Bat population appears is maintained as the last habitat of these species in the La Ca Pagoda(old)area of the Khmer ethnic people in Tra Vinh.Methods are interview,count individuals in the habitat,species,population,d...Bat population appears is maintained as the last habitat of these species in the La Ca Pagoda(old)area of the Khmer ethnic people in Tra Vinh.Methods are interview,count individuals in the habitat,species,population,determine the type of plants,the height of the living bats;results of the current status of species,quantity,distribution,residence and reproduction of species;impacts on 2 species of horse bats related to the conservation of horse bats;compared to previous by the Ehb function,with the parameters Hchb(Horseback bat community)the existence of the community compared to the previous time,at least 1 breeding season;Hhhb(Horse bat habitat)on living conditions;Hfhb(Horse bat food)on food sources for the community to live;Hphb(Horse bat protection)on conditions to protect the community;evaluated by score(0–1);the results the species Pteropus vampyrus decreased by 79.51%,the species Pteropus lylei increased by 6.8 times.The total number is 1239 individuals,including 1072 THB and 168 LHB.Both of these species have been recorded in previous surveys.The number of individuals counted was larger than the previous survey(1239 individuals compared to 957 individuals);the number of LHB in this survey was much smaller than the previous count(168 individuals compared to 820 individuals);the number of THB was (1072 individuals compared to 137 individuals).Using a function-based assessment method with ecologically relevant parameters can objectively assess the distribution and status of threatened populations to effectively protect their survival.展开更多
[Objective]To systematically isolate and purify the polysaccharide from the mycelium of Streptomyces rochei D74(SRP),elucidate its fine structure,and evaluate the effect of the purified polysaccharide fraction on the ...[Objective]To systematically isolate and purify the polysaccharide from the mycelium of Streptomyces rochei D74(SRP),elucidate its fine structure,and evaluate the effect of the purified polysaccharide fraction on the growth of Salvia miltiorrhiza hairy roots and the biosynthesis of tanshinones,along with the underlying mechanism.[Methods]The crude polysaccharide was extracted using hot water,which was followed by ethanol precipitation and deproteinization via the Sevag method.Further purification was performed using DEAE-52 anionexchange chromatography and Sephadex G-100 gel filtration chromatography.The physicochemical properties and structural features of the main active fraction,SRP-W-2,were systematically characterized by Fourier transform infrared spectroscopy(FTIR),high performance liquid chromatography-mass spectrometry(HPLC-MS),and nuclear magnetic resonance(NMR).The effects of SRP-W-2 on hairy root growth and the biosynthesis of tanshinones were assessed by measuring biomass,tanshinone content,and the expression levels of key biosynthetic genes.[Results]SRP-W-2 was obtained with a yield of 2.41%.It was primarily composed of glucose and galactose at a molar ratio of 12.53:1.Structural analysis revealed that the backbone of SRP-W-2 consisted of→4)-α-D-Glcp-(1→and→4)-α-D-Galp-(1→residues,with branching points at→4,6)-α-D-Glcp-(1→and→4,6)-α-D-Galp-(1→.The side chain was identified asα-D-Glcp-(1→4)-α-DGlcp-(1→.Bioactivity assays demonstrated that SRP-W-2 significantly enhanced both the biomass of S.miltiorrhiza hairy roots and the accumulation of tanshinones.After 15 d of treatment with 50 mg/L SRP-W-2,the dry weight of the hairy roots increased by 37.52%.Meanwhile,the content of cryptotanshinone(CT),dihydrotanshinone I(DT-I),tanshinone I(T-I),and tanshinone IIA(TIIA)was increased by 19.0-fold,6.4-fold,2.8-fold,and 4.8-fold,respectively.Gene expression analysis further indicated that SRP-W-2 up-regulated key genes involved in the tanshinone biosynthetic pathway,including HMGR,DXS,DXR,and GGPPS.[Conclusion]The polysaccharide fraction SRP-W-2 from S.rochei D74 simultaneously promoted the growth of S.miltiorrhiza hairy roots and the biosynthesis of tanshinones,demonstrating its potential as an effective elicitor.This study provided a new strategy for the utilization and development of S.miltiorrhiza resources.展开更多
The current economic development is the process of improving the physical and spiritual living conditions for people through the production of material wealth and the improvement of social relations as well as the imp...The current economic development is the process of improving the physical and spiritual living conditions for people through the production of material wealth and the improvement of social relations as well as the improvement of cultural quality.In recent years,Vietnam showed robust growth in terms of economic development,along with the fast pace of urbanization and population increase.However,the economic growth has led to serious problems relating to the environment,such as the pollution of the air,water,and soil,which hugely affected the quality of human life.The Environmental Kuznets Curve(EKC)implied that a country with strong economic background shifting to industrialization or mechanization of agriculture will have positive GDP and the environmental damage level will decrease.The analysis and assessment showed that the environmental problems caused by economic activities are:air pollution in the urban area still maintained at high level;water pollution in rivers and limited fresh water supply;and the soil pollution and declining water supply underneath soil are developing.展开更多
Stand age plays a crucial role in forest biomass estimation and carbon cycle modeling.Assessing the uncertainty of stand age prediction models and identifying the key driving factors in the modeling process have becom...Stand age plays a crucial role in forest biomass estimation and carbon cycle modeling.Assessing the uncertainty of stand age prediction models and identifying the key driving factors in the modeling process have become major challenges in forestry research.In this study,we selected the Shaanxi-Gansu-Ningxia region of Northeast China as the research area and utilized multi-source datasets from the summer of 2019 to extract information on spectral,textural,climatic,water balance,and stand characteristics.By integrating the Random Forest(RF)model with Monte Carlo(MC)simulation,we constructed six regression models based on different combina-tions of features and evaluated the uncertainty of each model.Furthermore,we investigated the driving factors influencing stand age modeling by analyzing the effects of different types of features on age inversion.Model performance and accuracy were assessed using the root mean square error(RMSE),mean absolute error(MAE),and the coefficient of determination(R^(2)),while the relative root mean square error(rRMSE)was employed to quantify model uncertainty.The results indicate that the scenarios with more obvious improve-ment in accuracy and effective reduction in uncertainty were Scenario 3 with the inclusion of climate and water balance information(RMSE=25.54 yr,MAE=18.03 yr,R^(2)=0.51,rRMSE=19.17%)and Scenario 5 with the inclusion of stand characterization informa-tion(RMSE=18.47 yr,MAE=13.05 yr,R^(2)=0.74,rRMSE=16.99%).Scenario 6,incorporating all feature types,achieved the highest accuracy(RMSE=17.60 yr,MAE=12.06 yr,R^(2)=0.77,rRMSE=14.19%).In this study,elevation,minimum temperature,and diameter at breast height(DBH)emerged as the key drivers of stand-age modeling.The proposed method can be used to identify drivers and to quantify uncertainty in stand-age estimation,providing a useful reference for improving model accuracy and uncertainty assessment.展开更多
Heavy metal contamination of soil is one of the major challenges to sustainable agriculture.This contamination can be transmitted through the soil food chain and poses a serious threat to human health.In this study,we...Heavy metal contamination of soil is one of the major challenges to sustainable agriculture.This contamination can be transmitted through the soil food chain and poses a serious threat to human health.In this study,we found that freeze-thaw leaching(FTL)effectively complements the low removal rate of chemical leaching,and investigated the effects of different numbers of FTL on Cd contamination,soil chemical properties and microbial communities.The results showed that repeated FTL significantly reduced(P<0.05)the total Cd content in the top soil(19.02%-49.35%)and subsoil(0.41%-21.13%)and promoted the transformation of Cd to a more stable form,mainly through various removal mechanisms such as complexation,ion-exchange,and chemical precipitation.This finding was supported by reductions in several soil properties,including pH,available potassium(AK),and available phosphorus(AP).FTL treatment initially increased the bioavailability of Cd compared to chemical leaching,but bioavailability of Cd progressively decreased as the number of freeze-thaw cycles increased.Additionally,FTL reduced the richness and diversity of bacteria communities,destabilized ecological symbiotic networks,while increasing the richness and diversity of fungi in the soil.Various model analyses indicated that FTL treatment,available Cd,soil pH,AP and AK were the key drivers influencing the changes in microbial community structure.This study provides new insights and scientific bases for the effective management of heavy metal pollution in agricultural soils,the restoration of ecosystem health,and the improvement of soil sustainability.展开更多
