Miyun District Research Articles

Simulation and Management Impact Evaluation of Debris Flow in Dashiling Gully Based on FLO-2D Modeling

Dashiling Gully, located in Miyun District, Beijing, exhibits a high susceptibility to debris flow due to its unique geological and topographical characteristics. The area is characterized by well-developed rock joints and fissures, intense weathering, a steep gradient, and a constricted gully morphology. These factors contribute to the accumulation of surface water and loose sediment, significantly increasing the risk of debris flow events. Following a comprehensive field geological investigation of Dashiling Gully, key parameters for simulation were obtained, including fluid weight, volume concentration, and rainfall. The formation and development conditions of potential mudslides were analyzed, and numerical simulations were conducted using FLO-2D software (version 2009) to assess scenarios with rainfall probabilities of 1 in 30, 50, and 100 years. The simulations accurately reconstructed the movement velocity, deposition depth, and other critical movement characteristics of mudslides under each rainfall scenario. Using ArcGIS, pre- and post-treatment hazard zoning maps were generated for Dashiling Gully. Furthermore, the efficacy of implementing a retaining wall as a mitigation measure was evaluated through additional numerical simulations. The results indicated that mudslide velocities ranged from 0 to 3 m/s, with deposition depths primarily between 0 and 3 m. The maximum recorded velocity reached 3.5 m/s, corresponding to a peak deposition depth of 4.31 m. Following the implementation of the retaining wall, the maximum deposition depth significantly decreased to 1.9 m, and high-risk zones were eliminated, demonstrating the intervention’s effectiveness. This study provides a rigorous evaluation of mudslide movement characteristics and the impact of mitigation measures within Dashiling Gully. The findings offer valuable insights and serve as a reference for forecasting and mitigating similar mudslide events triggered by heavy rainfall in gully mudslides.

Comparative Analysis of Campground Development in China and the United States: A Grounded Theory Approach

In a global context where camping is increasingly recognized as a key leisure activity, this study examines the development discrepancies of campgrounds between countries, focusing on China and the United States. Employing Grounded Theory, it analyzes a natural resort in Beijing's Miyun district, identifying and categorizing 48 dimensions such as infrastructure, economic factors, management, environment, culture, and policy. These dimensions are then refined into three primary themes: development process, gap analysis, and optimization strategies. The study provides a detailed comparative analysis of these campgrounds across six key aspects, ultimately offering strategic recommendations for enhancing Chinese campground development. These recommendations focus on industrial growth, spatial planning, and operational improvements, contributing academic insights to the field of global leisure and campground development.

A follow-up study on the pain changes trend and effects in patients diagnosed with herpes zoster in Beijing City

Objective: To understand the changes in pain and its effects in patients with the diagnosis of herpes zoster. Methods: A total of 3 487 patients diagnosed with herpes zoster (HZ) for the first time at the outpatient department of Miyun District Hospital from January 1, 2017, to December 31, 2019, were included in the study. The information of patients was registered and issued with a record card. Patients were required to record the time of pain and rash by themselves. Telephone follow-up was conducted at 21, 90, 180 and 365 days after the onset of rashes, including hospitalization, location of rash and pain, and the time of start and end. The impact of pain on life was evaluated by the Zoster Brief Pain Inventory (ZBPI). Results: The age of 2 999 HZ patients included in the analysis were (53±16) years old, including 1 377 (45.91%) males and 1 903 (63.45%) patients aged 50 years and older. After 21 days of rash, mild, moderate and severe pain accounted for 20.87% (626 cases), 37.98% (1 139 cases) and 33.81% (1 014 cases), respectively. Only 5.07% (152 cases) had no pain or discomfort, and 2.27% (68 cases) had no pain but discomfort. Most of the pain sites were consistent with the rash sites. The chest and back and waist and abdomen were the most common, accounting for 35.58% (1 067 cases) and 29.18% (875 cases), respectively, followed by the limbs and face and neck, accounting for 16.74% (502 cases) and 16.40% (492 cases), respectively. The M (Q1, Q3) of pain days in the HZ patients was 14 (8, 20) days, and the incidence of post-herpetic neuralgia (PHN) was 6.63% (171/2 580) (excluding 419 patients who refused to visit or lost to visit on 90 days after the onset of rash). The pain score of HZ patients within 21 days after the rash was (5.19±2.73) points, and the pain score of PHN patients was (7.61±2.13) points, which was significantly higher than that of non-PHN patients [(5.04±2.69) points] (P<0.001). Daily activities, emotions, walking ability, work, social interaction, sleep and recreation were affected for 21 days after the rash in HZ patients, ranging from 60.79% to 83.83%, with sleep being the most affected (83.83%). The impact scores of pain and life dimensions in PHN patients ranged from 4.59 to 7.61 points on the ZBPI scale, which were higher than those in non-PHN patients (2.49-5.04) (t values ranged from 8.86 to 11.67, all P values <0.001). Conclusion: The proportion of pain in HZ patients after the diagnosis is high, and the pain is more obvious in patients with PHN and HZ patients aged 50 and older, which has a greater impact on their daily lives.

