Environmental characteristics of sandstorm of Minqin Oasis in China for recent 50 years

The purpose of this present study is to investigate the frequency and variation of sandstorm in Minqin Oasis. Using daily observational data of sandstorm and other meteorologic data from 1954 to 2000, we have illuminated the relationship between sandstorm, meteorological parameters and human activities. The results of the analysis show that the highest frequency of sandstorms occurrence and their duration mainly focus on March, April and May, especially in April. Most of sandstorms occur from midday to nightfall, but relative few appear from midnight to forenoon, which apparently correlates to the daily variations of atmospheric thermal stability within atmospheric boundary layer. Monthly mean and annual mean duration of sandstorms coincide well with the frequencies of sandstorm occurrence.

Analysis on Characteristics of Architectural Environment of Traditional Villages in Southwest Mountainous Area:Taking Heijing Ancient Town of Chuxiong as an Example

The formation of the ancient town of Heijing conforms to the natural conditions and local conditions,and makes effective use of the natural mountains,water bodies,trees and other resources of the ancient town,so that the ancient town and nature rely on each other and unify harmoniously.Through the analysis of the environmental characteristics of the ancient town,this paper further explores its cultural connotation.

Analysis of a Large-Scale Strong Convective Weather under a Weak Water Vapor Condition in Shanxi, China in Spring

This article uses NCEP 1° × 1° grid point reanalysis data, conventional meteorological observation data, FY2G satellite TBB data, radar combined reflectivity data, ground-encrypted automatic station observation data, etc., through the synoptic diagnostic analysis method for a comprehensive analysis of a large-scale underreporting of a strong convective weather process under weak water vapor conditions on the 13th April 2017. The results show that the severe convective weather process is affected by the short-wave disturbance in the northwesterly airflow, triggered by the uplift of the westerly trough, the mid-low shear line and the mesoscale front of the boundary layer in the dry northwest. The jet stream is also an important system for the development of this strong convective weather. In the case of weak water vapor and energy conditions, if there is strong dynamic uplift, vertical wind shear and large temperature differences, strong convection can still occur;the convection occurrence area corresponds to the high potential vorticity abnormal area. The movement speed and direction of the cloud cluster are also consistent with the movement of the high potential vorticity anomaly area;the potential vorticity anomaly will cause the cyclonic circulation to increase, and the upward movement will also increase, which is conducive to the development of strong convective weather. According to the position of the dew point front in the β mesoscale, the ground cold pool corresponds to the small value area of the convective cloud cluster TBB. The front of the cold pool is accompanied by a mesoscale ground convergence line, and the uplift is strengthened, which is conducive to the development and forward movement of thunderstorms;the outflow of the cold pool is guided by 700 hPa. When the wind direction is the same, the movement speed will increase, and the stronger the outflow, the faster the movement speed.

Erosion environment in the sediment-rich area on the Loess Plateau

Based on the investigation and analysis of characteristics of precipitation, natural environment, socio-economic factors and soil erosion, this paper indicates that the precipitation is the main driving force for the soil erosion in the sediment-rich area, its variability determines the characteristics of soil and water loss; the natural conditions such as the drainage systems, geological and topographic features, the composition of soil and land surface materials, vegetation and climate determine the seriousness of soil and water loss; irrational socio-economic activities of human beings usually accelerated soil and water loss; meanwhile, the low preservation rate and inferiority of soil and water conservation measures made it impossible to make rapid progress on soil and water loss control. Furthermore, the characteristics of erosion environment endowed this area with more sediment that is the main reason for the flooding disasters by the Yellow River. Therefore, more emphasis should be placed on the enhancement of soil and water conservation. The soil loss prediction models will provide scientific basis for the planning of soil and water conservation, the designing of soil and water conservation measures and the valuation of effects of soil and water loss control. According to the analysis of the previous studies on soil loss prediction, and the water-sediment variation features, it is thought that study on soil loss prediction under various rainfall conditions and soil-water conservation measures should be carried out.

Indoor microbiome and allergic diseases:From theoretical advances to prevention strategies

The prevalence of allergic diseases,such as asthma,rhinitis,eczema,and sick building syndrome(SBS),has increased drastically in the past few decades.Current medications can only relieve the symptoms but not cure these diseases whose development is suggested to be greatly impacted by the indoor microbiome.However,no study comprehensively summarizes the progress and general rules in the field,impeding subsequent translational application.To close knowledge gaps between theoretical research and practical application,we conducted a comprehensive literature review to summarize the epidemiological,environmental,and molecular evidence of indoor microbiome studies.Epidemiological evidence shows that the potential protective indoor microorganisms for asthma are mainly from the phyla Actinobacteria and Proteobacteria,and the risk microorganisms are mainly from Bacilli,Clostridia,and Bacteroidia.Due to extremely high microbial diversity and geographic variation,different health-associated species/genera are detected in different regions.Compared with indoor microbial composition,indoor metabolites show more consistent associations with health,including microbial volatile organic compounds(MVOCs),lipopolysaccharides(LPS),indole derivatives,and flavonoids.Therefore,indoor metabolites could be a better indicator than indoor microbial taxa for environmental assessments and health outcome prediction.The interaction between the indoor microbiome and environmental characteristics(surrounding greenness,relative humidity,building confinement,and CO_(2) concentration)and immunology effects of indoor microorganisms(inflammatory cytokines and pattern recognition receptors)are briefly reviewed to provide new insights for disease prevention and treatment.Widely used tools in indoor microbiome studies are introduced to facilitate standard practice and the precise identification of health-related targets.