Paddy soil in carbonate regions is susceptible to cadmium(Cd)contamination from geogenic or anthropogenic sources.However,Cd solubility in carbonate-derived alkaline paddy soils with contrasting Cd sources and propert...Paddy soil in carbonate regions is susceptible to cadmium(Cd)contamination from geogenic or anthropogenic sources.However,Cd solubility in carbonate-derived alkaline paddy soils with contrasting Cd sources and properties under redox alternations is poorly understood.In this study,paddy soils enriched with geogenic or mine drainage-derived Cd and presenting contrasting manganese and sulfur abundances were incubated under alternating redox conditions.The changes in aqueous chemistry,Cd bioavailability and speciation were investigated.The results revealed that mine drainage significantly elevated the content of soluble sulfate and the abundance of sulfur-related bacteria(e.g.,Sulfurifustis and Thiobacillus)in paddy soils.For contaminated soils,the reductive dissolution of Fe/Mn oxides and cation exchange induce Cd mobilization from soils during the initial reduction period.More than 90%of the soluble Cd was subsequently re-sequestered,concomitant with the increase in residual and organically bound Cd fractions.Nevertheless,the soluble Cd gradually decreased in geogenic soil during the reduction period.During the reoxidation period,the Cd solubility increased in all the soils in the initial 3 days.Afterward,soluble Cd was partially immobilized by different soil constituents.As a result of Cd redistribution,Cd bioavailability decreased with reduction time and increased with ongoing oxidization of the soil.These results indicate that the solubility and fate of Cd vary in soils and strongly depend on soil biogeochemical properties in the karst region.展开更多
The continuous supply of phosphorus(P)is indispensable in crop production.However,P resources are non-renewable,and environmental concerns like eutrophication associated with its loss from agroecosystems make the sust...The continuous supply of phosphorus(P)is indispensable in crop production.However,P resources are non-renewable,and environmental concerns like eutrophication associated with its loss from agroecosystems make the sustainable management of P resources essential for ensuring global food security.This study was designed to reduce mineral P inputs through management practices.A field experiment comprising a wheat-maize rotation system was conducted in the Guanzhong Plain of Shaanxi Province,China from 2018-2023.The eight treatments included CK(without P),FP(conventional P application);RP(recommended P);RP80(20% reduction in RP);SRP80(20% reduction in RP with straw wrapping);ARP80(20% reduction in RP with ammonium sulfate instead of urea);SARP80(20% reduction in RP with straw wrapping and ammonium sulfate instead of urea);and SARP60(40% reduction in RP with straw wrapping and ammonium sulfate instead of urea).Crop yield,P uptake,and P fertilizer use efficiency were measured during harvest and throughout the entire period of the study.At the end of the experiment,P fractions were estimated using the Tiessen-Moir P classification method.The results revealed that the grain yields of all the treatments except for RP80 were significantly increased compared to CK,with increases of 14.9-28.8%.Furthermore,agronomic efficiency,apparent P use efficiency,P recovery rate,and partial factor productivity were significantly improved for the treatments that received 20% less P with straw wrapping.Moreover,the enhancement measures significantly increased labile and moderately labile P in the soil.Therefore,straw wrapping with ammonium sulfate instead of urea is one of the most effective ways to reduce mineral P inputs while increasing the efficiency of P in wheat-maize rotation systems.展开更多
Human health is seriously jeopardized by infections caused by pathogenic microorganisms.The current traditional disinfection technologies have many defects,such as producing harmful by-products,being affected by water...Human health is seriously jeopardized by infections caused by pathogenic microorganisms.The current traditional disinfection technologies have many defects,such as producing harmful by-products,being affected by water turbidity,and high energy consumption.The growing concern for microbial safety has brought non-thermal plasma(NTP)disinfection technology into the spotlight.NTP is a promising disinfection technology with advantages such as environmental protection,safety,room temperature disinfection,short disinfection cycle,and wide applicability.Researchers are continuously optimizing NTP reactions to improve disinfection efficiency.This paper provides an integrated analysis of both plasma disinfection in water and plasma-activated water(PAW)disinfection on object surfaces.NTP can directly treat bacterial contaminated water,and can also be employed to produce PAW as a disinfectant for treating bacteria on surfaces.This review introduces the fundamental concepts and commonly used equipment related to NTP technology,analyzes the influencing factors and mechanisms of disinfection,and concludes by outlining the future directions of NTP technology in the field of disinfection.We hope to provide a reference for the research and practice of bacterial pollution issues.展开更多
Industrial activities have caused widespread arsenic(As)contamination in soil and medicinal crops across south-ern Asia.This study constructed interplanting systems combing medicinal crops with Pteris vittata L.,aimin...Industrial activities have caused widespread arsenic(As)contamination in soil and medicinal crops across south-ern Asia.This study constructed interplanting systems combing medicinal crops with Pteris vittata L.,aiming to mitigate the risk of As exposure in medicinal crops,while simultaneously achieving ecological remediation of contaminated soil.The results revealed that interplanting with P.vittata significantly enhanced the yield of Gynos-temma pentaphyllum by 31.90%(P<0.05)compared with monoculture systems.Under monoculture conditions,the As concentration in G.pentaphyllum leaves reached 2.34 mg/kg,exceeding the national food safety standard(GB2762–2017,2 mg/kg).However,interplanting with P.vittata effectively reduced the As concentration in G.pentaphyllum leaves to 1.82 mg/kg.Furthermore,the interplanting of P.vittata with Rhus chinensis significantly inhibited As translocation from belowground to aboveground tissues in R.chinensis.Compared to monoculture,the stem biomass of P.vittata was significantly increased by 57.50%and 70.32%when interplanted with G.pentaphyllum and Cassia obtusifolia L.(P<0.05).So the As enrichment of P.vittata was enhanced in interplanting systems,which is beneficial for the As removal from contaminated soil.The study demonstrated that interplant-ing primarily regulates plant As uptake through modifications of rhizosphere physicochemical properties and As bioavailability,especially for water-soluble As that is easily absorbed by plants.In conclusion,the interplant-ing models integrating medicinal crops and P.vittata can achieve the goal of“remediating while producing”in As-contaminated soil.展开更多
The development of wheat cultivars with improved nitrogen(N),phosphorus(P),and potassium(K)use efficiency is essential for sustainable agriculture.Genetic dissection and identification of causative genes underlying nu...The development of wheat cultivars with improved nitrogen(N),phosphorus(P),and potassium(K)use efficiency is essential for sustainable agriculture.Genetic dissection and identification of causative genes underlying nutrient use efficiency represent a key strategy toward this goal.We conducted an extensive genome-wide association study(GWAS)using a panel of 431 wheat cultivars,identifying 1,659 significant single-nucleotide polymorphisms(SNPs)(LOD>5)through genotyping-by-sequencing.This analysis revealed 534 quantitative trait loci(QTLs)associated with 12 nutrient use efficiency traits across five distinct environments,among which 14 QTLs were consistently detected in at least three environments.Notably,meta-QTL analysis,showed that QTL80(72.12–74.24 Mb,chr2A),QTL387(32.88–33.56 Mb,chr6A),and QTL500(535.53–540.80 Mb,chr7B)exhibit clear co-localization with MQTL-2A-2,MQTL-6A-1,and MQTL-7B-2,respectively.This overlap highlights their robustness across diverse environmental conditions.Within these regions,critical candidate genes-including members of the bZIP transcription factor family and a potassium transporter gene-were identified in relation to nutrient use efficiency.Furthermore,a novel locus,QTL234,was discovered,harboring key candidate genes such as dof zinc finger protein,Ankyrin repeat family protein,and cytochrome P450.To validate the SNP within QTL234 associated with nitrogen harvest index(NHI),we developed a dCAPS marker for AX-109095537.These findings demonstrate the effectiveness of high-resolution SNP-based GWAS in rapidly pinpointing promising candidate genes.They also establish a foundation for large-scale QTL fine mapping,candidate gene validation,and the development of functional markers essential for enhancing nutrient use efficiency in wheat breeding programs.展开更多
