Characteristics Of Annual Runoff And Its Response To Climate Change Of Baghrash Lake Based On Wavelet Analysis

In this paper, Kai Du River, Huang Shui Gou and Qing Shui River were selected as the main researchobject in the basin of Bagrash Lake, the data of hydrological stations and weather stations at the basin wereused, Morlet wavelet analysis method was applied and the time series of cyclical change rule of the climateand runoff of the three river in the Bagrash basin was studied. This study shows:1) In the Kai Du River basin, the interannual variability of Runoff, precipitation and temperature isrelatively stable, the year’s distribution is mainly concentrated in the6-8months, and the average runoff,average precipitation and average temperature all appear in July. In the midstream of Kai Du River, thecontribution of summer precipitation to runoff is the most significant one, meanwhile, the contribution oftemperature to runoff is more significant than the precipitation to runoff at the downstream. According tothe wavelet trend analysis results, there were significant periods at scale of16a,28a for runoff,precipitation and temperature. Therefore, responses of the runoff variations to regional climate anomalies atthe midstream of Kai Du River were impressionable. At the downstream, there were significant periods atscale of28a for runoff and precipitation; it shows that the response of runoff variations to precipitation wasimpressionable while the temperature was not. In the small time scale, it will be dry season for3to4yearsafter2012, and the precipitation also going to be a fewer period, the temperature will be higher for4yearsafter2014. In the big time scale, it is predictable that the runoff will enter a wet season after2032, theprecipitation will enter a bullish period after2031，the temperature will enter a higher stage after2029.2) In Huang Shui Gou basin, the interannual variability of Runoff, precipitation and temperature isrelatively stable, the year’s distribution is mainly concentrated in the6-8months, and the average runoff,average precipitation and average temperature all appear in July. The contribution of summer temperatureto runoff is the most significant one, the contribution of temperature to runoff is more significant than theprecipitation to runoff. According to the wavelet trend analysis results, there were significant periods atscale of28a for runoff, precipitation and temperature. Therefore, responses of the runoff variations toregional climate anomalies at the Huang Shui Gou were impressionable; furthermore, the first main periodswere all28a except the temperature, therefore the response of the runoff variations to precipitation is moreimpressionable than to temperature. In the small time scale, it will be wet season after2012, and theprecipitation also enter a bullish period after2014, the temperature will be higher after2012. In the bigtime scale, it is predictable that the runoff will enter a wet season after2032, the precipitation will enter abullish period after2025，the temperature will enter a higher stage after2016.3）In Qing Shui River basin, the interannual variability of Runoff, precipitation and temperature isrelatively stable, the year’s distribution is mainly concentrated in the6-8months, and the average runoff,average precipitation and average temperature all appear in July. The contribution of summer precipitationto runoff is the most significant one; According to the wavelet trend analysis results, there were significantperiods at scale of28a for runoff, precipitation and temperature. Therefore, responses of the runoffvariations to regional climate anomalies at the Huang Shui Gou were impressionable. In the small timescale, it will be wet season after2012, and the precipitation also enter a bullish period after2013, thetemperature will be lower after2012. In the big time scale, it is predictable that the runoff will enter a wetseason after2032, the precipitation will enter a bullish period after2028，the temperature will enter a higher stage after2016.