Distribution and influencing factors of microeukaryote in different water layers of the southwestern Indian Ocean Ridge

Microeukaryotes play a vital role in shaping marine ecosystems,especially in marine productivity,the microbial food web,and carbon cycle.The Indian Ocean is one of the largest oligotrophic areas in the world,but little is known about the biodiversity of microeukaryotes in the area.The community composition and geographical distribution of microeukaryotes collected from the surface(SUR)and deep chlorophyll maximum(DCM)layers in the southwestern Indian Ocean were studied using high-throughput sequencing of the 18S rRNA gene.The metagenomic data helped quantify the impact of environmental factors on microeukaryotic communities.The relative abundance of different taxa groups exhibited distinct patterns between SUR and DCM layers,except for the most dominant Dinoflagellata that accounted for more than 40.6%abundance in each sample.Radiolaria was much more abundant in the nutrient-rich DCM layer than the SUR layer.The community similarity of microeukaryotes decreased with increasing of geographic distance,whereas the temperature and inorganic nitrogen were the most important environmental parameters to community structure.Abundant communities were more influenced by dispersal limitations and rare communities were more responsive to environmental factors.Correlation network analyses revealed strong biotic interactions indicative of parasitism,predation and competition,and their contribution to microeukaryotic population in diverse environments.Overall,this study provided insights into the biodiversity of microeukaryotes by characterizing the differences between water layers and identifying the driving factors in the ocean.

Modern pollen-vegetation relationships along altitudinal vegetation belts in the Leigong Mountain of southwestern China

Understanding the distribution,dispersal,and correlation of modern pollen with vegetation in mountainous regions is essential for establishing accurate modern analogs for fossil pollen records.This study,conducted in Leigong Mountain on the YunnanGuizhou Plateau of southwestern China,involved the collection of 35 surface soil samples from diverse vegetation communities along an elevational gradient ranging from 1210 to 1875 meters.The results reveal a close correspondence between modern pollen assemblages and vegetation zones.Principal Component Analysis(PCA)results indicate that pollen assemblages can effectively distinguish between subtropical montane evergreen broad-leaved forest(SEBF)and subtropical montane deciduous broadleaved forest(SDBF).However,both SEBF and SDBF show significant overlap with subtropical montane evergreen-deciduous broad-leaved mixed forest(SEMF).Detrended Correspondence Analysis(DCA)results clearly distinguish the three vegetation zones,and the first axis of DCA shows a significant positive correlation with elevation(p<0.01,R=0.48).Discriminant Analysis(DA)successfully assigns 94.4%of the modern pollen samples to their respective vegetation zones.Pollen taxa such as Impatiens,Astertype,and Rosaceae exhibit significant indicative capabilities for the SEBF zone,effectively distinguishing this vegetation zone from others.Pinus and Alnus display overrepresentation in the Leigong Mountain region,while Quercus(D,deciduous-type)and Poaceae exhibit high representation in the SEBF zone.In the SEBF zone,both pollen diversity and richness are the lowest.Our study reveals the complex relationship between the richness and diversity of pollen and vegetation.The diversity and richness of tree and shrub pollen are found to be lower than those of the corresponding plants.The pollen-vegetation relationship elucidated in this study serves as a critical reference for reconstructing ancient environments from fossil pollen retrieved in this region.

Metamorphic P-T conditions and ages of garnet-biotite schists in the Dahongshan Group from the southwestern Yangtze Block

