In recent years, the frequency of geological disasters gradually increases in the gully region of the Loess Plateaus centred with Yanhe River Basin. The research on the forming of the geological disasters in gully reg...In recent years, the frequency of geological disasters gradually increases in the gully region of the Loess Plateaus centred with Yanhe River Basin. The research on the forming of the geological disasters in gully region and the disaster process will help us further understand the development of geological disasters and the disaster process. According to the detailed survey of geological disasters in Yan’an City, the river and gully erosion is the main natural predisposing factor that caused the geological disasters in the river gully region. In the forming of ditches and gullies, the surface water system changes the stress form of the original slope and reduces the strength combination of the slope in ways of water erosion and gravity erosion. Gully’s forming stage and stratigraphic contact form have some influence on the geological disasters and disaster process.展开更多
[Objective] The aim was to study the climate changes of Yanhe watershed during 1974-2004. [Method] The monthly temperature and precipitation during 1974-2004 in seven representative stations in Yanhe watershed were ch...[Objective] The aim was to study the climate changes of Yanhe watershed during 1974-2004. [Method] The monthly temperature and precipitation during 1974-2004 in seven representative stations in Yanhe watershed were chosen. By dint of climate statistics analysis method, accumulated anomaly and signal/noise ratio method, the regional temperature and precipitation changes in recent 31 years were expounded and its changes features and the year having climate mutation were found out. [Result] The climate changes in Yanhe watershed in recent 31 years rose at a speed of 0.44 ℃/10 a. The temperature increase range enlarged after 1990s. Precipitation decreased at a speed of 26.3 mm/10 a. Precipitation reduced most distinctly in summer and autumn, and the reduction range enlarged in 1990s. 1996 was the year of abrupt temperature changes year in the region. 1993 was the year of temperature transition year. 1994 was the year of precipitation mutation year. 1990 was the year of precipitation transition year. [Conclusion] The study provided references for the agricultural production, life and disaster pre-warning in Yanhe watershed.展开更多
基金“Twelfth National Five-Year Plan” for science in 2013 “Research and demonstration of key technology of engineering construction in loess hill-gully area” (Item number: 2013BAJ06B03, 2013BAJ06B04)Science and technology co-ordinating innovative engineering projects in Shaanxi Province in 2013 “Research on geological and geotechnical engineering construction in loess hill-gully area of Yan’an City” (Item number: 2012KTZD03-04, 07)
文摘In recent years, the frequency of geological disasters gradually increases in the gully region of the Loess Plateaus centred with Yanhe River Basin. The research on the forming of the geological disasters in gully region and the disaster process will help us further understand the development of geological disasters and the disaster process. According to the detailed survey of geological disasters in Yan’an City, the river and gully erosion is the main natural predisposing factor that caused the geological disasters in the river gully region. In the forming of ditches and gullies, the surface water system changes the stress form of the original slope and reduces the strength combination of the slope in ways of water erosion and gravity erosion. Gully’s forming stage and stratigraphic contact form have some influence on the geological disasters and disaster process.
基金Supported by National Natural Science Youth Fund (41001374)Basic Scientific Research Business of Central Universities and Basic Research Support Fund of Chang'an University (CHD2009JC167)Basic Science and Research Business of Central University (Human Social Science Fund) (Y1014)
文摘[Objective] The aim was to study the climate changes of Yanhe watershed during 1974-2004. [Method] The monthly temperature and precipitation during 1974-2004 in seven representative stations in Yanhe watershed were chosen. By dint of climate statistics analysis method, accumulated anomaly and signal/noise ratio method, the regional temperature and precipitation changes in recent 31 years were expounded and its changes features and the year having climate mutation were found out. [Result] The climate changes in Yanhe watershed in recent 31 years rose at a speed of 0.44 ℃/10 a. The temperature increase range enlarged after 1990s. Precipitation decreased at a speed of 26.3 mm/10 a. Precipitation reduced most distinctly in summer and autumn, and the reduction range enlarged in 1990s. 1996 was the year of abrupt temperature changes year in the region. 1993 was the year of temperature transition year. 1994 was the year of precipitation mutation year. 1990 was the year of precipitation transition year. [Conclusion] The study provided references for the agricultural production, life and disaster pre-warning in Yanhe watershed.
