Phthalic acid esters(PAEs)are a group of compounds widespread in the environment.To investigate the occurrence and accumulation characteristics of PAEs,surface water samples were collected from the Three Gorges Reserv...Phthalic acid esters(PAEs)are a group of compounds widespread in the environment.To investigate the occurrence and accumulation characteristics of PAEs,surface water samples were collected from the Three Gorges Reservoir area,China.The total concentrations of∑_(11)analyzed PAEs(11PAEs)in the collected water samples ranging from 197.7 to 1,409.3 ng/L(mean±IQR:583.1±308.4 ng/L).While DEHP was the most frequently detected PAE,DnBP and DnNP were the most predominant PAEs in the analyzed water samples with a mean contribution of 63.3%of the∑_(11)PAEs.The concentrations of the∑_(11)PAEs in the water samples from the upper reaches of the Yangtze River were significantly higher than those from themiddle reaches.To better understand the transport and fate of the PAEs,seven detected PAEs were modeled by Quantitative Water Air Sediment Interaction(QWASI).The simulated and measured values were close for most PAEs,and differences are within one order of magnitude even for the worst one.For all simulated PAEs,water and particle inflow were main sources in the reservoir,whereas water outflow and degradation in water were important removal pathways.The contribution ratios of different sources/losses varied fromPAEs,depending on their properties.The calculated risk quotients of DnNP in the Three Gorges Reservoir area whether based onmonitoring or simulating results were all far exceeded the safety threshold value,implying the occurrence of this PAE compound may cause potential adverse effects for the aquatic ecology of the Three Gorges Reservoir area.展开更多
As a crucial human activity,dam construction can profoundly impact the surface hydrology patterns.The Three Gorges Reservoir(TGR),as one of the largest hydraulic engineering projects in the world,has gained continuous...As a crucial human activity,dam construction can profoundly impact the surface hydrology patterns.The Three Gorges Reservoir(TGR),as one of the largest hydraulic engineering projects in the world,has gained continuous attention for its eco-hydrological effects.However,further investigation is necessary to understand the runoff and social impacts of the TGR on the Upper Yangtze River.This study first employed a modified SWAT model to simulate runoff,compared scenarios with and without the TGR,and finally evaluated water supply and demand in the Upper Yangtze River.The results showed a significant increasing trend in the surface water area of the Upper Yangtze River from 2000-2020.The modified SWAT model performs well in simulating the runoff,with Nash-Sutcliffe Efficiency and Percent Bias improved by 0.04-0.30 and 2-31.90,respectively.Scenario simulation results revealed that the TGR reduced seasonal differences in runoff.During the flood season,the runoff volume at the Yichang Station in the scenario with the TGR is lower than in the scenario without the TGR,peaking at 4500 m3/s.Conversely,in the dry season,the runoff volume of the scenario with TGR is higher,with a maximum increase of 1500 m3/s.The region exhibiting the greatest runoff variations is the Yangtze River's main stem in the Three Gorges Reservoir region.Besides,the TGR notably alleviated the water supply-demand imbalance in Chongqing during the winter and spring seasons,with a maximum increase of 0.16 in the supplydemand index.This study can contribute significantly to understanding the natural and social impacts of the TGR from the perspective of hydrological and scenario simulation.展开更多
Interaction between the Yangtze River and its tributaries in the Three Gorges Reservoir has an important influence on tributary algal blooms.Taking the Xiaojiang River as a typical tributary,a binary mixing model used...Interaction between the Yangtze River and its tributaries in the Three Gorges Reservoir has an important influence on tributary algal blooms.Taking the Xiaojiang River as a typical tributary,a binary mixing model used stable isotopes of hydrogen and oxygen to quantitatively analyze the water contribution and nutrient source structure of the tributary backwater area.Results showed that the isotope content(δD:−54.7‰,δ^(18)O−7.8‰)in the Yangtze River was higher than that in the tributaries(δD:−74.2‰,δ^(18)O−17.0‰)in the non-flood season and lower than that in the tributaries in the flood season.The Yangtze River contributed more than 50%water volume of the tributary backwater area in the non-flood season.The total nitrogen and total phosphorus concentrations in the backwater area were estimated based on water contribution ratio,and the results were in good agreement with the monitoring results.Load estimation showed that the nitrogen and phosphorus contribution ratio of the Yangtze River to the tributary backwater area was approximately 40%-80%in the non-flood season,and approximately 20%-40%in the flood season,on average.This study showed that the interaction between the Xiaojiang River and the Yangtze River is significant,and that Yangtze River recharge is an important source of nutrients in the Xiaojiang backwater area,which may play a driving role in Xiaojiang River algal blooms.展开更多
Spring dinoflagellate blooms are always severe in the Three Gorges Reservoir(TGR),China,threatening water ecological health.Many dinoflagellates are capable of mixotrophism,yet the influence of dissolved organic matte...Spring dinoflagellate blooms are always severe in the Three Gorges Reservoir(TGR),China,threatening water ecological health.Many dinoflagellates are capable of mixotrophism,yet the influence of dissolved organic matter(DOM)on their growth and blooms in spring remains unclear.This study characterized the source and composition of DOM from sediment,soil,and plant,and assessed their effects on the growth of bloom-forming algal species(Peridiniopsis sp.and Microcystis aeruginosa)under different temperatures.The results showed that sediment and soil DOM promoted Peridiniopsis sp.growth,plant DOM slightly inhibited it.However,DOM had no significant effect on M.aeruginosa growth.The promotion of sediment and soil DOM on Peridiniopsis sp.growth was higher at 15℃and 20℃ than at 25℃.Moreover,the effect of DOM on Peridiniopsis sp.growth was more significant than that of high nitrogen and phosphorus.Fulvic acid-like,humic-like and tyrosine-like substances of DOM in sediment and soil might be the effective components promoting the Peridiniopsis sp.growth,while tryptophan-like substance of plant DOM might hinder it.Sediment and soil DOM might promote the Peridiniopsis sp.growth mainly by providing adequate organic carbon,increasing protein content,and improving photosynthesis.The findings will provide important information for the formation and control of dinoflagellate blooms in TGR.展开更多