Impact of herpes zoster and post-herpetic neuralgia on health-related quality of life in Miyun District of Beijing, China: An EQ-5D survey

BackgroundHerpes zoster (HZ) and post-herpetic neuralgia (PHN) cause considerable morbidity, especially in elderly adults, but the burden is under-recognized in mainland China. MethodsWe conducted a case registry and follow-up study of HZ in Miyun District, Beijing from January 1, 2017 through December 31, 2018. Registered HZ cases were followed-up for pain to 365 days. The first 50 patients with HZ in each age group (≤14, 15–29, 30–39, 40–49, 50–59, 60– 69, 70–79, ≥80 years) and all those with PHN completed the EuroQoL five dimensions questionnaire (EQ-5D) to evaluate health-related quality of life (HRQoL) in patients with HZ and PHN. Ratings using the EQ-5D dimensions, visual analogue scale (VAS), health utility score (HUS) and quality-adjusted life years (QALYs) lost were compared among age groups. ResultsIn total, 2008 patients with HZ were followed for a median 22 days (interquartile range[IQR] = 20–90), with an estimated incidence of 4.39 per 1000 person-years. We identified 122 (6.08 %) PHN cases. The median age of patients with PHN (65 years, IQR = 55–71) was older than that of patients with HZ (54 years, IQR = 43–64) (P < 0.001). The median duration of pain was 170 days (IQR = 144–355.5) for PHN and 15 days (IQR = 9–25) for HZ. All 95 patients with PHN and 319 sampled patients with HZ completed the EQ-5D survey. The median QALY loss of HZ increased from 0.004 (IQR = 0.001–0.02) in patients 50–59 years old to 0.02 (IQR = 0.01–0.06) in those ≥ 80 years old (P < 0.01). After weighting for age, the mean QALY loss per HZ case was estimated at 0.02 (standard deviation [SD] 0.04). The mean QALY loss per PHN case was 0.13 years (SD 0.12). ConclusionsHZ and PHN caused a substantial burden, especially among adults aged ≥ 50 years in Miyun District, Beijing, China. Vaccination should be considered to alleviate the burden of this painful disease.

Estimation of Agricultural Greenhouse Gas Emissions and Emission Reduction Potential of Beijing During the 14th Five-Year Plan Period Under the Background of "Carbon Peak and Neutrality"

