The objectives of the current study were to estimate evapotranspiration（ET） over the grassland and assess seasonal variation of moisture availability at the wind-water erosion crisscross region in the northern Loess...The objectives of the current study were to estimate evapotranspiration（ET） over the grassland and assess seasonal variation of moisture availability at the wind-water erosion crisscross region in the northern Loess Plateau of China. The Liudaogou Catchment which has the representative climatic and hydrological characteristics of the wind-water erosion crisscross region was chosen as the study location. The reference crop evapotranspiration（ET 0） was estimated by Penmen method, which was recommended by FAO56 and the evapotranspiration over the grassland（ET） was estimated by Penmen-Monteith equation using the observed meteorological data with time unit of 1 h. The soil moisture availability factor was defined by m a =ET/ET 0. The calculated results for 2006 indicated that the total ET 0 was slightly more than the total yearly precipitation and ET accounted for 37 % of that, ET increased distinctly after the intensive rainfall event in the rainy season. Most of the m a was less than 0.4 and its annual mean was 0.34. It was expected that the results provided a basis for studies on dynamic functional analysis of soil moisture, relationship between soil water and crop growth at the wind-water erosion crisscross region in the northern Loess Plateau.展开更多
The objective of this study was to analyze the water budget of a small basin in the northern of Loess Plateau. A small basin, Liudaogou in the northern Loess Plateau was chosen as the study area. The numerical calcula...The objective of this study was to analyze the water budget of a small basin in the northern of Loess Plateau. A small basin, Liudaogou in the northern Loess Plateau was chosen as the study area. The numerical calculation of surface runoff was applied to results of the field survey, and components of monthly water budget were estimated. The unit area of 1 km2 was selected as the index area for the estimation. A component of habitant water consumption was added to the water budget to consider the contribution of human activity. Results indicated that the water storage was negative in May, June and July while the annual amount was approximately 0.0. Evaportanspiration attained maximum in August and its annual total accounted for 74.2% of annual precipitation. Results of this study are significant for the sustainable water conservation and utilization in the northern of Loess Plateau where annual water resources are relatively deficient.展开更多
The Soil Conservation Monitorins Information System (SCMIS) presented in this paper is oriented to soil erosion control, resources exploitation, utilization, planning and management for a small watershed (about 10 sq....The Soil Conservation Monitorins Information System (SCMIS) presented in this paper is oriented to soil erosion control, resources exploitation, utilization, planning and management for a small watershed (about 10 sq. km.) on the Loess Plateau. It sums up Remote sensing (RS), Geographical Information System (GIS) and Expert System (ES) and consists of a integrated system. As a basic level information system of Loess Plateau, its perfection and psreading will bring about a great advance in resources exploitation and management of Loess Plateau.展开更多
Modern meteorological observations have proved that climate change in the northeast Tibet plateau is characteristic of alternations of plateau summer and winter monsoons, and climate change in Chinese Loess plateau is...Modern meteorological observations have proved that climate change in the northeast Tibet plateau is characteristic of alternations of plateau summer and winter monsoons, and climate change in Chinese Loess plateau is geared by variations of East Asian summer and winter monsoon strengths. A transitional zone between regions dominated by plateau monsoon and East Asian monsoon respectively is located at around 110°E in China. The two monsoon systems are driven by different forcing aspects.Here we show the two climatic systems change during the last interglacial period (IG) by examining geological records. Two aeolian loess\|paleosol sequences,one is located in northeast Tibet plateau closed to Xining and the other one in the northwest Loess plateau closed to Huanxian, were investigated. Age frames of the paleosol and intercalated loess are achieved by Thermoluminescence dating, palaeomagnetic measurements and stratigraphy correlation. Samples taken from Huanxian section were at 5cm intervals, and samples from Xining section were taken at every 10cm. The samples were measured for magnetic susceptibility (MS), rubidium/strontium value (Rb/Sr), Calcium carbonate content (CaCO\-3) and grain\|size distribution (GS). Detail time scale is obtained by two steps. First, correlate MS curves with deep\|sea oxygen isotope time series of stage 4,5 and 6 of Martinson et al (1987) to assign ages of boundaries of stratigraphic units. Second, linearly interpolate ages between the obtained ages and therefore get age of each sampling point.展开更多