The relationship between landslides,land use,and sediment connectivity is not only a critical interdisciplinary topic,but also remains a challenging issue in assessing dynamic landslide susceptibility within reservoir...The relationship between landslides,land use,and sediment connectivity is not only a critical interdisciplinary topic,but also remains a challenging issue in assessing dynamic landslide susceptibility within reservoir areas.To explore the interactions among landslide,land use changes,and sediment dynamic,this study took Zigui Basin,the head area of the Three Gorges Reservoir,as the study area to examine this triadic relationship by single-factor detection and interactive detection.Here,we utilized Dynamic Attitude(DA)analysis to quantify land use changes and applied the Index of Connectivity(IC)to assess sediment connectivity evolution from 2018 to 2023.A multi-temporal analysis using the Landslide Susceptibility Index(LSI)was conducted to evaluate the degree of transformation in the three objects and the influence of these changes on the landslide susceptibility.According to the spatial analyst and statistics tools in ArcGIS,the results reveal that most of the landslides distributed in areas with high land use dynamic attitude,such as cultivated land transfers to forestland or garden plot,and the garden plot continuously increased across the study period with largest variation of 5%and an increment of 1.9%.Furthermore,linkage between land use and sediment transport can be effectively quantified by IC,and the resulting map indicated that garden plot increased,and catchment channel characteristics had a greater influence on the IC value than differences in vegetation cover.A comprehensive evaluation of the differences among the susceptibility maps reveals that the very high susceptibility classes are predominantly influenced by enhanced connectivity,whereas land use change has a greater effect on medium-low susceptibility region than that of sediment evolution.That is,both changes of land use and connectivity have positively correlated with landslide activity,but they exhibit differential influences on landslides susceptibility.展开更多
The Three Gorges Region(TGR)of the Yangtze River basin exhibited warm and dry climatic characteristics in 2024.The annual mean temperature in the TGR was 18.6℃,which was 1.2℃above normal and marked the highest level...The Three Gorges Region(TGR)of the Yangtze River basin exhibited warm and dry climatic characteristics in 2024.The annual mean temperature in the TGR was 18.6℃,which was 1.2℃above normal and marked the highest level since 1961.All four seasons were warmer than normal,with spring and autumn both recording their highest temperatures since 1961.Additionally,the TGR recorded 57.2 high-temperature days in 2024,reaching a historic high since 1961 and exceeding the previous record set in 2022 by 2.4 days.Annual rainfall was 11.2%below normal,with spring,summer,and autumn all being drier than normal.However,the number of heavy rain days was slightly higher than normal.The annual mean wind speed in the TGR ranked as the second-highest since 1961,only slightly lower than in 2022.The annual mean relative humidity was below normal and the number of fog days across large areas of the TGR decreased compared to 2023.In 2024,the TGR experienced extreme high-temperature events characterized by exceptional intensity and prolonged duration,accompanied by generally severe meteorological drought conditions.During the year,the TGR also experienced frequent and intense cooling events,an early onset of heavy rainfall(including severe convective weather),and exceptionally extreme rainstorm events.展开更多
0 INTRODUCTION.The global availability of digital elevation model(DEM)data,such as 90-m Shuttle Radar Topography Mission(SRTM)DEM and 30-m Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital ...0 INTRODUCTION.The global availability of digital elevation model(DEM)data,such as 90-m Shuttle Radar Topography Mission(SRTM)DEM and 30-m Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model(ASTER GDEM),has been extensively utilized in morphotectonic analyses(e.g.,Wang et al.,2024;Cheng et al.,2018;Pérez-Pe?a et al.,2010;El Hamdouni et al.,2008).展开更多
The Three Gorges Project,the largest water conservation initiative globally,is located within the Three Gorges Reservoir Area(TGRA),a critical zone for water conservation and ecological protection.There is an urgent n...The Three Gorges Project,the largest water conservation initiative globally,is located within the Three Gorges Reservoir Area(TGRA),a critical zone for water conservation and ecological protection.There is an urgent need to better understand and protect the evolving water conservation functions of the TGRA,alongside identifying the driving mechanisms within its ecological barrier re-gion.This paper explores the spatial and temporal evolution of water conservation function in the TGRA from 1990 to 2020 and its fu-ture trends under different development scenarios from 2020 to 2030.Key driving factors influencing the water conservation function are identified,and a comprehensive development scenario is proposed.The findings indicate a general upward trend in the water conser-vation function of the TGRA,characterized by an initial increase,a subsequent decline,and a final recovery.Moreover,land use changes are found to be the primary factor driving these variations,followed by climatic factors such as precipitation.Under various de-velopment scenarios,the prioritization of water conservation outcomes is ranked as follows:ecological protection>cropland protec-tion>natural development>urban development.The results of this study offer valuable insights for balancing economic development with ecological preservation.展开更多
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
This study investigates the long-term performance of laboratory dam concrete in different curing environments over ten years and the microstructure of 17-year-old laboratory concrete and actual concrete cores drilled ...This study investigates the long-term performance of laboratory dam concrete in different curing environments over ten years and the microstructure of 17-year-old laboratory concrete and actual concrete cores drilled from the Three Gorges Dam.The mechanical properties of the laboratory dam concrete,whether cured in natural or standard environments,continued to improve over time.Furthermore,the laboratory dam concrete exhibited good resistance to diffusion and a refined microstructure after 17 years.However,curing and long-term exposure to the local natural environment reduced the frost resistance.Microstructural analyses of the laboratory concrete samples demonstrated that moderate-heat cement and fine fly ash(FA)particles were almost fully hydrated to form compact micro structures consisting of large quantities of homogeneous calcium(alumino)silicate hydrate(C-(A)-S-H)gels and a few crystals.No obvious interfacial transition zones were observed in the microstructure owing to the longterm pozzolanic reaction.This dense and homogenous microstructure was the crucial reason for the excellent long-term performance of the dam concrete.A high FA volume also played a significant role in the microstructural densification and performance growth of dam concrete at a later age.The concrete drilled from the dam surface exhibited a loose microstructure with higher microporosity,indicating that concrete directly exposed to the actual service environment suffered degradation caused by water and wind attacks.In this study,both macro-performance and microstructural analyses revealed that the application of moderate-heat cement and FA resulted in a dense and homogenous microstructure,which ensured the excellent long-term performance of concrete from the Three Gorges Dam after 17 years.Long-term exposure to an actual service environment may lead to microstructural degradation of the concrete surface.Therefore,the retained long-term dam concrete samples need to be further researched to better understand its microstructural evolution and development of its properties.展开更多