To achieve the goal of "carbon peak and neutrality," the strict requirements for greenhouse gas (GHG) emissions control in the agricultural sector were recommended in relevant plans for Beijing during the 14th Five-Year Plan period. Through collecting agricultural activity data and calculating and screening the emission factors, the amount and emission characteristics of agricultural GHG emissions in Beijing in 2020 were estimated and set as the baseline condition. On this basis, the GHG emissions in 2025 with optimized measurements implemented, which were selected in combination with the natural conditions and planting-breeding mode of Beijing, were set as the reduction condition. The emission reduction potential and its distribution during the 14th Five-Year Plan Period were predicted simultaneously. Meanwhile, the reduction effects on the GHG emissions of optimized measurements were evaluated. In addition, relevant policy recommendations on GHG reduction were proposed accordingly. The results revealed that the total agricultural GHG emissions in Beijing were estimated to be 456000 t (CO2-eq) in 2020, primarily from sources of animal intestinal fermentation and manure management, with contribution rates of 50.7% and 26.7%, respectively. Spatially, it was mainly distributed in districts with large livestock and poultry breeding scales, such as Shunyi District, Miyun District, and Yanqing District, etc. It was predicted that in 2025, the total agricultural GHG emissions would be 349000 t (CO2-eq), and the emission reduction potential in the 14th Five-Year Plan period would be 107000 t (CO2-eq). Animal intestinal fermentation would be the emission source with the largest reduction potential (60000 tons, CO2-eq), followed by the emission source of animal manure management (37000 tons, CO2-eq). Adjusting fodder composition and optimizing manure management were analyzed to be the most effective optimized measurements for agricultural GHG emission reduction. Moreover, the emission reduction potential of CH4 would be greater than that of N2O. The emission reduction potential would be mainly distributed in Miyun District, Shunyi District, Yanqing District, Fangshan District, Tongzhou District, and other suburbs with large livestock and poultry breeding scales, accounting for more than 10% of the total emission reduction potential for each. These regions with large emission reduction potential should be prioritized and then the assessments should be extended to the whole city. The measurements were recommended as follows:① the research and promotion of technologies such as fodder optimization and the efficient treatment of manure should be strengthened, ② the scope of the combination of planting and breeding model should be expanded to promote the development of circular agriculture, and ③ relevant standards, guidelines, and specifications for green and low-carbon agriculture should be formulated, and the regulatory and policy system for synergy reduction of agricultural pollution and GHG should be developed.

Analysis of big data characteristics of allergic rhinitis patients in Beijing City from 2016 to 2021

To explore the characteristics of big data of patients with allergic rhinitis, including the time, population and spatial distribution of allergic rhinitis in Beijing from 2016 to 2021, so as to provide reference for the prevention and treatment of this disease. Descriptive epidemiological methods were used to analyze the distribution (including gender, age and location)and trend of allergic rhinitis patients in 30 pilot hospitals from January 2016 to December 2021, T test and Kruskal-Wallis rank sum test were used to test the statistical differences. The results showed that the number of patients with allergic rhinitis in 30 hospitals increased year by year from 2016 to 2019, with an increase of 97.9%. In 2020, the number of patients decreased. In 2021, the number of visits returned to the pre-epidemic level (461 332); The number of patients with allergic rhinitis was the highest in September, with a seasonal index of 177.6%, while the lowest number was in February, accounting for only 47.2%; a significant difference was observed in the number of patients in different age groups(H=45 319.48, P<0.05), and patients under 15 years old accounted for the highest proportion(819 284 visits); There were significant differences between patients of different genders in the 45-59 year old group (t=-4.26, P<0.05).There were relatively more patients with allergic rhinitis in Dongcheng District(31.1%) than in Huairou District and Miyun District (0.4%). In conclusion, since 2016, the number of patients increased significantly, with a varied trend in different seasons. Most patients were children. There were more patients in the central urban area than in the outer suburbs.

Genotyping Characteristics of Human Fecal Escherichia coli and Their Association with Multidrug Resistance in Miyun District, Beijing

ObjectiveTo explore the genotyping characteristics of human fecal Escherichia coli (E. coli) and the relationships between antibiotic resistance genes (ARGs) and multidrug resistance (MDR) of E. coli in Miyun District, Beijing, an area with high incidence of infectious diarrheal cases but no related data. MethodsOver a period of 3 years, 94 E. coli strains were isolated from fecal samples collected from Miyun District Hospital, a surveillance hospital of the National Pathogen Identification Network. The antibiotic susceptibility of the isolates was determined by the broth microdilution method. ARGs, multilocus sequence typing (MLST), and polymorphism trees were analyzed using whole-genome sequencing data (WGS). ResultsThis study revealed that 68.09% of the isolates had MDR, prevalent and distributed in different clades, with a relatively high rate and low pathogenicity. There was no difference in MDR between the diarrheal (49/70) and healthy groups (15/24). ConclusionWe developed a random forest (RF) prediction model of TEM.1 + baeR + mphA + mphB + QnrS1 + AAC.3-IId to identify MDR status, highlighting its potential for early resistance identification. The causes of MDR are likely mobile units transmitting the ARGs. In the future, we will continue to strengthen the monitoring of ARGs and MDR, and increase the number of strains to further verify the accuracy of the MDR markers.

