Abstract: Land resources in mountainous areas are limited. Reasonable suitability evaluation of land development and functional zoning can comprehensively reflect spatial differences, which is conducive to the coordinated management of regional social and economic development and environmental protection. We quantitatively evaluated the suitability of the productionlivingecological (PLE) functions. Ecological function zone in the watershed was divided using ELI function clusters at township level. The results showed that the optimal and suitable areas of production function in the watershed ware 1894.36 km² and 1789.13 km², respectively, which together accounted for 28.78% of the total available area. The most suitable area and suitable area of living function were 568.10 km² and 909.10 km², respectively, together accounting for 11.54%. The suitability distribution of production and living functions had some overlap. The high suitability was mainly distributed in the northern part of Tanchang, the northeast of Wudu, and TanchangZhouquWudu section of the bothbank areas of Bailongjiang. The extremely important area and important area of ecological function ware 1776.49 km² and 3594.21 km², respectively,accounting for 41.96% of total area. They were patchily gathered in the mountainous areas of Diebu and Zhouqu, south of Wenxian and southeast of Wudu. According to the results of clusters, there were tradeoffs among ecological, production, and living function. The Bailongjiang Watershed could be divided into seven ecofunctional zones. We also proposed corresponding regulatory opinions. Our results provide reference for the scientific management and sustainable development of watershed land ecosystems.

Key words: green roof, water quantity and quality, urban region, rainfall runoff.