Jinan City Research Articles

Study on Renovation of Rural Public Landscape and Environment: A Case Study of Dongquan Village in Jinan City

With the rapid development of the social economy in China, protecting and inheriting the ecological environment and cultural heritage in rural areas has become an important issue. According to the situation of Dongquan Village, Caishi Town, Jinan City, this study discusses the importance of rural public landscape and environment design. Through field research, it is found that the public landscape of many rural areas has not been fully renovated in the process of pursuing modern B&B design. In order to renovate the landscape of Dongquan Village, some suggestions are provided on the landscape design of public space. By analyzing the landscape design case of Xijiegang Village in Zhangjiagang City, the importance of ecological livability and regional culture in the landscape design of the rural public environment is explored, which shows that the sustainability and adaptability of landscape design are one of the key factors of the whole village landscape. It also provides some ideas for the better development of Dongquan Village. Generally speaking, the landscape design of a rural public environment needs to comprehensively consider ecological, cultural, community and economic factors to ensure its long-term sustainability. The changes in villages are closely related to farmers' income, rural tourism, and rural community construction, which provides a guarantee for rural sustainable development.

A hybrid rainfall-runoff model: integrating initial loss and LSTM for improved forecasting

Accurate rainfall-runoff modeling is crucial for disaster prevention, mitigation, and water resource management. This study aims to enhance precision and reliability in predicting runoff patterns by integrating physical-based models like HEC-HMS with data-driven models, such as LSTM. We present a novel hybrid model, Ia-LSTM, which combines the strengths of HEC-HMS and LSTM to improve hydrological modeling. By optimizing the “initial loss” (Ia) with HEC-HMS and utilizing LSTM to capture the effective rainfall-runoff relationship, the model achieves a substantial improvement in precision. Tested in the Yufuhe basin in Jinan City, Shandong province, the Ia-LSTM consistently outperforms individual HEC-HMS and LSTM models, achieving notable average Nash-Sutcliffe Efficiency (NSE) values of 0.873 and 0.829, and average R2 values of 0.916 and 0.870 for calibration and validation, respectively. The study shows the potential of integrating physical mechanisms to enhance the efficiency of data-driven rainfall-runoff modeling. The Ia-LSTM model holds promise for more accurate runoff estimation, with wide applications in flood forecasting, water resource management, and infrastructure planning.

The Impact of Land Use/Cover Change on Ecological Environment Quality and Its Spatial Spillover Effect under the Coupling Effect of Urban Expansion and Open-Pit Mining Activities

Suburban open-pit mining concentration areas are both the frontline of urban expansion and the main battlefield in mineral resource development. These dual forces have resulted in significant land use/cover changes (LUCC), which play a crucial role in determining the ecological environment quality (EEQ). However, research examining how LUCC affects EEQ under the coupled impact of these two development events is currently lacking. In this study, the response of EEQ to LUCC was evaluated using Landsat images from 2000, 2010, and 2020 for the southern suburban open-pit mining concentration area in Jinan City. A relative contribution index was used to address the ecological and environmental effects of non-dominant land use/cover types, and the impact of LUCC on EEQ and its spatial spillover effects were revealed by also carrying out a buffer zone analysis. The findings of this study indicate that: (1) the dominant land use/cover types that influence the EEQ spatial pattern are farmland, grassland, and construction land. Among them, the area of farmland was the largest, with more than 1800 km2. Changes in non-dominant land use/cover types to mining land and mine rehabilitation made the most significant relative contribution to the changes in EEQ, i.e., 0.0735 and 0.0184, respectively. (2) The transformation of farmland into construction land and mining land and woodland into mining land was shown to exacerbate the deterioration of the EEQ in the study area, with a deterioration area of 1367.54 km2 and spatial spillovers of up to 1000 m. (3) Returning farmland to woodland and grassland, as well as returning mine rehabilitation, were found to be the main factors contributing to the improvement of EEQ in the study area, with an improvement area of 1335.67 km2 and spatial spillover extending from 500 to 800 m. (4) Nevertheless, uneven changes in land use/cover continue to aggravate the agglomerative effect of EEQ deterioration. Further refinement and enhancement of the methods and standards of ecological governance are urgently needed to counterbalance the uneven spatial spillover effects between ecological degradation and improvement. This study provides a scientific reference for the promotion of ecological protection and sustainable development in mining cities.

