scholarly journals Effects of Air Pollutants on Summer Precipitation in Different Regions of Beijing

Atmosphere ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 141
Author(s):  
Yan Yang ◽  
Wei Zhou ◽  
Qian Gao ◽  
Delong Zhao ◽  
Xiange Liu ◽  
...  

Many studies have shown that air pollutants have complex impacts on urban precipitation. Meteorological weather station and satellite Aerosol Optical Depth (AOD) product data from the last 20 years, combined with simulation results from the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem), this paper focuses on the effects of air pollutants on summer precipitation in different regions of Beijing. These results showed that air pollution intensity during the summer affected the precipitation contribution rate (PCR) of plains and mountainous regions in the Beijing area, especially in the plains. Over the past 20 years, plains PCR increased by ~10% when the AOD augmented by 0.15, whereas it decreased with lower pollution levels. In contrast, PCR in mountainous areas decreased with higher pollution levels and increased with lower pollution levels. Our analysis from model results indicated that aerosol increases reduce the effective particle size of cloud droplets and raindrops. Smaller cloud raindrops more readily transport to high air layers and participate in the generation of ice-phase substances in the clouds, increasing the total amount of cloud water in the air in a certain time, which ultimately enhanced precipitation intensity on the plains. The removal of pollutants caused by increased precipitation in the plains decreased rainfall levels in mountainous areas.

2016 ◽  
Vol 20 (10) ◽  
pp. 4129-4142 ◽  
Author(s):  
Emma Daniels ◽  
Geert Lenderink ◽  
Ronald Hutjes ◽  
Albert Holtslag

Abstract. The effects of historic and future land use on precipitation in the Netherlands are investigated on 18 summer days with similar meteorological conditions. The days are selected with a circulation type classification and a clustering procedure to obtain a homogenous set of days that is expected to favor land impacts. Changes in precipitation are investigated in relation to the present-day climate and land use, and from the perspective of future climate and land use. To that end, the weather research and forecasting (WRF) model is used with land use maps for 1900, 2000, and 2040. In addition, a temperature perturbation of +1 °C assuming constant relative humidity is imposed as a surrogate climate change scenario. Decreases in precipitation of, respectively, 3–5 and 2–5 % are simulated following conversion of historic to present, and present to future, land use. The temperature perturbation under present land use conditions increases precipitation amounts by on average 7–8 % and amplifies precipitation intensity. However, when also considering future land use, the increase is reduced to 2–6 % on average, and no intensification of extreme precipitation is simulated. In all, the simulated effects of land use changes on precipitation in summer are smaller than the effects of climate change, but are not negligible.


2021 ◽  
Vol 875 (1) ◽  
pp. 012037
Author(s):  
S Glushkov ◽  
D Boyadzhiev ◽  
P I Popikov ◽  
I V Chetverikova ◽  
V V Abramov ◽  
...  

Abstract The article presents the results of a study of the process of operation of the Mounty 4000 machine in mountain conditions. The main goal of the research is to establish production rates for harvesting when using Mounty 4000 machines in mountainous areas. The need for research in this direction is due to the lack of such data in the current regulations, as well as in the scientific literature. To study the operation of the Mounty 4000, a passive production experiment was carried out in the mountainous regions of Bulgaria. The obtained data on the rates of output and operating time of the Mounty 4000 allows you to make scientifically based decisions in the selection of effective technical means from a large number of alternatives for forest harvesting technologies in mountainous areas.


Atmosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 496
Author(s):  
Kyung Hwan Kim ◽  
Kyung-Hwan Kwak ◽  
Jae Young Lee ◽  
Sung Ho Woo ◽  
Jong Bum Kim ◽  
...  

In this work, a 2-D gridded air pollution map with a high resolution of 50 × 50 m2 was proposed to help the exposure assessment studies focusing on the association between air pollutants and their health effects. To establish a reliable air pollution map in a 2 × 2 km2 urban area, a mobile monitoring procedure and a data process were developed. Among the various vehicle-related air pollutants, the particle-bound polycyclic aromatic hydrocarbon (pPAH) was chosen as a sensitive indicator. The average pPAH concentration on major roads (293.1 ng/m3) was found to be 35 times higher than that at a background location (8.4 ng/m3). Based on the cell-based pPAH concentrations, the 50 × 50 m2 cells in the air pollution map were categorized into five pollution levels. The higher air pollution levels were generally shown by the cells close to the major traffic emission points. The proposed map can be used to make various policies regarding land use and traffic flow control in urban areas. Estimation of the personal exposure level to air pollutants is possible at a reliable location using the highly resolved 2-D gridded air pollution map in exposure assessment studies.


Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 328 ◽  
Author(s):  
Dong Nam ◽  
Man-Il Kim ◽  
Dong Kang ◽  
Byung Kim

Recently, human and property damages have often occurred due to various reasons—such as landslides, debris flow, and other sediment-related disasters—which are also caused by regional torrential rain resulting from climate change and reckless development of mountainous areas. Debris flows mainly occur in mountainous areas near urban living communities and often cause direct damages. In general, debris flows containing soil, rock fragments, and driftwood temporarily travel down to lower parts along with a mountain torrent. However, debris flows are also often reported to stream down from the point where a slope failure or a landslide occurs in a mountain directly to its lower parts. The impact of those debris flows is one of the main factors that cause serious damage to structures. To mitigate such damage of debris flows, a quantitative assessment of the impact force is thus required. Moreover, technologies to evaluate disaster prevention facilities and structures at disaster-prone regions are needed. This study developed two models to quantitatively analyze the damages caused by debris flows on structures: Type-1 model for calculating the impact force, which reflected the flow characteristics of debris flows and the Type-2 model, which calculated the impact force based on the topographical characteristics of mountainous regions. Using RAMMS a debris flow runoff model, the impact forces assessed through Type-1 and Type-2 models were compared to check reliability. Using the assessed impact forces, the damage ratio of the structures was calculated and the amount of damage caused by debris flows on the structures was ultimately assessed. The results showed that the Type-1 model overestimated the impact force by 10% and the Type-2 model by 4% for Mt. Umyeon in Seoul, compared to the RAMMS model. In addition, the Type-1 model overestimated the impact force by 3% and Type-2 by 2% for Mt. Majeok in Chuncheon, South Korea.


2019 ◽  
Vol 11 (22) ◽  
pp. 2619 ◽  
Author(s):  
Enping ◽  
Yunlin ◽  
Hui ◽  
Guangxing ◽  
Dengkui

Spectral reflectance distortions caused by terrain and solar illumination seriously reduce the accuracy of mapping forest carbon density, especially in mountainous regions. Many models have been developed for mitigating or eliminating the terrain effects on the quality of remote sensing images in hilly and mountainous areas. However, these models usually use global parameters, which may lead to overcorrections for regions with poor illumination and steep slopes. In this study, we present a local parameter estimation (LPE) method based on a pixel-moving window for topographic correction (TC), which can be considered as a general optimization framework for most semiempirical TC models. We set seven kernel sizes for the presented framework, which are 15 pixels, 25 pixels, 50 pixels, 100 pixels, 250 pixels, 500 pixels, and 1000 pixels, respectively. The proposed method was then applied to four traditional TC models, Minnaert (MIN), C Correction (CC), Sun Canopy Sensor + C (SCSC) and Statistical Empirical Correction (SEC), to form four new TC models. These new models were used to estimate forest carbon density of a mountainous area in Southern China using field plot data and a Landsat 8 image. Four evaluation methods, including correlation analysis, the stability of land covers, comparison of reflectance between sunlit and shaded slopes, and accuracy assessment of forest carbon density, were employed to evaluate the contributions of moving window sizes, and assess the performance of the TC models for forest carbon density estimation. The results show that the four TC models with LPE perform much better than the traditional TC models in reducing the topographic effects and improving the estimation accuracy of forest carbon density for the study area. Among the traditional TC models, SEC performs slightly better than SCSC, CC, and MIN. Therefore, the SEC-based model with LPE, that is, LPE-SEC, gets greater R2 and smaller relative RMSE values in estimating forest carbon density than other models. Moreover, all the means of the predicted forest carbon density values fall in the confidence interval of the validation data at a significant level of 0.05. Overall, this study implies that the proposed method with LPE provides great potential to improve the performance of TC and forest carbon density estimation for the study area. It is expected that the improved TC method can be applied to other mountainous areas to improve the quality of remotely sensed images.


2015 ◽  
Vol 15 (10) ◽  
pp. 5803-5814 ◽  
Author(s):  
C. Jiang ◽  
H. Wang ◽  
T. Zhao ◽  
T. Li ◽  
H. Che

Abstract. To study the influence of particulate matter (PM) transported from surrounding regions on the high PM2.5 pollution levels in Beijing, the GRAPES-CUACE model was used to simulate a serious haze episode that occurred on 6–7~December 2013. The results demonstrate the model's suitability for describing haze episodes throughout China, especially in the Beijing–Tianjin–Hebei (Jing–Jin–Ji) region. A very close positive correlation was found between the southerly wind speed over the plain to the south of Beijing and changes in PM2.5 in Beijing, both reaching maximum values at about 900 hPa, suggesting that the lower atmosphere was the principal layer for pollutant PM transport from its southern neighbouring region to Beijing. During haze episodes, and dependent upon the period, Beijing was either a pollution source or sink for its surrounding area. PM input from Beijing's environs was much higher than the output from the city, resulting in the most serious pollution episode, with the highest PM2.5 values occurring from 00:00 to 10:00 UTC (08:00 to 18:00 LT), 7 December 2013. PM pollutants from the environs of the city accounted for over 50 % of the maximum PM2.5 values reached in Beijing. At other times, the Beijing area was a net contributor to pollution in its environs.


