环境科学最新文献

{"title":"[Low-carbon Development Path of Ordos Based on LEAP Model].","authors":"Yang-Wan-Qing Yu, Biao Liu, Xiao-Hong Zhu, Jun-Yu Zhang, Bing-Hao Wang, Ming-Pei Wang, Jian-Gong Yang, Yang Bai, Fu-Yuan Yang","doi":"10.13227/j.hjkx.202308032","DOIUrl":"https://doi.org/10.13227/j.hjkx.202308032","url":null,"abstract":"<p><p>To determine the low-carbon development path of Ordos, three scenarios （baseline scenario, low carbon scenario, and enhanced low carbon scenario） were constructed based on the LEAP model to forecast the energy demand and carbon emission in Ordos from 2020 to 2050 and to analyze the contribution of various policy initiatives to reduce carbon emission. The results showed that under the enhanced low carbon scenario, the energy demand in Ordos peaked at 52 million tons of standard coal equivalent in 2025 and decreased to 40 million tons of standard coal equivalent in 2050, and carbon emissions peaked at 163 million tons in 2025 and decreased to 16 million tons in 2050, which was 88% lower than that in 2020. Regarding emission reduction contribution, comparing the baseline scenario and the enhanced low-carbon scenario, the increase in renewable energy power generation installation, the reduction in energy consumption of terminal energy use, and the increase in terminal electrification rate contributed to the emission reductions of 43%, 25%, and 24%, respectively. The Ordos should vigorously develop renewable energy and make full use of the rich endowment of wind and light resources； at the same time, it should promote economic transformation and gradually increase the proportion of high-value-added and low-energy-consuming industries in the industrial structure. For the power sector, the power generation structure should be adjusted. Traditional thermal power generation should be replaced by zero-carbon and low-carbon power generation technologies. For the industrial and transportation sectors, the terminal electrification rate should be increased, and the energy intensity should be reduced.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 9","pages":"5097-5105"},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142355656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Stabilization of Cd-contaminated Soil with Thiol-modified Biochar and Response of Soil Microorganisms].","authors":"Zhi-Qiang Jiao, Shi-Ji Ge, Wen-Xiu Zheng, Jin-Hui Liu, Ming Chen, Yu-Ke Kong, Yang-Yang Wang","doi":"10.13227/j.hjkx.202311107","DOIUrl":"https://doi.org/10.13227/j.hjkx.202311107","url":null,"abstract":"<p><p>To explore the stabilization effect of livestock manure biochar on Cd-contaminated soil and its impact on the soil environment, a pot experiment was conducted to investigate the stabilization efficiency of cattle manure-biochar （BC） and thiol-modified biochar （SBC） on Cd in soil and their effect on the soil properties and microbial community. The structural equation model （SEM） was used to analyze the effect pathways of BC and SBC on the soil microbial community. The results showed that BC and SBC increased soil pH, available potassium, available phosphorus, and organic matter content but decreased soil available nitrogen content compared with those in CK. The stabilization efficiency of BC for Cd in soil was 14.97%, which was much lower than that of SBC （85.71%）. Moreover, SBC increased the abundance of dominant bacterial phyla in soil, with Proteobacteria, Bacteroidota, and Cyanobacteria increasing most significantly. SBC decreased the diversity of soil microorganisms, but the decrease was insignificant （<i>P</i>≥0.05） compared with that in CK and BC. SEM analysis indicated that the available phosphorus, available potassium, organic matter, and soil pH were the key factors influencing Cd availability in soil, whereas organic matter and Cd availability were the key factors affecting the soil microbial community. Overall, SBC could stabilize Cd effectively and increase the abundance of dominant bacteria and has great potential in the remediation of Cd-contaminated soil.