环境科学最新文献

{"title":"[Hydrochemical Characteristics and Formation Mechanism of Typical River Wetlands in Xi'an Section at the Northern Foothills of Qinling Mountains].","authors":"Yong-Qi Zang, Pan-Pan Xu, Yan-Jun Shen, Hui Qian, Jian-Bing Peng","doi":"10.13227/j.hjkx.202501260","DOIUrl":"https://doi.org/10.13227/j.hjkx.202501260","url":null,"abstract":"<p><p>To investigate the hydrochemical characteristics and genesis mechanisms of typical river wetlands in the Xi'an section at the northern foothills of the Qinling Mountains, this study focused on three types of wetlands, including the bedrock mountain wetland(upper Heihe River wetland), the agricultural activity area wetland(lower Heihe River wetland), and the urban residential area wetland(Bahe Baqiao wetland). A total of 26 surface water samples were collected in January 2024 (dry season) and August 2024 (wet season). Piper trilinear diagrams, Gibbs diagrams, ion ratios, and principal component analysis were comprehensively used to clarify the distribution characteristics of major ions, further identify their sources, and reveal the formation mechanisms of surface water hydrochemistry. The results showed that the surface water in the study area was slightly alkaline. Compared with that during the dry season, the total dissolved solids (TDS) and the concentrations of major ions in the surface water of each wetland were lower during the wet season. The dominant cation was Ca²⁺, followed by Na⁺ or Mg²⁺. The dominant anion was HCO₃^-, while the remaining anions exhibited significant variability across different wetlands and periods. The hydrochemical types of the Heihe River wetlands were mainly HCO₃-Ca and HCO₃·SO₄-Ca, while the Bahe Baqiao wetland was dominated by HCO₃-Ca·Na. The hydrochemical characteristics of the upper Heihe River wetland were mainly controlled by the weathering of carbonate rocks and evaporite salts. The main controlling factors for the hydrochemical characteristics of the lower Heihe River wetland, from strongest to weakest, were carbonate rock weathering, agricultural fertilizer application, and evaporite salt weathering. The hydrochemical components of the Bahe Baqiao wetland were primarily controlled by rock weathering, followed by domestic sewage discharge, with evaporation having a stronger impact compared to the other two wetlands. The impact of agricultural non-point source activities and domestic sewage discharge in the plain area on the wetland water environment in Xi'an cannot be ignored, and it is also necessary to prevent pollutant inputs from human activities into the surface water of the bedrock mountain wetlands. These findings can provide scientific basis for improving wetland ecological environments and system restoration and further ensuring water safety of Xi'an as a \"dual-center\" city and the function of the Qinling Central Water Tower.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"47 3","pages":"1709-1721"},"PeriodicalIF":0.0,"publicationDate":"2026-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147460397","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":"[Impact Mechanism of Digital Economy on Carbon Emissions in the Construction Industry: A Case Study of Yangtze River Delta Urban Agglomeration].","authors":"Jin Huang, Lin-Yi Kuai, Hui An","doi":"10.13227/j.hjkx.202502152","DOIUrl":"https://doi.org/10.13227/j.hjkx.202502152","url":null,"abstract":"<p><p>Under the background of the continuous advancement of the digital Yangtze River Delta construction and the \"dual carbon\" goals, the digital economy, as a new driving force integrating digitalization and low-carbon development, helps the construction industry achieve green and low-carbon transformation and high-quality development by directly reducing carbon emissions and indirectly promoting green technological innovation. Based on the data of 41 cities in the Yangtze River Delta region from 2011 to 2022, this study analyzes the current situation and spatial-temporal characteristics of carbon emissions in the construction industry and further explores the impact and mechanism of digital economy and green technological innovation on carbon emission reduction in the construction industry by combining panel data regression models and mediation effect tests. The results showed that: ① From 2011 to 2022, although the carbon emissions from the construction industry in Yangtze River Delta cities increased in a low-amplitude wave pattern and spatial agglomeration weakened, the level of digital economy development in various provinces and cities has significantly improved, with an overall cumulative increase of nearly 1.3 times, among which Anhui had the fastest growth, and most cities had achieved positive growth. ② There was a significant positive correlation between the digital economy and carbon emission intensity, and this influence remained after robustness and endogeneity tests. The impact varied with urban resource endowments, with resource-based cities showing significant effects. ③ In the context of digital economy promoting the low-carbon development of the construction industry, green technological innovation played a positive mediating role. The research results are of great significance for formulating relevant policies of digital economy in the field of construction emission reduction and provide theoretical support for achieving the goal of green and low-carbon development.