Multi-hazard risk assessment of the Great Wall relics: a case study in the Miyun District, Beijing

Multi-hazard risk assessment of the Great Wall relics: a case study in the Miyun District, Beijing

A spatio-temporal prediction model theory based on deep learning to evaluate the ecological changes of the largest reservoir in North China from 1985 to 2021

Miyun Reservoir, located in the Miyun District, Beijing, China, is the largest comprehensive water conservancy project and is an important ecological protection area in the North China region. Changes within the basin are the driving factors affecting the ecosystem in the watershed; therefore, it is important to analyze the changes in the ecological environment of Miyun Reservoir. For the analysis of a long time series of image data remotely sensed by satellite, the outliers caused by atmospheric, lighting, and sensor measurement errors are significant, and it is difficult for traditional algorithms to effectively recover the true image value. To address this, this paper proposes a theoretical model for predicting spatio-temporal variation based on deep learning to identify and correct invalid and anomalous values in extended time series data. This study corrected and analyzed the results of Remote Sensing based Ecological Index inversion of Landsat data of the Miyun Reservoir watershed from 1985 to 2021. The findings and conclusions of this study are important for the analysis of long time series image data from satellite remote sensing and for improving regional ecological evaluation and sustainable development planning.

Dynamic monitoring of the largest reservoir in North China based on multi-source satellite remote sensing from 2013 to 2022: Water area, water level, water storage and water quality

The Miyun Reservoir, located in the Miyun District of Beijing, China, is the largest comprehensive water conservancy project in northern China and an important ecological protection area. The combined effects of many factors produce ecosystem changes in the basin; thus, it is important to analyze the spatial and temporal changes that occur here. Based on multi-source satellite remote sensing data, we analyzed changes in water body area, water level height, and water storage in the Miyun Reservoir from 2013 to 2022 and determined whether these changes were natural or caused by human activity. As traditional water body area extraction methods can misidentify buildings and mountainous areas as water bodies, we fused multiple deep learning models (U-Net and SegNet) using the adboost method, which combined the advantages of the basic models and achieved an overall recognition accuracy of > 90 %. Using annual variations in water storage at the reservoir, we determined that the water body area increased to 157.58 km2 between 2013 and 2022, nearly doubling in size, which corresponded to decreases in cultivated land and vegetated areas. Cultivated land is the main land use type affected by water body erosion. The overall water level height exhibited an upward trend (cumulative increase of 14.8 %), eventually reaching 146.11 m. The water storage volume also increased over time, with a cumulative increase of approximately 436 million m3. On this basis, the influences of temperature, precipitation, and human activity on the spatial and temporal variability of the Miyun Reservoir basin were analyzed. The findings have important implications for global change research within and outside the ecosystem.

Plasma Levels of Vitamin A in Early Pregnancy and Correlationship with Hypertensive Disorder.

Objective. Analyzing the vitamin A content in early pregnancy and finding out the relationship between the serum levels of vitamin A of pregnant women and hypertensive disorder. Method. A total of 4,188 pregnant women who had took part in vitamin A testing in Miyun District Hospital from November 2016 to March 2020 were collected. The serum levels of vitamin A were determined by high performance liquid chromatography, and clinical and testing data were collected for statistical analysis. The original data outcome was finally analyzed with the SPSS. Results. 266 Hypertensive disorder cases and 2836 normal pregnancy cases were analyzed with 27 cases of twin pregnancy, 315 cases without follow-up and 744 of diabetic pregnancies excluded. The 266 women were divided into four groups: 110 women were diagnosed gestational hypertension, 65 women were diagnosed preeclampsia, 78 women were diagnosed pregnancy with chronic hypertension, and 13 women were diagnosed chronic hypertension with preeclampsia. The results shows that vitamin A level of the hypertensive group was 0.46(±0.08) mg/L, 0.47 (±0.012) mg/L, 0.47 (±0.09) mg/L, and 0.52 (±0.012) mg/L, respectively, while the level of normal group was 0.44 (±0.09) mg/L. We found that there were differences between the normal pregnant group and the preeclampsia group with statistical significance (P < 0.05). The difference between the pregnancy with chronic hypertension group and the normal group was statistically significant (P < 0.05). The difference between the chronic hypertension with preeclampsia group and the normal group was also statistically significant (P < 0.05). Conclusion. Serum levels of vitamin A in early pregnant women have a certain correlation with the hypertensive disorder.