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 9","pages":"5570-5577"},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142355703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Distribution Characteristics of Soil Aggregate Stability and Organic Carbon of Different Grassland Types in the Temperate Desert of Longzhong Loess Plateau].","authors":"Ya-Li Li, Guo-Xing He, Xiao-Ni Liu, De-Gang Zhang, He-Guang Xu, Tong Ji, Jia-Chang Jiang","doi":"10.13227/j.hjkx.202309164","DOIUrl":"https://doi.org/10.13227/j.hjkx.202309164","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Soil aggregate stability and organic carbon （SOC） are important indicators of soil structure and quality and play a key role in the improvement of soil quality in temperate deserts. This study aimed to investigate the distribution patterns, stability of soil aggregates, and variation characteristics of the content of aggregate organic carbon in different grassland types in temperate deserts and their interrelationships. Four grassland types in a temperate desert （&lt;i&gt;Kalidium foliatum&lt;/i&gt; type, &lt;i&gt;Reaumuria songarica&lt;/i&gt; type, &lt;i&gt;Salsola passerina&lt;/i&gt; type, and &lt;i&gt;Sympegma regelii&lt;/i&gt; type） in the Longzhong Loess Plateau as research objects, and the soil aggregate particle size distribution characteristics were determined using the wet sieving method. The stability of soil aggregates was analyzed by calculating aggregate stability indicators and the contribution of aggregate particle size SOC to bulk soil SOC content. Correlation analysis, principal component analysis, and linear fitting equations were used to reveal the relationship between the soil aggregate content and aggregate particle size SOC and aggregate stability. The results showed that the content of &gt;0.25 mm aggregates （&lt;i&gt;R&lt;/i&gt;&lt;sub&gt;0.25&lt;/sub&gt;）, mean weight diameter （MWD）, geometric mean diameter （GMD）, and bulk soil SOC content in each soil layer （0-10, 10-20, and 20-30 cm） of the &lt;i&gt;K. foliatum&lt;/i&gt; type grassland were significantly higher than that of the &lt;i&gt;R. songarica&lt;/i&gt; type and &lt;i&gt;S. regelii&lt;/i&gt; type （&lt;i&gt;P&lt;/i&gt;&lt;0.05）. The SOC content of 0.053-0.25 mm and &lt;0.053 mm particle size in each soil layer of the &lt;i&gt;K. foliatum&lt;/i&gt; type grassland were significantly higher than that of the &lt;i&gt;S. regelii&lt;/i&gt; type （&lt;i&gt;P&lt;/i&gt;&lt;0.05）. Surface and subsurface soils （0-10 cm and 10-20 cm） had the significantly highest contribution of 0.25-2 mm particle size SOC to the bulk soil SOC content （&lt;i&gt;P&lt;/i&gt;&lt;0.05）. Additionally, as the soil layer deepened, the &lt;i&gt;R&lt;/i&gt;&lt;sub&gt;0.25&lt;/sub&gt;, MWD, GMD, bulk soil, and aggregate SOC contents of the &lt;i&gt;K. foliatum&lt;/i&gt; type grassland showed a tendency to increase first and then decrease, with the highest contents from 10-20 cm. &lt;i&gt;Kalidium foliatum&lt;/i&gt; type grassland aggregate content was dominated by 0.25-2 mm aggregates, whereas the other three grassland types were dominated by 0.053-0.25 mm aggregates. In addition, bulk soil SOC content was significantly correlated with &lt;i&gt;R&lt;/i&gt;&lt;sub&gt;0.25&lt;/sub&gt;, MWD, GMD, and &lt;i&gt;E&lt;/i&gt;&lt;sub&gt;LT&lt;/sub&gt; （&lt;i&gt;P&lt;/i&gt;&lt;0.01）, and the 0.25 mm aggregate was the critical size of positive and negative correlation. &lt;i&gt;R&lt;/i&gt;&lt;sub&gt;0.25&lt;/sub&gt;, MWD, GMD, and &lt;i&gt;E&lt;/i&gt;&lt;sub&gt;LT&lt;/sub&gt; values were the key factors influencing bulk soil SOC in grassland. The equation fitted to bulk soil SOC content, and GMD was the most suitable to describe the relationship between SOC content and the stability of soil aggregates. Therefore, compared with other grassland types, &lt;i&gt;K. foliatum&lt;/i&gt; type grassland had a promoting effect on the soil aggregate","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 9","pages":"5431-5440"},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142355652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Recharge Sources and Hydrochemical Evolution Mechanism of Surface Water and Groundwater in Typical Karst Mining Area].","authors":"Zhi-Qiang Zhou, Qi-Bo Huang, Yu-Song Wang, Fei Luo, Jian-Hong Liang, Jiang-Yu Xiong","doi":"10.13227/j.hjkx.202310156","DOIUrl":"https://doi.org/10.13227/j.hjkx.202310156","url":null,"abstract":"<p><p>To study the recharge source, hydrochemical characteristics, and evolution process of karst underground water and surface water in the Xianghualing Mining area, we collected 32 groups of samples from karst underground water and surface water sources in and around the mining area. Based on multivariate