A high crop yield with the minimum possible cost to the environment is generally desirable.However,the complicated relationships among crop production,nitrogen(N) use efficiency and environmental impacts must be clear...A high crop yield with the minimum possible cost to the environment is generally desirable.However,the complicated relationships among crop production,nitrogen(N) use efficiency and environmental impacts must be clearly assessed.We conducted a series of on-farm N application rate experiments to establish the linkage between crop yield and N_2 O emissions in the Guanzhong Plain in Northwest China.We also examined crop yield,partial factor productivity of applied N(PFPN) and reactive N(Nr) losses through a survey of 1 529 and 1 497 smallholder farms that grow wheat and maize,respectively,in the region.The optimum N rates were 175 and 214 kg ha^(-1) for winter wheat and summer maize,respectively,thereby achieving the yields of 6 799 and 7 518 kg ha^(-1),correspondingly,with low N_2 O emissions based on on-farm N rate experiments.Among the smallholder farms,the average N application rates were 215 and 294 kg ha^(-1) season^(-1),thus producing 6 490 and 6 220 kg ha^(-1) of wheat and maize,respectively.The corresponding PFPN values for the two crops were 36.8 and 21.2 kg N kg^(-1),and the total N_2 O emissions were 1.50 and 3.88 kg ha^(-1),respectively.High N balance,large Nr losses and elevated N_2 O emissions could be explained by the overdoses of N application and low grain yields under the current farming practice.The crop yields,N application rates,PFPN and total N_2 O for wheat and maize were 18 and 24% higher,42 and 37% less,75 and 116% higher,and 42 and 47% less,correspondingly,in the high-yield and high-PFPN group than in the average smallholder farms.In conclusion,closing the PFPN gap between the current average and the value for the high-yield and high-PFPN group would increase crop production and reduce Nr losses or the total N_2 O emissions for the investigated cropping system in Northwest China.展开更多
Yield gap analysis could provide management suggestions to increase crop yields,while the understandings of resource utilization efficiency could help judge the rationality of the management.Based on more than 110 pub...Yield gap analysis could provide management suggestions to increase crop yields,while the understandings of resource utilization efficiency could help judge the rationality of the management.Based on more than 110 published papers and data from Food and Agriculture Organization (FAO,www.fao.org/faostat) and the Global Yield Gap and Water Productivity Atlas (www.yieldgap.org),this study summarized the concept,quantitative method of yield gap,yield-limiting factors,and resource utilization efficiency of the three major food crops (wheat,maize and rice).Currently,global potential yields of wheat,maize and rice were 7.7,10.4 and 8.5 t ha^(–1),respectively.However,actual yields of wheat,maize and rice were just 4.1,5.5 and 4.0 t ha^(–1),respectively.Climate,nutrients,moisture,crop varieties,planting dates,and socioeconomic conditions are the most mentioned yield-limiting factors.In terms of resource utilization,nitrogen utilization,water utilization,and radiation utilization efficiencies are still not optimal,and this review has summarized the main improvement measures.The current research focuses on quantitative potential yield and yield gap,with a rough explanation of yield-limiting factors.Subsequent research should use remote sensing data to improve the accuracy of the regional scale and use machine learning to quantify the role of yield-limiting factors in yield gaps and the impact of change crop management on resource utilization efficiency,so as to propose reasonable and effective measures to close yield gaps.展开更多
Previous studies have extensively explored the critical influence of the built environment on land values,but the non-linear relationship has yet to be fully revealed.This study aims to uncover the non-linear relation...Previous studies have extensively explored the critical influence of the built environment on land values,but the non-linear relationship has yet to be fully revealed.This study aims to uncover the non-linear relationship between land values and the five built environment dimensions using machine learning algorithms and Shapley Additive ex Planation(SHAP).The results highlight that the Gradient Boost Decision Tree (GBDT) outperforms e Xtreme Gradient Boosting (XGBoost),Ordinary Least Squares (OLS),and Multiscale Geographically Weighted Regression (MGWR) in land value estimation,exhibiting higher R^(2) and lower Root Mean Square Error (RMSE) and Mean Absolute Error (MAE).The results illustrate that density and destination accessibility are the dominant factors,contributing 32.48%and37.38%to land value variation,respectively.We observed that the top three factors affecting land values are the built-floor area ratio,the number of floors and the number of restaurants.Additionally,the results revealed the non-linear relationship between the built environment and land values,suggesting that maintaining built environment features at optimal thresholds may increase land values.Neglecting interaction effects may lead to bias in determining relationships between land values and the built environment.This study contributes to the literature by providing non-linear and threshold identification evidence in land value determinants,offering valuable insights for urban planners and real estate managers.展开更多
Salt-affected soils, caused by natural or human activities, are a common environmental hazard in semi-arid and arid landscapes. Excess salts in soils affect plant growth and production, soil and water quality and, the...Salt-affected soils, caused by natural or human activities, are a common environmental hazard in semi-arid and arid landscapes. Excess salts in soils affect plant growth and production, soil and water quality and, therefore, increase soil erosion and land degradation. This research investigates the performance of five different semi-empirical predictive models for soil salinity spatial distribution mapping in arid environment using OLI sensor image data. This is the first attempt to test remote sensing based semi-empirical salinity predictive models in this area: the Kingdom of Bahrain. To achieve our objectives, OLI data were standardized from the atmosphere interferences, the sensor radiometric drift, and the topographic and geometric distortions. Then, the five semi-empirical predictive models based on the Normalized Difference Salinity Index (NDSI), the Salinity Index-ASTER (SI-ASTER), the Salinity Index-1 (SI-1), the Soil Salinity and Sodicity Index-1 and Index-2 (SSSI-1 and SSSI-2), developed for slight and moderate salinity in agricultural land, were implemented and applied to OLI image data. For validation purposes, a fieldwork was organized and different important spots-locations representing different salinity levels were visited, photographed, and localized using an accurate GPS (σ ≤ ±30 cm). Based on this a priori knowledge of the soil salinity, six validation sites were selected to reflect non-saline, low, moderate, high and extreme salinity classes, descriptive statistics extracted from polygons and/or transects over these sites were used. The obtained results showed that the models based on NDSI, SI-1 and SI-ASTER all failed to detect salinity bounds for both extreme salinity (Sabkhah) and non-saline conditions. In Fact, NDSI and SI-ASTER gave respectively only 35% dS/m and 25% dS/m in extreme salinity validation site, while SI-1 and SI-ASTER indicated 38% dS/m and 39% dS/m in non-saline validation site. Therefore, these three models were deemed inadequate for the study site. However, both SSSI-1 and SSSI-2 allowed a detection of the previous salinity bounds and furthermore described similarly and correctly the urban-vegetation areas and the open-land areas. Their predicted EC is around 10% dS/m for non-saline urban soil, about 25% dS/m for low salinity urban-vegetation soil, approximately 30% to 75% dS/m, respectively, for moderate to high salinity soils. SSSI-2 based semi-empirical salinity models was able to differentiate the high salinity versus extreme salinity in areas where both exist and was very accurate to highlight the pure salt where SSSI-1 has reach saturation for both salinity classes. In conclusion, reliable salinity map was produced using the model based on SSSI-2 and OLI sensor data that allows a better characterization of the soil salinity problem in an Arid Environment.展开更多
According to the particularity of the open pit, the main influencing factors of mining quantity about mineral resources have been summarized systematically in life cycle and the structured hierarchical relation of its...According to the particularity of the open pit, the main influencing factors of mining quantity about mineral resources have been summarized systematically in life cycle and the structured hierarchical relation of its influencing factors has been constructed. In the light of the production process of open pit, the functional relationships between investment, mining cost and mining quantity have been defined based on the process of mining and loading so that the relation of the life cycle cost and mining quantity can be set up. And what’s more, in order to obtain the maximum economic profit of mining enterprises in life cycle, the planning model of mining quantity has been established based on the life cycle cost. The rational distribution of mining quantity will have been found on the condition of obtaining optimal solution about the planning model so as to determine scientifically the production scale of mining enterprises from the point of view of the sustainable development.展开更多
