Assessment And Early Warning Of Roadside Ecological Environmental Security

In recent decades, ecological environmental security problem has become such an important component of national security. With road networks stretching through almost every corner of the planet, the fact that roads influence ecological environment should come as no surprise, but the ecological environmental security problem of roadside environment have received little attention as a comprehensive category for research and conservation plans. Studies on assessment and early warning of roadside ecological environmental security are of global environment significance and in accordance with economic research demands for national environmental security construct of China.This dissertation was supported by the Key Foundation of Science and Technology Commission of Shanghai Municipality (No. 05DZ12007) and National Nature Science Foundation of China (No.40571006). Base on the field observations data, the relationship between roadside ecological environmental security and intensive human activities were analyzed, the assessment indicator set and assessment method of ecological environmental security were set up. Assessment of typical roadside ecological environmental security state was carried out, and main environmental pressures of roadside ecological environmental security were analyzed. Base on the changing of environmental pressures, early warning of roadside ecological environmental security was studied. Several major conclusions are shown as follows:(1) Roadside ecological environmental factors were analyzed; the result indicated that roadside soil environment, biotic environment, atmosphere environment, acoustical environment and water environment were most osculate to roadside ecological environment. Adopting Muller land accumulation index, the environmental factors' quality were assessment, the result shown that that roadside soil was mainly contaminated by cadmium and lead. Compared to the criterion of farmland environmental quality evaluation standards for edible agricultural products (HJ332-2006), lead was the main heavy metal contamination in roadside vegetable. Road dust was an important source of heavy metal contaminations in the roadside environment.(2) Use the pressure-state-response framework model for reference, the indicators set of roadside ecological environmental security state were set up which include atmosphere environment, soil environment, biotic environment, acoustical environment and water environment. By means of AHP-IEM method, the weights of assessment indicators were confirm. Plant Pb, Cd contents and soil Pb, Cd contents were the most important component of assessment indicators. (3) On the basis of analysis of the advantages and disadvantages of all present environmental and ecological assessment models, the optimized comprehensive assessment models of the roadside ecological environmental security, namely AHP-aggregative index-fuzzy correlation compound models, were set up. Assessments of typical roadside ecological environmental security were carried out. It was shown that ecological environmental security state of Chenhai, Beiyan, Huangnan and Gezhong road were reached level I-II; Huning and Ninglian road were reached level II-III, close to the middle warning state; security state of Zhengbian road was poor, which reached level III-IV.(4) The security state of roadside environmental factors was discussed, which indicated that security state of atmosphere; soil and biotic environment were poor. And dust Cd content, soil Pb, Cd content and plant Pb content contribute more to the roadside environmental security. Correlation analysis indicated that there was significant negative correlation between index VTF (VTF = Vehicle Flow * Time * Factor of Emission) and security state index (SI_RES).(5) Aim at the changing of vehicle flow and emission intension, simulation study of early warning of roadside ecological environmental security was carried out. The result shown that security state of Chenhai and Beiyan road were good during 20years, if the vehicle flow maintains 5000 pcu/d. If Vehicle flow reaching 15000 pcu/d, index SI_RES would fall below 0.75 after 2010. When the vehicle flow reached 70000 pcu/d, the security state of roadside environment would reach middle warning level.(6) The method to improving roadside ecological environmental security was compared. The result indicated emission control regulations of motor vehicles reaching Euro III standard before 2008 could increase 30000 vehicles per day. The appropriate method to improving security state includes (a) reaching Euro III emission control standard as soon as possible; (b) alter the land using type of roadside land 50m within; (c) construct roadside shelter-forest belt.