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Indexed by:期刊论文

Date of Publication:2016-08-01

Journal:JOURNAL OF HYDROLOGIC ENGINEERING

Included Journals:SCIE

Volume:21

Issue:8

ISSN No.:1084-0699

Key Words:Hydraulic project construction; Climate variability; Climate elasticity; Runoff decrease

Abstract:Many hydraulic projects as reservoirs, ponds, paddy fields, and soil and water conservation engineering projects have been constructed upstream of the Wudaogou station basin in northeast China. This study investigates the impact of climate variability and hydraulic project construction on the runoff decrease through the concept of climate elasticity. The elasticity of streamflow in relation to precipitation and potential evapotranspiration is calculated by four methods: two nonparametric estimators, two parametric estimators. Results show that for the period 1936-2010 the two nonparametric climate elasticity methods show a smaller value of the elasticity of streamflow in relation to precipitation (1.85 and 2.47) but a larger value of the elasticity of streamflow in relation to potential evapotranspiration (-0.02 and -0.48) than the parametric estimators. It is estimated that climate variability is responsible for 47.3% (40.3mm) of the streamflow reduction between 1936-1956 and 1957-2010, while hydraulic project construction contribute to 52.7% (45.1mm) of the reduction. From 1957 to 2010, the amount of construction for water conservancy has been growing. To further investigate the effect of hydraulic project construction, the study period (1957-2010) is split into three subperiods using two faint jump points (1975 and 1987), and the effect of hydraulic project construction on the runoff during each subperiod is evaluated. The results indicate that as the cumulative storage of hydraulic projects increases, hydraulic project construction plays an increasingly important role (from 12.8 to 90.8%) in streamflow change. Almost all the results show that streamflow changes due to hydraulic project construction are less than the cumulative storage of the hydraulic projects, which verifies the reliability of the theoretical calculation.