Spatio-Temporal Variation and Influencing Factors of Ozone Pollution in Beijing

The temporal and spatial distribution and variation characteristics of ozone (O3) in Beijing, China, are investigated using hourly monitoring data from 2020. Kriging interpolation analysis and correlation analysis are applied to describe the spatial-temporal distribution and to identify associated influencing factors. The average concentration of O3 was found to be 59.58 μg·m−3. The daily maximum sliding 8 h average ozone concentration values exceeded the primary standard (100 μg·m−3) for 129 days and exceeded the secondary standard (160 μg·m−3) for 48 days. Temporally, the general pattern of daily maximum 8 h average O3 concentration was high in spring and summer and low in autumn and winter. Monthly average values showed a maximum in June. The highest daily concentrations appeared between 13:00 and 18:00 local time, and O3 concentrations had a distinct weekly pattern of variability with daily average concentrations at weekends higher than those during working days. Spatially, annual average O3 concentrations were highest in the northeast and lowest in the southeast of the city, and the seasonal variation of O3 was most significant in the southwest of the city. In relation to city districts and counties, the annual average O3 concentrations in the Miyun District were the highest, while those in the Haidian District were the lowest. On the whole, annual average O3 concentrations in Beijing were higher in the suburbs than in central areas. Based on daily average values, there was no significant correlation between O3 concentrations and rainfall (p &gt; 0.05), but there were significant correlations between O3 concentration and sunshine hours, wind speed, maximum temperature and minimum temperature (p &lt; 0.05), with correlation coefficients of 0.158, 0.267, 0.724 and 0.703, respectively. O3 concentrations increased with an increasing number of sunshine hours, first increased and then decreased with increasing wind speed and increased with increasing temperature. O3 concentrations were correlated with SO2 concentrations (0.05 &lt; p &gt; 0.001), CO concentrations (p &lt; 0.001) and NO2 concentrations (p &lt; 0.001), the latter having the highest correlation coefficient of −0.553 and exhibiting opposite trends in daily and monthly variations to O3 variations. Analysis of ozone pollution sources showed that automobile exhaust, coal and oil combustion and volatile organic compounds released by industrial plants were the main sources. Terrain affected the distribution of ozone, as well as human activities and industry.