Evaluating the Ability of the Pre-Launch TanSat-2 Satellite to Quantify Urban CO2 Emissions

TanSat-2, the next-generation Chinese greenhouse gas monitoring satellite for measuring carbon dioxide (CO2), has a new city-scale observing mode. We assess the theoretical capability of TanSat-2 to quantify integrated urban CO2 emissions over the cities of Beijing, Jinan, Los Angeles, and Paris. A high-resolution emission inventory and a column-averaged CO2 (XCO2) transport model are used to build an urban CO2 inversion system. We design a series of numerical experiments describing this observing system to evaluate the impacts of sampling patterns and XCO2 measurement errors on inferring urban CO2 emissions. We find that the correction in systematic and random flux errors is correlated with the signal-to-noise ratio of satellite measurements. The reduction in systematic flux errors for the four cities are sizable, but are subject to unbiased satellite sampling and favorable meteorological conditions (i.e., less cloud cover and lower wind speed). The corresponding correction to the random flux error is 19–28%. Even though clear-sky satellite data from TanSat-2 have the potential to reduce flux errors for cities with high CO2 emissions, quantifying urban emissions by satellite-based measurements is subject to additional limitations and uncertainties.

The impact of LUCC on the spatial pattern of ecological network during urbanization: A case study of Jinan City

Urbanization, driven by rapid economic growth, has resulted in dramatic land use/cover change (LUCC), posing substantial risks to urban ecological security. While constructing ecological networks is a productive strategy for achieving a balance between ecological protection and urbanization, the limited research conducted on the impacts of LUCC on the spatial patterns of ecological networks during urbanization poses a hindrance to the scientific construction of ecological networks. Therefore, this study focuses on Jinan City, an important city situated in the downstream region of the Yellow River Basin, China. The study utilized simulation approaches, including MSPA, MCR, InVEST model and gravity model, to investigate and analyze the ecological networks of Jinan City from 2000 to 2020. A set of patterns capturing the changes in ecological network elements was proposed to explore the evolutionary characteristics of the spatial pattern of ecological networks. Finally, Geodetector was utilized to investigate the impact mechanism of LUCC on the spatial pattern of ecological networks. The study findings indicate that: (1) During the last two decades, the urban development in Jinan City has witnessed an expansion of approximately 588.83 km2, and the proportion of ecological land has also increased, but the overall structure and spatial distribution of construction and ecological land are not balanced. (2) Despite the expansion of ecological areas, the escalation of ecological resistance has resulted in significant degradation of the functional capacity of ecological corridors, with a decrease of 8.37 % in the number of primary corridors. The reduced spatial connectivity of the ecological networks has impeded the efficient cycling of ecological processes between ecosystems. (3) The complex interactions and cumulative effects of LUCC during urbanization led to the evolution of the spatial pattern of ecological networks. The transformation of cropland and construction into ecological land has improved the composition elements of the ecological network, while the encroachment on ecological land and disorderly changes in internal types are the principal factors causing the degradation of ecological network composition elements. (4) The spatial pattern of ecological networks in Jinan City is influenced by the coupling of urban expansion and ecological protection policies. However, there is a need for the government to strengthen policy coordination and optimize spatial layout to better manage and conserve ecological networks. This study holds the potential to offer valuable scientific insights and references for guiding spatial planning, ecological protection, and the formulation of sustainable development policies throughout the urbanization process.

Different bacterial and fungal community patterns in restored habitats in coal-mining subsidence areas.