Aerobic anoxygenic phototrophic bacteria(AAPB)are significant bacterial groups in aquatic ecosystems,known for their rapid growth and photoheterotrophic characteristics.However,the distribution and ecological assembly...Aerobic anoxygenic phototrophic bacteria(AAPB)are significant bacterial groups in aquatic ecosystems,known for their rapid growth and photoheterotrophic characteristics.However,the distribution and ecological assembly process of AAPB in low irradiation freshwater basins remain unclear,warranting further investigation.In this study,we present the diversity,abundance,spatial variations,ecological process,and community interaction of AAPB in sediment of Three Gorges Reservoir(TGR)under low irradiation.Our findings demonstrate the dominant genera of AAPB community that exist in the TGR area also are appeared in different waters,with some regional preference.Moreover,the concentration of pufM gene,an indicator for AAPB,maintains a consistently high numerical level ranging from(2.21±0.44)×10^(4)to(9.98±0.30)×10^(7)gene copies/g.Although solar irradiation is suggested as the major factor affecting AAPB,it remains unclear whether and how AAPB differ between regions due to varying solar irradiation levels.Our results show spatial differences between total bacteria and AAPB communities,with significant differences observed only in AAPB.Geographical and environmental factor contributed less than 10%to the spatial difference of community,with sediment type and environmental factors being the key factors influencing microbial community structure.The stochastic process plays a dominant role in the aggregation and replacement of AAPB communities,among which the most contribution is dispersal limitation.For AAPB network,Yoonia and Gemmobacter are the hubs for modules.Those results valuable insights into the AAPB communities in TGR with low irradiation.展开更多
Based on daily observation data of the Three Gorges Region(TGR)of the Yangtze River basin and global reanalysis data,the climate characteristics,climate events,and meteorological disasters of the TGR in 2022 and 2023 ...Based on daily observation data of the Three Gorges Region(TGR)of the Yangtze River basin and global reanalysis data,the climate characteristics,climate events,and meteorological disasters of the TGR in 2022 and 2023 were analyzed.For the TGR,the average annual temperature for 2022 and 2023 was 0.8℃ and 0.4℃ higher than normal,respectively,making them the two warmest years in the past decade.In 2022,the TGR experienced its warmest summer on record.The average air temperature was 2.4℃ higher than the average,and there were 24.8 days of above-average high temperature days during summer.Rainfall in the TGR varied significantly between 2022 and 2023.Annual rainfall was 18.4%below normal and drier than normal in most parts of the region.In contrast,the precipitation in 2023 was considerably higher than the long-term average,and above normal for almost the entire year.The average wind speed exhibited minimal variation between the two years.However,the number of foggy days and relative humidity increased in 2023 compared to 2022.In 2022–2023,the TGR mainly experienced meteorological disasters such as extreme high temperatures,regional heavy rain and flooding,overcast rain,and inverted spring chill.Analysis indicates that the abnormal western Pacific subtropical high and the abnormal persistence of the eastward-shifted South Asian high were the two important drivers of the durative enhancement of record-breaking high temperature in the summer of 2022.展开更多
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
Flow and sediment problem is one of the key factors which affect the dispatching operation and life of the Three Gorges Project(TGP).Many approaches have been employed to research the flow and sediment problems of the...Flow and sediment problem is one of the key factors which affect the dispatching operation and life of the Three Gorges Project(TGP).Many approaches have been employed to research the flow and sediment problems of the TGP during its demonstration,planning,design,construction and operation,and many important results have been obtained.To understand the progress of flow and sediment measurement in China's representative projects and the experience of sediment observation in super large reservoirs,the flow and sediment measurement of the TGP is mainly introduced in this paper.It includes the general situation of the TGP,the distribution of the hydrological station network,the measurement factors,the new measurement technology,and the sediment changes in the reservoir and downstream after the impoundment of the TGP.The sediment measurement results show that the basic situation of sediment problems is good,and these sediment problems may probably accumulate,develop,and transform over time,so they should be paid continuous attention.展开更多
More than 5000 landslides or potential landslides have been triggered in the Three Gorges Reservoir(TGR)area since the impoundment in 2003.This study aims at investigating the reservoirinduced landslides spatiotempora...More than 5000 landslides or potential landslides have been triggered in the Three Gorges Reservoir(TGR)area since the impoundment in 2003.This study aims at investigating the reservoirinduced landslides spatiotemporal and size distribution and its influence factors in the TGR by taking 790 landslides as statistical samples.The landslides exhibit significant regional and sub-regional spatial differences,and numerous landslides occurred at the initial three impoundment stages and the corresponding 2-3 cycles of reservoir operations followed,but the landslide frequency decreased dramatically after 2010 from temporal perspective.The relationship between landslide development and topographical,geological as well as hydrological factors were analyzed qualitatively.The reservoir-induced landslides in TGR area exhibit self-organized criticality and the rollover is nearly 2.5×10^(4) m^(2),which could not be attributed to the missing data but the coupled influences imposed by affecting factors.Both the double Pareto and inverse gamma functions are more suitable than the power-law function to present the landslide size characteristics.In term of the fitting precious,the adaptability of the inverse gamma function is better if the landslide inventories are limited.The research results provide foundation for the landslide susceptibility maps and hazard risk assessment.展开更多