2014 ◽  
Vol 1 (2-3) ◽  
pp. 215-218
Author(s):  
Ruslana Romanyshyn

The paper highlights the challenges of establishment and characteristics of educationalinstitutions functioning in the highlands. It is analyzed the work of preparatory groups that aremeant to replace kindergartens in the remote mountainous areas in terms of preparing children forschool. In the context of logical and mathematical development of senior preschool children weanalyze the Program "Sure Start" and the issue of elementary mathematics education. It isconcluded that the acquisition of this knowledge in preschool institutions and preparatory groupsaffects the quality of further mathematics education. In this regard effective solution to theimplementation of the tasks of the Program "Sure Start" in mountainous regions is seen incooperation on the part of kindergartens, schools and parents


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yijia Hu ◽  
Yuan Sun ◽  
Yao Ha ◽  
Yimin Zhu ◽  
Zhixian Luo

During the summer in the western mountainous regions of China (WMR), the disasters such as mountain floods, landslides, and debris flows caused by heavy rain occur frequently, which often result in huge economic losses and many casualties. Therefore, it is of great significance to predict the precipitation accurately in these regions. In this paper, a statistical model is established to predict the precipitation in the WMR using the linear regression statistical method, in which the summer area-averaged precipitation anomaly in WMR is taken as the predictand and the prewinter Niño3 SST is taken as the predictor. The results of the return cross test for the historical years from 1979 to 2008 and independent sample return test from 2009 to 2018 show that this statistical model has a good performance in predicting the summer precipitation in the WMR, especially in the flood years. It has better skill in the prediction of WMR precipitation than the dynamical model SINTEX-F.


2021 ◽  
Author(s):  
Arnab Mondal ◽  
Asha Sunilkumar ◽  
Shishir Kumar Singh ◽  
Surajit Mondal ◽  
Amit Kumar Mondal

Abstract In the beginning of March 2020, cases of CoVID-19 infections began rising worldwide, reacting to which the Government of India called for nationwide lockdown initially for March 25th to April 14th, 2020 and later extended it in phases till May 31st, 2020. Due to the forced restrictions pan-India on every level, the move led to drastic drop in pollution levels. The results demonstrated that during lockdown air quality is significantly improved and the pollution levels of PM2.5, PM10, SO2 and NO2 reduced drastically during the lockdown period than the preceding year for the same time frame. A direct relationship has been established between the high level of air pollutants (PM2.5, PM10, NO2 and SO2) and CoVID-19 infections being reported in these Indian cities. The correlation indicates that the air pollutants like PM2.5, PM10, NO2 and SO2 are aggravating the number of casualties due to the CoVID-19 infections. The high-level exposure of PM2.5 over a long period is found to be significantly correlated with the mortality per unit confirmed CoVID-19 cases as compared to other air pollutant parameters like PM10, NO2 and SO2.


Author(s):  
Zainab B. Mohammed ◽  
Ali Abdul Khaliq Kamal ◽  
Ali S. Resheq ◽  
Waleed M. Sh. Alabdraba

Baghdad, considered one of the most polluted and populated cities in Iraq, waschoosen for mapping the distribution of air pollutants and the overall pollution levels by using the ArcGIS techniques. Six of main observation stations werechoosen in a particular location. Then, the recorded data from these stations were spatially interpolated using two types of ArcGIS interpolation techniques. The spatial interpolation techniques used in this work were Inverse distance weighting (IDW) and fuzzy logic. This study includes measuring the main air pollutants, which were nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), nitrogen oxide (NOx), and nitrogen monoxide (NO) during the period from January 2018 to December 2018. The data recorded by the stations during the work period and the distribution maps of air pollutants, which resulted from spatial interpolation (IDW) method, showed that the concentration of NO2 was within the International limits of World Health Origination (WHO) which is about 0.11 ppm. SO2 concentrations were exceeding the WHO limits in all stations for the study area. The concentrations of CO ranged from 0.484 ppm to 7.027 ppm that were within acceptable limits of WHO standards that is 9 ppm. NOx concentrations ranged between 0.01506 ppm – 0.214 ppm, which were exceeding acceptable limits of WHO standards (0.01 ppm). The concentrations of NO did not exceed the WHO standard limits, which are 0.08 ppm. Finally, the fuzzsy logic method of spatial interpolation in ArcGIS was applied to evaluate the air pollution over Baghdad city.


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