Soil microbiota, which plays a fundamental role in ecosystem functioning, is sensitive to environmental changes. Studying soil microbial ecological patterns can help to understand the consequences of environmental disturbances on soil microbiota and hence ecosystem services. The different habitats with critical environmental gradients generated through the restoration of coal-mining subsidence areas provide an ideal area to explore the response of soil microbiota to environmental changes. Here, based on high-throughput sequencing, we revealed the patterns of soil bacterial and fungal communities in habitats with different land-use types (wetland, farmland, and grassland) and with different restored times which were generated during the ecological restoration of a typical coal-mining subsidence area in Jining City, China. The α-diversity of bacterial was higher in wetland than in farmland and grassland, while that of fungi had no discrepancy among the three habitats. The β-diversity of bacterial community in the grassland was lower than in the farmland, and fungal community was significant different in all three habitats, showing wetland, grassland, and farmland from high to low. The β-diversity of the bacterial community decreased with restoration time while that of the fungal community had no significant change in the longer-restoration-time area. Furthermore, soil electrical conductivity was the most important driver for both bacterial and fungal communities. Based on the taxonomic difference among different habitats, we identified a group of biomarkers for each habitat. The study contributes to understand the microbial patterns during the ecological restoration of coal-mining subsidence areas, which has implications for the efficient ecological restoration of subsidence areas.

Spatiotemporal Variation and Quantitative Attribution of Carbon Storage Based on Multiple Satellite Data and a Coupled Model for Jinan City, China

Rapidly predicting and revealing the spatiotemporal characteristics and driving factors of land-use changes in carbon storage within megacities under different scenarios is crucial to achieving sustainable development. In this study, Jinan City (JNC) is taken as the study area, and the Markov-FLUS-InVEST model is utilized to predict and analyze the spatiotemporal variation in carbon storage in 2030 under three scenarios, namely, the natural development scenario (S1), the ecological conservation scenario (S2), and the economic development scenario (S3). The drivers of carbon storage changes were identified using an optimal parameter-based geographic detection (OPGD) model. The findings indicate that (1) land use from 2010 to 2018 shows a trend of continuous expansion of construction land and reduction in arable land. (2) The main types of carbon pools were cropland, forest, and grassland, accounting for more than 96% of the total amount. Carbon storage showed a decreasing trend from 2010 to 2018, and the main type of carbon pool that decreased was cropland. The center of gravity of carbon storage increases and decreases was located in the southern Lixia District, and the center of gravity of increase and decrease moved to the southwest by 3057.48 m and 1478.57 m, respectively. (3) From 2018 to 2030, the reductions in carbon stocks were 3.20 × 106 t (S1), 2.60 × 106 t (S2), and 4.26 × 106 t (S3), and the carbon release was about 9 times (S1), 4 times (S2), and 10 times (S3) that of the carbon sink. (4) The contribution of slope (A2) ∩ nighttime light index (B6) and elevation (A1) ∩ nighttime light index (B6) to the regional heterogeneity of carbon stocks was the largest among the interaction drivers. To sum up, this study deepens the simulation of spatial and temporal dynamics of carbon storage under land-use changes in megacities and the related driving mechanism, which can provide the basis for scientific decision-making for cities to conduct territorial spatial planning and ecological protection and restoration.

Spatiotemporal changes of aerosol optical depth and its response to urbanization: a case study of Jinan City, China, 2009-2018.