statistical analysis, the Piper three-line diagram, Gibbs diagram, and ion ratio coefficient, this study analyzed the hydrogeochemical characteristics of karst underground water and surface water in the Xianghualing Mining area. The study systematically revealed the recharge source, recharge age, and hydrochemical evolution law of both water sources. The results showed that the karst underground water and surface water in the Xianghualing Mining area were weakly alkaline, with the main anions being HCO₃^- and the main cations being Ca²⁺. The hydrochemical types mainly included HCO₃-Ca, HCO₃-Ca·Mg, and HCO₃·SO₄-Ca·Mg types. Atmospheric precipitation was the primary source of recharge for karst underground water and surface water, and it was also influenced by evaporation during the runoff process. However, the evaporation effect of karst groundwater was relatively small, which was closely related to modern hydrology, and the cycle replacement process was more rapid. The hydrochemical evolution characteristics of karst underground water and surface water were mainly affected by rock weathering, cation exchange adsorption, mineral dissolution, and human activities （such as agricultural and mining activities）. Ca²⁺, Mg²⁺, and HCO₃^- were primarily derived from the dissolution of carbonate minerals, with a small portion also originating from the weathering and dissolution of silicate minerals. Na⁺ and Cl^- were primarily derived from the dissolution of rock salts. Among them, Cl^-, NO₃^-, and SO₄^2- were greatly affected by external inputs from agricultural activities, domestic sewage discharge, and mining activities. The research results are of great significance to the cyclical evolution process of karst underground water and surface water, as well as the protection and utilization of water resources in the Xianghualing Mining area.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 9","pages":"5264-5276"},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142355668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Spatial and Temporal Changes in Habitat Quality and Driving Forces in Typical Loess Hill and Gully Areas：A Case Study of the Zuli River Basin].","authors":"Hong-Sheng Liao, Wei Wei, Le Chen, Yu Shi","doi":"10.13227/j.hjkx.202310078","DOIUrl":"https://doi.org/10.13227/j.hjkx.202310078","url":null,"abstract":"<p><p>Loess hills and gully areas are one of the important ecological barriers in China, and the study of the spatial and temporal changes of its habitat quality and its driving force is of great significance to guaranteeing the ecological security of China and safeguarding the national ecological rights and interests. Taking the Zuli River Basin as an example, the spatiotemporal distribution of the remote-sensing ecological index （RSEI） from 2000 to 2020 was systematically investigated using the Google Earth Engine platform and Landsat remote-sensing data. Combined with the coefficient of variation CV, the Theil-Sen Median slope estimation, the Mann-Kendall test of significance, and the Hurst index, the spatial and temporal changes of habitat quality in the study area were analyzed over a period of 20 years, and the effects of six major driving factors on the spatial distribution of RSEI were investigated using the geodetector method. The results of the study showed that： ① From 2000 to 2020, the value of the RSEI showed a downward and then upward trend, with an average annual increase of 0.084 5·（10 a）^-1. ② During the 20-year period, the habitat quality improvement area accounted for 92.06%, of which the significant improvement area accounted for 28.49%, and the improvement area was mainly in Huining County, whereas the habitat degradation area only accounted for 7.82%. The trend of future ecological conditions showed that 74.98% of the areas would show a trend of continuous improvement or future improvement, but there would still be a potential risk of ecological degradation in 23.48% of the areas in the future. ③ Climate factors such as precipitation were the key factors affecting the habitat quality in the Zu Li River Basin； the interaction between factors had a higher explanatory power than that of any single factor on the habitat quality, among which the interaction between the precipitation factor and the elevation factor had the strongest explanatory power. The interaction between the terracing factor and the environmental factor significantly increased the explanatory power of the spatial variance, which indicated that terracing played an important role in improving habitat quality. The results of this study can provide a scientific basis for the management and sustainable development of the ecological environment in the loess hills and gullies.