The Dahongshan Group,situated at the southwestern margin of the Yangtze Block,represents a geological unit characterized by relatively high-grade metamorphism in the region.This paper investigates the garnet-biotite schist from the Laochanghe Formation of the Dahongshan Group,employing an integrated approach that includes petrological analysis,phase equilibrium modeling,and zircon U-Pb dating.The schist is mainly composed of garnet,biotite,plagioclase,quartz,rutile,and ilmenite.Phase equilibrium modeling revealed the peak metamorphic conditions of 8-9 kbar and 635-675°C.By further integrating the prograde metamorphic profile of garnet and geothermobarometric results,a clockwise P-T metamorphic evolution path is constructed,which includes an increase in temperature and pressure during the prograde stage.LA-ICP-MS zircon U-Pb dating and zircon Ti thermometry constrains the post-peak metamorphic age of 831.2±7.2 Ma.Integrated with previously reported results,it is revealed that the southwestern margin of the Yangtze Block experienced a large-scale regional metamorphism during the Neoproterozoic(890-750 Ma),which is related to the collisional orogenic process.This may be associated with the late-stage assembly of the Rodinia supercontinent or with local compression and subduction processes during the breakup of the Rodinia supercontinent.

IEC Promotion Center (Nanjing) signs an agreement with State Grid Fujian Electric Power

The IEC Promotion Center(Nanjing)signed a development cooperation agreement with State Grid Fujian Electric Power Co.,Ltd.on April 23 in Nanjing city,Jiangsu province.The signing ceremony was witnessed by Shu Yinbiao,the 36th President of IEC,Academician of Chinese Academy of Engineering,and President of Chinese Society for Electrical Engineering,Ruan Qiantu,Chair of the Board and Party Secretary of State Grid Fujian Electric Power Co.,Ltd.,Shan Shewu,Chair of the Board and Party Secretary of NARI Group,as well as Fan Xiangqian and Yu Qing,Director and Deputy Director of Management Committee of Nanjing Chilin Technology Innovation Park.

Explicitation Employed in the Translation of Food Culture—Based on the Research of Fujian Cuisine

Fujian cuisine is a distinctive Chinese cuisine.Today,there are many faults and mistakes in the translation of the dish names,which leads to the failure and inconvenience of cross-cultural communication.The paper is an attempt to probe into the appropriate translation of Fujian dish names by the employment of explicitation.

Investigation and analysis of vascular plant resources and diversity in Wuyi Mountain,Fujian Province

Wuyi Mountain,located in the north of Fujian Province,China,is renowned for its abundant medicinal plant resources.In July 2014,the 8th(second team)of Shenyang Pharmaceutical University’s Chinese Medicine Resources Scientific Expedition Team conducted field investigation in the area.Through specimen collection and extensive literature review,the team identified and analyzed 223 vascular plant species from 175 genera and 85 families.The most dominant families were Compositae and Rosaceae,and perennial herbs were the predominant species,accounting for 44.39%of the total species identified.Notably,we documented five precious and rare medicinal plants unique to Wuyi Mountain.This study updates the database of plant resources and diversity in the region,providing a valuable reference for future studies.Finally,we put forward some suggestions to enhance the conservation and sustainable utilization of Wuyi Mountain’s plant resources.

Reflection on the Integrated Development of Marine Fisheries and Tourism Based on the Transformation of Fishery Facilities: A Case Study of Ningde City of Fujian Province, China

Based on the analysis on the current situation of marine fishery resources and development in Ningde City,this paper plans a spatial pattern for the integration of marine fishery and tourism of the“one belt,three zones,and multiple points”,designs key projects,analyzes the existing problems in the integrated development of fishery and tourism,and proposes relevant countermeasures and suggestions.

Geochronology and Geochemical Characteristics of the Early Mesozoic Tangquan Pluton in Southwestern Fujian and Its Tectonic Implications

