Abstract: As a typical plateau lake basin, the Qilu Lake drainage basin is vulnerable to ecological damage. In this research we select such indicators as elevation, slope, population density, road buffer zone, residential buffer zone, and water buffer zone to construct an index system for ecological sensitivity assessment. By combining the “G1” method and the variable weight grid theory, we calculate the weight of each index, and on this basis, assessed the basin's ecological sensitivity and analyzed the basin's land use for ecological security. Results demonstrate that: 1) incorporating variable weight grid theory effectively avoids the interference among factors; 2) the areas of high, medium and low sensitivity regions account for 3.66%, 71.08%, 22.83% of the total area of the river basin, respectively, while insensitive area accounts for 2.44%; 3) 93.81% of forest land, 99.22% of waters, and 79.52% of other land locate in highly sensitive and moderately sensitive areas, whereas 63.02% of construction land and 54.79% of cultivated land are located in areas of low sensitivity and insensitivity.Analyzing the ecological land use in the river basin would provide an important basis for promoting sustainable land resource use and exploitation as well as eco-environmental protection.

Key words: ecological sensitivity, ecological security land use, variable weight grid theory, G1 method, Qilu Lake Basin