title: Changes in stream peak flow and regulation in Naoli River watershed as a result of wetland loss.
abstract: Hydrology helps determine the character of wetlands; wetlands, in turn, regulate water flow, which influences regional hydrology. To understand these dynamics, we studied the Naoli basin where, from 1954 to 2005, intensive marshland cultivation took place, and the watershed's wetland area declined from 94.4 × 10(4)ha to 17.8 × 10(4)ha. More than 80% of the wetland area loss was due to conversion to farmland, especially from 1976 to 1986. The processes of transforming wetlands to cultivated land in the whole Naoli basin and subbasins can be described using a first order exponential decay model. To quantify the effects of wetlands cultivation, we analyzed daily rainfall and streamflow data measured from 1955 to 2005 at two stations (Baoqing Station and Caizuizi Station). We defined a streamflow regulation index (SRI) and applied a Mann-Kendall-Sneyers test to further analyze the data. As the wetland area decreased, the peak streamflow at the Caizuizi station increased, and less precipitation generated heavier peak flows, as the runoff was faster than before. The SRI from 1959 to 2005 showed an increasing trend; the SRI rate of increase was 0.05/10a, demonstrating that the watershed's regulation of streamflow regulation was declined as the wetlands disappeared.
authors.affiliation: College of Wildlife Resource, Northeast Forestry University, Harbin 150040, China ; Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, CAS, Changchun, Jilin 130012, China.
authors.forename: Yunlong
authors.initials: Y
authors.lastname: Yao
authors.affiliation: College of Architecture and Civil Engineering, Heilongjiang Institute of Science and Technology, Harbin 150027, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, CAS, Changchun, Jilin 130012, China.
authors.forename: Xianguo
authors.initials: X
authors.lastname: Lv
authors.affiliation: College of Wildlife Resource, Northeast Forestry University, Harbin 150040, China.
authors.forename: Hongxian
authors.initials: H
authors.lastname: Yu
authors.affiliation: College of Wildlife Resource, Northeast Forestry University, Harbin 150040, China.
authors.forename: Guofu
authors.initials: G
authors.lastname: Li
mesh_terms: D005843:Geography; D062070:Hydrology; D008962:Models, Theoretical; D045483:Rivers; D053833:Wetlands