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"47 3","pages":"1463-1473"},"PeriodicalIF":0.0,"publicationDate":"2026-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147460442","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":"[Identification of Habitat Quality Sensitive Areas and Their Driving Mechanisms in Yunnan Province Based on Frequency-amplitude Sensitivity Analysis].","authors":"Zi-Yi Zhu, Shuang-Yun Peng, Zhi-Qiang Lin, Dong-Ling Ma, Shuang-Fu Shi, Yi-Lin Zhu, Bi-Ting Cui, Rong Jin","doi":"10.13227/j.hjkx.202502212","DOIUrl":"https://doi.org/10.13227/j.hjkx.202502212","url":null,"abstract":"<p><p>Accurate identification of habitat quality sensitive areas and analysis of their driving mechanisms is crucial for ecological protection and governance. Traditional methods for identifying sensitive areas primarily rely on static assessments, which fail to consider the dynamic characteristics of habitat quality and its full response to environmental changes. Therefore, this study used Yunnan Province as a case study, employing the InVEST model, Sen's slope estimator, and the Mann-Kendall trend test to evaluate habitat quality and its changing trends from 1990 to 2020. A novel frequency-amplitude sensitivity framework was constructed to identify sensitive areas, followed by an analysis of spatial differentiation characteristics and driving mechanisms using spatial autocorrelation and the optimal parameters-based geographical detector (OPGD). The results show that from 1990 to 2020, habitat quality was high in the southeast and northwest and low in the east and west of Yunnan Province, with an overall favorable condition. However, habitat quality has shown a significant degradation trend over the past 30 years, with degraded areas accounting for 12.91%, primarily concentrated in economically active regions in central Yunnan and around lakes. Additionally, 59.27% of Yunnan Province was identified as a habitat quality sensitivity area, with H-H clusters concentrated in the central, eastern, and western regions. Shifts in population distribution were identified as the dominant factor affecting habitat quality sensitivity. Moreover, the interaction between population distribution and DEM primarily determined the spatial distribution of habitat quality sensitivity in Yunnan Province. The new method proposed in this study provides an innovative approach for the dynamic assessment and early warning of regional habitat quality. The research findings offer a scientific basis for habitat protection and sustainable development in Yunnan Province and beyond.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"47 3","pages":"1819-1832"},"PeriodicalIF":0.0,"publicationDate":"2026-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147460445","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":"[Evolution Characteristics of Carbon Budgets and Pressure of Carbon Neutrality in Jiangsu Province].","authors":"Yong-Hua Liu, Xiao-Wei Chuai, Yu-Fei Liang, Hai-Dong Li, Jian-Bao Li, Yan Zhou, Jing Wu, Guo-Qiang Liu, Jia-Ling Zhang","doi":"10.13227/j.hjkx.202501153","DOIUrl":"https://doi.org/10.13227/j.hjkx.202501153","url":null,"abstract":"<p><p>To achieve the goal of carbon neutrality, it is necessary to comprehensively and accurately check the regional carbon budget and its evolution characteristics. Accordingly, taking Jiangsu Province as an example, this study constructed a carbon budget accounting system from the perspective of the \"natural-human\" binary structure. The major anthropogenic carbon emission items, carbon sources/sinks of the ecosystem, and the changes of the carbon storage in Jiangsu Province from 2000 to 2020 were calculated, and the pressure of carbon neutrality was evaluated entirely. The results showed that during 2000-2020, the anthropogenic carbon emissions in Jiangsu Province increased from 54.380 6 to 233.841 9 million tons. Carbon emissions associated with industrial energy consumption consistently dominated, accounting for 61% to 72% of total emissions. Emissions from industrial production processes represented the second-largest source, with a fluctuating upward trend in its proportion. Moreover, 11.25% of the land in Jiangsu Province was transferred, resulting in a reduction of ecosystem carbon storage by 2.638 9 million tons. Although the ecosystems functioned as a carbon sink overall, with an annual average carbon sequestration of 6.63 million tons, this capacity has shown fluctuations and a declining trend in recent years. As a whole, Jiangsu Province had high carbon emissions coupled with relatively low carbon sequestration capacity, with carbon sinks offsetting only approximately 4.17% of anthropogenic emissions during the study period, which demonstrates high pressure on realizing the goal of carbon neutrality.