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地区经济和社会的高速发展,给区域的生态环境造成巨大的生态压力,成为影响地区可持续发展的制约因素.生态环境功能区划是根据生态环境要素特征、生态服务功能空间分异规律及生态承载力,将一个区域划分为不同生态环境功能区的过程,是生态市(县)建设规划的重要组成部分.本文以生态承载力理论为生态环境功能区划技术基础,分析探讨了市(县)域生态功能区划的主要功能和需要解决的核心问题,并以福清市为例探讨了生态环境功能区划的实际应用方法,供读者商榷. 相似文献
945.
青海省塔拉滩草原利用方向探讨 总被引:12,自引:0,他引:12
青海省共和县塔拉滩是一个平坦开阔的大草原,近40多年来一直有宜农与宜牧之争。本文就此,从3个方面作了重点论述:垦滩种粮的后果严重;超载过牧也有潜在生态危机;最佳出路是将根治沙源与合理利用草原结合起来,发展季节畜牧业,走一条治用结合、滩谷互补、农牧业相互促进的道路,建设一个新型草原。 相似文献
946.
黄土丘陵“梯田退耕”生态重建及地域分异特征 总被引:6,自引:1,他引:6
基于黄土丘陵区过去10年科技攻关成果及延安燕沟流域示范成功经验,在总结“梯田退耕”生态重建模式特点的基础上,根据土地利用、坡耕地和1999年农业人口数据计算了各县(市、区)需新修梯田、园地扩建、林草植被恢复的面积及投资需求额度。通过构建并采用基本农田扩建指数、园地扩建指数、林草植被恢复指数以及投资需求密度等指标对55个县(市、区)进行了类型划分和地域分异特征分析。结果表明:黄土丘陵区需新修梯田面积69.16×104hm2,新扩建经济林果园地面积79.2×104hm2,林草植被恢复面积541.02×104hm2,投资需求总额度158.2×108元;生态重建在地域分布上明显存在两个重点区,一个位于陕北和晋西北交界地区,另一个位于陇东和宁南地区;宜及早制定区域性分类指导政策,并应将有限的资金集中在重点区。 相似文献
947.
干旱区水资源承载能力综合评价研究——以新疆和田河流域为例 总被引:98,自引:0,他引:98
本文以新疆和田河流域为例,重点探讨了我国西北干旱区水资源承载能力综合评价的方法,并将模糊综合评判方法应用于该研究,建立了分析评价模型。最后应用该模型对和田河流域水资源承载能力进行了评价研究。从而为该流域水资源合理利用提供了决策依据。同时,本研究也为干旱区水资源承载能力研究提供了经验和模式。 相似文献
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Vaiskunaite R Baltrenas P Spakauskas V 《Environmental science and pollution research international》2005,12(5):297-301
Aim, Scope and Background Human economic activities cause emissions of various pollutants of an organic nature: butanol, butyl acetate, methanol, formaldehyde,
phenol, benzene, toluene, xylene, etc. These compounds are emitted to atmosphere by various enterprises of food, chemistry,
wood processing industries, from transportation means, agricultural enterprises, etc. Therefore, when purifying air from these
pollutants, it is necessary to apply efficient and inexpensive air purification methods. In this dimension, the biological
air purification is chosen from all possible air cleaning methods. An experimental biofilter with the activated charge of
pine bark was developed at the Department of Environment Protection of the Vilnius Gediminas Technical University. In the
course of the experimental investigation, it was determined that this air purification method is efficient. Filter efficiency,
when purifying air of volatile organic compounds (butanol, butyl acetate and xylene), to a great extent, depending on the
nature and concentrations (up to 100 mg/m3) of pollutants injected, might go up to
70-98%. The mathematical model of the biofilter was developed based on the research results and fully taking into consideration
physical, chemical, and biological processes going on during its operations.
Main Features The aim of this article is to determine biodegradation constant , absorption capacity , and half empiric expressions of
filter efficiency. Knowing this, it is possible to find out the dependence of the filter efficiency on the operational parameters
of the filter (i.e. on the concentrations and the height of biocharge of the initial pollutants (butanol, butyl acetate, xylene)
fed through it).
Conclusions With the help of mathematical modeling, the biodegradation constants and absorption capability of volatile organic compounds
(butanol, butyl acetate, and xylene) fed into the biofilter charged with the activated pine bark and used for the cleaning
of volatile organic compounds, as well as the efficiency of the biofilter in half empiric expression, have been established.
It has been discovered that the constant of pollutant biodegradation is a value inverse to the time during which the amount
of pollutants in the filter becomes times higher. It is rather complicated to carry out theoretical calculation of the biodegradation
constant at a molecular level, therefore this constant has been established based on the results obtained in the course of
research. The equations describing pollutant dynamics in the filter charge and the air cleaning processes going on in it have
been derived from diffusion equations in a mobile medium. The modeling helped to find out the absorption capacity of the
examined pollutants, which by its numeric value is equal to the volume unit of the absorbed gas amount. The latter factor,
the same as the biodegradation constant, was determined basing on the experimental results. Mathematical modeling brought
a range of formulas expressing dependences of each pollutant's efficiency on its initial concentrations and filter charge
height.
Recommendation /Outlook. Based on the experimental data, a mathematical model has been developed which will allow the measuring of the filter
efficiency not only with regard to the absorption and biodegradation of the pollutants under examination, but also with regard
to other pollutants and their compounds, etc., having an impact on the filter performance. The results of the mathematical
modeling have revealed that the modeling of processes going on in the filter is much simpler than isthe performance of long
and costly experiments. The developed mathematical model makes it possible to measure the filter efficiency at the present
moment. 相似文献