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
The Yichang section of the Three Gorges of the Yangtze River boasts abundant cultural resources and historical heritage.Thorough exploration and development of these cultural tourism resources,combined with the creati...The Yichang section of the Three Gorges of the Yangtze River boasts abundant cultural resources and historical heritage.Thorough exploration and development of these cultural tourism resources,combined with the creation of a unique cultural tourism identity for this section,can not only invigorate the development of the region’s tourism industry but also contribute significantly to cultural preservation and transmission.This study examines the development and current state of cultural tourism in the Three Gorges of the Yangtze River,focusing specifically on the Yichang section.Using the SWOT analysis method,it offers an in-depth analysis and proposes suggestions for cultural tourism development in this area,aiming to provide a reference for future tourism development strategies in the region.展开更多
It is well known that, in most cases, soil water doesn't move in the form of laminar flow as described by Darcy law. Only when Reynolds number ( Re ) is no more than 10, does water movement follow Darcy law. A s...It is well known that, in most cases, soil water doesn't move in the form of laminar flow as described by Darcy law. Only when Reynolds number ( Re ) is no more than 10, does water movement follow Darcy law. A soil profile with 2 9 m long and 2 13 2 60 m deep was excavated on a lower slope located at Zigui County, Hubei Province, China. Field observation found that soil pipes were mainly distributed in the transient layer between horizon B with higher degree of granite weathering and horizon C with lower degree of granite weathering. At the foot of the slope, about 5 7 soil pipes per meter were observed along the vertical direction of the slope. The observed results, obtained by continuous observation of soil pipes and pipe flow processes at granite slope for many rainfall events, indicate that the relationship between velocity of pipe flow and hydraulic gradient along the pipe is parabolic rather than linear. Based on the investigated data of soil, landform, and land use etc., combined with observed data of pipe flow derived from many rainfall events, a pipe flow model was developed. For velocity V p, discharge Q p of pipe flow and radius r of soil pipe, great similarity was found between simulated and observed values. Particularly, the simulated length of soil pipes reflects the great difference among soil pipes as a result of its different position in the soil profile. The length values of 4 soil pipes were estimated to be 98 1%, 27 6%, 11 0% and 3 0% of the longest distance of the catchment, respectively. As a special case of water movement, soil pipe flow follows Darcy Weisbach law. Discharge of pipe flow is much greater than infiltration discharge in common. Only when the depth of groundwater is more than the diameter of soil pipe and water layer submerges soil pipes during rainfall, may pipe flow occur. Under these circumstances, discharge of pipe flow is directly proportional to the depth of groundwater.展开更多
Based on the field-survey prototype hydrology data in typical years, the effect during the running periods of different dispatch modes of the Three Gorges Reservoir on the water regimes in Dongting Lake area is compar...Based on the field-survey prototype hydrology data in typical years, the effect during the running periods of different dispatch modes of the Three Gorges Reservoir on the water regimes in Dongting Lake area is comparatively analyzed. The results are shown as follows. （1） The influence periods are from 25 May to 10 June, from 1 July to 31 August, from 15 September to 31 October and from December to the next April, among which the influence of the water-supplement dispatch in the dry season is not very sensitive. （2） During the period under the pre-discharge dispatch, the runoff volume slightly increases as well as both the average water level and the highest water level rise in the usual year. While in the wet and dry years, the average increase in the runoff volume is 40.25×1 08 m3 and the average rises of the average water level and the highest water level are both 1.06 m. （3） As for the flood-storage dispatch, the flood volume increases slightly, in the dry and wet years, the flood volume, the average water level and the highest water level averagely reduce by 444.02×108 m3, 2.64 m and 1.42 m respectively. （4） Under the water-storage dispatch, the runoff volume slightly in- creases and the water level heightens in a sort in the usual year. And in the dry and wet years the average decreases in the runoff volume, the average water leve/and the highest water levels are respectively 185.27×108 m3, 3.13 m and 2.14 m. （5） During the period under the water-supplement dispatch, the runoff volume, the average water level and the highest water levels averagely decline by 337.7×108 m3, 1.89 m and 2.39 m respectively in the usual and wet years. However, in the dry year, the runoff volume increases as well as the average and highest water levels slightly go up.展开更多
The spatial composition of natural environment and settlement in the Three Gorges region along the Yangtze River was analyzed from a macro perspective,which emphasized its characteristics of the interdependence among ...The spatial composition of natural environment and settlement in the Three Gorges region along the Yangtze River was analyzed from a macro perspective,which emphasized its characteristics of the interdependence among its buildings,landform and waterscape,between buildings and landscape,and integration of nature and human culture.Then the spatial features of folk houses were analyzed,while special attention was paid to its "upward","grey",and dynamic characteristics.The courtyard-type residence and stilted building in South China were taken as examples in order to explain their exterior spatial characteristics,and the interior spatial features were analyzed from the pursuit of courtyard layout,the preference of courtyard space and the emphasis of central room space.The paper exposed the builders' rational thinking about natural environment and living place conveyed through the traditional folk houses,as well as the practical value of this architectural style in the special natural environment of the Three Gorges region,and explained the artistic achievements from the integration of architecture and environment,aiming to provide references for the urban and living environment construction in this region during the "Post Three-Gorges Project Era".展开更多
基金supported by the Innovation Fund of Nanjing Institute of Environmental Science,Ministry of Ecology and Environment,China(No.ZX2023QT003)the National Natural Science Foundation of China(No.22306130)+1 种基金Jiangsu Funding Program for Excellent Postdoctoral Talent(No.2022ZB789)the Ecological Environment Research Project of Jiangsu Province,China(No.2022014).