With the insidiously growing impact of urban development on the environment, the issue of air quality has attracted extensive attention nationally and globally. It is of great significance to study the influence of urbanization on air quality for the rational development of cities. MODIS-MAIAC (Moderate Resolution Imaging Spectroradiometer-Multi-Angle Implementation of Atmospheric Correction) Aerosol optical depth (AOD) product, DMSP/OLS (Defense Meteorological Satellite Program/Operational Linescan System) and NPP/VIIRS (Suomi National Polar-orbiting Partnership/Visible Infrared Imaging Radiometer Suite) night-light were used to explore the spatiotemporal variation and correlation between AOD and urbanization development before and after the promulgation of environmental governance policies in Jinan City from 2009 to 2018. Results show that (1) the spatial distribution of AOD in Jinan had the characteristics of high in the north and low in the south, high in the west and low in the east, and low in some parts of the central region; there was a significant seasonal variation in time, with the highest AOD in summer and the lowest in winter. During 2009-2013, the annual average variation of AOD increased by 20.6%, while during 2014-2018, it decreased by 35.3%; (2) The distribution of night-light in Jinan City has progressively expanded, mirroring the city's ongoing development. The spatial distribution of aerosols in urban areas was relatively low compared to the surrounding areas of the city. (3) From 2009 to 2013, there existed a significant positive correlation between the spatial and temporal distribution of AOD and night-light. However, from 2014 to 2018, with the implementation of environmental governance policies, this relationship shifted to a significant negative correlation between the spatial and temporal distribution of AOD and night-light. Through an analysis of the correlation between urban development and aerosol depth in Jinan City over the past decade, it can be concluded that urban development does not inevitably result in elevated AOD levels. Notably, the Jinan government has achieved remarkable results in controlling the atmospheric environment, as evidenced by recent years' improvements.

Assessment of urban flooding vulnerability based on AHP-PSR model: a case study in Jining City, China

Expanding urbanization has led to an increased risk of urban flooding, which poses a hazard to humans. Scientific assessment of urban flooding vulnerability (UFV) is essential to protect human health and reduce losses. In this study, UFV was assessed using the Analytic Hierarchy Process-Press-State-Response (AHP-PSR) model in Jining City, China. The urban flooding index (UFI) was calculated from 13 indicators. Based on the magnitude of UFI, the vulnerability was classified into five classes. Among them, the areas of very high, high, medium, low and very low vulnerability are 897.21 km2 (8.02%), 3192.14 km2 (28.53%), 2063.22 km2 (18.44%), 39773.96 km2 (35.52%) and 1060.47 km2 (9.48%), respectively. Finally, suggestions were proposed for further urban flooding management based on the results. The results of the study can provide an important reference for the government to prevent and mitigate urban flooding. Meanwhile, the modeling framework can be easily transferred to other cities, providing new ideas for UFV assessment.

An urban hydrological model for flood simulation in piedmont cities: Case study of Jinan City, China

Urbanization has great potential to adversely affect the local hydrological cycle, as well as result in severe ecological and environmental problems. Piedmont cities have a special topography and complicated overland flow processes, thus creating challenges for the simulation of urban flooding/waterlogging processes. The TVGM-USWM model, a new distributed urban hydrological model that considers the flow routing in urban drainage systems and complicated overland flow processes, was developed in this study. We applied this model to the Huangtaiqiao drainage basin of Jinan City, China and set up two simulation scenarios. The spatial heterogeneity of the proportion of directly connected impervious area (DCIA) and disconnected impervious area (DIA) in sub-catchments was considered in scenario B, but not in scenario A. We conducted sensitivity analysis on model parameters by using the Sobol method. Results showed that: (1) model parameters have a certain degree of uncertainty, and the parameter characterizing the proportion of the DCIA and DIA showed a relatively high sensitivity under rainstorms of different levels and different accuracy assessment standards; (2) The simulation of scenario A was poor (with a mean Nash coefficient of 0.59), which ignored the different flow paths followed by runoff from DCIA and DIA; and (3) Considering the spatial differences in the overland flow process, the prediction accuracy of scenario B significantly increased (with a mean Nash coefficient of 0.82). This indicated the importance of the disconnected impervious area and the lateral water exchange across the impervious-pervious interface on the flood simulation in a piedmont city. Compared to most urban hydrological models, the TVGM-USWM model can represent complex rainfall-runoff mechanisms in urban areas with varied terrain. The findings of this study can provide scientific decision-making for the planning and construction of a sponge city in Jinan City.