As the mesoscale eddies in oceans and semi-enclosed seas are significant in horizontal dispersion of pollutants,we investigate the seasonal variations of these eddies in the Persian Gulf(PG)that are usually generated ...As the mesoscale eddies in oceans and semi-enclosed seas are significant in horizontal dispersion of pollutants,we investigate the seasonal variations of these eddies in the Persian Gulf(PG)that are usually generated due to seasonal winds and baroclinic instability.The sea surface height(SSH)data from 2010 to 2014 of AVISO are used to identify and track eddies,using the SSH-based method.Then seasonal horizontal dispersion coefficients are estimated for the PG,using the properties of eddies.The results show an annual mean of 78 eddies with a minimum lifetime of one week.Most of the eddies are predominantly cyclonic(59.1%)and have longer lifetimes and higher diffusion coefficients than the anti-cyclonic eddies.The eddy activity is higher in warm seasons,compared to that of cold seasons.As locations with high eddy diffusion coefficients are high-risk areas by using maps of horizontal eddy diffusion coefficients,perilous times and locations of the release of pollutants are specified to be within the longitude from 51.38°E to 55.28°E.The mentioned areas are located from the Strait of Hormuz towards the northeast of the PG,closer to Iranian coast.Moreover,July can be considered as the most dangerous time of pollution release.展开更多
The average temperature of Thailand is projected to increase by 2-3 °C, and the annual rainfall is projected to increase by 25% and up to 50% in certain areas. The climate change in future is expected to provide ...The average temperature of Thailand is projected to increase by 2-3 °C, and the annual rainfall is projected to increase by 25% and up to 50% in certain areas. The climate change in future is expected to provide changes in hydrological cycle and therefore impacts the groundwater resources too. In this study, we analyzed the general climate change trends and reviewed the groundwater conditions of Thailand. The climate changes, hydrologic variability and the impact of climate change on groundwater sustainability are also discussed based on a national groundwater monitoring program. Currently, there are 864 groundwater monitoring stations and 1 524 monitoring wells installed in Thailand. Moreover, the impact of climate change on groundwater-dependent systems and sectors is also discussed according to certain case studies, such as saline water intrusion in coastal and inland areas. Managing aquifer recharge and other projects are examples of groundwater adaptation project for the future.展开更多
The aim of this research is to map the salt-affected soil in an arid environment using an advanced semi-empirical predictive model, Operational Land Imager (OLI) data, a digital elevation model (DEM), field soil sampl...The aim of this research is to map the salt-affected soil in an arid environment using an advanced semi-empirical predictive model, Operational Land Imager (OLI) data, a digital elevation model (DEM), field soil sampling, and laboratory and statistical analyses. To achieve our objectives, the OLI data were atmospherically corrected, radiometric sensor drift was calibrated, and distortions of topography and geometry were corrected using a DEM. Then, the soil salinity map was derived using a semi-empirical predictive model based on the Soil Salinity and Sodicity Index-2 (SSSI-2). The vegetation cover map was extracted from the Transformed Difference Vegetation Index (TDVI). In addition, accurate DEM of 5-m pixels was used to derive topographic attributes (elevation and slope). Visual comparisons and statistical validation of the semi-empirical model using ground truth were undertaken in order to test its capability in an arid environment for moderate and strong salinity mapping. To accomplish this step, fieldwork was organized and 120 soil samples were collected with various degrees of salinity, including non-saline soil samples. Each one was automatically labeled using a digital camera and an accurate global positioning system (GPS) survey (σ ≤ ± 30 cm) connected in real time to the geographic information system (GIS) database. Subsequently, in the laboratory, the major exchangeable cations (Ca2+, Mg2+, Na+, K+, Cl- and SO42-), pH and the electrical conductivity (EC-Lab) were extracted from a saturated soil paste, as well as the sodium adsorption ratio (SAR) being calculated. The EC-Lab, which is generally accepted as the most effective method for soil salinity quantification was used for statistical analysis and validation purposes. The obtained results demonstrated a very good conformity between the derived soil salinity map from OLI data and the ground truth, highlighting six major salinity classes: Extreme, very high, high, moderate, low and non-saline. The laboratory chemical analyses corroborate these results. Furthermore, the semi-empirical predictive model provides good global results in comparison to the ground truth and laboratory analysis (EC-Lab), with correlation coefficient (R2) of 0.97, an index of agreement (D) of 0.84 (p < 0.05), and low overall root mean square error (RMSE) of 11%. Moreover, we found that topographic attributes have a substantial impact on the spatial distribution of salinity. The areas at a relatively high altitude and with hard bedrock are less susceptible to salinity, while areas at a low altitude and slope (≤2%) composed of Quaternary soil are prone to it. In these low areas, the water table is very close to the surface (≤1 m), and the absence of an adequate drainage network contributes significantly to waterlogging. Consequently, the intrusion and emergence of seawater at the surface, coupled with high temperature and high evaporation rates, contribute extensively to the soil salinity in the study area.展开更多
The Khao Ya Puk Formation (>400 m thick) is well exposed in the Nakhon Thai Region, and is subdivided into three members. The Khao Ya Puk Formation overlies conformably on top of the anhydrite layer of the upper ro...The Khao Ya Puk Formation (>400 m thick) is well exposed in the Nakhon Thai Region, and is subdivided into three members. The Khao Ya Puk Formation overlies conformably on top of the anhydrite layer of the upper rock salt Maha Sarakham Formation. In turn, it is overlain unconformably by the Phu Khat Formation. The Khao Ya Puk Formation is interpreted to have been deposited by freshwater lake area in arid climate inland subkha in the Late Cretaceous. Lithostatigraphically, Khao Ya Puk Formation can be correlated with the Phu Tok Formation that has been deposited in the Khorat-Ubon basin and Udon-Sakon basin of the Khorat Plateau.展开更多
The analysis of the relationship between oceanographic and environmental factors and fish production and productivity reveals that during the Southwest monsoon season,fish production and productivity are typically hig...The analysis of the relationship between oceanographic and environmental factors and fish production and productivity reveals that during the Southwest monsoon season,fish production and productivity are typically higher and more variable compared to the Northeast monsoon season.These metrics exhibit a relatively strong relationship with oceanographic structural variables,with a multiple correlation coefficient of R0=0.56 during the Southwest monsoon season,which decreases to R0=0.4 in the Northeast monsoon season.Specifically,fish production and productivity show a positive correlation with seawater temperature during the Northeast monsoon season,a negative correlation during the Southwest monsoon season,and a negative correlation with salinity in both seasons.Multivariate regression analysis further highlights a significant relationship between marine resource productivity and various oceanographic and environmental factors.Notably,factors such as Tday(Bottom Water Temperature),H0,PHY(Phytoplankton),and ZOO(Zooplankton)demonstrate high pairwise correlation coefficients with fish production and are positively correlated with each other.Additionally,fishing productivity peaks in areas with low flow speeds(20-40 cm/s)and regions characterized by alternating cyclonic and anticyclonic circulations.展开更多
文摘Bat population appears is maintained as the last habitat of these species in the La Ca Pagoda(old)area of the Khmer ethnic people in Tra Vinh.Methods are interview,count individuals in the habitat,species,population,determine the type of plants,the height of the living bats;results of the current status of species,quantity,distribution,residence and reproduction of species;impacts on 2 species of horse bats related to the conservation of horse bats;compared to previous by the Ehb function,with the parameters Hchb(Horseback bat community)the existence of the community compared to the previous time,at least 1 breeding season;Hhhb(Horse bat habitat)on living conditions;Hfhb(Horse bat food)on food sources for the community to live;Hphb(Horse bat protection)on conditions to protect the community;evaluated by score(0–1);the results the species Pteropus vampyrus decreased by 79.51%,the species Pteropus lylei increased by 6.8 times.The total number is 1239 individuals,including 1072 THB and 168 LHB.Both of these species have been recorded in previous surveys.The number of individuals counted was larger than the previous survey(1239 individuals compared to 957 individuals);the number of LHB in this survey was much smaller than the previous count(168 individuals compared to 820 individuals);the number of THB was (1072 individuals compared to 137 individuals).Using a function-based assessment method with ecologically relevant parameters can objectively assess the distribution and status of threatened populations to effectively protect their survival.