The Tangquan granodioritic pluton in Dalian County, southwestern Fujian, China, which extends in a NE direction with an exposed area of about 130 km2, used to be considered a product of Early Cretaceous magmatism. The present study suggests for the first time that the pluton was formed in the Early Jurassic by using multiple methods for isotopic dating, which give zircon U-Pb ages of 186.8 Ma and 179.0 Ma, Rb-Sr isochron age of 162.02±4.5 Ma, and biotite 40Ar/39Ar plateau age of 158.1±0.7 Ma. The cooling rate for the pluton was relatively low (4.76℃/Ma) during the early stage (183-162 Ma) because of the compressional environment. It was emplaced in a higher cooling rate (50℃/Ma) in an extensional environment during the later stage (162-158 Ma). The granodiorites are metaluminous-peraluminous, relatively enriched in Na2O and depleted in K2O, and characteristic of I-type granites of crust-mantle mixed sources. They are moderately enriched in Rb, Th, Hf and LREE, and depleted in Ti, Nb, Ta and Sr, and have geochemical features of cal-alkaline rocks of an island arc or active continental margin. Their (87Sr/86Sr)i ratio varies from 0.70769 to 0.70822, εNd(t) from -9.68 to -10.07 and TDM from 1.52 to 1.55 Ga. They were formed by mixing of mantle-derived mafic magma with the granitic magma resulting from partial melting of crust-derived materials in an upwelling of the asthenospheric mantle in South China during the Early Mesozoic.

Late Paleozoic to Mesozoic extension in southwestern Fujian Province, South China： Geochemical, geochronological and Hf isotopic constraints from basic-intermediate dykes

The tectonic evolution of SE China block since late Paleozoic remains debated. Here we present a new set of zircon U-Pb geochronological, Lu-Hf isotopic data and whole-rock geochemistry for two stages of basicintermediate dykes from the southwestern Fujian. The samples were collected from the NE-trending （mainly diabases） and NW-trending （mainly diabasic diorites） dykes and yielded zircon U-Pb ages of 315 and 141 Ma, with eHf（t） values of -8.90 to 7.49 and -23.39 to -7.15 （corresponding to TDM2 values of 850 to 1890 Ma and 737 to 2670 Ma）, respectively. Geochemically these rocks are characterized by low TiO2 （0.91-1.73 wt.%） and MgO （3.04-7.96 wt.%）, and high A1203 （12.5-16.60 wt.%） and K20 （0.60-3.63 wt.%）. Further they are enriched in LREEs and LILEs （Rb, Ba, Th and K）, but depleted in HFSEs （Nb, Ta and Zr）. The tectonic discrimination analysis revealed that the dykes were formed in an intraplate extensional envi- ronment. However, the NW trending dykes show crust-mantle mixed composition, which indicate an extensional tectonic setting with evidence for crustal contamination. The SE China block experienced two main stages of extensional tectonics from late Carboniferous to early Cretaceous. The tectonic evolution of the SE China block from late Devonian to Cretaceous is also evaluated.

Transgression regression event element geochemistry records of southwestern Fujian in Late Triassic-Middle Jurassic

Southwest Fujian area has experienced a large-scale transgression regression cycle in Late Triassic-Middle Jurassic and the maximum transgression has taken place in Early Jurassic. The migration and enrichment of geochemical element in the continuous fine-grained sediments in the basin recorded the paleosalinity and the paleodepth. The changes of paleosalinity and paleodepth indicate the sea(lake) level relative change in every period of Late Triassic-Middle Jurassic in southwestern Fujian. The relative change curve of sea(lake) level in southwestern Fujian is established based on the m value(m=100×w(MgO)/w(Al2 O3)) and the ratios of w(B)/w(Ga), w(Sr)/w(Ba) and w(Ca)/w(Mg). The curve indicates that level I sea-level relative change in southwestern Fujian is composed of the transgression in Late Triassic-Early Jurassic and the regression in the late period of Early Jurassic-Middle Jurassic. The level III sea-level relative change is frequent, which is composed by the lake level descent lake level rise lake level descent of Wenbin Shan formation in Late Triassic, the regression transgression regression of Lishan formation in Early Jurassic and the lake level rise lake level descent-lake level rise lake level descent of Zhangping formation in Middle Jurassic. The transgression regression cycle in southwestern Fujian is significantly controlled by the sea-level change in the north of South China Sea. The relative change curve trends of the level I sea-level in the north of South China Sea and the one in southwestern Fujian are the same. The maximum transgressions both occur in Early Jurassic. The level III sea-level curve reflects the fluctuation of a transgression and two regressions in the early period of Early Jurassic.