Study on Groundwater Function Zoning and Sustainable Development and Utilization in Jining City Planning Area

The sustainable development and utilization of groundwater resources are of paramount importance for the progress of society, the economy, and the environment. This study focuses on the planning area of Jining City and establishes an evaluation index system for groundwater functional zoning by analyzing key factors such as resource supply function, geo-environmental stability function, and ecological environmental protection function. To evaluate the groundwater functions, this study employs the barrel effect AHP. Through the overlay analysis of different groundwater functions, the planning area of Jining City is categorized into distinct zones based on their groundwater functions. These zones include centralized development and utilization areas (5.69%), decentralized development and utilization areas (65.67%), fragile geo-environmental areas (10.44%), ecological protection areas (8.38%), and unsuitable development and utilization areas (9.82%). The comprehensive zoning map of groundwater functions in the planning area of Jining City is generated. Taking into account the challenges posed by human activities, such as groundwater pollution, this study proposes recommendations for the sustainable development of groundwater in the planning area of Jining City. By systematically examining the functional zoning and sustainable management of groundwater, this study provides a scientific foundation for the responsible development and protection of groundwater resources.

Availability and Adequacy of Facilities in 15 Minute Community Life Circle Located in Old and New Communities

The 15 minute Community Life Circle (15 min-CLC) concept is an urban planning approach that aims to provide various daily services for citizens within a short distance. It has been widely adopted in China, especially in large cities. However, there is a lack of research on how to apply the 15 min-CLC concept in second-tier cities, which have high population densities and lower quality of life. This study chose Jinan City as a case study to explore the underdeveloped areas and facilities of 15 min-CLCs in rapidly developing and medium-size cities, called second-tier cities. First, it analyzed the distribution of facilities and residential POIs in old communities, new communities, and the whole city, to find out which types of facilities are missing at the community level. Second, it examined the relationship between facilities and population in each 15 min-CLC by using the Facility to Population Ratio (FPR), to evaluate the sufficiency of facilities to meet the daily needs of residents. Through the analysis of facility distribution and Facility to Population Ratio, our study found that old communities have all the required facility types within each 15 min-CLC, but they do not have enough number of facilities to support the population. At the same time, identified the underdeveloped regions and provided specific development directions for each 15 min-CLC. The FPR methodology developed in this study can be used to evaluate whether the existing facilities can meet the daily needs of residents in a certain region.

Evaluation of Jining Mining Subsidence Susceptibility Based on Three Multiple-criteria Decision Analysis Methods

This study selected ten condition factors from the perspectives of topography, geological structure, hydrology and human for mining subsidence mapping by two types of models (knowledge-driven model and data-driven model) by taking Jining City, China as an example. The knowledge-driven model is achieved by analytic hierarchy process (AHP), and the data-driven model is achieved by frequency ratio (FR), combined with fuzzy comprehensive evaluation (FCE) and entropy evaluation method (EWM). Based on these models, the areas under receiver operating characteristic curve are 0.777, 0.949, and 0.938, which means FR-FCE obtained the highest accuracy. The differences reflected by the three methods are concentrated in Liangshan County and central to northern areas of Weishan County. The best model was proposed for the protection measures and land use management. Finally, the factors system and methods used in this study can be widely applied to the mining subsidence susceptibility evaluation in plain areas.

Study on the Spatial and Temporal Distribution of Urban Vegetation Phenology by Local Climate Zone and Urban–Rural Gradient Approach

Understanding variations in the temporal and spatial distribution of vegetation phenology is essential for adapting to and mitigating future climate change and urbanization. However, there have been limited vegetation phenology studies within small-scale areas such as urban environments over the past decades. Therefore, the present study focuses on Jinan city, Shandong Province, China as the study area and employs a more refined local climate zone (LCZ) approach to investigate spatial and temporal variations in vegetation phenology. The three phenological indicators used in this study from 2007 to 2018, namely, the start of growing season (SOS), the end of growing season (EOS), and the length of growing season (LOS), were provided by MODIS satellite data. The SOS, EOS, and LOS were superimposed on the LCZ and urban–rural gradient to analyze the changes in vegetation phenology, and the applicability of these two analysis methods in the study of urban vegetation phenology was compared by the honest significant difference test. We found that the SOS, EOS, and LOS of vegetation in the study area generally showed an advance, delay, and extension trend, respectively. The means of the SOS and EOS along different LCZ types varied noticeably more than those along urban–rural gradients. In 2016, 77.5%, 80.0%, and 75.8% of LCZ pairs indicated statistically significant differences for SOS, EOS, and LOS, respectively. This study provides a new perspective for the study of urban vegetation phenology which can help in management of urban-scale environments, identification of areas rich in biodiversity, and conservation and restoration of biodiversity in urban areas.

