Present Situation and Development Countermeasures of Meteorological Services for Ecological Tourism in Shaanxi Province

The present situation of meteorological services for ecological tourism in Shaanxi Province was analyzed firstly,and then the problems existing in the meteorological services were analyzed.Finally,corresponding measures were put forward.

Changes of Extreme Precipitation and its Associated Mechanisms in Northwest China

Characterized by scarce water resources and fragile ecosystems,Northwest China(NWC)has experienced a climate shift from warm-dry to warm-wet conditions since the 1980s that has garnered extensive concern in recent years.In this study,the variability in extreme precipitation(EP)during 1961-2016 in different climate zones of NWC and the possible mechanisms for this variation are investigated.The results show that the EP trends significantly increased in most of the westerly zone(WZ)and plateau zone(PZ),while the EP trends did not significantly decrease in the monsoon zone(MZ).The start dates of extreme precipitation(SDEP)and end dates of extreme precipitation(EDEP)advanced and were postponed,respectively,in the WZ and PZ,while the opposite occurred in the MZ.Summer atmospheric circulation,water vapor transport,and atmospheric instability over NWC varied greatly with the interdecadal shift in EP before and after 1986.During 1986-2016,upper-level divergence and lower-level convergence occurred in the MZ and PZ,which strengthened ascending flow.In addition,the summer water vapor and atmospheric instability increased in the WZ and PZ.These characteristics created favorable conditions for increased occurrences of EP in the WZ and PZ in summer.Conversely,the upper-level convergence and lower-level divergence in the MZ strengthened descending flow.Decreases in summer water vapor and atmospheric instability occurred in the MZ after 1986.Hence,the environmental conditions in the MZ may have prevented the occurrence and development of EP in summer during 1986-2016.

Comparative Analysis of Pollutant Characteristics during a Fog,Haze and Sandstorm

Characteristics of air pollutants during three types of low-visibility weather in west-central Inner Mongolia were analyzed.The results showed that in the three processes,air pollution was slight during the heavy fog and serious during the haze and sandstorm.PM 10 concentration had the biggest difference among the six pollutants.During the heavy fog,the hourly concentration of PM 2.5 in Hohhot City varied from tens to 100 μg/m^3,while that of PM10 ranged from tens to 200 μg/m^3,and that of O3,NO2,SO2 and CO was low.During the haze,the hourly concentration of PM2.5 and PM10 in Hohhot City ranged from tens to 600 μg/m^3.The heavy atmospheric pollution was caused by both PM2.5 and PM10 .The O3 concentration during the haze was lower than that during the heavy fog.The accumulation of NO2,SO2 and CO had a significant effect on the aggravation of atmospheric pollution.During the sandstorm,the hourly concentration of PM 10 in Hohhot City varied from about 100 to 5 000 μg/m^3.It had a hysteresis effect on the position and intensity of sandstorm,and there was no obvious daily change.The stronger the sandstorm was,the larger the hourly concentration of PM10 was.The hourly concentration of PM2.5 ranged from tens to 500 μg/m^3,and there was no obvious daily variation.When the sandstorm was the strongest,PM10 was the main contributor to air pollution,but the air pollution caused by PM2.5 was also serious.The atmospheric pollution from O3 was considerable.The hourly concentration of NO2,SO2 and CO during the sandstorm was obviously lower than that during the heavy fog and haze,and there was no obvious daily change.

The Influence of Urbanization on Cooling Energy Consumption in Xi＇an

Based on data of daily air temperature during 1951-2013,long-term variation characteristics of cooling degree days（ CDD） in Xi＇an and Chang＇an in summer were analyzed by using CDD to evaluate cooling energy consumption and 26 ℃ as the basic temperature of CDD. The results indicated that the changing trends of CDD in Xi＇an and Chang＇an were basically identical within a year,and the demand for cooling refrigeration was large mainly from June to August,especially in July. The maximum of urban-rural difference of CDD between Xi＇an and Chang＇an appeared in June.In order to achieve the same temperature,energy needed by the urban area was 5-7 ℃·d more than the suburb from June to August. Temperature and the cooling energy consumption were closely related,and the correlation degree increased with the rise of temperature. The effects of temperature increase of 1 ℃ on cooling energy consumption rate in Xi＇an were more obvious than that in Chang＇an. In both Xi＇an and Chang＇an,the effects of temperature increase of 1 ℃ on cooling energy consumption rate in July and August were greater than that in May,June and September.Evaluation models of cooling energy consumption in summer in Xi＇an and Chang＇an were built using temperature anomaly and CDD variability and can be applied to business systems.