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"47 3","pages":"1513-1520"},"PeriodicalIF":0.0,"publicationDate":"2026-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147460437","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":"[Evaluation of the Comprehensive Benefits of Soil Improvement and Restoration Models in Typical Counties of Shandong Province].","authors":"Lin Yang, Yu-Hu Cui, Pan Yang, Xue-Shi Xie, Li Zhou, Wen-Tao Wu, Xi-Bai Zeng, Zhao-Hui Liu, Guang-Xue Wan","doi":"10.13227/j.hjkx.202502256","DOIUrl":"https://doi.org/10.13227/j.hjkx.202502256","url":null,"abstract":"<p><p>To explore the benefit of soil improvement and restoration models in typical counties of Shandong Province，we constructed a multi-dimensional system of \"soil condition-ecological environment-economic society\" comprehensive benefit evaluation index system and utilized the entropy-weighted TOPSIS comprehensive evaluation model，Kernel density estimation，coupling coordination model，and obstacle factor diagnostic model to fully analyze the comprehensive benefits of soil improvement and restoration model in typical counties of Shandong Province from 2019 to 2022. The results showed that：① The comprehensive benefit level of soil improvement and restoration model in typical counties showed a fluctuating upward trend，the gap between counties was narrowing，and there was a non-synchronization in the development of subsystems. ② The coupling coordination degree of soil improvement and restoration model in various counties showed a fluctuating increasing trend，which revealed a strong \"Matthew effect.\" ③ The influence of each system layer on the level of comprehensive benefits，in descending order，was the economic and social system，the soil condition system，and the ecological environment system，and the main obstacles were the use of agricultural plastic film，the use of agricultural fertilizers，the effective phosphorus of the soil，and the total power of agricultural machinery. The results of the study have important reference value for enhancing the comprehensive benefits of soil ecological remediation，promoting the safe utilization of contaminated arable land，and contributing to the guarantee of national food security.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"47 3","pages":"1905-1913"},"PeriodicalIF":0.0,"publicationDate":"2026-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147460461","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":"[A Comprehensive Comparative Analysis of Land Use Change Prediction Models Based on Land Types].","authors":"Song-Jie Qu, Ling Han, Liang-Zhi Li","doi":"10.13227/j.hjkx.202502015","DOIUrl":"https://doi.org/10.13227/j.hjkx.202502015","url":null,"abstract":"<p><p>Increasing human activities and climate change have intensified the shift of land use, and the construction of land use models has become a hot spot in the study of land use change. Taking Shaanxi Province as the study area, the prediction performances of four models, namely, CA-Markov, CLUES, FLUS, and PLUS, were comprehensively compared, and the contribution of driving factors was analyzed by combining the LightGBM model. The model accuracy was verified based on the land use data from 2017 to 2022 to explore the applicability and differences of different models in predicting land use changes. The results show that: ① From 2017 to 2022, the areas of forest land, cultivated land, and construction land in Shaanxi Province increased, while the area of grassland decreased significantly by 4 085.63 km². ② The LightGBM model verified the high explanatory power of driving factors on land use patterns and showed that natural factors dominated the distribution of ecological land (forest land, grassland, and water), while socio-economic factors significantly affected the changes in construction land. ③ The OA of CA-Markov, CLUES, FLUS, and PLUS were 0.90, 0.92, 0.92, and 0.93, respectively, and the Kappa coefficients were 0.86, 0.88, 0.88, and 0.90, respectively. The prediction accuracy of PLUS was higher, and the prediction performance of PLUS in the main land types was relatively accurate. The total deviation of FLUS in different land types was the smallest, followed by the PLUS model. ④ For the spatial distribution results, CA-Markov had a single model, but its operation was the most convenient. The patch distribution of CLUES was relatively clustered, and the patches predicted by the FLUS model were distributed in patches. The expansion pattern was closer to the actual situation. The patch distribution in the PLUS result was the most dispersed and fragmented. Different models had different usage conditions and parameter requirements, and the setting of driving factors may also have affected the prediction effect. This study can provide important methodological support and data reference for land use change prediction and provide a scientific basis for future spatial optimization management and sustainable development planning.