Abstract: The hydrological response to land use change and the detectability of such response are researched in thispaper by SWAT model. The hydrological processes in Fujiangqiao catchment under two land use scenarios (1985and 1995) are simulated, and diagrams of land use conversion are obtained for analysis. Identical climate drivers are used in both scenarios to eliminate the effect of climate difference. Results reveal that no apparent hydrological responses are detected in spite of dramatic land use changes in Fujiangqiao catchment from 1985 to 1995. The similarity of hydrological effect of different land use types, the variation of hydrological effect of different land use types, the statistical compensation effect, and the statistical average effect are main reasons of the difficulty in detecting the hydrological responses. In view of this, a hydrological dynamic response degree is proposed to eliminate the statistical compensation effect, which helps researchers understand the degree of hydrological responses.

Key words: land use change, hydrological response, detectability, SWAT model, scenario analysis, Fujiangqiao catchment