文摘[Objective]To systematically isolate and purify the polysaccharide from the mycelium of Streptomyces rochei D74(SRP),elucidate its fine structure,and evaluate the effect of the purified polysaccharide fraction on the growth of Salvia miltiorrhiza hairy roots and the biosynthesis of tanshinones,along with the underlying mechanism.[Methods]The crude polysaccharide was extracted using hot water,which was followed by ethanol precipitation and deproteinization via the Sevag method.Further purification was performed using DEAE-52 anionexchange chromatography and Sephadex G-100 gel filtration chromatography.The physicochemical properties and structural features of the main active fraction,SRP-W-2,were systematically characterized by Fourier transform infrared spectroscopy(FTIR),high performance liquid chromatography-mass spectrometry(HPLC-MS),and nuclear magnetic resonance(NMR).The effects of SRP-W-2 on hairy root growth and the biosynthesis of tanshinones were assessed by measuring biomass,tanshinone content,and the expression levels of key biosynthetic genes.[Results]SRP-W-2 was obtained with a yield of 2.41%.It was primarily composed of glucose and galactose at a molar ratio of 12.53:1.Structural analysis revealed that the backbone of SRP-W-2 consisted of→4)-α-D-Glcp-(1→and→4)-α-D-Galp-(1→residues,with branching points at→4,6)-α-D-Glcp-(1→and→4,6)-α-D-Galp-(1→.The side chain was identified asα-D-Glcp-(1→4)-α-DGlcp-(1→.Bioactivity assays demonstrated that SRP-W-2 significantly enhanced both the biomass of S.miltiorrhiza hairy roots and the accumulation of tanshinones.After 15 d of treatment with 50 mg/L SRP-W-2,the dry weight of the hairy roots increased by 37.52%.Meanwhile,the content of cryptotanshinone(CT),dihydrotanshinone I(DT-I),tanshinone I(T-I),and tanshinone IIA(TIIA)was increased by 19.0-fold,6.4-fold,2.8-fold,and 4.8-fold,respectively.Gene expression analysis further indicated that SRP-W-2 up-regulated key genes involved in the tanshinone biosynthetic pathway,including HMGR,DXS,DXR,and GGPPS.[Conclusion]The polysaccharide fraction SRP-W-2 from S.rochei D74 simultaneously promoted the growth of S.miltiorrhiza hairy roots and the biosynthesis of tanshinones,demonstrating its potential as an effective elicitor.This study provided a new strategy for the utilization and development of S.miltiorrhiza resources.
文摘The current economic development is the process of improving the physical and spiritual living conditions for people through the production of material wealth and the improvement of social relations as well as the improvement of cultural quality.In recent years,Vietnam showed robust growth in terms of economic development,along with the fast pace of urbanization and population increase.However,the economic growth has led to serious problems relating to the environment,such as the pollution of the air,water,and soil,which hugely affected the quality of human life.The Environmental Kuznets Curve(EKC)implied that a country with strong economic background shifting to industrialization or mechanization of agriculture will have positive GDP and the environmental damage level will decrease.The analysis and assessment showed that the environmental problems caused by economic activities are:air pollution in the urban area still maintained at high level;water pollution in rivers and limited fresh water supply;and the soil pollution and declining water supply underneath soil are developing.
基金Under the auspices of the Natural Science Foundation of China(No.32371875,32001249)。
文摘Stand age plays a crucial role in forest biomass estimation and carbon cycle modeling.Assessing the uncertainty of stand age prediction models and identifying the key driving factors in the modeling process have become major challenges in forestry research.In this study,we selected the Shaanxi-Gansu-Ningxia region of Northeast China as the research area and utilized multi-source datasets from the summer of 2019 to extract information on spectral,textural,climatic,water balance,and stand characteristics.By integrating the Random Forest(RF)model with Monte Carlo(MC)simulation,we constructed six regression models based on different combina-tions of features and evaluated the uncertainty of each model.Furthermore,we investigated the driving factors influencing stand age modeling by analyzing the effects of different types of features on age inversion.Model performance and accuracy were assessed using the root mean square error(RMSE),mean absolute error(MAE),and the coefficient of determination(R^(2)),while the relative root mean square error(rRMSE)was employed to quantify model uncertainty.The results indicate that the scenarios with more obvious improve-ment in accuracy and effective reduction in uncertainty were Scenario 3 with the inclusion of climate and water balance information(RMSE=25.54 yr,MAE=18.03 yr,R^(2)=0.51,rRMSE=19.17%)and Scenario 5 with the inclusion of stand characterization informa-tion(RMSE=18.47 yr,MAE=13.05 yr,R^(2)=0.74,rRMSE=16.99%).Scenario 6,incorporating all feature types,achieved the highest accuracy(RMSE=17.60 yr,MAE=12.06 yr,R^(2)=0.77,rRMSE=14.19%).In this study,elevation,minimum temperature,and diameter at breast height(DBH)emerged as the key drivers of stand-age modeling.The proposed method can be used to identify drivers and to quantify uncertainty in stand-age estimation,providing a useful reference for improving model accuracy and uncertainty assessment.
基金supported by the National Natural Science Foundation of China(No.42077135).