文摘Phthalic acid esters(PAEs)are a group of compounds widespread in the environment.To investigate the occurrence and accumulation characteristics of PAEs,surface water samples were collected from the Three Gorges Reservoir area,China.The total concentrations of∑_(11)analyzed PAEs(11PAEs)in the collected water samples ranging from 197.7 to 1,409.3 ng/L(mean±IQR:583.1±308.4 ng/L).While DEHP was the most frequently detected PAE,DnBP and DnNP were the most predominant PAEs in the analyzed water samples with a mean contribution of 63.3%of the∑_(11)PAEs.The concentrations of the∑_(11)PAEs in the water samples from the upper reaches of the Yangtze River were significantly higher than those from themiddle reaches.To better understand the transport and fate of the PAEs,seven detected PAEs were modeled by Quantitative Water Air Sediment Interaction(QWASI).The simulated and measured values were close for most PAEs,and differences are within one order of magnitude even for the worst one.For all simulated PAEs,water and particle inflow were main sources in the reservoir,whereas water outflow and degradation in water were important removal pathways.The contribution ratios of different sources/losses varied fromPAEs,depending on their properties.The calculated risk quotients of DnNP in the Three Gorges Reservoir area whether based onmonitoring or simulating results were all far exceeded the safety threshold value,implying the occurrence of this PAE compound may cause potential adverse effects for the aquatic ecology of the Three Gorges Reservoir area.
基金supported by the National Natural Science Foundation of China(Nos.41975044,42371354,41801021,42101385)Open Fund of Hubei Luojia Laboratory(No.2201000043)the Fundamental Research Funds for National Universities,China University of Geosciences,Wuhan。
文摘As a crucial human activity,dam construction can profoundly impact the surface hydrology patterns.The Three Gorges Reservoir(TGR),as one of the largest hydraulic engineering projects in the world,has gained continuous attention for its eco-hydrological effects.However,further investigation is necessary to understand the runoff and social impacts of the TGR on the Upper Yangtze River.This study first employed a modified SWAT model to simulate runoff,compared scenarios with and without the TGR,and finally evaluated water supply and demand in the Upper Yangtze River.The results showed a significant increasing trend in the surface water area of the Upper Yangtze River from 2000-2020.The modified SWAT model performs well in simulating the runoff,with Nash-Sutcliffe Efficiency and Percent Bias improved by 0.04-0.30 and 2-31.90,respectively.Scenario simulation results revealed that the TGR reduced seasonal differences in runoff.During the flood season,the runoff volume at the Yichang Station in the scenario with the TGR is lower than in the scenario without the TGR,peaking at 4500 m3/s.Conversely,in the dry season,the runoff volume of the scenario with TGR is higher,with a maximum increase of 1500 m3/s.The region exhibiting the greatest runoff variations is the Yangtze River's main stem in the Three Gorges Reservoir region.Besides,the TGR notably alleviated the water supply-demand imbalance in Chongqing during the winter and spring seasons,with a maximum increase of 0.16 in the supplydemand index.This study can contribute significantly to understanding the natural and social impacts of the TGR from the perspective of hydrological and scenario simulation.
基金supported by the National Natural Science Foundation of China(No.U2040210).
文摘Interaction between the Yangtze River and its tributaries in the Three Gorges Reservoir has an important influence on tributary algal blooms.Taking the Xiaojiang River as a typical tributary,a binary mixing model used stable isotopes of hydrogen and oxygen to quantitatively analyze the water contribution and nutrient source structure of the tributary backwater area.Results showed that the isotope content(δD:−54.7‰,δ^(18)O−7.8‰)in the Yangtze River was higher than that in the tributaries(δD:−74.2‰,δ^(18)O−17.0‰)in the non-flood season and lower than that in the tributaries in the flood season.The Yangtze River contributed more than 50%water volume of the tributary backwater area in the non-flood season.The total nitrogen and total phosphorus concentrations in the backwater area were estimated based on water contribution ratio,and the results were in good agreement with the monitoring results.Load estimation showed that the nitrogen and phosphorus contribution ratio of the Yangtze River to the tributary backwater area was approximately 40%-80%in the non-flood season,and approximately 20%-40%in the flood season,on average.This study showed that the interaction between the Xiaojiang River and the Yangtze River is significant,and that Yangtze River recharge is an important source of nutrients in the Xiaojiang backwater area,which may play a driving role in Xiaojiang River algal blooms.
基金supported by the National Key Research and Development Program(No.2021YFC3201003)。
文摘Spring dinoflagellate blooms are always severe in the Three Gorges Reservoir(TGR),China,threatening water ecological health.Many dinoflagellates are capable of mixotrophism,yet the influence of dissolved organic matter(DOM)on their growth and blooms in spring remains unclear.This study characterized the source and composition of DOM from sediment,soil,and plant,and assessed their effects on the growth of bloom-forming algal species(Peridiniopsis sp.and Microcystis aeruginosa)under different temperatures.The results showed that sediment and soil DOM promoted Peridiniopsis sp.growth,plant DOM slightly inhibited it.However,DOM had no significant effect on M.aeruginosa growth.The promotion of sediment and soil DOM on Peridiniopsis sp.growth was higher at 15℃and 20℃ than at 25℃.Moreover,the effect of DOM on Peridiniopsis sp.growth was more significant than that of high nitrogen and phosphorus.Fulvic acid-like,humic-like and tyrosine-like substances of DOM in sediment and soil might be the effective components promoting the Peridiniopsis sp.growth,while tryptophan-like substance of plant DOM might hinder it.Sediment and soil DOM might promote the Peridiniopsis sp.growth mainly by providing adequate organic carbon,increasing protein content,and improving photosynthesis.The findings will provide important information for the formation and control of dinoflagellate blooms in TGR.