基于动物适宜栖息地的北京市自然保护地保护成效评估

PDF HTML阅读 XML下载 导出引用 引用提醒 基于动物适宜栖息地的北京市自然保护地保护成效评估 DOI: 10.5846/stxb202109022475 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31872240）；国家林业和草原局项目（2021080323-1）；北京绿色生态空间保护空缺分析项目（2021XJL02） Assess the conservation effectiveness of the natural protected areas in Beijing based on the suitable habitat of wild animals Author: Affiliation: Fund Project: The National Natural Science Foundation of China (General Program, Key Program, Major Research Plan) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:栖息地是野生动物赖以生存的基础，明晰物种的适宜栖息地分布是切实加强野生动物保护、提高生物多样性保护成效的重要基础。北京市野生动植物资源丰富，也建立了一系列自然保护地以加强对野生动物的保护。当前亟需系统评估北京市现有自然保护地体系对野生动物适宜栖息地的保护成效，为未来北京市野生动物保护管理和自然保护地体系整合工作优化提供科学指导。研究选取了北京地区6个较为典型的野生动物为主要研究对象，包括黑鹳（Ciconia nigra）、褐马鸡（Crossoption mantchuricum）、大鸨（Otis tarda）、鸳鸯（Aix galericulata）、金雕（Aquila chrysaetos）和斑羚（Naemorhedus griseus），利用MaxEnt模型和ArcGIS的空间分析功能分析其适宜栖息地的分布；将自然保护地与适宜栖息地相叠加，识别其适宜栖息地的分布热点和保护空缺，进而评估了北京市现有自然保护地体系的保护成效。研究结果表明，6个研究物种在现有的自然保护地体系中均得到了不同程度的保护，其中褐马鸡的受保护率最高（92.82%），鸳鸯的受保护率最低（13.66%）。各类自然保护地的物种热点区覆盖率不同，风景名胜区类型覆盖率最高（14.74%）。6个物种适宜栖息地的热点区域总面积为280.01km2，保护空缺占热点区域总面积的49.45%，其中密云区、门头沟区和房山区的保护空缺面积最大。基于现有自然保护地体系对野生动物适宜栖息地的保护效率以及存在的空缺，建议因地制宜，采取扩大或合并现有自然保护地、增设新的自然保护地或营造微生境等方式来提升自然保护地的整体保护效率。研究结果可为北京市自然保护地的整合优化提供重要依据，为野生动物重要栖息地的识别与划定提供可行方案，并为加强野生动物的保护管理提供科学指导。 Abstract:Habitats are essential for the survival of wild animals, and clarifying the distribution of a species' suitable habitat can be helpful to strengthen wildlife conservation and to increase the conservation effectiveness for biodiversity. As the capital of China, Beijing holds abundant wild animals and the government has established different types of natural protected areas to provide the refuge for the wildlife. Nowadays, it is urgent to assess the effectiveness of these natural protected areas on the protection of habitats of the wild animals, which will provide scientific guidance to wildlife conservation management and integration of natural protected areas in Beijing. Based on the relative importance and the availability of the distribution data, we selected 6 typical wild animals in Beijing, i.e., Black stork (Ciconia nigra), Brown eared-pheasant (Crossoption mantchuricum), Great bustard (Otis tarda), Mandarin duck (Aix galericulata), Golden eagle (Aquila chrysaetos) and Chinese goral (Naemorhedus griseus), and collected the distribution data of these species through field investigations, open databases and literature. We then analyzed the suitable habitats using the MaxEnt model and spatial analysis function of ArcGIS. We also identified the hotspots and GAPs (GAP analysis) of these species' suitable habitats in Beijing. The results indicated that the natural protected areas covered various proportions of these animals' suitable habitats with a range from 13.66% (Mandarin duck) to 92.82% (Brown-eared pheasant). The total area of the suitable habitat hotspots was 280.01 km2, and mainly distributed in Miyun District, Yanqing District, Mentougou District and Fangshan District. However, the coverage of species hotspots differed among different natural protected areas, with it being highest in scenic spots (14.74%). The GAPs were responsible for 49.45% of the hotspots and mainly distributed in Miyun District, Mentougou District, Fangshan District, and the border of Miyun, Huairou and Yanqing. In particular, Miyun District, Mentougou District and Fangshan District held the largest areas of GAPs. Based on the distribution of the suitable habitats and the protection gaps, it is suggested to take suitable measures to improve the conservation effectiveness of the natural protected areas according to the local circumstances, and adopt different protection strategies for different protection objects, including expanding or merging some natural protected areas, establishing new natural protected areas, and creating micro-habitats. Our study provides feasible solutions for the identification and delineation of important wildlife habitats in Beijing, provides some scientific guidelines for the wildlife management and integration and optimization of the natural protected area system. 参考文献 相似文献 引证文献

Analysis of Pregnancy Testing Index Results in Miyun District, Beijing from 2017 to 2021

Analysis of Pregnancy Testing Index Results in Miyun District, Beijing from 2017 to 2021

Spatial accessibility of fever clinics for multi-tiered prevention and control on COVID-19 in Beijing

