wei Zhong 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2016年第3期197-204,共8页
Objective To investigate the impact of impoundment and active public health interventions on rodent populations and rodent-borne diseases in the Three Gorges reservoir region from 1997 to 2012. Methods Surveillance da... Objective To investigate the impact of impoundment and active public health interventions on rodent populations and rodent-borne diseases in the Three Gorges reservoir region from 1997 to 2012. Methods Surveillance data from 1997 to 2012 were extracted from the Public Health Surveillance System of The Three Gorges established in 1997. Temporal changes in the incidences of hemorrhagic fever with renal syndrome (HFRS) and leptospirosis, rodent density, pathogen-carrying rates, and their correlations were analyzed. Results The average indoor and outdoor rodent densities decreased overall from 1997 to 2012. The average densities decreased by 47.72% (from 4.38% to 2.29%) and 39.68% (from 4.41% to 2.66%), respectively, after impoundment (2003-2012) compared with before impoundment (1997-2002). The average annual incidence rates of HFRS and leptospirosis were 0.29/100,000 and 0.52/100,000, respectively, and decreased by 85.74% (from 0.68/100,000 to 0.10/100,000) and 95.73% (from 1.47/100,000 to 0.06S/100,000), respectively, after impoundment compared with before impoundment. Incidences of HFRS and leptospirosis appear to be positively correlated with rodent density in the reservoir area. Conclusion This study demonstrated that rodent density and incidences of rodent-borne diseases decreased and were maintained at low levels during construction of the Three Gorges dam. Measures that reduce rodent population densities could be effective in controlling rodent-borne diseases during large-scale hydraulic engineering construction. 展开更多
关键词 three gorges reservoir Rodent density Rodent-borne diseases
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Surface Microtextures of Slipping Zone Soil of Some Landslides in the Three Gorges Reservoir District and Their Significance 被引量:5
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作者 YAN Chunjie SUN Yunzhi TANG Huiming 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2000年第2期349-352,共4页
The mineral assemblage and content and surface microtextures of slipping zone soil of several landslides in the Three Gorges Reservoir District have been analyzed using the scanning electron microscope (SEM) and X-ray... The mineral assemblage and content and surface microtextures of slipping zone soil of several landslides in the Three Gorges Reservoir District have been analyzed using the scanning electron microscope (SEM) and X-ray diffractometer (XRD). All the mineral assemblages are similar in these landslides. The main minerals are montmorillonite, illite, kaolinite, chlorite, quartz and feldspar. There are two kinds of surface microtexture in the slipping zone soil, i.e., linear scratches and arcuate scratches. Based on analyses of the changes of the microtextures, one can obtain information about the number, directions and stages of landslide movements. The authors have also studied the mechanism of landslide formation, evaluated the stability of landslides and revival possibility of ancient landslides and forecasted the activity of similar landslides in different districts. The surface microtexture features of stable landslides and mobile landslides are summarized and it is concluded that the existence of filamentous bacteria may result in or increase movements of landslides. 展开更多
关键词 the three gorges reservoir district LANDSLIDE surface microtexture scanning electron microscope (SEM)
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Land Use of the Three Gorges Reservoir Area and the Effect on Its Landscape Pattern in the Recent 50 Years 被引量:7
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作者 HUANG Zhiqin 1,2,3 , ZHOU Wancun 1 ,ZHOU Jieming 4 , ZHU Mingcang 3,5 1. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences , Chengdu 610041, Sichuan, China 2. Graduate University of Chinese Academy of Sciences, Beijing 100049, China +2 位作者 3. Sichuan Institute of Land Resource Management, Chengdu 610041, Sichuan , China 4. Department of Resources and Environment Science, Sichuan Normal University , Chengdu 610061, Sichuan, China 5. College of Information Engineering, Chengdu University of Technology, Chengdu 610059, Sichuan, China 《Wuhan University Journal of Natural Sciences》 EI CAS 2006年第4期910-914,共5页
The paper makes detailed analysis on the changing processes of the main types of land use in Three Gorges Reservoir Area through the techniques of RS (Remote Sense) and GIS (Geography Information System). Based on... The paper makes detailed analysis on the changing processes of the main types of land use in Three Gorges Reservoir Area through the techniques of RS (Remote Sense) and GIS (Geography Information System). Based on the theory of landscape ecology, many types of landscape pattern indexes are calculated and made correlation analysis. The results indicate that: in 1995 the ecological environment of Three Gorges Reservoir Area was the most vulnerable in the recent 50 years, but resumed in 2002; the landscape pattern diversity index, fractal dimension index and fragmentation index has close correlation with the area of land use/cover change (LUCC). The research also releases that the increase of the cultivated land, grassland and construction land deteriorates the landscape ecological pattern, while the increase of forest land area will help restore the landscape ecological pattern to its original state. The rapid change of grassland is an important index of the change of landscape pattern, because it has the most effect on change of landscape pattern index. 展开更多
关键词 the three gorges reservoir Area land use/cover change landscape pattern.
