Evaluation of ecological marine islands construction based on material flow analysis: A case study of Changhai county

Abstract

Material flow analysis (MFA) has widely been used in the field of sustainable development research, but it was hardly applied in the sustainability valuation of marine islands eco-economic system. Marine islands eco-economic system is a critical component of the large marine eco-economic system. The construction of ecological marine islands is an important approach to establish marine islands eco-economic system in the course of sustainable development. Taking four indices as measurement, namely the direct material input (DMI), total material requirement (TMR), domestic direct material output (DMO) and total direct material output (TMO), the material input and output of Changhai County during 2003-2009 has been analyzed in this paper based on material flow analysis (MFA). According to these four basic indices, material input intensity, waste emission intensity and environmental pressure intensity are calculated to analyze the County's ecological efficiency. The contribution of technological progress to reducing the ecological pressure of these marine islands is also considered through elasticity coefficient of ecological pressure and contribution rate of technological progress. The first result shows that material input quantity, waste emission quantity and environmental pressure quantity have National Marine Environmental Monitoring Center, State Oceanic Administration People's Republic of China, Dalian 116023, China increased rapidly during 2003-2009. The direct material input (DMI) presents rising tendency, up from 1.12 million ton in 2003 to 1.85 million ton in 2009, and the average annual growth rate is 8.8%; total material requirement (TMR) increases faster than DMI, with the average annual growth rate at about 9.7%. However, the growth rates of two indices of material output, namely domestic direct material output(DMO) and total direct material output(TMO), whose average annual growth rates are 12.60% and 12.53% respectively, reflect that waste emission growth are the fastest-growing indices. Fresh water is the largest input material in DMI, and the average annual proportion is about 34.67%. With more and more material imports during the seven years, the import material share of DMI rises from 12.09% in 2003 to 20.12% in 2009. Waste gas and waste water emission are main parts of DMO, whose average annual proportions of DMO are 54.77% and 42.64% respectively. The second result shows that ecological efficiency of the marine islands county has been greatly improved during the construction of ecological marine inlands since 2003. Material use intensity declines from 7.06 ton per ten thousand yuan in 2003 to 5.24 ton per ten thousand yuan in 2009, and the average annual decreasing rate is 4.85%. Average annual decreasing rates of waste emission intensity and environmental pressure intensity are 1.53% and 3.31% respectively, which are slower than that of material use intensity. This indicates that the sustainable development capability of the marine islands eco-economic system has been improving continuously. The third result shows that the contribution of technological progress to reduce ecological stress hardly neutralizes the increasing amount of ecological pressure caused by economic growth during the same period. The decrease amount of resources use resulting from material use intensity reduction only accounts for 38.65% of the increase amount of resources use caused by GDP growth. Contribution of waste emission intensity and environmental pressure intensity to relieving ecological stress are 12.16% and 26.35% respectively, both of which are less than that of material use intensity. In order to slow down material input,waste emission and relieve the pressure from economic activity on marine islands ecological system, it is essential to continue improving ecological efficiency through technological progress based on establishing innovative management mechanism.