Objective To simulate the different prevalence of corona virus disease 2019 (COVID-19) in Beijing as the spreading and the outbreak city and analyze the response capacity of its medical resources of fever clinics, and to provide a scientific basis for optimizing the spatial layout in Beijing under severe epidemics. Methods The study obtained epidemiological indicators for COVID-19, factors about medical resources and population movement as parameters for the SEIR model and utilized the model to predict the maximum number of infections on a single day at different control levels in Beijing, simulated as an epidemic spreading city and an epidemic outbreak city respectively. The modified two-step floating catchment area method under ArcGIS 10.6 environment was used to analyze spatial accessibility to fever clinics services for the patients in Beijing. Results According to the results of the SEIR model, the highest number of infections in a single day in Beijing simulated as an epidemic spreading city at low, medium and high levels of prevention and control were 8 514, 183, and 68 cases, the highest number of infections in a single day in Beijing simulated as an outbreak city was 22 803, 10 868 and 3 725 cases, respectively. The following result showed that Beijing was simulated as an epidemic spreading city: among the 585 communities in Beijing, under the low level of prevention and control, there were 17 communities (2.91%) with excellent accessibility to fever clinics, and that of 41 communities (7.01%) with fever clinics was good. Spatial accessibility of fever clinics in 56 communities (9.57%) was ranked average, and 62 communities' (10.60%) accessibility was fair and 409 communities (69.91%) had poor accessibility; at the medium level of prevention and control, only the west region of Fangshan District and Mentougou District, the north region of Yanqing District, Huairou District and Miyun District had poor accessibility; under the high level of prevention and control, 559 communities' (95.56%) had excellent accessibility. The accessibility in 24 communities (4.10%) was good and in 2 communities (0.34%) was average. In brief, the existing fever clinics could meet the common demand. Beijing was simulated as an outbreak city: under the low level of prevention and control, only 1 community (0.17%) had excellent accessibility to fever clinics, and 5 communities (0.86%) had good accessibility. The accessibility of fever clinics in 10 communities (1.71%) was average and in 12 communities (2.05%) was fair. The accessibility of fever clinics in 557 communities (95.21%), nearly all areas of Beijing, was poor; under the middle and high level of prevention and control, the accessibility of ecological conservation areas was also relatively poor. Conclusion The distribution of fever clinic resources in Beijing is uneven. When Beijing is simulated as an epidemic spreading city: under the high level of prevention and control, the number of fever clinics can be appropriately reduced to avoid cross-infection; at the medium level of prevention and control, the fever clinics can basically meet the needs of patients with fever in Beijing, but the accessibility of fever clinics in ecological conservation areas is insufficient, and priority should be given to the construction of fever clinics in public hospitals above the second level in the ecological conservation areas. When the level of prevention and control is low, the accessibility of fever clinics in ecological conservation areas is poor. Priority should be given to the construction of fever clinics in ecological conservation areas, and temporary fever sentinels can be established to relieve the pressure of fever clinics. When Beijing is simulated as an outbreak city and has low prevention and control, due to a large number of infections, it is necessary to upgrade the prevention and control level to reduce the flow of people to curb the development of the epidemic.

Spatiotemporal variation of surface ozone and its causes in Beijing, China since 2014

The surface ozone (O3) spatiotemporal distribution, variations and its causes in Beijing in 2014–2020 are revealed by quantitative estimates of the trends of 12 ozone metrics relevant to human health and tropospheric NO2 and formaldehyde (HCHO) column concentration, based on the air quality monitoring network data and satellite retrievals from the Ozone Monitoring Instrument (OMI). Results showed that the maximum O3 concentrations decreased slightly since 2014. The annual 90th percentile of the daily maximum 8-h average (MDA8) O3 and the “ozone-season” (April–September) MDA8 decreased by 0.32 and 0.19 μg m−3 year−1, respectively. The changes in Beijing contrast the widespread and significant O3 increases in the Beijing–Tianjin–Hebei region in recent years. However, significant positive trends in MDA8-90th and ozone-season MDA8 were observed in 7% and 14% of monitoring sites in Beijing (p < 0.05), most of which are located in urban areas and suburbs close to urban areas. The spatial distribution of high O3 values in Beijing has changed significantly. The areas with high O3 concentrations shifted from the northern suburbs (Changping and Miyun districts) to the northeastern and southwestern suburbs and the east of the central urban area. The ozone-season NO2 and HCHO tropospheric columns showed reductions of 4.2% and 0.4% year−1, respectively, from 2014 to 2019 in Beijing, which suggested that the decrease in NOX emissions was much greater than the decrease in volatile organic compound (VOC) emissions. Such an extremely inappropriate control ratio of ozone precursor NOX/VOCs led to an overall trend of slow declining fluctuations of O3 and an increasing trend of individual sites in Beijing. Obviously, the reduction of VOCs in Beijing is far from sufficient, and the significant decrease of Beijing's O3 concentration can only be achieved by a drastically reduction in VOC emissions.

Evaluation and Classification of Rural Multifunction at a Grid Scale: A Case Study of Miyun District, Beijing

