A Case Study On Caculation Of Atmospheric Environment Capacity For City Region

The environmental capacity is the Earth biosphere's or some region environment's bearing apacity to the population growth and the economical development. It generally refers to, under the premise of crowd health and non-harmed natural ecology, the natural environment's or some kind of essential factor's maximum capacity to pollutants. The environmental capacity is the basic attribute of natural ecological environment, which reflects the environment's bearing capacity to pollutants. The region environmental capacity refers to, considering pollutants' background density (external pollution influence and natural background density), current discharge pattern of pollution sources and local actual meteorology condition, maximum discharge quantity of pollutants allowed in the limited region. The atmospheric environment capacity refers to, according to environment goal requirements of different function areas, under the premise of the human normal survival and the ecosystem balance, as well as the atmospheric environment quality goal, the atmospheric environment's maximum bearing capacity to pollutants. This paper focuses on the atmospheric environment capacity.In 1968, Japanese scholars firstly put forward the concept of environmental capacity. At the end of 1970s, the concept of environmental capacity was introduced to China and gave rise to widespread attention and application in the environment scientific circles, and has had profound influence. Since long time China carries out the pollution strategy giving priority to density control, but along with high speed economy development as well as environment management requirements enhancement, a single density control has not been able to satisfy the environment quality requirements. Chinese atmospheric environment quality management is transiting from the density control, the target total quantity control to the capacity total quantity control. The environmental capacity calculation is the fundamental work for implementing city atmospheric environment capacity total quantity control, and the environment total quantity control is an effective management tool for city atmospheric environment quality improvement.The environmental capacity is one kind of useful and limited resources. At present, many countries are carrying on relevant research and practices of atmospheric environment capacity total quantity control. US are the earliest country studying the theory of pollutant total quantity charge right transaction. Recent years China has begun to research city region atmospheric environment capacity calculation in those key environmental protection cities one after another. This paper took Changchun as an example, collected and analyzed foundation technical data of atmospheric environment capacity, and calculated Changchun atmospheric environment capacity based on reasonable calculating model.This paper introduced basic principles and research methodologies of city region atmospheric environment capacity calculation, discussed basic concepts, definitions, classifications and characteristics of environmental capacity. Basically atmospheric environment capacity can be divided into three types: The first can be obtained based on the capability balance of pollution and elimination in finite space, which is called ideal environmental capacity; The second can be obtained under the condition of current pollution source pattern situation and the region ground environment quality guaranteed to achieved functional requirements, which is called actual environment capacity; The third can be obtained in the industrial structure adjustment and under the condition of pollution source pattern optimization, at the same time the region ground environment quality guaranteed to achieve functional requirements, which is called planning environmental capacity. This paper mainly studied ideal environmental capacity and actual environment capacity. This paper introduced domestic and foreign environmental capacity development situation, the development progresses of environmental capacity calculation model, the categories, respective characteristics and applicable scope. This paper analyzed the major natural factors influencing air pollution, climatic factor and geography factor, in which climatic factor is the dominate factor. Based on atmospheric environment capacity theories, this paper studied several calculation methods of atmospheric environment capacity: A value, A-P value, multi-source modeling and linear programming. This paper discussed these four methods' principles, calculation process, characteristics and application scope.This paper used A value and multi-source modeling methods, which are recommended by the National Environmental Protection Bureau, to calculate Changchun environmental capacity. The A value is one method developed in environment management practice total quantity control early stage. It is based on box modeling with clear pattern and convenient calculation, and can be used to determine the ideal environmental capacity. The multi-source modeling is, with relevant software, according to the requirements of ground environment quality, to optimize the source of pollution and reduce pollutant discharge, and finally obtain the allowable discharge capacity of city pollution sources. This method can be used to determine the actual environment capacity. This paper applied "the region air pollutant total quantity control model" to calculate Changchun actual environment capacity.(1) Changchun, the capital of Jilin Province, entire provincial politics, economy, cultural center, is located in the center of northeast Songliao Plain. Changchun landform is composed of mountainous region and plain. Changchun belongs to continental monsoon climatic region, and its precipitation decreases progressively from the east to the west, In spring it is dry with multi- winds; In summer it is hot and damp with multi- rain; In autumn it has clear sky and fresh air; In winter it is cold long. Changchun has distinct four seasons. Changchun annual mean temperature is 4.8℃, maximum temperature is 39.5℃, and most low temperature is -39.8℃. The leading wind direction is southwest wind, the average wind velocity is 3.9 m/s. Changchun urban district area is 3,603 km2, built-up district area is 228 km~2. Changchun governs 6 districts (Chaoyang, Nanguan, Erdao, Kuancheng, Lvyuan, Shuangyang) and 3 development zones (Changchun economic development zone, Changchun high-tech industry development zone and Changchun Jingyuntan traveling economic development zone).(2) In this paper capacity calculation can be divided into two scopes: One is the city control area, two is the urban control area. After defined air pollution factor and environment background value, divided control area according to 1 km~2 grid, evaluated present atmospheric environment quality, analyzed atmosphere pollution sources (point source and non-point source) and meteorology conditions, with the A value and the multi-source modeling methods, this paper obtained Changchun atmospheric environment capacity.(3) In fact the ideal environmental capacity calculation is to control the total quantity in the macroscopic stage. It is still in the start stage in China to apply environmental capacity in environment management. The ideal environmental capacity is to apply simple methods to determine approximate region environment capacity, which can simplify those complex questions and be advantageous to set up and execute the capacity total quantity control system. The actual environment capacity calculation can provide powerful support for the city air pollution control. The actual environment capacity calculation can establish the relationship between current pollution sources and environment quality, and effectively distinguish key factors influencing region environment quality. Since urban environment quality in most of Chinese cities occupies the improving stage, the actual environment capacity calculation has important practical significance.Through a series of research and discussion, it can be concluded that: As a natural science, the atmospheric environment capacity researches the basic processes of pollutants' transition in atmosphere, which may help people to understand the basic rules of regional air pollutants' creation and change; As a applied science, the atmospheric environment capacity research can obtain region atmospheric environment capacity, which can be used as the government's important technical support in determining region total quantity control targets, assigning region total quantity. This paper calculated and obtained Changchun atmospheric environment capacity, which may enable the limited atmospheric capacity resources to obtain more reasonable use, promote implementing the city air pollutant total quantity system and discharge permit system, and has important significance to local economy, society and environment harmony development.