Seasonal Prediction of Extreme High-Temperature Days in Southwestern China Based on the Physical Precursors

Extreme high temperatures frequently occur in southwestern China,significantly impacting the local ecological system and economic development.However,accurate prediction of extreme high-temperature days(EHDs)in this region is still an unresolved challenge.Based on the spatiotemporal characteristics of EHDs over China,a domain-averaged EHD index over southwestern China(SWC-EHDs)during April-May is defined.The simultaneous dynamic and thermodynamic fields associated with the increased SWC-EHDs are a local upper-level anticyclonic(high-pressure)anomaly and wavy geopotential height anomaly patterns over Eurasia.In tracing the origins of the lower boundary anomalies,two physically meaningful precursors are detected for SWC-EHDs.They are the tripolar SST change tendency from December-January to February-March in the northern Atlantic and the February-March mean snow depth in central Asia.Using these two selected predictors,a physics-based empirical model prediction was applied to the training period of 1961–2005 to obtain a skillful prediction of the EHDs index,attaining a correlation coefficient of 0.76 in the independent prediction period(2006–19),suggesting that 58%of the total SWC-EHDs variability is predictable.This study provides an estimate for the lower bound of the seasonal predictability of EHDs as well as for the hydrological drought over southwestern China.

The Geochemistry of Carbonate Rocks in Igwe Igarra, Southwestern Nigeria

Nigeria has an abundance of valuable solid minerals and rocks which can generate revenue for the government if they are fully exploited. Carbonate rock is one of such rocks that occur prominently in Igwe Igarra area of Edo State. Five (5) carbonate rock samples (Four marble and One Calcsilicate) were subjected to geochemical analyses. A petrographic study reveals that marble and calcsilicate contain calcite, quartz, microcline, plagioclase, biotite and opaque minerals. Geochemical data shows that carbonate rocks have variable geochemical characteristics: Igwe marble is highly Calcitic (96% - 98%) and very low in dolomite Mg(CO3). Calcsilicate rock is low in CaO (27.5%) and higher in marble. The Igwe marble is pure and contains fewer impurities compared to calcsilicate rock which makes it unideal for usage. Based on these characteristics the marble from Igwe is suitable as raw materials for the productions of glass, papers, beet sugar, aggregates, lubricants and fillers.

Origin of a giant fuzzy reflection zone and its implication for natural gas exploration in the southwestern Qiongdongnan Basin of the South China Sea

The southwestern depression of the Qiongdongnan Basin(QDNB)hosts thick Cenozoic sediments and awaits major hydrocarbon discovery.Multichannel seismic(MCS)profile CFT2011 across the southwestern QDNB reveals a~60-km-wide fuzzy reflection zone(FRZ)within the sediments,but its origin and distribution remain unclear.Here ocean bottom seismometer(OBS)data of Line CFT2011 are processed with focus on the velocity structures by traveltime tomography inversion and analyzed together with the coincident and adjacent MCS profiles.The OBS velocity results show that the giant FRZ features lower velocity with difference up to 1.5 km/s and smaller vertical velocity gradient than the surrounding sedimentary sequences at the same depth,likely resulting from enhanced fluid infilling.The MCS profile exhibits that the giant FRZ is about 3-9-km thick and extends from the Paleogene strata rich in organic matters upward to the lower Pleistocene sediments.Within the shallow overlying sediments,multiple bright spots with reverse polarity are imaged and their reflection amplitudes increase with offset,consistent with the features of gas-charged sediments.They are probably shallow gas reservoirs with gases sourced from the deep FRZ.Therefore,the FRZ is proposed to be a giant gas-charged zone,which probably contains lots of hydrocarbon gases migrated vertically from the deep Paleogene source rocks through the boundary faults of the depressions and the minor fractures generated under overpressure.This FRZ is also imaged on the adjacent MCS profiles MCS-L1 and MCS-L2 with the width of about 40 km and 68 km,respectively.It is roughly estimated to cover an area of~1900 km2 and host a volume of~11400 km3 assuming an average thickness of 6 km,implying huge natural gas potential in the sedimentary depression of the southwestern QDNB of the South China Sea.