Coupling the effects of extreme temperature and air pollution on non-accidental mortality in Rencheng, China.

Extreme temperatures and air pollution have raised widespread concerns about their impact on population health. To explore the quantitative exposure risks of high/low temperatures and types of air pollutants on the health of various populations in urban areas in China, this study assessed the effects of temperature and air pollutants on daily non-accidental deaths in Rencheng District, Jining City, China from 2019 to 2021. A combination of Poisson regression models and distributed lag non-linear models was used to examine the relationships between temperature, air pollutants, and daily non-accidental deaths. We found that temperature and air pollutants had a significant non-linear effect on non-accidental mortality. Both high and low temperatures had a noticeable impact on non-accidental deaths, with heat effects occurring immediately and lasting 2-3 days, while cold effects lasted for 6-12 days. The relative risks of non-accidental deaths from PM2.5, NO2, and SO2 were highest in winter and lowest in autumn. The relative risk of non-accidental deaths from O3 was highest in spring, with no significant variations in other seasons. Older adults (≥75) and outdoor workers were at the greatest risk from temperature and air pollutant exposure. Exposure to extreme temperatures and air pollutants in the Rencheng District was associated with an increased mortality rate. Under the influence of climate change, it is necessary for policymakers to take measures to reduce the risk of non-accidental deaths among residents.

First report of jujube anthracnose caused by Colletotrichum siamense in China.

Jujube (Zizyphus jujuba Mill.), a native small deciduous tree of China, is widely cultivated in China, Korea, India, Japan, Europe, and the United States (Chen et al. 2020). The fruit have been commonly consumed as healthy food supplements and traditional Chinese medicine for over 2000 years (Li et al. 2007). In August 2019, anthracnose-like leaf spot symptoms were observed on jujube plants in Xiaomenya Village, Jinan City, Shandong Province, China (36°27'39″N, 117°3'13″E), with over 30% leaf disease incidence. The spots were circular, sunken, brown in the center and with dark brown edges. As the spots enlarged and coalesced, it resulted in leaf perforation and early defoliation. Sometimes acervuli were observed on the lesions (Fig. S1a, b). To identify the causal agent, 20 diseased leaves were sampled, the margins of the lesions were cut into pieces (5 × 5 mm), sterilized and cultured following the protocol described previously (Wan et al. 2020) at 25 ℃ for 5 days. Twelve monospore isolates showing identical colony morphology were obtained. Three representative isolates, JNZG11, JNZG311, JNZG313, were used for further study. When grown on PDA the colony color was initially white and then turned pale-gray to gray in 5-day-old cultures. On the reverse, colonies were brown-black with an orange pigmentation near the center. Aerial mycelium was cottony, dense, white to pale-gray. Conidia were hyaline, 1-celled, smooth-walled, subcylindrical, oblong, attenuated with slightly rounded ends, (11.1-) 12.7-13.3 (-17.8) ×(-4.4) 5.2-5.5 (-6.3) μm (n=50). Appressoria were dark-brown, oval or irregular, (7.3-) 8.6-9.2 (-9.8) ×(-5.1) 5.8-6.9 (-7.0) μm (n=50) (Fig. S1c-g). The morphology resembled those of Colletotrichum gloeosporioides species complex (Cannon et al. 2012). For accurate identification, the sequences of the ribosomal internal transcribed spacer (ITS), actin (ACT), β-tub2 (TUB2), calmodulin (CAL), chitin synthase (CHS-1), and glyceraldehyde-3phosphate dehydrogenase (GAPDH) of the 3 isolates were sequenced (Weir et al. 2012), and deposited into GenBank (Accession Nos. see Table 1). The six loci (ITS, GAPDH, ACT, CHS-1, CAL, and TUB2) were concatenated and the aligned sequences (1904 bp) were 99.7% homologous to ex-type C. siamense ICMP18578. The sequences of 38 Colletotrichum species (44 isolates) were downloaded from GenBank for phylogenetic analyses. In the maximum likelihood phylogenetic tree generated, the highest log likelihood was -8798.90 and the three isolates were all in the C. siamense clade (bootstrap support 94 %) (Fig. S2). To complete Koch's postulates, 60 healthy, mature jujube leaves on 12 branches (5 leaves per branch) (variety 'Zhongqiuhong') were inoculated with 20 μL of spore suspension (106 conidia/mL) or sterile water as a control. The branches were placed in sterile beakers containing a small amount of sterile water sealed with plastic wrap and maintained at 28 °C, 12 h light/dark. Five days after inoculation, all treated leaves showed the typical anthracnose symptom, similar to that observed in the field (Fig. S1h). The same fungus was re-isolated from the margins of the lesions using the aforementioned methods. Whereas no fungus were isolated from the controls. Previously, C. siamense has been reported to infect Z. mauritiana in China (Shu et al. 2020). To our knowledge, this is the first report of C. siamense causing anthracnose on Z. jujuba in China. This finding provides crucial information for the effective management of this disease.

