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11.
Based on regionalized variable theory, semivariograms of geo-statistics were used to research the spatial variation of soil properties quantitatively. The results showed that the semivariogram of soil organic matter is best described by spherical model, the best model for semivariograms of soil total N and available K is exponential models and that of available P belongs to linear with sill model. Those soil properties have different spatial correlations respectively, the lag of organic matter is the highest and that of available P is the lowest, the spatial correlation of N and available K belongs to moderate degree. Spatial heterogeneities are different too, the degree of organic matter and total N are higher, the degree of available K is in the next place and that of available P is the lowest. Influenced by the shape, topography and soil of the study area, all isotropies of available P are obvious in all directions while anisotropies of others are manifested. According to the analytical results, supported by GIS, Kriging and IDW methods are applied to describe and analyze the spatial distribution of soil properties. The results indicate that soil organic matter, total N and available K are distributed regularly from northeast to southwest, while available P is distributed randomly. 相似文献
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利用丹东地区1951—2009年4个测站逐日降水资料,对丹东地区暴雨变化进行了分析。结果表明:丹东地区年暴雨日数和暴雨量呈减少趋势,汛期洪涝贡献率趋势变化不明显;2001—2009年6月份暴雨日数明显增多,7月份暴雨日数偏少,暴雨初期和终期提前。 相似文献
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Chemical characteristics and environmental significance of fresh snow deposition on Urumqi Glacier No. 1 of Tianshan Mountains, China 总被引:2,自引:0,他引:2
Ice and snow chemistry of alpine glaciers is crucial for the research of regional atmospheric environment change. Fresh snow samples were weekly collected from Urumqi Glacier No.1 in the Tianshan Mountains, Xin- jiang, China, and the chemical characteristics and seasonal variations of major ions, mineral dust, δ18O and trace metals were measured. Results show that the concentrations of major ions in the snow are Ca2+ SO42- NH4+ NO3- Cl- Na+ Mg2+ K+, in which Ca2+ is the dominant cation, and SO42-is the dominant anion. All major ions have close positive correlations with each other except NO3-. δ18O shows positive correlation with air temperature change during the study period. Mineral dust particle and major ionic concentrations in fresh snow have obvious seasonal change, with high concentration in spring but low concentration in summer and autumn, which indicates that the chemical mass input from Asian dust activity to snow is very significant. Temporal changes of trace metals in fresh snow, e.g., Cd, Pb, Zn, Al, Fe, have shown that human-induced pollution of central Asian region also has large contribution to the snow chemistry on alpine glaciers of the Tianshan Mountains. 相似文献
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Decomposition and Evolution of Intracontinental Strike-Slip Faults in Eastern Tibetan Plateau 总被引:2,自引:0,他引:2
Little attention had been paid to the intracontinental strike-slip faults of the Tibetan Plateau. Since the discovery of the Longriba fault using re-measured GPS data in 2003, an increasing amount of attention has been paid to this neglected fault. The local relief and transverse swath profile show that the Longriba fault is the boundary line that separates the high and flat tomography of the Tibet plateau from the high and precipitous tomography of Orogen. In addition, GPS data shows that the Longriba fault is the boundary line where the migratory direction of the Bayan Har block changed from eastward to southeastward. The GPS data shows that the Longriba fault is the boundary fault of the sub-blocks of the eastern Bayan Har block. We built three-dimensional models containing the Longriba fault and the middle segment of the Longmenshan fault, across the Bayan Har block and the Sichuan Basin. A nonlinear finite element method was used to simulate the fault behavior and the block deformation of the Eastern Tibetan Plateau. The results show that the low resistivity and low velocity layer acts as a detachment layer, which causes the overlying blocks to move southeastward. The detachment layer also controls the vertical and horizontal deformation of the rigid Bayan Har block and leads to accumulation strain on the edge of the layer where the Longmenshan thrust is located. After a sufficient amount of strain has been accumulated on the Longmenshan fault, a large earthquake occurs, such as the 2008 Wenchuan earthquake. The strike slip activity of the Longriba fault, which is above the low resistivity and low velocity layer, partitions the lateral displacements of the Bayan Har block and adjusts the direction of motion of the Bayan Har block, from the eastward moving Ahba sub-block in the west to southeastward moving Longmenshan sub-block in the east. 相似文献
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天山乌鲁木齐河源1号冰川消融对气候变化的响应 总被引:5,自引:0,他引:5
目前气候变暖导致的冰川退缩,引起了全世界的广泛关注。 以新疆天山乌鲁木齐河源1号冰川为例,根据1958年以来的观测资料,研究了冰川消融对气候变化的响应。结果表明,近50 a来冰川在表面粒雪特征、成冰带、冰川温度、面积、厚度及末端位置等方面发生了显著变化,而这些变化均与气温的升高有着密切的联系;20世纪80年代以来的快速升温,使冰川的退缩出现了加速趋势,冰川融水径流量也呈加速增大趋势。 相似文献
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陆域与海域的社会经济发展是沿海区域可持续发展的重要表现,共同作用于沿海区域经济,但在长期“重陆轻海”的理念下,陆域与海域社会经济关系并未得到有序发展,两者需在长期发展中寻求社会经济关系的平衡点,促进沿海区域绿色协调发展。从海洋经济与沿海陆域经济发展、陆海联动、陆海一体化、陆海统筹等4个方面综述了陆海社会经济关系的研究进展,并指出未来陆海社会经济关系研究应突破现有的研究视角与方法;加强陆海社会经济统计指标体系的构建研究;注重陆海社会经济不同尺度下的时空序列研究;强化陆海社会经济战略下综合性管理监督机制;同时优化其理论体系的构建,注重实践性与对比性的研究。 相似文献
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