文摘Heavy metal contamination of soil is one of the major challenges to sustainable agriculture.This contamination can be transmitted through the soil food chain and poses a serious threat to human health.In this study,we found that freeze-thaw leaching(FTL)effectively complements the low removal rate of chemical leaching,and investigated the effects of different numbers of FTL on Cd contamination,soil chemical properties and microbial communities.The results showed that repeated FTL significantly reduced(P<0.05)the total Cd content in the top soil(19.02%-49.35%)and subsoil(0.41%-21.13%)and promoted the transformation of Cd to a more stable form,mainly through various removal mechanisms such as complexation,ion-exchange,and chemical precipitation.This finding was supported by reductions in several soil properties,including pH,available potassium(AK),and available phosphorus(AP).FTL treatment initially increased the bioavailability of Cd compared to chemical leaching,but bioavailability of Cd progressively decreased as the number of freeze-thaw cycles increased.Additionally,FTL reduced the richness and diversity of bacteria communities,destabilized ecological symbiotic networks,while increasing the richness and diversity of fungi in the soil.Various model analyses indicated that FTL treatment,available Cd,soil pH,AP and AK were the key drivers influencing the changes in microbial community structure.This study provides new insights and scientific bases for the effective management of heavy metal pollution in agricultural soils,the restoration of ecosystem health,and the improvement of soil sustainability.
基金supported by the National Natural Science Foundation of China(Nos.42330712 and 42373065)the Youth Innovation Promotion Association CAS(No.2021399)the Department of Human Resources and Social Security of Guizhou Province(No.2020[10]).
文摘Paddy soil in carbonate regions is susceptible to cadmium(Cd)contamination from geogenic or anthropogenic sources.However,Cd solubility in carbonate-derived alkaline paddy soils with contrasting Cd sources and properties under redox alternations is poorly understood.In this study,paddy soils enriched with geogenic or mine drainage-derived Cd and presenting contrasting manganese and sulfur abundances were incubated under alternating redox conditions.The changes in aqueous chemistry,Cd bioavailability and speciation were investigated.The results revealed that mine drainage significantly elevated the content of soluble sulfate and the abundance of sulfur-related bacteria(e.g.,Sulfurifustis and Thiobacillus)in paddy soils.For contaminated soils,the reductive dissolution of Fe/Mn oxides and cation exchange induce Cd mobilization from soils during the initial reduction period.More than 90%of the soluble Cd was subsequently re-sequestered,concomitant with the increase in residual and organically bound Cd fractions.Nevertheless,the soluble Cd gradually decreased in geogenic soil during the reduction period.During the reoxidation period,the Cd solubility increased in all the soils in the initial 3 days.Afterward,soluble Cd was partially immobilized by different soil constituents.As a result of Cd redistribution,Cd bioavailability decreased with reduction time and increased with ongoing oxidization of the soil.These results indicate that the solubility and fate of Cd vary in soils and strongly depend on soil biogeochemical properties in the karst region.
基金supported by the National Key Research and Development Program of China(2023YFD1900300 and 2017YFD0200205)the Agricultural Key-scientific and Core-technological Project of Shaanxi Province,China(2024NYGG011)。
文摘The continuous supply of phosphorus(P)is indispensable in crop production.However,P resources are non-renewable,and environmental concerns like eutrophication associated with its loss from agroecosystems make the sustainable management of P resources essential for ensuring global food security.This study was designed to reduce mineral P inputs through management practices.A field experiment comprising a wheat-maize rotation system was conducted in the Guanzhong Plain of Shaanxi Province,China from 2018-2023.The eight treatments included CK(without P),FP(conventional P application);RP(recommended P);RP80(20% reduction in RP);SRP80(20% reduction in RP with straw wrapping);ARP80(20% reduction in RP with ammonium sulfate instead of urea);SARP80(20% reduction in RP with straw wrapping and ammonium sulfate instead of urea);and SARP60(40% reduction in RP with straw wrapping and ammonium sulfate instead of urea).Crop yield,P uptake,and P fertilizer use efficiency were measured during harvest and throughout the entire period of the study.At the end of the experiment,P fractions were estimated using the Tiessen-Moir P classification method.The results revealed that the grain yields of all the treatments except for RP80 were significantly increased compared to CK,with increases of 14.9-28.8%.Furthermore,agronomic efficiency,apparent P use efficiency,P recovery rate,and partial factor productivity were significantly improved for the treatments that received 20% less P with straw wrapping.Moreover,the enhancement measures significantly increased labile and moderately labile P in the soil.Therefore,straw wrapping with ammonium sulfate instead of urea is one of the most effective ways to reduce mineral P inputs while increasing the efficiency of P in wheat-maize rotation systems.
基金support by National Natural Science Foundation of China(No.22006069)Natural Science Foundation of Jiangsu Province in China(No.BK20200801)Jiangsu Special Foundation on Technology Innovation of Carbon Dioxide Peaking and Carbon Neutrality(No.BK20220016).
文摘Human health is seriously jeopardized by infections caused by pathogenic microorganisms.The current traditional disinfection technologies have many defects,such as producing harmful by-products,being affected by water turbidity,and high energy consumption.The growing concern for microbial safety has brought non-thermal plasma(NTP)disinfection technology into the spotlight.NTP is a promising disinfection technology with advantages such as environmental protection,safety,room temperature disinfection,short disinfection cycle,and wide applicability.Researchers are continuously optimizing NTP reactions to improve disinfection efficiency.This paper provides an integrated analysis of both plasma disinfection in water and plasma-activated water(PAW)disinfection on object surfaces.NTP can directly treat bacterial contaminated water,and can also be employed to produce PAW as a disinfectant for treating bacteria on surfaces.This review introduces the fundamental concepts and commonly used equipment related to NTP technology,analyzes the influencing factors and mechanisms of disinfection,and concludes by outlining the future directions of NTP technology in the field of disinfection.We hope to provide a reference for the research and practice of bacterial pollution issues.
基金supported by the National Key Research and Development Program of China(No.2020YFC1807805)the Science and Technology Planning Project of Guangzhou,Guangdong Province,China(No.202206010176).
文摘Industrial activities have caused widespread arsenic(As)contamination in soil and medicinal crops across south-ern Asia.This study constructed interplanting systems combing medicinal crops with Pteris vittata L.,aiming to mitigate the risk of As exposure in medicinal crops,while simultaneously achieving ecological remediation of contaminated soil.The results revealed that interplanting with P.vittata significantly enhanced the yield of Gynos-temma pentaphyllum by 31.90%(P<0.05)compared with monoculture systems.Under monoculture conditions,the As concentration in G.pentaphyllum leaves reached 2.34 mg/kg,exceeding the national food safety standard(GB2762–2017,2 mg/kg).However,interplanting with P.vittata effectively reduced the As concentration in G.pentaphyllum leaves to 1.82 mg/kg.Furthermore,the interplanting of P.vittata with Rhus chinensis significantly inhibited As translocation from belowground to aboveground tissues in R.chinensis.Compared to monoculture,the stem biomass of P.vittata was significantly increased by 57.50%and 70.32%when interplanted with G.pentaphyllum and Cassia obtusifolia L.(P<0.05).So the As enrichment of P.vittata was enhanced in interplanting systems,which is beneficial for the As removal from contaminated soil.The study demonstrated that interplant-ing primarily regulates plant As uptake through modifications of rhizosphere physicochemical properties and As bioavailability,especially for water-soluble As that is easily absorbed by plants.In conclusion,the interplant-ing models integrating medicinal crops and P.vittata can achieve the goal of“remediating while producing”in As-contaminated soil.