基金supported by the National Key R&D Program of China(Grant No.2024YFC3012702)National Natural Science Foundation of China(Grant No.42371014)+2 种基金Hubei Provincial Engineering Research Center of Slope Habitat Construction Technique Using Cement-based Materials Open Research Program(Grant No.2022SNJ11)National Natural Science Foundation of China(Grant No.42201094)Hubei Key Laboratory of Disaster Prevention and Mitigation(China Three Gorges University)Open Research Program(Grant No.2022KJZ12)。
文摘The relationship between landslides,land use,and sediment connectivity is not only a critical interdisciplinary topic,but also remains a challenging issue in assessing dynamic landslide susceptibility within reservoir areas.To explore the interactions among landslide,land use changes,and sediment dynamic,this study took Zigui Basin,the head area of the Three Gorges Reservoir,as the study area to examine this triadic relationship by single-factor detection and interactive detection.Here,we utilized Dynamic Attitude(DA)analysis to quantify land use changes and applied the Index of Connectivity(IC)to assess sediment connectivity evolution from 2018 to 2023.A multi-temporal analysis using the Landslide Susceptibility Index(LSI)was conducted to evaluate the degree of transformation in the three objects and the influence of these changes on the landslide susceptibility.According to the spatial analyst and statistics tools in ArcGIS,the results reveal that most of the landslides distributed in areas with high land use dynamic attitude,such as cultivated land transfers to forestland or garden plot,and the garden plot continuously increased across the study period with largest variation of 5%and an increment of 1.9%.Furthermore,linkage between land use and sediment transport can be effectively quantified by IC,and the resulting map indicated that garden plot increased,and catchment channel characteristics had a greater influence on the IC value than differences in vegetation cover.A comprehensive evaluation of the differences among the susceptibility maps reveals that the very high susceptibility classes are predominantly influenced by enhanced connectivity,whereas land use change has a greater effect on medium-low susceptibility region than that of sediment evolution.That is,both changes of land use and connectivity have positively correlated with landslide activity,but they exhibit differential influences on landslides susceptibility.
基金supported by the Innovation and Development Special Project of the China Meteorological Administration[grant number CXFZ2024J071]the National Key Research and Development Program of China[grant number 2023YFC3206001].
文摘The Three Gorges Region(TGR)of the Yangtze River basin exhibited warm and dry climatic characteristics in 2024.The annual mean temperature in the TGR was 18.6℃,which was 1.2℃above normal and marked the highest level since 1961.All four seasons were warmer than normal,with spring and autumn both recording their highest temperatures since 1961.Additionally,the TGR recorded 57.2 high-temperature days in 2024,reaching a historic high since 1961 and exceeding the previous record set in 2022 by 2.4 days.Annual rainfall was 11.2%below normal,with spring,summer,and autumn all being drier than normal.However,the number of heavy rain days was slightly higher than normal.The annual mean wind speed in the TGR ranked as the second-highest since 1961,only slightly lower than in 2022.The annual mean relative humidity was below normal and the number of fog days across large areas of the TGR decreased compared to 2023.In 2024,the TGR experienced extreme high-temperature events characterized by exceptional intensity and prolonged duration,accompanied by generally severe meteorological drought conditions.During the year,the TGR also experienced frequent and intense cooling events,an early onset of heavy rainfall(including severe convective weather),and exceptionally extreme rainstorm events.
基金supported by the National Key Research and Development Project of China(No.2023YFC3007303)the Open Research Project of the Hubei Key Laboratory of Intelligent Geo-Information Processing(No.KLIGIP-2019B08)。
文摘0 INTRODUCTION.The global availability of digital elevation model(DEM)data,such as 90-m Shuttle Radar Topography Mission(SRTM)DEM and 30-m Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model(ASTER GDEM),has been extensively utilized in morphotectonic analyses(e.g.,Wang et al.,2024;Cheng et al.,2018;Pérez-Pe?a et al.,2010;El Hamdouni et al.,2008).
基金Under the auspices of Key Project of the Ministry of Water Resources(No.E202291801,E203101901)National Key R&D Program of China(No.2019QZKK0401)。
文摘The Three Gorges Project,the largest water conservation initiative globally,is located within the Three Gorges Reservoir Area(TGRA),a critical zone for water conservation and ecological protection.There is an urgent need to better understand and protect the evolving water conservation functions of the TGRA,alongside identifying the driving mechanisms within its ecological barrier re-gion.This paper explores the spatial and temporal evolution of water conservation function in the TGRA from 1990 to 2020 and its fu-ture trends under different development scenarios from 2020 to 2030.Key driving factors influencing the water conservation function are identified,and a comprehensive development scenario is proposed.The findings indicate a general upward trend in the water conser-vation function of the TGRA,characterized by an initial increase,a subsequent decline,and a final recovery.Moreover,land use changes are found to be the primary factor driving these variations,followed by climatic factors such as precipitation.Under various de-velopment scenarios,the prioritization of water conservation outcomes is ranked as follows:ecological protection>cropland protec-tion>natural development>urban development.The results of this study offer valuable insights for balancing economic development with ecological preservation.
基金funding from the NFR COMBINED (Grant No.328935)The BCPU hosted YZ visit to University of Bergen (Trond Mohn Foundation Grant No.BFS2018TMT01)+2 种基金supported by the National Key Research and Development Program of China (Grant No.2023YFA0805101)the National Natural Science Foundation of China (Grant Nos.42376250 and 41731177)a China Scholarship Council fellowship and the UTFORSK Partnership Program (CONNECTED UTF-2016-long-term/10030)。
文摘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.