Influence of Urban Spatial Structure on the Spatial Distribution of Gaseous Pollutants

The spatial distribution pattern of urban spatial structure affects air flow and local meteorological conditions, which in turn influence the diffusion of air pollutants. This study built the urban spatial structure index system based on DEM, urban road networks, and big data. The ordinary kriging interpolation method was used to analyze the spatial distribution of gaseous pollutant concentrations in Jinan City. Correlation analysis, stepwise regression analysis, and bivariate global spatial autocorrelation analysis were used to study the influence of the urban spatial structure index on the spatial distribution of gaseous pollutant concentration. The main conclusions were as follows: (1) Evident spatial and temporal differences were observed in the concentration distribution of gaseous pollutants in Jinan. The spatial distribution of NO2 and CO concentrations showed a gradual decrease from north to south. Spatial heterogeneity was observed in the distribution of SO2 and O3 concentrations. (2) The urban spatial structure indicators had varying effects on the spatial distribution of different gaseous pollutant concentrations. The important factors that influenced the spatial distribution of urban gaseous pollutant concentrations included terrain elevation, building density, building volume, and floor area ratio. The greater the terrain undulation, the denser the building distribution, the greater the difference in building volume, and the greater the plot ratio, the greater the impact on the diffusion and spatial distribution of urban gaseous pollutants. (3) The spatial distribution of urban gaseous pollutant concentrations was significantly affected by the urban spatial structure indicators in the surrounding areas. Furthermore, the spatial distributions of NO2, SO2, CO, and O3 concentrations had a significant negative spatial correlation with the average DEM and standard deviation of the surrounding adjacent areas and a significant positive spatial correlation with the average and standard deviation of building height, standard deviation of building area, and building density in the surrounding adjacent areas (in June).

Analysis on epidemiological characters and HIV care continuum of HIV-infected students: a retrospective cohort study in Shandong province, China

