宁夏近60 a大气环境容量变化特征及其影响因子

Atmospheric environmental capacity characteristics and influencing factors of Ningxia over the past 60 years

为研究宁夏大气环境容量变化及其影响因子,利用1961—2018年气象站逐日历史观测资料,根据箱模型原理对宁夏大气环境容量A(污染物排放总量控制系数)值时空分布及其主要气象影响因子进行分析,并对2018年大气环境容量进行区划评估。结果表明:宁夏各季节大气环境容量A值总体呈减小趋势,速率为-0.47×10^(4)~-0.24×10^(4)km^(2)·(10a)^(-1)。各季节A值夏季最大,春季次之,秋季和冬季较小。月A值呈单峰型变化,8月最大、12月最小,空间上呈南高北低的分布特点。受贺兰山、六盘山地形及区域降水量等因素影响,A值低值中心位于银川市和石嘴山市,高值中心位于固原市南部地区。风速和混合层高度变化对宁夏大气环境容量A值年代际演变趋势具有决定影响;降水和风速对其影响存在明显季节和地区差异,风速对北部春季A值贡献较大,降水对中南部夏秋季A值贡献较大。受冶金、火电、化工、建筑等高耗能产业和车辆排放影响,平罗县和利通区属于宁夏大气环境SO_(2)、NO_(x)临界及以下等级承载区,利通区以南各地为高承载区。

This study has aimed to evaluate the characteristics of the atmospheric environmental capacity and its influencing factors in Ningxia.The temporal and spatial distribution of the A value of the atmospheric environmental capacity and its main meteorological influencing factors were analyzed using daily fixed time historical observation data from meteorological stations between 1961 and 2018,based on the box model principle.The atmospheric environmental capacity in 2018 was also evaluated and zoned.The results showed that the A value of the atmospheric environmental capacity showed a decreasing trend in all seasons,with a rate of-0.47×10^(4)~-0.24×10^(4) km^(2)·(10a)^(−1).The annual average A value was largest in the summer,followed by the spring,and then autumn and winter.The monthly A value showed a single peak pattern,with a maximum in August and minimum in December.It was generally high in the south and low in the north in space,and influenced by the topography of Helan Mountain and Liupan Mountain,regional precipitation,and other climatic factors.The low value center for A was located in Yinchuan and Shizuishan City,while the high value center was located in the south of Guyuan City.Wind speed and mixed layer height changes had a significant influence on the interdecadal evolution trend of the atmospheric environmental capacity of A in the Ningxia Hui Autonomous Region.There were obvious seasonal and regional differences on the impacts of precipitation and wind speed.For example,wind speed had a greater contribution to the A value in spring in the north,and precipitation had a greater contribution to the A value in summer and autumn in the south.This was affected by high energy consuming industries such as metallurgy,thermal power,the chemical industry,and construction and vehicle emissions.Pingluo County and Litong District were the critical overload and overload areas for the SO_(2) and NO_(x) atmospheric environments,and the counties south of Litong District were high bearing areas in Ningxia.