基金the financial supports provided by the National Natural Science Foundation of China(U2040222,52293431,and 52278259)。
文摘This study investigates the long-term performance of laboratory dam concrete in different curing environments over ten years and the microstructure of 17-year-old laboratory concrete and actual concrete cores drilled from the Three Gorges Dam.The mechanical properties of the laboratory dam concrete,whether cured in natural or standard environments,continued to improve over time.Furthermore,the laboratory dam concrete exhibited good resistance to diffusion and a refined microstructure after 17 years.However,curing and long-term exposure to the local natural environment reduced the frost resistance.Microstructural analyses of the laboratory concrete samples demonstrated that moderate-heat cement and fine fly ash(FA)particles were almost fully hydrated to form compact micro structures consisting of large quantities of homogeneous calcium(alumino)silicate hydrate(C-(A)-S-H)gels and a few crystals.No obvious interfacial transition zones were observed in the microstructure owing to the longterm pozzolanic reaction.This dense and homogenous microstructure was the crucial reason for the excellent long-term performance of the dam concrete.A high FA volume also played a significant role in the microstructural densification and performance growth of dam concrete at a later age.The concrete drilled from the dam surface exhibited a loose microstructure with higher microporosity,indicating that concrete directly exposed to the actual service environment suffered degradation caused by water and wind attacks.In this study,both macro-performance and microstructural analyses revealed that the application of moderate-heat cement and FA resulted in a dense and homogenous microstructure,which ensured the excellent long-term performance of concrete from the Three Gorges Dam after 17 years.Long-term exposure to an actual service environment may lead to microstructural degradation of the concrete surface.Therefore,the retained long-term dam concrete samples need to be further researched to better understand its microstructural evolution and development of its properties.
基金supported by the National Natural Science Foundation of China(Nos.52070179,52270190,52131003)the Scientific research instrument development project of Chinese Academy of Sciences(No.YJKYYQ2020004)the Outstanding Scientist of Chongqing Talent Program(No.CQYC20210101288)。
文摘Aerobic anoxygenic phototrophic bacteria(AAPB)are significant bacterial groups in aquatic ecosystems,known for their rapid growth and photoheterotrophic characteristics.However,the distribution and ecological assembly process of AAPB in low irradiation freshwater basins remain unclear,warranting further investigation.In this study,we present the diversity,abundance,spatial variations,ecological process,and community interaction of AAPB in sediment of Three Gorges Reservoir(TGR)under low irradiation.Our findings demonstrate the dominant genera of AAPB community that exist in the TGR area also are appeared in different waters,with some regional preference.Moreover,the concentration of pufM gene,an indicator for AAPB,maintains a consistently high numerical level ranging from(2.21±0.44)×10^(4)to(9.98±0.30)×10^(7)gene copies/g.Although solar irradiation is suggested as the major factor affecting AAPB,it remains unclear whether and how AAPB differ between regions due to varying solar irradiation levels.Our results show spatial differences between total bacteria and AAPB communities,with significant differences observed only in AAPB.Geographical and environmental factor contributed less than 10%to the spatial difference of community,with sediment type and environmental factors being the key factors influencing microbial community structure.The stochastic process plays a dominant role in the aggregation and replacement of AAPB communities,among which the most contribution is dispersal limitation.For AAPB network,Yoonia and Gemmobacter are the hubs for modules.Those results valuable insights into the AAPB communities in TGR with low irradiation.
基金supported by the National Key Research and Development Program of China[grant number 2023YFC3206001]the Three Gorges Project Comprehensive Monitoring Program for Operational Safety[grant number SK2023019]which funded by the Ministry of Water Resources of China.
文摘Based on daily observation data of the Three Gorges Region(TGR)of the Yangtze River basin and global reanalysis data,the climate characteristics,climate events,and meteorological disasters of the TGR in 2022 and 2023 were analyzed.For the TGR,the average annual temperature for 2022 and 2023 was 0.8℃ and 0.4℃ higher than normal,respectively,making them the two warmest years in the past decade.In 2022,the TGR experienced its warmest summer on record.The average air temperature was 2.4℃ higher than the average,and there were 24.8 days of above-average high temperature days during summer.Rainfall in the TGR varied significantly between 2022 and 2023.Annual rainfall was 18.4%below normal and drier than normal in most parts of the region.In contrast,the precipitation in 2023 was considerably higher than the long-term average,and above normal for almost the entire year.The average wind speed exhibited minimal variation between the two years.However,the number of foggy days and relative humidity increased in 2023 compared to 2022.In 2022–2023,the TGR mainly experienced meteorological disasters such as extreme high temperatures,regional heavy rain and flooding,overcast rain,and inverted spring chill.Analysis indicates that the abnormal western Pacific subtropical high and the abnormal persistence of the eastward-shifted South Asian high were the two important drivers of the durative enhancement of record-breaking high temperature in the summer of 2022.
基金the National Natural Science Foundation of China(41971215,42371205)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2022317).
文摘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.
基金National Key Research and Development Program of China,Grant/Award Number:2022YFC3201801。
文摘Flow and sediment problem is one of the key factors which affect the dispatching operation and life of the Three Gorges Project(TGP).Many approaches have been employed to research the flow and sediment problems of the TGP during its demonstration,planning,design,construction and operation,and many important results have been obtained.To understand the progress of flow and sediment measurement in China's representative projects and the experience of sediment observation in super large reservoirs,the flow and sediment measurement of the TGP is mainly introduced in this paper.It includes the general situation of the TGP,the distribution of the hydrological station network,the measurement factors,the new measurement technology,and the sediment changes in the reservoir and downstream after the impoundment of the TGP.The sediment measurement results show that the basic situation of sediment problems is good,and these sediment problems may probably accumulate,develop,and transform over time,so they should be paid continuous attention.