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 9","pages":"5361-5371"},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142355573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Pollution Characteristics and Source Apportionment of Heavy Metals in Topsoil of Counties Along the Shandong Section of the Yellow River].","authors":"Cong Hou, Shao-Kai Wang, Qi Wang, Chen-Xiao Hou, Wei-Cui Li, Cong Wang, Zhen-Hua Ma","doi":"10.13227/j.hjkx.202311031","DOIUrl":"https://doi.org/10.13227/j.hjkx.202311031","url":null,"abstract":"<p><p>The 25 counties along the Shandong section of the Yellow River are the core areas for promoting the ecological protection and high-quality development of the Yellow River in Shandong Province. Moreover, it is of great significance to study the current situation, sources, and potential risks of heavy metal pollution in the topsoil in this region. In this study, 103 soil samples were collected from the 25 counties along the Shandong section of the Yellow River, and the contents of eight heavy metals （As, Cu, Pb, Cr, Zn, Ni, Cd, and Hg） were determined. The pollution characteristics of heavy metals were analyzed and evaluated using the geological accumulation index and potential ecological risk index. Correlation analysis and the positive matrix factorization （PMF） model were used to analyze the sources of heavy metals. The results showed that the average contents of Cu and Cr were lower than that of the background values of soils, whereas the average contents of As, Pb, Zn, Ni, Cd, and Hg were 1.16, 1.42, 1.05, 1.14, 2.29, and 1.85 times higher than that of the background values, respectively, and the average contents of all eight elements were lower than the screening value of soil pollution risk in agricultural land. In terms of different heavy metal variations, the coefficient of variation （CV） of Cu and Cd was higher than 0.500, indicating high variations, whereas As, Pb, Cr, Zn, Ni, and Hg showed moderate variation. Cd and Hg were slightly polluted, whereas the other six elements were not polluted. Cd and Hg had a moderate potential ecological risk level, whereas the other six elements were at a low level. Correlation analysis and PMF model showed that the sources of heavy metals in the study area were influenced by four factors, i.e., agricultural activities, natural sources, industrial emissions, and atmospheric dust from coal combustion and vehicle exhaust emissions, and the relative contribution rates were 32.4%, 34.9%, 16.5%, and 16.2%, respectively.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 9","pages":"5485-5493"},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142355661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Effect of Three Foliar Inhibitors on Accumulation of Cd and As in Rice Grains].","authors":"Jun-Fan Yao, Yu-Ling Liu, Wei-Yu Zhang, De Yan, Nan Li, Bo-Qing Tie","doi":"10.13227/j.hjkx.202309102","DOIUrl":"https://doi.org/10.13227/j.hjkx.202309102","url":null,"abstract":"<p><p>This study investigated the impact of single and combined applications of three foliar inhibitors on the accumulation of cadmium （Cd） and arsenic （As） in rice grains. Two rice varieties, Songyazao 1 （for early rice） and Wuxiang Youyue （for late rice）, were selected for this experiment. We established nine treatments using a pot experiment method, including a control （CK） treated with no foliar inhibitor and three individual foliar inhibitors： cysteine （L-Cys）, potassium sulfide （K₂S）, and dipotassium hydrogen phosphate （K₂HPO₄）. We then combined the applications of two foliar inhibitors： L-Cys with low/high concentrations of K₂S, L-Cys with low/high concentrations of K₂HPO₄, and K₂S with a low concentration of K₂HPO₄. The results showed that the single and combined applications of foliar inhibitors reduced Cd and As concentrations in rice grains. The Cd content in brown rice treated with L-Cys and K₂S/K₂HPO₄ was reduced below the standard limit for food safety of 0.20 mg·kg^-1. Compared to the CK, the content of inorganic arsenic （IAs） in early and late rice decreased by 4.68%-56.75% and 2.84%-16.91%, respectively. Foliar inhibitors applied individually or in combinations facilitated the transport of Cd and As from the stem to the leaf while inhibiting their transport from the leaf to the rice grain. This resulted in the sequestration of Cd and As within the leaf cell wall, ultimately reducing the content of these elements in rice grains. Among the combination treatments, the application of L-Cys and high-concentration K₂S achieved the best results. The Cd content in early and late rice decreased by 37.64% and 26.37%, respectively, falling below 0.20 mg·kg^-1. The IAs content in early and late rice was reduced to 0.10 mg·kg^-1 （below 0.20 mg·kg^-1） and 0.24 mg·kg^-1, respectively. This study provides a valuable theoretical foundation and empirical data to support the achievement of safe rice production practices.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 9","pages":"5548-5556"},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142355654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Characteristics and Indicative Significance of Groundwater Stable Isotopes in the Loess Plateau at the Regional Scale].","authors":"Wei Xiang, Xin Liu, Bing-Cheng Si","doi":"10.13227/j.hjkx.202311066","DOIUrl":"https://doi.org/10.13227/j.hjkx.202311066","url":null,"abstract":"<p><p>Regional groundwater recharge is a critical scientific issue for sustainable groundwater resource development and management. However, spatial variations in groundwater recharge in the Loess Plateau （LP） remain poorly understood. To fill this knowledge gap, a systematic sampling campaign and stable isotope analysis were carried out for groundwater （shallow aquifer） in 13 major catchments during July 2019. The main objectives of this study were： ① to understand<b>t</b>he spatial distribution and influencing factors of stable isotopes in groundwater and <b>②</b> to reveal the groundwater recharge sources and pathways and their spatial variations, combined with the precipitation stable isotope datasets. Stable isotopes in groundwater had poor spatial variations at the regional scale； however, they became isotopically depleted with the increase in annual average precipitation on the catchment scale （<i>r</i> = -0.87）. Compared with the stable isotope of precipitation, stable isotopes of groundwater were generally depleted and were similar to the precipitation of the rainy season （July-September）. These together indicated that there was pronounced seasonality of groundwater recharge, and the main recharge period was the rainy season. In particular, the recharge seasonality index （<i>δ</i>_P/G） was closely related to the catchment's average annual precipitation （<i>r</i> = -0.77） and leaf area index （<i>r</i> = -0.63）. In addition, groundwater lc-excess was generally negative, with the catchment-mean value ranging from -4.3‰ to -0.7‰. Hydrologically, this indicated that groundwater recharge pathways （ratio of matrix flow vs. preferential flow） were different among these catchments, which should be quantitatively determined by combining the saturated zone （groundwater） and the unsaturated zone （soil） in future work. Our findings can improve the understanding of groundwater recharge in LP and provide a scientific basis for sustainable management of groundwater resources at the regional scale.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 9","pages":"5290-5297"},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142355637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Analysis of Water Quality of Le'an River in Poyang Lake Basin Based on CCME-WQI Method].","authors":"Yi Wu, Cheng Wang, Hua Wang, Xiao-Ying Li, Hao-Sen Xu","doi":"10.13227/j.hjkx.202309243","DOIUrl":"https://doi.org/10.13227/j.hjkx.202309243","url":null,"abstract":"<p><p>As the largest freshwater lake in China, Poyang Lake plays a key role in supporting the balance of aquatic ecosystems, and the water quality of its inlet rivers affects the lake's water quality. Le'an River, a typical inlet river of Poyang Lake, was selected as the research object. Based on the water quality data of six monitoring points in the upper, middle, and lower reaches of the mainstream of Le'an River from 2012 to 2020, the CCME-WQI method was used to evaluate the water quality of the river after systematically analyzing the spatiotemporal