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"47 3","pages":"1792-1804"},"PeriodicalIF":0.0,"publicationDate":"2026-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147460570","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 Distribution and Source Apportionment of Soil Heavy Metals Around a Typical Industrial Park in Central South China].","authors":"Zong-de Jiang, Ming-Song Zhao, Yun-Jin Wu, Jian Wang, Min Yang","doi":"10.13227/j.hjkx.202502019","DOIUrl":"https://doi.org/10.13227/j.hjkx.202502019","url":null,"abstract":"<p><p>A total of 242 sampling points were established around a typical industrial park in central-southern China, where 726 soil samples were collected from three depths. The contents of Cd, Pb, Zn, As, and Ni were measured, followed by spatial distribution pattern mapping and potential pollution zoning using sequential Gaussian simulation. Source apportionment was quantitatively analyzed through positive matrix factorization. The results indicated that surface layer contents of Cd, Zn, Pb, and As were significantly higher than those in the lower layers, with high-value areas concentrated in the southern and eastern parts of the study area. In contrast, Ni exhibited similar concentrations across all three depths, showing predominantly high values in northern and western regions. Pollution zoning revealed high-risk areas predominantly in southern and eastern sectors, where Cd demonstrated the highest contamination risk. Notably, the probability of Cd exceeding the regulatory threshold for soil pollution risk in agricultural land exceeded 95% across 80.45% of the total study area. Source apportionment showed that industrial activities and transportation collectively contributed 87.86%, 76.47%, and 68.68% to Cd, Zn, and Pb pollution, respectively. Agricultural practices involving irrigation and agrochemical application accounted for 69.23% of As contamination, while natural sources dominated Ni inputs with an 85.62% contribution.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"47 3","pages":"1986-1994"},"PeriodicalIF":0.0,"publicationDate":"2026-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147460299","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":"[Systemic Characterization of Phosphorous in the Sediments of Retired Aquaculture Lakes in the Yangtze River Basin].","authors":"Zhao-Nan Du, Qing-Feng Xu, Wan-Yu Feng, Yong-Hui Han, Lu-Lu Zhang, Wen-Zhong Tang, Hong Zhang","doi":"10.13227/j.hjkx.202501275","DOIUrl":"https://doi.org/10.13227/j.hjkx.202501275","url":null,"abstract":"<p><p>The study of phosphorus release from sediments in retired aquaculture lakes is a crucial aspect of phosphorus management in the Yangtze River Basin. In this research, Qinglan Lake(a retired aquaculture lake within the Poyang Lake area of the Yangtze River Basin)was selected as the study site. By analyzing the physicochemical properties, phosphorus speciation, and the composition of organophosphorus compounds in both surface and core sediment samples, this study investigates the occurrence characteristics of phosphorus in sediments from degraded lakes and assesses its impact on the overlying water quality.The results indicated that the average total phosphorus (TP) content in the surface sediments was 797.67 mg·kg^-1, exceeding the ecological risk threshold of 600 mg·kg^-1, which is associated with the lowest level of sediment-induced ecological risk. Inorganic phosphorus was the dominant phosphorus form in surface sediments, accounting for 89.15% of the total phosphorus. Among these, calcium-bound phosphorus (Ca-P) represented the largest fraction at 30.91%. Monoester phosphorus (Mono-P) was the predominant organic phosphorus fraction in surface sediments, constituting between 7.57% and 42.88% of the TP extracted by NaOH-EDTA. Aluminum-bound phosphorus (Al-P) was identified as the primary source of bioavailable phosphorus (BAP) in surface sediments, with some areas exhibiting mild to moderate pollution levels.Furthermore, using the diffusive gradients in thin films (DGT) technique, the sediment was confirmed as a significant source of endogenous phosphorus pollution in the lake, releasing approximately 313.50 kg annually. These findings provide valuable data and a scientific foundation for phosphorus pollution control in retired aquaculture lakes within the Yangtze River Basin.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"47 3","pages":"1688-1698"},"PeriodicalIF":0.0,"publicationDate":"2026-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147460480","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":"[Levels and Influencing Factors of the County's Agricultural Net Carbon Sink in Jiangsu Coastal].","authors":"Ming-Dong Jiang, Rong Yan, Xiao-Mei Shen, Xin-Xin Yu, Ze-Peng Wu","doi":"10.13227/j.hjkx.202502093","DOIUrl":"https://doi.org/10.13227/j.hjkx.202502093","url":null,"abstract":"<p><p>Emission reduction and remittance enhancement in the agricultural sector are crucial to achieving the dual-carbon goal. Taking the Jiangsu Coastal Economic Belt (JCEB) as the research object, the carbon emission coefficient method and the parameter estimation method are adopted to measure the total carbon emission, carbon sink, and net carbon sink (NCS) of the 20 districts and counties from 2005 to 2023 in JCEB. On this basis, the study further analyzes spatial-temporal characteristics and dynamic evolution trends. The spatio-temporal geographically weighted regression model (GTWR) is used to explore the spatio-temporal heterogeneity and evolutionary pattern of each influencing factor. The results showed that: ① The agricultural NCS (measured by C) in JCEB decreased from 3.12×10⁶ t