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Conflict between wild boars(Sus scrofa) and farmers:distribution, impacts,and suggestions for management of wild boars in the Three Gorges Reservoir Area 被引量:3
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作者 LIU Qin YAN Kun +2 位作者 LU Ya-feng LI Ming YAN Yang-yang 《Journal of Mountain Science》 SCIE CSCD 2019年第10期2404-2416,共13页
Economic losses caused by wild boars(Sus scrofa)continue to increase in the Three Gorges Reservoir Area.We selected 206 farmers in Wuqiaohe Basin as survey respondents using random stratified sampling.The distribution... Economic losses caused by wild boars(Sus scrofa)continue to increase in the Three Gorges Reservoir Area.We selected 206 farmers in Wuqiaohe Basin as survey respondents using random stratified sampling.The distribution and impacts of wild boars were examined using a questionnaire survey and spatial analysis.The results showed that:(1)The density of farmer settlements is low and most peasants’households are located on the forest edge.Due to large-scale labor migration,a high proportion of farmland(25.85%)has been abandoned and an even higher proportion of farmland(40.48%)has been returned to forest.(2)The probability of wild boar damage to peasant households was 67.96%.Yields of corn and sweet potato decreased by 24.87%and 28.24%,respectively,with a total economic loss of approximately 2,590,100 RMB/yr in the Wuqiaohe basin.Sixty-five percent of the affected cultivatedlands were located within approximately 150 m of the forest edges.(3)The wild boar damage coefficient was significantly and negatively correlated with the distance between the peasants’household and the forest edge,the density of the settlements,and the area of cultivated land.The wild boar damage coefficient shows a significant positive correlation with the area of farmland returned to forest.(4)The damage activity caused by wild boars began to occur7-8 years ago,and the destruction has been more frequently and seriously observed in the last 4-5 years.(5)We make suggestions for wild boar control and management measures including developing a compensation policy.The compensation standard is related to the land area returning from farmland to forests and the actual cultivated land area. 展开更多
关键词 DISTRIBUTION features Economic loss MANAGEMENT three gorges reservoir Area Wild BOAR
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Seasonal succession of phytoplankton in response to the variation of environmental factors in the Gaolan River, Three Gorges Reservoir, China 被引量:8
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作者 彭成荣 张浪 +1 位作者 郑杨忠 李敦海 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2013年第4期737-749,共13页
To understand the responses of a freshwater ecosystem to the impoundment of the Three Gorges Reservoir (TGR), phytoplankton was monitored in the tributaries of the TGR area. From August 2010 to July 2011, algal spec... To understand the responses of a freshwater ecosystem to the impoundment of the Three Gorges Reservoir (TGR), phytoplankton was monitored in the tributaries of the TGR area. From August 2010 to July 2011, algal species composition, abundance, chlorophyll a and other environmental parameters were investigated in the Gaolan River, which is a tributary of Xiangxi River. Thirty-one algal genera from seven phyla were identified. Results show that the lowest concentrations of total phosphorus (TP) and total nitrogen (TN) were 0.06 mg/L and 1.08 rag/L, respectively. The values of TP and TN exceeded the threshold concentration of the eutrophic state suggested for freshwater bodies. In the Gaolan River, the succession of phytoplankton showed clear seasonal characteristics. Different dominant species were observed among seasons under the control of environment factors. In spring and summer, the dominant species were Nitzschia sp. and Aphanizomenon flos-aquae (L.) Ralfs, the limiting nutrient was NO3^--N, and the key environmental factor for phytoplankton population succession was water temperature (WT). In autumn and winter, the dominant species were A.flos-aquae and Chlorella sp., the limiting nutrient was pO3--P, and the key environmental factors were transparency and WT. This study illustrates the influence of physical and chemical factors on phytoplankton seasonal succession in a tributary of TGR since the downstream regions of Xiangxi River and Gaolan River became reservoirs after impoundment of the Three Gorges Dam. We suggest that this activity has significantly affected water quality in the dam area. 展开更多