基金funded by the National Key R&D Program of China(2021YFD1900700)。
文摘The development of wheat cultivars with improved nitrogen(N),phosphorus(P),and potassium(K)use efficiency is essential for sustainable agriculture.Genetic dissection and identification of causative genes underlying nutrient use efficiency represent a key strategy toward this goal.We conducted an extensive genome-wide association study(GWAS)using a panel of 431 wheat cultivars,identifying 1,659 significant single-nucleotide polymorphisms(SNPs)(LOD>5)through genotyping-by-sequencing.This analysis revealed 534 quantitative trait loci(QTLs)associated with 12 nutrient use efficiency traits across five distinct environments,among which 14 QTLs were consistently detected in at least three environments.Notably,meta-QTL analysis,showed that QTL80(72.12–74.24 Mb,chr2A),QTL387(32.88–33.56 Mb,chr6A),and QTL500(535.53–540.80 Mb,chr7B)exhibit clear co-localization with MQTL-2A-2,MQTL-6A-1,and MQTL-7B-2,respectively.This overlap highlights their robustness across diverse environmental conditions.Within these regions,critical candidate genes-including members of the bZIP transcription factor family and a potassium transporter gene-were identified in relation to nutrient use efficiency.Furthermore,a novel locus,QTL234,was discovered,harboring key candidate genes such as dof zinc finger protein,Ankyrin repeat family protein,and cytochrome P450.To validate the SNP within QTL234 associated with nitrogen harvest index(NHI),we developed a dCAPS marker for AX-109095537.These findings demonstrate the effectiveness of high-resolution SNP-based GWAS in rapidly pinpointing promising candidate genes.They also establish a foundation for large-scale QTL fine mapping,candidate gene validation,and the development of functional markers essential for enhancing nutrient use efficiency in wheat breeding programs.
基金the National Key Research and Development Program of China (2016YFD0800105)
文摘A high crop yield with the minimum possible cost to the environment is generally desirable.However,the complicated relationships among crop production,nitrogen(N) use efficiency and environmental impacts must be clearly assessed.We conducted a series of on-farm N application rate experiments to establish the linkage between crop yield and N_2 O emissions in the Guanzhong Plain in Northwest China.We also examined crop yield,partial factor productivity of applied N(PFPN) and reactive N(Nr) losses through a survey of 1 529 and 1 497 smallholder farms that grow wheat and maize,respectively,in the region.The optimum N rates were 175 and 214 kg ha^(-1) for winter wheat and summer maize,respectively,thereby achieving the yields of 6 799 and 7 518 kg ha^(-1),correspondingly,with low N_2 O emissions based on on-farm N rate experiments.Among the smallholder farms,the average N application rates were 215 and 294 kg ha^(-1) season^(-1),thus producing 6 490 and 6 220 kg ha^(-1) of wheat and maize,respectively.The corresponding PFPN values for the two crops were 36.8 and 21.2 kg N kg^(-1),and the total N_2 O emissions were 1.50 and 3.88 kg ha^(-1),respectively.High N balance,large Nr losses and elevated N_2 O emissions could be explained by the overdoses of N application and low grain yields under the current farming practice.The crop yields,N application rates,PFPN and total N_2 O for wheat and maize were 18 and 24% higher,42 and 37% less,75 and 116% higher,and 42 and 47% less,correspondingly,in the high-yield and high-PFPN group than in the average smallholder farms.In conclusion,closing the PFPN gap between the current average and the value for the high-yield and high-PFPN group would increase crop production and reduce Nr losses or the total N_2 O emissions for the investigated cropping system in Northwest China.
基金supported by the National Key Research and Development Program of China(2016YFD0300100)the Innovation Program of Chinese Academy of Agricultural Sciencesthe Elite Youth Program of the Chinese Academy of Agricultural Science。
文摘Yield gap analysis could provide management suggestions to increase crop yields,while the understandings of resource utilization efficiency could help judge the rationality of the management.Based on more than 110 published papers and data from Food and Agriculture Organization (FAO,www.fao.org/faostat) and the Global Yield Gap and Water Productivity Atlas (www.yieldgap.org),this study summarized the concept,quantitative method of yield gap,yield-limiting factors,and resource utilization efficiency of the three major food crops (wheat,maize and rice).Currently,global potential yields of wheat,maize and rice were 7.7,10.4 and 8.5 t ha^(–1),respectively.However,actual yields of wheat,maize and rice were just 4.1,5.5 and 4.0 t ha^(–1),respectively.Climate,nutrients,moisture,crop varieties,planting dates,and socioeconomic conditions are the most mentioned yield-limiting factors.In terms of resource utilization,nitrogen utilization,water utilization,and radiation utilization efficiencies are still not optimal,and this review has summarized the main improvement measures.The current research focuses on quantitative potential yield and yield gap,with a rough explanation of yield-limiting factors.Subsequent research should use remote sensing data to improve the accuracy of the regional scale and use machine learning to quantify the role of yield-limiting factors in yield gaps and the impact of change crop management on resource utilization efficiency,so as to propose reasonable and effective measures to close yield gaps.
文摘Previous studies have extensively explored the critical influence of the built environment on land values,but the non-linear relationship has yet to be fully revealed.This study aims to uncover the non-linear relationship between land values and the five built environment dimensions using machine learning algorithms and Shapley Additive ex Planation(SHAP).The results highlight that the Gradient Boost Decision Tree (GBDT) outperforms e Xtreme Gradient Boosting (XGBoost),Ordinary Least Squares (OLS),and Multiscale Geographically Weighted Regression (MGWR) in land value estimation,exhibiting higher R^(2) and lower Root Mean Square Error (RMSE) and Mean Absolute Error (MAE).The results illustrate that density and destination accessibility are the dominant factors,contributing 32.48%and37.38%to land value variation,respectively.We observed that the top three factors affecting land values are the built-floor area ratio,the number of floors and the number of restaurants.Additionally,the results revealed the non-linear relationship between the built environment and land values,suggesting that maintaining built environment features at optimal thresholds may increase land values.Neglecting interaction effects may lead to bias in determining relationships between land values and the built environment.This study contributes to the literature by providing non-linear and threshold identification evidence in land value determinants,offering valuable insights for urban planners and real estate managers.
文摘Salt-affected soils, caused by natural or human activities, are a common environmental hazard in semi-arid and arid landscapes. Excess salts in soils affect plant growth and production, soil and water quality and, therefore, increase soil erosion and land degradation. This research investigates the performance of five different semi-empirical predictive models for soil salinity spatial distribution mapping in arid environment using OLI sensor image data. This is the first attempt to test remote sensing based semi-empirical salinity predictive models in this area: the Kingdom of Bahrain. To achieve our objectives, OLI data were standardized from the atmosphere interferences, the sensor radiometric drift, and the topographic and geometric distortions. Then, the five semi-empirical predictive models based on the Normalized Difference Salinity Index (NDSI), the Salinity Index-ASTER (SI-ASTER), the Salinity Index-1 (SI-1), the Soil Salinity and Sodicity Index-1 and Index-2 (SSSI-1 and SSSI-2), developed for slight and moderate salinity in agricultural land, were implemented and applied to OLI image data. For validation purposes, a fieldwork was organized and different important spots-locations representing different salinity levels were visited, photographed, and localized using an accurate GPS (σ ≤ ±30 cm). Based on this a priori knowledge of the soil salinity, six validation sites were selected to reflect non-saline, low, moderate, high and extreme salinity classes, descriptive statistics extracted from polygons and/or transects over these sites were used. The obtained results showed that the models based on NDSI, SI-1 and SI-ASTER all failed to detect salinity bounds for both extreme salinity (Sabkhah) and non-saline conditions. In Fact, NDSI and SI-ASTER gave respectively only 35% dS/m and 25% dS/m in extreme salinity validation site, while SI-1 and SI-ASTER indicated 38% dS/m and 39% dS/m in non-saline validation site. Therefore, these three models were deemed inadequate for the study site. However, both SSSI-1 and SSSI-2 allowed a detection of the previous salinity bounds and furthermore described similarly and correctly the urban-vegetation areas and the open-land areas. Their predicted EC is around 10% dS/m for non-saline urban soil, about 25% dS/m for low salinity urban-vegetation soil, approximately 30% to 75% dS/m, respectively, for moderate to high salinity soils. SSSI-2 based semi-empirical salinity models was able to differentiate the high salinity versus extreme salinity in areas where both exist and was very accurate to highlight the pure salt where SSSI-1 has reach saturation for both salinity classes. In conclusion, reliable salinity map was produced using the model based on SSSI-2 and OLI sensor data that allows a better characterization of the soil salinity problem in an Arid Environment.
