Estimation of monetary value for vegetation´s air purification services supported by GIS - A case study in Xi´an, China

In the present study an attempt has been made to evaluate the value of vegetations´ air purification supported by Geographic Information System. Based on the theory and model about valuation of vegetations´ air purification services, the material quantities and value of vegetations´ air purification in Xi´an city were achieved. The results showed as the follows. Vegetations´ air purification services included CO₂ fixation, O₂ release, pollutants absorption (SO₂, HF, NO_X), dust retention, and sterilization. The total value of vegetations´ air purification was 3426.35 million Yuan per year, which was six percent of Xian´s GDP in 1999. Its value of CO₂ fixation and O₂ release was 2718.31 million Yuan per year, and that of absorbing the three pollutants, SO₂, HF, NO_X, was 182.9031 million Yuan. Their dust retention and sterilization value were 182.51 and 342.64 million Yuan respectively. Using GIS´s capabilities for inputting, storage, mapping, analysis and display of spatial data, we obtained spatial map of vegetations´ air purification value in Xi´an and discussed the discrepancies of different vegetation types´ air purification services