关键词 environmental factors PHYTOPLANKTON SUCCESSION three gorges reservoir (TGR)
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Spatial-temporal Pattern and Differences of Land Use Changes in the Three Gorges Reservoir Area of China during 1975-2005 被引量:9
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作者 CAO Yingui ZHOU Weit +1 位作者 WANG Jing YUAN Chun 《Journal of Mountain Science》 SCIE CSCD 2011年第4期551-563,共13页
Regional land use changes are an important part of global changes.The research on land use changes in the Three Gorges Reservoir Area of China attracts a lot of attention owing to the Three Gorges Dam building.The Thr... Regional land use changes are an important part of global changes.The research on land use changes in the Three Gorges Reservoir Area of China attracts a lot of attention owing to the Three Gorges Dam building.The Three Gorges Reservoir Area becomes one of the important research areas.This study analyzed the transforming processes and traits of each land use type and the regional differences of land use changes during the past 30 years,summarized the distribution of different land use types in different buffer zones and regresses the equation areas and different buffer distances based on buffer analyses and regression analyses,and then analyzed the transforming rules in different buffer distances,got the optimal influence distances.The research results indicate that,(1) cultivated land lies at the northwest of the reservoir and was decreasing,however,the construction land was increasing,especially the urban construction land,a large number of land was flooded because of the reservoir water level rise;(2) urban area was sprawling quickly in developed and neighboring areas,and a great deal of cultivated land and a considerable amount of grassland were occupied;in the earlier time,rural settlements occupied lots of cultivated land and a sum of forestry land in the later time;(3) the optimum influenced distances for cultivated land and forestry land were 10-35 km,and for urban and rural settlements were in 5-20 km.Overall,this research can reflect the spatial-temporal characteristics of land use changes during the 30 years,and it is helpful for urban planning and land use planning in the reservoir area. 展开更多
关键词 Land use Spatial-temporal changes DIFFERENCES three gorges reservoir Area
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Spatial distribution,sources and ecological risk assessment of heavy metals in Shenjia River watershed of the Three Gorges Reservoir Area 被引量:10
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作者 WANG Yong-yan WEN An-bang +2 位作者 GUO Jin SHI Zhong-lin YAN Dong-chun 《Journal of Mountain Science》 SCIE CSCD 2017年第2期325-335,共11页
Surface soil/sediment samples were collected from the Water-Level Fluctuation Zone(WLFZ), cultivated land and forest land at 50 different grid points from Shenjia watershed, the Three Gorges Reservoir area in August 2... Surface soil/sediment samples were collected from the Water-Level Fluctuation Zone(WLFZ), cultivated land and forest land at 50 different grid points from Shenjia watershed, the Three Gorges Reservoir area in August 2013. The spatial distribution, sources and ecological risk assessment for Arsenic(As), Cadmium(Cd),Chromium(Cr), Copper(Cu), Nickel(Ni), Lead(Pb)and Zinc(Zn) were analyzed in this study. The results showed all tested metals had similar distribution patterns except Ni and Cr, with areas of high concentrations distributed in the southwest(WLFZ and watershed outlet) of the study area. Ni and Cr,which were highly positively correlated and present in high concentrations, were primarily distributed in the south and middle zones of the study area. Lower concentration areas of all metals were uniformly distributed west of the high-elevation zones and forest land. Factor analysis(FA) and factor analysismultiple linear regression(FA-MLR) showed that the major sources of Cd were fertilizer and traffic sources,which together accounted for 87% of Cd. As, Zn and Cu levels were primarily supplied by industrial and domestic sources, accounting for 76% of As, 75% of Cu and 67% of Zn. Surface soils/sediments of the study watershed contaminated by Cd represent a high ecological risk, whereas other metals represent low ecological risks. The potential ecological risk index(PERI) analysis indicated that it had a low(widerange) ecological risk and a moderate(small-range)ecological risk primarily distributed in the outlet of the study watershed. Fertilizers and traffic are the primary sources of Cd pollution, which should be more closely controlled for the purposes of water quality and ecological conservation. 展开更多