文摘According to the particularity of the open pit, the main influencing factors of mining quantity about mineral resources have been summarized systematically in life cycle and the structured hierarchical relation of its influencing factors has been constructed. In the light of the production process of open pit, the functional relationships between investment, mining cost and mining quantity have been defined based on the process of mining and loading so that the relation of the life cycle cost and mining quantity can be set up. And what’s more, in order to obtain the maximum economic profit of mining enterprises in life cycle, the planning model of mining quantity has been established based on the life cycle cost. The rational distribution of mining quantity will have been found on the condition of obtaining optimal solution about the planning model so as to determine scientifically the production scale of mining enterprises from the point of view of the sustainable development.
文摘As the mesoscale eddies in oceans and semi-enclosed seas are significant in horizontal dispersion of pollutants,we investigate the seasonal variations of these eddies in the Persian Gulf(PG)that are usually generated due to seasonal winds and baroclinic instability.The sea surface height(SSH)data from 2010 to 2014 of AVISO are used to identify and track eddies,using the SSH-based method.Then seasonal horizontal dispersion coefficients are estimated for the PG,using the properties of eddies.The results show an annual mean of 78 eddies with a minimum lifetime of one week.Most of the eddies are predominantly cyclonic(59.1%)and have longer lifetimes and higher diffusion coefficients than the anti-cyclonic eddies.The eddy activity is higher in warm seasons,compared to that of cold seasons.As locations with high eddy diffusion coefficients are high-risk areas by using maps of horizontal eddy diffusion coefficients,perilous times and locations of the release of pollutants are specified to be within the longitude from 51.38°E to 55.28°E.The mentioned areas are located from the Strait of Hormuz towards the northeast of the PG,closer to Iranian coast.Moreover,July can be considered as the most dangerous time of pollution release.
文摘The average temperature of Thailand is projected to increase by 2-3 °C, and the annual rainfall is projected to increase by 25% and up to 50% in certain areas. The climate change in future is expected to provide changes in hydrological cycle and therefore impacts the groundwater resources too. In this study, we analyzed the general climate change trends and reviewed the groundwater conditions of Thailand. The climate changes, hydrologic variability and the impact of climate change on groundwater sustainability are also discussed based on a national groundwater monitoring program. Currently, there are 864 groundwater monitoring stations and 1 524 monitoring wells installed in Thailand. Moreover, the impact of climate change on groundwater-dependent systems and sectors is also discussed according to certain case studies, such as saline water intrusion in coastal and inland areas. Managing aquifer recharge and other projects are examples of groundwater adaptation project for the future.
文摘The aim of this research is to map the salt-affected soil in an arid environment using an advanced semi-empirical predictive model, Operational Land Imager (OLI) data, a digital elevation model (DEM), field soil sampling, and laboratory and statistical analyses. To achieve our objectives, the OLI data were atmospherically corrected, radiometric sensor drift was calibrated, and distortions of topography and geometry were corrected using a DEM. Then, the soil salinity map was derived using a semi-empirical predictive model based on the Soil Salinity and Sodicity Index-2 (SSSI-2). The vegetation cover map was extracted from the Transformed Difference Vegetation Index (TDVI). In addition, accurate DEM of 5-m pixels was used to derive topographic attributes (elevation and slope). Visual comparisons and statistical validation of the semi-empirical model using ground truth were undertaken in order to test its capability in an arid environment for moderate and strong salinity mapping. To accomplish this step, fieldwork was organized and 120 soil samples were collected with various degrees of salinity, including non-saline soil samples. Each one was automatically labeled using a digital camera and an accurate global positioning system (GPS) survey (σ ≤ ± 30 cm) connected in real time to the geographic information system (GIS) database. Subsequently, in the laboratory, the major exchangeable cations (Ca2+, Mg2+, Na+, K+, Cl- and SO42-), pH and the electrical conductivity (EC-Lab) were extracted from a saturated soil paste, as well as the sodium adsorption ratio (SAR) being calculated. The EC-Lab, which is generally accepted as the most effective method for soil salinity quantification was used for statistical analysis and validation purposes. The obtained results demonstrated a very good conformity between the derived soil salinity map from OLI data and the ground truth, highlighting six major salinity classes: Extreme, very high, high, moderate, low and non-saline. The laboratory chemical analyses corroborate these results. Furthermore, the semi-empirical predictive model provides good global results in comparison to the ground truth and laboratory analysis (EC-Lab), with correlation coefficient (R2) of 0.97, an index of agreement (D) of 0.84 (p < 0.05), and low overall root mean square error (RMSE) of 11%. Moreover, we found that topographic attributes have a substantial impact on the spatial distribution of salinity. The areas at a relatively high altitude and with hard bedrock are less susceptible to salinity, while areas at a low altitude and slope (≤2%) composed of Quaternary soil are prone to it. In these low areas, the water table is very close to the surface (≤1 m), and the absence of an adequate drainage network contributes significantly to waterlogging. Consequently, the intrusion and emergence of seawater at the surface, coupled with high temperature and high evaporation rates, contribute extensively to the soil salinity in the study area.
文摘The Khao Ya Puk Formation (>400 m thick) is well exposed in the Nakhon Thai Region, and is subdivided into three members. The Khao Ya Puk Formation overlies conformably on top of the anhydrite layer of the upper rock salt Maha Sarakham Formation. In turn, it is overlain unconformably by the Phu Khat Formation. The Khao Ya Puk Formation is interpreted to have been deposited by freshwater lake area in arid climate inland subkha in the Late Cretaceous. Lithostatigraphically, Khao Ya Puk Formation can be correlated with the Phu Tok Formation that has been deposited in the Khorat-Ubon basin and Udon-Sakon basin of the Khorat Plateau.
基金funded by the project on marine fishery survey(02/QĐ-TCTS-KHTC dated March 19,2021,by the Director General of the Fisheries Department,Ministry of Agriculture and Rural Development of Vietnam),the Marine Fisheries Forecast Center,and the Institute of Marine Research,Vietnam.
文摘The analysis of the relationship between oceanographic and environmental factors and fish production and productivity reveals that during the Southwest monsoon season,fish production and productivity are typically higher and more variable compared to the Northeast monsoon season.These metrics exhibit a relatively strong relationship with oceanographic structural variables,with a multiple correlation coefficient of R0=0.56 during the Southwest monsoon season,which decreases to R0=0.4 in the Northeast monsoon season.Specifically,fish production and productivity show a positive correlation with seawater temperature during the Northeast monsoon season,a negative correlation during the Southwest monsoon season,and a negative correlation with salinity in both seasons.Multivariate regression analysis further highlights a significant relationship between marine resource productivity and various oceanographic and environmental factors.Notably,factors such as Tday(Bottom Water Temperature),H0,PHY(Phytoplankton),and ZOO(Zooplankton)demonstrate high pairwise correlation coefficients with fish production and are positively correlated with each other.Additionally,fishing productivity peaks in areas with low flow speeds(20-40 cm/s)and regions characterized by alternating cyclonic and anticyclonic circulations.