基金supported by the National Natural Science Foundation of China(Nos.42277187,42407279)the United Key Program of the National Natural Sciences Foundation of China(No.U23A202579)+4 种基金Hebei Provincial Natural Science Foundation(No.D2021202002)Hunan Provincial Natural Science Foundation(No.2022JJ40521)Changsha Municipal Natural Science Foundation(No.kq2202065)the Open Research Fund Program of Hunan Provincial Key Laboratory for Big Data Smart Application of Natural Disaster Risks Survey of Highway Engineering(No.BNH2024KFB04)the Conselleria de Innovación,Universidades,Ciencia y Sociedad Digital(No.CIAICO/2021/335)to Roberto Tomás。
文摘More than 5000 landslides or potential landslides have been triggered in the Three Gorges Reservoir(TGR)area since the impoundment in 2003.This study aims at investigating the reservoirinduced landslides spatiotemporal and size distribution and its influence factors in the TGR by taking 790 landslides as statistical samples.The landslides exhibit significant regional and sub-regional spatial differences,and numerous landslides occurred at the initial three impoundment stages and the corresponding 2-3 cycles of reservoir operations followed,but the landslide frequency decreased dramatically after 2010 from temporal perspective.The relationship between landslide development and topographical,geological as well as hydrological factors were analyzed qualitatively.The reservoir-induced landslides in TGR area exhibit self-organized criticality and the rollover is nearly 2.5×10^(4) m^(2),which could not be attributed to the missing data but the coupled influences imposed by affecting factors.Both the double Pareto and inverse gamma functions are more suitable than the power-law function to present the landslide size characteristics.In term of the fitting precious,the adaptability of the inverse gamma function is better if the landslide inventories are limited.The research results provide foundation for the landslide susceptibility maps and hazard risk assessment.
基金the Natural Science Foundation of Chongqing,China(No.cstc2020jcyj-msxmX0763)。
文摘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).
文摘The Yichang section of the Three Gorges of the Yangtze River boasts abundant cultural resources and historical heritage.Thorough exploration and development of these cultural tourism resources,combined with the creation of a unique cultural tourism identity for this section,can not only invigorate the development of the region’s tourism industry but also contribute significantly to cultural preservation and transmission.This study examines the development and current state of cultural tourism in the Three Gorges of the Yangtze River,focusing specifically on the Yichang section.Using the SWOT analysis method,it offers an in-depth analysis and proposes suggestions for cultural tourism development in this area,aiming to provide a reference for future tourism development strategies in the region.
文摘It is well known that, in most cases, soil water doesn't move in the form of laminar flow as described by Darcy law. Only when Reynolds number ( Re ) is no more than 10, does water movement follow Darcy law. A soil profile with 2 9 m long and 2 13 2 60 m deep was excavated on a lower slope located at Zigui County, Hubei Province, China. Field observation found that soil pipes were mainly distributed in the transient layer between horizon B with higher degree of granite weathering and horizon C with lower degree of granite weathering. At the foot of the slope, about 5 7 soil pipes per meter were observed along the vertical direction of the slope. The observed results, obtained by continuous observation of soil pipes and pipe flow processes at granite slope for many rainfall events, indicate that the relationship between velocity of pipe flow and hydraulic gradient along the pipe is parabolic rather than linear. Based on the investigated data of soil, landform, and land use etc., combined with observed data of pipe flow derived from many rainfall events, a pipe flow model was developed. For velocity V p, discharge Q p of pipe flow and radius r of soil pipe, great similarity was found between simulated and observed values. Particularly, the simulated length of soil pipes reflects the great difference among soil pipes as a result of its different position in the soil profile. The length values of 4 soil pipes were estimated to be 98 1%, 27 6%, 11 0% and 3 0% of the longest distance of the catchment, respectively. As a special case of water movement, soil pipe flow follows Darcy Weisbach law. Discharge of pipe flow is much greater than infiltration discharge in common. Only when the depth of groundwater is more than the diameter of soil pipe and water layer submerges soil pipes during rainfall, may pipe flow occur. Under these circumstances, discharge of pipe flow is directly proportional to the depth of groundwater.
基金National Natural Science Foundation of China, No.41071067 Program of the Key Discipline Construction of the Physical Geography in Hunan Province
文摘Based on the field-survey prototype hydrology data in typical years, the effect during the running periods of different dispatch modes of the Three Gorges Reservoir on the water regimes in Dongting Lake area is comparatively analyzed. The results are shown as follows. （1） The influence periods are from 25 May to 10 June, from 1 July to 31 August, from 15 September to 31 October and from December to the next April, among which the influence of the water-supplement dispatch in the dry season is not very sensitive. （2） During the period under the pre-discharge dispatch, the runoff volume slightly increases as well as both the average water level and the highest water level rise in the usual year. While in the wet and dry years, the average increase in the runoff volume is 40.25×1 08 m3 and the average rises of the average water level and the highest water level are both 1.06 m. （3） As for the flood-storage dispatch, the flood volume increases slightly, in the dry and wet years, the flood volume, the average water level and the highest water level averagely reduce by 444.02×108 m3, 2.64 m and 1.42 m respectively. （4） Under the water-storage dispatch, the runoff volume slightly in- creases and the water level heightens in a sort in the usual year. And in the dry and wet years the average decreases in the runoff volume, the average water leve/and the highest water levels are respectively 185.27×108 m3, 3.13 m and 2.14 m. （5） During the period under the water-supplement dispatch, the runoff volume, the average water level and the highest water levels averagely decline by 337.7×108 m3, 1.89 m and 2.39 m respectively in the usual and wet years. However, in the dry year, the runoff volume increases as well as the average and highest water levels slightly go up.
基金Supported by Humanities Fund of Ministry of Education (09YJAZH047)Scientific Research and Development Program of Yichang City (A09302-27)~~
文摘The spatial composition of natural environment and settlement in the Three Gorges region along the Yangtze River was analyzed from a macro perspective,which emphasized its characteristics of the interdependence among its buildings,landform and waterscape,between buildings and landscape,and integration of nature and human culture.Then the spatial features of folk houses were analyzed,while special attention was paid to its "upward","grey",and dynamic characteristics.The courtyard-type residence and stilted building in South China were taken as examples in order to explain their exterior spatial characteristics,and the interior spatial features were analyzed from the pursuit of courtyard layout,the preference of courtyard space and the emphasis of central room space.The paper exposed the builders' rational thinking about natural environment and living place conveyed through the traditional folk houses,as well as the practical value of this architectural style in the special natural environment of the Three Gorges region,and explained the artistic achievements from the integration of architecture and environment,aiming to provide references for the urban and living environment construction in this region during the "Post Three-Gorges Project Era".