关键词 Spatial distribution Ecological risk assessment Water-level fluctuation zone Heavy metals three gorges reservoir
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Assessment of the Ecological Security in the Three Gorges Reservoir Area by Using the Ecological Footprint Method 被引量:11
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作者 WANG Haiming WANG Hai'e +4 位作者 SUN Hongyang WANG Xiaolan LIAO Xiaoyong CHEN Zhijian LI Xianwei 《Journal of Mountain Science》 SCIE CSCD 2012年第6期891-900,共10页
The ecological footprint concept and its calculation models are useful for the measurement of the sustainable level of social and economic development.The ecological security situation of the Three Gorges Reservoir Ar... The ecological footprint concept and its calculation models are useful for the measurement of the sustainable level of social and economic development.The ecological security situation of the Three Gorges Reservoir Area(TGRA) was evaluated using this concept in this study.The construction of the Three Gorges Reservoir has led to the change in the ecology and immigration status of TGRA.The ecological footprint method is an important means to study the regional ecological security.Our results suggested that,by excluding the areas for biodiversity conservation(12% of the total land),the ecological footprint per capita was 0.57895 ha,which exceeded the ecological carrying capacity in TGRA.The total ecological deficit was found to be 11,522,193.34 ha,accounting for 95.02% of the ecological carrying capacity.These findings suggested that the ecological security of TGRA was not good.In order to compensate for the ecological deficit,it was essential to introduce natural resources from other regions. 展开更多
关键词 three gorges reservoir Area(TGRA) Ecological footprint Ecological security
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Spatial heterogeneity of fine root biomass of Pinus massoniana forests in the Three Gorges Reservoir Area, China 被引量:4
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作者 Rui-Li WANG Rui-Mei CHENG +4 位作者 Wen-Fa XIAO Xiao-Hui FENG Ze-Bin LIU Xiao-Rong WANG Zhi-Bo WANG 《Forestry Studies in China》 CAS 2013年第1期13-23,共11页
Environmental heterogeneity is a constant presence in the natural world that significantly affects plant behavior at a variety of levels of complexity. In order to estimate the spatial pattern of fine root biomass in ... Environmental heterogeneity is a constant presence in the natural world that significantly affects plant behavior at a variety of levels of complexity. In order to estimate the spatial pattern of fine root biomass in the Three Gorges Reservoir Area, the spatial heterogeneity of fine root biomass in the upper layer of soils (0-10 cm) in three Mas- son pine (Pinus massoniana) stands in the Three Gorges Reservoir Area, China, was studied in 30 m x 30 m plots with geostatistical analysis. The results indicate that 1) both the live and dead fine root biomass of stand 2 were less than those of other stands, 2) the spatial variation of fine roots in the three stands was caused together by structural and ran- dom factors with moderate spatial dependence and 3) the magnitude of spatial heterogeneity of live fine roots ranked as: stand 3 〉 stand 1 〉 stand 2, while that of dead fine roots was similar in the three stands. These findings suggested that the range of spatial autocorrelation for fine root biomass varied considerably in the Three Gorges Reservoir Area, while soil properties, such as soil bulk density, organic matter and total nitrogen, may exhibit great effect on the spatial distribution of fine roots. Finally, we express our hope to be able to carry out further research on the quantitative relation- ship between the spatial heterogeneous patterns of plant and soil properties. 展开更多
关键词 spatial heterogeneity GEOSTATISTICS Pinus massoniana fine root biomass three gorges reservoir Area
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