in 2005 to 1.32×10⁶ t in 2023, showing an overall trend of fluctuating decline. Spatially, the total NCS showed a distribution pattern of \"high in the center and low in the north and south, \" with most areas being low-carbon surplus areas. ② Among the influencing factors, the intensity of financial support for agriculture (FSA), the grain to economy crop ratio (GER), and agricultural development levels (ADL) had positive driving effects on the agricultural NCS. The positive effects of the first two factors continued to strengthen, while the contribution of the latter showed a \"U\"-shaped change trend. Fertilizer application intensity (FAI), agricultural machinery use intensity (AMI), and rural residents' income level (RRI) generally inhibited the growth of the agricultural NCS. The inhibitory effects of the first two factors were declining, while the negative effect of the latter decreased with economic growth. ③ The impact direction and intensity of each driving factor on the agricultural NCS in different counties showed significant differences. The impact effects of FSA and FAI were distinctly different in the north and south. The impact effects of GER and ADL showed agglomeration characteristics at the municipal level. In contrast, the influence intensity of AMI and RRI on the agricultural NCS presented an overall pattern of interlaced distribution in the north and south.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"47 3","pages":"1532-1543"},"PeriodicalIF":0.0,"publicationDate":"2026-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147459809","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":"[Calculation and Spatial Characteristics of Dilution Factors Across the Yellow River Basin].","authors":"An-Ran Liao, Zhuo Chen, Yin-Hu Wu, Yun Lu, Dong-Bin Wei, Ying-Cai Tang, Hua-Nan Gao, Zi-Tong Liao, Hong-Ying Hu","doi":"10.13227/j.hjkx.202411146","DOIUrl":"https://doi.org/10.13227/j.hjkx.202411146","url":null,"abstract":"&lt;p&gt;&lt;p&gt;The dilution factor (DF) quantifies the extent to which wastewater is diluted after being discharged into a receiving water body. It serves as a critical indicator for establishing effluent discharge standards and assessing aquatic ecological risks. Although extensive research has been conducted on river DF, limited attention has been paid to the rationality of DF calculation methods. Typically, the accumulated wastewater volume (AWV) within a catchment-rather than the wastewater volume in the nearby receiving river-is commonly used for DF calculation. During this process, the delineation of the sub-catchment plays a critical role in determining AWV. However, the impact of sub-catchment delineation on DF calculation remains unclear. This study utilizes a comprehensive dataset comprising streamflow records from 235 hydrological stations, effluent discharge data from 544 municipal wastewater treatment plants (WWTPs), and sub-catchment information within the Yellow River Basin to examine the influence of sub-catchment delineation on DF. The results revealed that when the sub-catchment area was less than 3 000 m&lt;sup&gt;2&lt;/sup&gt;, there was no significant correlation between DF and streamflow. However, this correlation became pronounced when the sub-catchment area ranged between 3 000 and 5 000 m&lt;sup&gt;2&lt;/sup&gt;. This trend may have primarily resulted from the higher spatial heterogeneity in the distribution of WWTP within smaller sub-catchments compared to that within larger ones. Such heterogeneity led to greater variability in AWV and consequently in the DF. As the sub-catchment area increased, the spatial geographic elements such as number of WWTPs became more spatially homogenized, and the spatial distribution of geographic elements such as WWTPs became more homogeneous, resulting in more stable AWV estimates. This spatial averaging effect highlights the correlation between DF and streamflow in larger sub-catchments. When sub-catchment boundaries were not defined, and wastewater discharge was assumed to flow throughout the entire river network in the Yellow River Basin, the resulting DF was significantly underestimated. Using such underestimated DF values as basis for regulatory decision-making may lead to overly stringent effluent discharge standards that do not reflect actual environmental capacity. Therefore, accurate delineation of sub-catchment boundaries is essential. It is recommended that pollutant transport models be used in combination with observed pollutant concentration data in the river to determine an appropriate sub-catchment boundary. Based on DF results that incorporated sub-catchment boundaries, the median DF values were 6 358.8 for the main stream and 28.5, 21.5, and 5.1 for third-, fourth-, and fifth-order tributaries, respectively. Additionally, the median DF values for rivers in the upper, middle, and lower reaches of catchment were 1 346.5, 9.3, and 48, respectively. Notably, temporal variation in DF was much smaller than spa","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"47 3","pages":"1665-1674"},"PeriodicalIF":0.0,"publicationDate":"2026-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147460191","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}