基金Supported by the National Natural Science Foundation of China(NSFC)(41271046)Postdoctoral Science Foundation of China(Oversea scholar,87328)+1 种基金Heilongjiang Provincial Department of Education Scientific Research Foundation for overseas scholars,China(1251H017)Scientific Research Foundation of Northeast Agricultural University of China(115-180152)
文摘The objectives of the current study were to estimate evapotranspiration（ET） over the grassland and assess seasonal variation of moisture availability at the wind-water erosion crisscross region in the northern Loess Plateau of China. The Liudaogou Catchment which has the representative climatic and hydrological characteristics of the wind-water erosion crisscross region was chosen as the study location. The reference crop evapotranspiration（ET 0） was estimated by Penmen method, which was recommended by FAO56 and the evapotranspiration over the grassland（ET） was estimated by Penmen-Monteith equation using the observed meteorological data with time unit of 1 h. The soil moisture availability factor was defined by m a =ET/ET 0. The calculated results for 2006 indicated that the total ET 0 was slightly more than the total yearly precipitation and ET accounted for 37 % of that, ET increased distinctly after the intensive rainfall event in the rainy season. Most of the m a was less than 0.4 and its annual mean was 0.34. It was expected that the results provided a basis for studies on dynamic functional analysis of soil moisture, relationship between soil water and crop growth at the wind-water erosion crisscross region in the northern Loess Plateau.
基金Supported by JSPS Core University Program, Japan CAS "Western Light" (2006YB04)
文摘The objective of this study was to analyze the water budget of a small basin in the northern of Loess Plateau. A small basin, Liudaogou in the northern Loess Plateau was chosen as the study area. The numerical calculation of surface runoff was applied to results of the field survey, and components of monthly water budget were estimated. The unit area of 1 km2 was selected as the index area for the estimation. A component of habitant water consumption was added to the water budget to consider the contribution of human activity. Results indicated that the water storage was negative in May, June and July while the annual amount was approximately 0.0. Evaportanspiration attained maximum in August and its annual total accounted for 74.2% of annual precipitation. Results of this study are significant for the sustainable water conservation and utilization in the northern of Loess Plateau where annual water resources are relatively deficient.
文摘The Soil Conservation Monitorins Information System (SCMIS) presented in this paper is oriented to soil erosion control, resources exploitation, utilization, planning and management for a small watershed (about 10 sq. km.) on the Loess Plateau. It sums up Remote sensing (RS), Geographical Information System (GIS) and Expert System (ES) and consists of a integrated system. As a basic level information system of Loess Plateau, its perfection and psreading will bring about a great advance in resources exploitation and management of Loess Plateau.
文摘Modern meteorological observations have proved that climate change in the northeast Tibet plateau is characteristic of alternations of plateau summer and winter monsoons, and climate change in Chinese Loess plateau is geared by variations of East Asian summer and winter monsoon strengths. A transitional zone between regions dominated by plateau monsoon and East Asian monsoon respectively is located at around 110°E in China. The two monsoon systems are driven by different forcing aspects.Here we show the two climatic systems change during the last interglacial period (IG) by examining geological records. Two aeolian loess\|paleosol sequences,one is located in northeast Tibet plateau closed to Xining and the other one in the northwest Loess plateau closed to Huanxian, were investigated. Age frames of the paleosol and intercalated loess are achieved by Thermoluminescence dating, palaeomagnetic measurements and stratigraphy correlation. Samples taken from Huanxian section were at 5cm intervals, and samples from Xining section were taken at every 10cm. The samples were measured for magnetic susceptibility (MS), rubidium/strontium value (Rb/Sr), Calcium carbonate content (CaCO\-3) and grain\|size distribution (GS). Detail time scale is obtained by two steps. First, correlate MS curves with deep\|sea oxygen isotope time series of stage 4,5 and 6 of Martinson et al (1987) to assign ages of boundaries of stratigraphic units. Second, linearly interpolate ages between the obtained ages and therefore get age of each sampling point.
