The Huolin River is one of the most important water sources for Xianghai wetland, Horqin wetland, and Chaganhu wetland in the western Songnen Plain of Northeast China. The annual runoff series of 46 years at Baiyunhus...The Huolin River is one of the most important water sources for Xianghai wetland, Horqin wetland, and Chaganhu wetland in the western Songnen Plain of Northeast China. The annual runoff series of 46 years at Baiyunhushuo Hydrologic Station, which is located in the middle reaches of the Huolin River, were analyzed by using wavelet analysis. Main objective was to discuss the periodic characteristics of the runoff, and examine the temporal patterns of the Huolin River recharging to the floodplain wetlands in the lower reaches of the river, and the corresponding effects of recharging variation on the environmental evolution of the wetlands. The results show that the annual runoff varied mainly at three time scales. The intensities of periodical signals at different time scales were strongly characterized by local distribution in its time frequency domain. The interdecadal variation at a scale of more than 30yr played a leading role in the temporal pattern ofrnnoffvariation, and at this scale, the runoffat Baiyunhushuo Hydrologic Station varied in turn of flood, draught and flood. Accordingly, the landscape of the floodplain wetlands presented periodic features, especially prominent before the 1990s. Compared with intense human activities, the runoff periodic pattern at middle （10-20yr） and small （1-10yr） scales, which has relatively low energy, exerted unobvious effects on the environmental evolution of the floodplain wetlands, especially after the 1990s.展开更多
The water budget of the examined wetland was extremely variable in the past six years. Principally, it was affected by the water regime of the River Danube and the climatic factors. In order to investigate the changes...The water budget of the examined wetland was extremely variable in the past six years. Principally, it was affected by the water regime of the River Danube and the climatic factors. In order to investigate the changes of these elements, and to succeed to forecast, statistical methods by using SPSS program were performed. The time series of the evaporation, of the precipitation and of the river＇s water-level were analysed by linear regression, by exponential smoothing, by deterministic models. In consequence of the river regulation, the low-water and the mean stage of Danube were decreasing during the last hundred years, because the riverbed was permanently deepening. Since the river has overflowed its bed and has inundated to the wide floodplain, the decrease of high-water did not appear. The decline of the flooded days signed the quicker passage of flood. These processes have prevented that the examined wetland is going to fill up from the floods. The difference in summer semester between the evaporation and the precipitation was increasing during the last fifty years. Therefore, the drying out of the wetland is going to be more frequent in the future. In the interests of the survival of this wetland, it is necessary to construct the restoring-system in the floodplain.展开更多
基金Under the auspices of Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX3-SW-332-01)
文摘The Huolin River is one of the most important water sources for Xianghai wetland, Horqin wetland, and Chaganhu wetland in the western Songnen Plain of Northeast China. The annual runoff series of 46 years at Baiyunhushuo Hydrologic Station, which is located in the middle reaches of the Huolin River, were analyzed by using wavelet analysis. Main objective was to discuss the periodic characteristics of the runoff, and examine the temporal patterns of the Huolin River recharging to the floodplain wetlands in the lower reaches of the river, and the corresponding effects of recharging variation on the environmental evolution of the wetlands. The results show that the annual runoff varied mainly at three time scales. The intensities of periodical signals at different time scales were strongly characterized by local distribution in its time frequency domain. The interdecadal variation at a scale of more than 30yr played a leading role in the temporal pattern ofrnnoffvariation, and at this scale, the runoffat Baiyunhushuo Hydrologic Station varied in turn of flood, draught and flood. Accordingly, the landscape of the floodplain wetlands presented periodic features, especially prominent before the 1990s. Compared with intense human activities, the runoff periodic pattern at middle （10-20yr） and small （1-10yr） scales, which has relatively low energy, exerted unobvious effects on the environmental evolution of the floodplain wetlands, especially after the 1990s.
文摘The water budget of the examined wetland was extremely variable in the past six years. Principally, it was affected by the water regime of the River Danube and the climatic factors. In order to investigate the changes of these elements, and to succeed to forecast, statistical methods by using SPSS program were performed. The time series of the evaporation, of the precipitation and of the river＇s water-level were analysed by linear regression, by exponential smoothing, by deterministic models. In consequence of the river regulation, the low-water and the mean stage of Danube were decreasing during the last hundred years, because the riverbed was permanently deepening. Since the river has overflowed its bed and has inundated to the wide floodplain, the decrease of high-water did not appear. The decline of the flooded days signed the quicker passage of flood. These processes have prevented that the examined wetland is going to fill up from the floods. The difference in summer semester between the evaporation and the precipitation was increasing during the last fifty years. Therefore, the drying out of the wetland is going to be more frequent in the future. In the interests of the survival of this wetland, it is necessary to construct the restoring-system in the floodplain.