BackgroudThe proportion of HIV-infected students in China showed an increasing trend. This study aimed to identify the epidemiological characteristics and the HIV care continuum for HIV-infected students in Shandong Province, China.MethodsCase report and follow-up data of HIV-infected students were obtained from the National HIV/AIDS comprehensive response information management system. Logistic regression analyses were used to analyze the associating factors of HIV-infected students accepting CD4 + T cells (CD4) test and antiviral therapy (ART) in 30 days, and ArcGIS software was used for the spatial anlysis.ResultsFrom 2017 to 2019, 403 HIV-infected students were reported in Shandong Province. The majority of them were male (99.5%) and transmitted through homosexual sexual activity(92.1%). Most of them lived in Jinan city and Qingdao city. 68.5% (276 cases) accepted CD4 test in 30 days, and 48.6% (196 cases) started ART in 30 days. The heterosexual transmitted cases (AOR = 0.458, 95%CI: 0.210–0.998), patients accepting HIV care in western area (AOR = 0.266,95%CI: 0.147–0.481) were less likely to test CD4 within 30 days; patients aged 23–25 (AOR = 2.316, 95%CI: 1.009–5.316) and patients who had tested CD4 within 30 days (AOR = 4.377; 95%CI: 2.572–7.447) prefered to receive ART within 30 days; patients accepted HIV care in central area (AOR = 0.407; 95%CI: 0.251–0.657) and western area (AOR = 0.508; 95%CI: 0.261–0.989) and patients diagnosed by voluntary blood donation (AOR = 0.352; 95%CI: 0.144–0.864) were less willing to receive ART in 30 days.ConclusionsThe HIV care continuum of HIV-infected students in Shandong Province still needed strenghthing. More health education and case management should be done for cases transmitted through heterosexual behavior, accepted HIV care in central and western area, and diagnosed by voluntary blood donation.

Understanding Travel Mode Choice Behavior: Influencing Factors Analysis and Prediction with Machine Learning Method

Building a multimode transportation system could effectively reduce traffic congestion and improve travel quality. In many cities, use of public transport and green travel modes is encouraged in order to reduce the emission of greenhouse gas. With the development of the economy and society, travelers’ behaviors become complex. Analyzing the travel mode choices of urban residents is conducive to constructing an effective multimode transportation system. In this paper, we propose a statistical analysis framework to study travelers’ behavior with a large amount of survey data. Then, a stacking machine learning method considering travelers’ behavior is introduced. The results show that electric bikes play a dominant role in Jinan city and age is an important factor impacting travel mode choice. Travelers’ income could impact travel mode choice and rich people prefer to use private cars. Private cars and electric bikes are two main travel modes for commuting, accounting for 30% and 35%, respectively. Moreover, the proposed stacking method achieved 0.83 accuracy, outperforming the traditional multinomial logit (MNL) mode and nine other machine learning methods.

The Mechanisms Controlling the CO2 Outgassing of a Karst Spring–River–Lake Continuum: Evidence from Baotuquan Spring Drainage Area, Jinan City, Northern China

The significance of CO2 emissions at the water–air interface from inland water bodies in the global carbon cycle has been recognized and is being studied more and more. Although it is important to accurately assess CO2 emission flux in a catchment, little research has been carried out to investigate the spatio-temporal variations in CO2 emissions in view of a water continuum. Here, we systematically compared the differences and control factors of CO2 degassing across the water–air interface of a spring–river–lake continuum in the discharge area of Baotuquan Spring in July 2017, which is a typical temperate karst spring area in Jinan city, northern China, using hydrogeochemical parameters, stable carbon isotope values, and CO2 degassing flux. Affected by the pCO2 concentration gradient between the water and ambient air, the spring water showed a high CO2 degassing flux (166.19 ± 91.91 mmol/(m2 d)). After the spring outlet, the CO2 degassing flux in the spring-fed river showed a slight increase (181.05 ± 155.61 mmol/(m2 d)) due to river flow rate disturbance. The river flow rate was significantly reduced by the “blockage” of the lake, which promoted the survival and reproduction of phytoplankton and provided favorable conditions for aquatic plant photosynthesis, increasing the plankton biomass in the lake to 3383.79 × 104/L. In addition, the significant decrease in the dissolved inorganic carbon (DIC) concentration and the increase in the δ13CDIC values in the lake also indicated that the photosynthesis of the lake’s aquatic plants resulted in a significant decrease in the pCO2 concentration, thus limiting the amount of CO2 off-gassing (90.56 ± 55.03 mmol/(m2 d)).