Quantitative characterization of vertical zonation of Mesozoic granite weathering reservoirs in the coastal area of eastern Fujian Province,China

Weathering crust reservoirs have obvious vertical zonation,which is the focus of weathering crust reservoir research,but there is a lack of quantitative characterization indexes.To achieve the quantitative characterization of granite weathering crust reservoir and provide the basis for oil exploration of granite weathering crust buried hill reservoir,in this paper,the vertical zonation of granite weathering crust reservoir is quantitatively divided by testing and analyzing the uniaxial compressive strength(UCS),magnetic susceptibility(MS),permeability,and chemical index of alteration(CIA)of the Mesozoic granite weathering crust in the coastal area of eastern Fujian.The results show that the granite weathering crust reservoir can be divided into four zones vertically:a soil zone(SZ),weathered and dissolved zone(WDZ),fracture zone(FZ),and bedrock zone(BZ).A cataclastic area is developed in the FZ and BZ,in which structural fractures are well-developed,the fracture surface density is usually greater than 200 m/m^(2),and the contribution to the fractures in the rock mass is up to about 50%,making this the sweet spot of the reservoir.In the SZ,the rocks are loose,and the pores are well-developed.The UCS is less than 10 MPa,and the average rate of change of the UCS(Δ_(σ))is 0.90.The average permeability is 2823.00 mD,and the average rate of change of the permeability(Δ_(κ))is 5.13.The average CIA is 74.9%.The average clay mineral content is 7%.The rocks in the WDZ have been significantly weathered by physical and chemical processes,and the weathering fractures and dissolution pores are well-developed.The average UCS is 18.2 MPa,and the averageΔ_(σ)is 0.70.The average permeability is 143.80 mD,and averageΔ_(κ)is 4.17.The average CIA is 65.3%.The average clay mineral content is 4%.Under the influence of tectonic movement and physical weathering,the rocks in the FZ have developed structural fractures and a few weathered fractures.The average UCS is 57.9 MPa,and the averageΔ_(σ)is 0.18.The average permeability is 5.50 mD,and the averageΔ_(κ)is 2.55.The average CIA is 61.6%.The average clay mineral content is 2%.In the BZ,the rocks are intact and hard.The average UCS is 69.9 MPa,and the average Ds is 0.13.The average permeability is 1.46 mD,and the averageΔ_(κ)is 1.43.The average CIA is 57.8%.The average clay mineral content is less than 1%.The multi-parameter combination of the UCS,Δ_(σ),permeability,Δ_(κ),CIA,and clay mineral content achieved good results in the division of the zones of the weathering crust.The UCS increases gradually from top to bottom,while Ds,permeability,Δ_(κ),CIA,and clay mineral content all decrease gradually.In addition,based on the petrophysical parameters of the rocks,including the density,resistivity,and acoustic velocity,a good division effect was also achieved,which can provide a basis for the vertical zonation of the granite buried-hill weathering crust reservoir.

The 12th China International Folk Arts Festival(CIFAF)Held in Fujian Province

Jointly sponsored by China Federation of Literary and Art Circles and Fujian Provincial People's Government and co-organised by Quanzhou Municipal People's Government and Fujian Federation of Literary and Art Circles,the 12th China International Folk Arts Festival(CIFAF)was held in Fujian Province from October 11th to 17th.Over 100 artists from 13 countries gave performances and brought to the local audience an art extravaganza of international style,national features and folk characteristics.Themed Carry Forward the Spirit of the Belt and Road.