variation of the concentration of pollutants in the mainstream of the river. Finally, the main influencing factors of the water quality of the river were extracted and analyzed according to the PCA method. The results showed that： ① The water volume upstream and downstream of the river was more seriously polluted in the pre-study time period, which was due to the presence of Dexing Copper Mine in the upstream and small and medium-sized mines and farmland downstream. ② Before 2017, the water volume downstream of Le'an River had the worst water quality, with TP and NH₄⁺-N exceeding the standard rate of 43.3% and 85.0%, respectively, and the lowest WQI mean value of 86.2. After 2017, due to the effective management of pollutant discharges in the watershed, the water volume downstream of the river improved significantly and continued to be in an excellent state, and the mean value of the WQI reached 100.0. ③ The factors influencing the water quality of the mainstem of the Le'an River could be divided into four categories： human activities, seasonal factors, atmospheric deposition of pollutants, and the physical and chemical properties of the water volume itself, with human activities being the dominant factor for water quality changes at Dawuhekou and Shizhenjie, whereas the seasonal factors had the greatest influence at the remaining locations. ④ Organic matter pollution was obvious in the upper and lower Le'an River water volume, and the water volume at Dawuhekou was mainly affected by nearby mining activities, whereas the water volume at Shizhenjie was mainly affected by agriculture. Le'an River had serious organic matter pollution downstream before 2017, and mining and agricultural activities in the watershed had a high degree of impact on water quality. The treatment of mineral processing wastewater should be upgraded, and the discharge of pollutants from agriculture in the downstream of the watershed should be regulated.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 9","pages":"5235-5243"},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142355635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Spatiotemporal Variation Characteristics of Ozone and Identification of Key Influencing Factors Based on Random Forest Model： A Case Study of Chuzhou City].","authors":"Bo-da Xin, Lian-Hong Lü, Pei Wang, Wei Li, Lei Wang, Chun Zhou, Jing-Jing Dong, Si-Yi Wang","doi":"10.13227/j.hjkx.202310113","DOIUrl":"https://doi.org/10.13227/j.hjkx.202310113","url":null,"abstract":"<p><p>The cause of ozone pollution is a complex scientific problem. Studying the spatiotemporal variation characteristics of O₃ at different time scales and analyzing the key influencing factors of O₃ concentration is of great significance for the precise formulation of urban air pollution control measures and the improvement of urban air quality. Based on the analysis of the spatiotemporal variation characteristics of O₃ concentration in Chuzhou City, we studied the 12 ozone-influencing factors of meteorology and pollutants at multiple time scales using Spearman correlation analysis and a random forest model. The results showed that： ① The O₃ pollution level of Chuzhou City showed an aggravating trend, and the O₃ concentration distribution showed a spatial pattern of \"high in the southeast and low in the northwest.\" ② From February to May, SO₂ concentration had a strong impact on the increase in O₃ concentration. From June to September, PM_2.5 and PM₁₀ were significantly positively correlated with ozone and had a greater impact. ③ Relative humidity, temperature, and wind speed had a significant impact on O₃, whereas barometric pressure and hourly rainfall had a weak impact. ④ The O₃ pollution mechanism in Chuzhou City changed from \"pollutant-controlled\" to \"meteorology-controlled.\" ⑤ Among meteorological and pollutant factors, the three influencing factors that had the greatest influence on O₃ concentration were temperature, wind speed, and relative humidity, with PM₁₀ concentration, PM_2.5 concentration, and SO₂ concentration also contributing. All of the above six influencing factors had a significant nonlinear relationship with the O₃ concentration.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 9","pages":"5117-5126"},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142355702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}