Rural areas are a natural, economic and social complex with multiple functions. Identifying rural multifunction scientifically is the basis for promoting efficient rural spatial planning and sustainable development strategy. In this paper, we calculated and characterized the rural production-living-ecological (PLE) functions at a grid scale of 300 × 300 m in Miyun District by establishing an evaluation index system. Several types of rural functional area were identified with the help of an ISO cluster unsupervised classification tool. Three main results were found as follows. (1) The values of the production, living, ecological functions and multifunction ranged from 0–0.101, 0–0.204, 0.009–0.241 and 0.009–0.302, respectively. Ecological function was dominant in this area. (2) The overall spatial patterns of production and living functions showed the characteristic of being “high in the south and low in the north”, and areas with high values were almost distributed around urban areas and the Miyun Reservoir. While for the ecological function and multifunction, they possessed the opposite characteristics to production and living functions, with high values concentrated in the mountainous areas in the northwest, northeast, east and south of Miyun District. (3) According to the clustering results, rural multifunction of Miyun District was divided into four types: ecological conservation, employment and residence, recreation and potential development, with the area proportions of 44.22%, 17.92%, 20.73% and 17.13%, respectively. Each functional type showed a characteristic of agglomeration. In the future, the study of rural multifunction at micro scales should be paid more attention to better understand the functional differences within the country. This research can provide a decision-making reference for demarcation of rural production-living-ecological space and compilation of spatial planning.

Spatial Distribution and Influencing Factors of Crop Loss Caused by Wildlife

The scope of wildlife has expanded with the implementation of ecological restoration projects. Therefore, the number of conflicts between humans and wildlife in agricultural production has also increased. By studying the spatial distribution and influencing factors of crop losses caused by wildlife, we can understand the distribution of the wildlife population, the effectiveness of ecological restoration projects, and take targeted measures towards reducing the spread of wildlife populations and mitigating the damage caused to crops. This paper examines the Miyun District of Beijing, an area in which wildlife frequently causes crop losses in China. We construct spatial statistical and pooled data regression models to analyse the spatial distribution and influencing factors of crop losses caused by wildlife in the study area. Results revealed the following: the spatial distribution of wildlife conflicts in Miyun District were agglomerated and expanded in the spatial scope, which indicates that the distribution of wildlife populations in Miyun District is spreading and afforestation projects are effective. There is a close relationship between the extent of crop loss caused by wildlife and wildlife types, crop types, types of protection and eviction measures, and the environment surrounding the agricultural land. The scope of wildlife can be controlled and losses caused by wildlife reduced through measures such as rationally planting crops, building a buffer area around farmland, physically driving wildlife away, and planting trees that wildlife will not consume as part of afforestation projects.

Application of deep neural networks in classification of medium resolution remote sensing image

Aiming at the problem that high misclassification rate of remote sensing image occurs due to the phenomenon of “same spectrum different matter” and “same object different spectrum”, the deep neural networks(DNN) is proposed to the classification of medium resolution remote sensing image. The deep neural networkstake advantage of the neural network with multiple hidden layers to learn the characteristics that can describe the essential attributes of data, and has achieved high accuracy in land cover classification in Miyun District, Beijing city. The experimental results indicate that the classification accuracy of this algorithm is the highest compared with SVM and BP neural network, the classification accuracy reaches 96.53%, and the classification accuracy is 10.39% higher than that of SVM. The kappa coefficient of DNN is 0.95, which is also the highest among the comparison algorithm. So, the DNN can apply to the classification of moderate resolution remote sensing image.

Numerical Simulation of Multi-Water-Source Artificial Recharge of Aquifer: A Case Study of the Mi-Huai-Shun Groundwater Reservoir

Artificial recharge is an effective way to alleviate water shortages and excessive groundwater exploitation. In this study, to explore environmental changes of surface water and groundwater during multi-water-sources recharge process, numerical simulation method was applied. Local reclaimed water, treated by wetland, and water from the South-to-North Water Transfer Project (SNWTP) were used to recharge groundwater reservoir in Mi-Huai-Shun District (Miyun District, Huairou District and Shunyi District). The Flow Model results showed that the accumulated loss of the groundwater resource in the Mi-Huai-Shun area from 2007 to 2016 reached – 1.784 × 109 m3. All the water sources contribute to the recharge of groundwater, raising the groundwater level and increasing the groundwater reserves. Meanwhile, the Solute Transport Model results show that different water source has different effects on the local groundwater environment. chloride concentration of reclaimed water source and wetland water source are higher than groundwater, and the artificial recharge caused the chloride concentration of groundwater in receiving area to rise. The water from the SNWTP played an important role on reducing chloride concentration due to dilution. In addition, Multi-Water-Source artificial recharge is also related to the local hydrogeological conditions. This study provides a comprehensive analysis of the impact of multi-water-source recharge on groundwater quantity and quality.