Review on Preparation and Research of Prescriptions for Snake Bites in Fujian Province

The history of research and preparation of prescriptions for snake bites in Fujian Province was reviewed, and the process of incorporating snake doctors into the system and the gradual establishment of snake bite treatment system in Fujian were explored. The composition of several main snake bite preparations in Fujian was preliminarily compared and analyzed to provide reference for the research and development of similar new preparations at present.

Migration of paleo-uplift in southwestern Tarim Basin and its implications for orogenesis and reservoir development, NW China

Based on well horizon calibration,the typical seismic profiles in southwestern Tarim Basin were interpreted systematically,regional geological sections were established,and the regional denudation thickness of each tectonic period was restored.On this basis,the plane morphology maps of ancient structures of the Cambrian pre-salt dolomites in different periods were compiled,and the spatial distribution,development,evolution and migration of paleo-uplift in the late Early Paleozoic were analyzed.In the late Early Paleozoic,there existed a unified regional paleo-uplift widely distributed in southwestern Tarim Basin,which is called the southwestern Tarim plaeo-uplift.The“Tarim SW paleo-uplift”and“Hetian paleo-uplift”proposed in previous literatures are not independent,but the result of the spatio-temporal migration and evolution of the southwestern Tarim paleo-uplift identified in this paper.The southwestern Tarim paleo-uplift emerged at the end of Middle Ordovician,and took its initial shape with increased amplitude in the Late Ordovician.During the Silurian,the southwestern Tarim paleo-uplift rose steadily and expanded rapidly to the east,incorporating Pishan-Hetian and other areas,with the structural high locating in the Pishan-Hetian area.During the Devonian,the southwestern Tarim paleo-uplift began to shrink gradually,to a limited range in the Pishan-Hetian area in the southern part of the basin.During the Carboniferous,the southwestern Tarim paleo-uplift became an underwater uplift,that is,the paleo-uplift gradually died out.The southwestern Tarim paleo-uplift belongs to the forebulge of the southwestern Tarim foreland basin in the late Early Paleozoic,and its formation and evolution are related to the early Paleozoic orogeny of the West Kunlun orogenic belt in the south of the Tarim Basin.The migration of the southwestern Tarim paleo-uplift from the northwestern part of the southwestern Tarim Basin to the Pishan-Hetian area indicates the early Paleozoic orogenic process of the West Kunlun orogenic belt,which started in the western section at the end of Middle Ordovician and extended from west to east in a“scissor”style.The migration and evolution of the southwestern Tarim paleo-uplift controlled the development of unconformities at the end of Middle Ordovician,the end of Late Ordovician,and the end of Middle Devonian,and the spatial distribution of dissolved fracture-cave reservoirs in weathered crust below the unconformities in the southwest of Tarim Basin.The migration of the structural high of the southwestern Tarim paleo-uplift also played an important role in controlling the development of dissolved fracture-cave reservoirs in weathered crust.

Pattern changes and early risk warning of Spartina alterniflora invasion:a study of mangrove-dominated wetlands in northeastern Fujian,China

The exotic saltmarsh cordgrass,Spartina alterniflora(Loisel)Peterson&Saarela,is one of the important causes for the extensive destruction of mangroves in China due to its invasive nature.The species has rapidly spread wildly across coastal wetlands,challenging resource managers for control of its further spread.An investigation of S.alterniflora invasion and associated ecological risk is urgent in China's coastal wetlands.In this study,an ecological risk invasive index system was developed based on the Driving Force-Pressure-State-Impact-Response framework.Predictions were made of'warning degrees':zero warning and light,moderate,strong,and extreme warning,by developing a back propagation(BP)artificial neural network model for coastal wetlands in eastern Fujian Province.Our results suggest that S.alterniflora mainly has invaded Kandelia candel beaches and farmlands with clustered distributions.An early warning indicator system assessed the ecological risk of the invasion and showed a ladder-like distribution from high to low extending from the urban area in the central inland region with changes spread to adjacent areas.Areas of light warning and extreme warning accounted for43%and 7%,respectively,suggesting the BP neural network model is reliable prediction of the ecological risk of S.alterniflora invasion.The model predicts that distribution pattern of this invasive species will change little in the next 10 years.However,the invaded patches will become relatively more concentrated without warning predicted.We suggest that human factors such as land use activities may partially determine changes in warning degree.Our results emphasize that an early warning system for S.alterniflora invasion in China's eastern coastal wetlands is significant,and comprehensive control measures are needed,particularly for K.candel beach.

