大气环境容量A-P值法中A值的修正算法

A值是A-P值法计算大气环境容量的关键参数之一，合理确定A值有利于保护大气环境质量和维护大气污染物排放单位的利益.以单箱模型中A值法的基本原理为基础，采用《环境影响评价技术导则 大气环境》(HJ/T2.2-93)的公式法确定混合层厚度(H_i)，对不同大气稳定度下计算A值的单箱模型法进行修正；以《制定地方大气污染物排放标准的技术方法》(GB/T13201－91)中给出的各地区A值的取值范围为基础，依据污染物日均质量浓度达标保证率，提出计算A值的达标保证率法，并根据确定达标保证率方法的不同细分为概率公式法和图表法，给出2种方法的使用说明.以长江三角洲地区某开发区为例，采用所提出的3种方法计算其A值，对计算结果进行可靠性验证，并对各计算方法的特点、适用情景进行了探讨. 

Research on the A Value Amending Algorithm for A-P Value Method in EPC Calculation

The value of A is one of the key parameters in calculating environmentpurification capacity (EPC) by A-P value method. Proper determination of A value is favorable to protecting the air quality as well as the benefits of the companies and organizations emitting air pollutants. Based on the general principlesof the A value method in single-box model, H_i was ascertained by Technical guidelines for environmental impact assessment-Atmospheric environment (HJ/T2.2-93), and the single-box model method amended for calculating the value of A at various atmospheric stabilization levels. Based on the range of A in various regions advanced by Technical methods for making local emission standards of air pollutants(GB/T13201-91), the standard compliance rate method was advanced accordingto daily averaged standard compliance rates, and differentiated as the probabilistic formula method and chart method in accordance with different methods in ascertaining compliance rates. The explanations on how to use the methods were also provided. Taking a developing area in the Yangtze River Delta as example, the value of A was calculated by the three methods and the reliability demonstrationof the results taken. The character of each method as well as their applicationconditions was finally analyzed