The impact of land use change on ecosystem service value in Lanzhou region of Gansu Province

Through changing ecosystem´s internal structure and functiong, land use change has affected the supply of ecosystem services. Taking Lanzhou as a study area, this paper used the land use dynamic degree model and ecosystem service value evaluation model to analyse the characteristic of land use change and evaluate the ecosystem service value of Lanzhou from 1997 to 2005. And sensitivity index was introduced to verify the reliability of ecological value coefficient. The results show:Firstly,there were greater changes in the dissimilar land use types during the period of 1997-2005. The area of garden plot, forestland,residential land, industrial and mining land and traffic land increased. In contrast, the area of cultivated land,grassland,water region and unutilized land land decreased. Among which the changes of area and speed of residential Land and industrial and mining land were all the largest, with the land use dynamic degree of 18.15%, and its area changes to 119395.09 hm2 from 48689.79hm2 in the study period. Secondly, the ecosystem service value presented rising trend totally with the trend rate of 0.13%, which indicates that environmental effect by afforestation and conversion of cropland to forest has won initial success in Lanzhou.