福建省农作物种质资源调查收集与多样性分析

2017-2022年,福建省在第三次全国农作物种质资源普查与收集行动中,共收集作物地方品种和野生近缘植物种质资源6235份,蔬菜、粮食、果树、经济作物、牧草绿肥分别占33.57%、25.91%、24.35%、14.59%、1.57%;所有资源隶属于83科,229属,313种,其中豆科种质资源份数最多,占总数的16.04%。不同地区和海拔是影响收集农作物种质资源种类和数量的重要因素。全省9个地级市中,三明市收集种质资源数量最多,占20.65%。全省收集农作物种质资源数量随着海拔升高而下降,不同海拔收集数量随着市辖县(市、区)、乡(镇)、村(街道)的数量减少呈现减少趋势。沿海地区如漳州、福州、宁德、泉州、莆田、厦门等6个地级市,海拔0~200 m是种质资源Shannon-Wiener多样性指数和Brillouin丰富度指数最高的海拔区间;闽西北山区,如龙岩、三明、南平等3个地级市,海拔200~400 m、400~600 m、600~800 m种质资源的Shannon-Wiener多样性指数和Brillouin丰富度指数较高。不同地级市、不同海拔区间与收集种质资源的物种多样性指数的相关性分析发现,三明和龙岩市与Shannon-Wiener多样性指数呈极显著正相关,莆田和龙岩市与Pielou均匀度指数呈现极显著负相关,这与全省农业经济分区有密切关系。通过梳理全省农作物种质资源的多样性,为因地制宜地开发、利用、挖掘全省地方农作物种质资源提供参考和科学依据。

Future meteorological drought conditions in southwestern Iran based on the NEX-GDDP climate dataset

Investigation of the climate change effects on drought is required to develop management strategies for minimizing adverse social and economic impacts.Therefore,studying the future meteorological drought conditions at a local scale is vital.In this study,we assessed the efficiency of seven downscaled Global Climate Models(GCMs)provided by the NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP),and investigated the impacts of climate change on future meteorological drought using Standard Precipitation Index(SPI)in the Karoun River Basin(KRB)of southwestern Iran under two Representative Concentration Pathway(RCP)emission scenarios,i.e.,RCP4.5 and RCP8.5.The results demonstrated that SPI estimated based on the Meteorological Research Institute Coupled Global Climate Model version 3(MRI-CGCM3)is consistent with the one estimated by synoptic stations during the historical period(1990-2005).The root mean square error(RMSE)value is less than 0.75 in 77%of the synoptic stations.GCMs have high uncertainty in most synoptic stations except those located in the plain.Using the average of a few GCMs to improve performance and reduce uncertainty is suggested by the results.The results revealed that with the areas affected by wetness decreasing in the KRB,drought frequency in the North KRB is likely to increase at the end of the 21st century under RCP4.5 and RCP8.5 scenarios.At the seasonal scale,the decreasing trend for SPI in spring,summer,and winter shows a drought tendency in this region.The climate-induced drought hazard can have vast consequences,especially in agriculture and rural livelihoods.Accordingly,an increasing trend in drought during the growing seasons under RCP scenarios is vital for water managers and farmers to adopt strategies to reduce the damages.The results of this study are of great value for formulating sustainable water resources management plans affected by climate change.