Here,we quantitatively determine temporal and spatial distribution characteristics of main grain crops in the West Liaohe River basin,Inner Mongolia,China,from 2000 to 2010 based on MODIS remote sensing data and NDVI ...Here,we quantitatively determine temporal and spatial distribution characteristics of main grain crops in the West Liaohe River basin,Inner Mongolia,China,from 2000 to 2010 based on MODIS remote sensing data and NDVI time series information for the years 2000,2005 and 2010.Phenological calendars and a decisionmaking tree extraction model were also used to obtain spatial distribution information of spring maize,spring wheat and soybean.We found that in 2010,the sown area of the main grain crops in the West Liaohe River basin was 11 965.08km2,of which,the sown area for spring maize accounted for 92.28%and was concentrated in the lower reaches of the region.Spring wheat accounted for 3.14% and was mainly in the middle reaches.Soybean accounted for 4.58% and was predominantly in the upper reaches.From 2000 to 2005,the sown area of these grain crops in the West Liaohe River basin grew by 29.77%,mainly in the lower reaches： spring maize grew by 38.99%,spring wheat by 39.04% and soybean by 21.27%.From 2005 to 2010,growth in the sown area of these crops was slow（5.18% growth） and mainly in the lower reaches of the basin.The sown area of spring maize increased,but decreased for both spring wheat and soybean.展开更多
[Objective] Study on the spatial distribution of summer precipitation patterns and interannual and interdecadal variability. [Method] The summer precipitation patterns were obtained from standard field of summer preci...[Objective] Study on the spatial distribution of summer precipitation patterns and interannual and interdecadal variability. [Method] The summer precipitation patterns were obtained from standard field of summer precipitation data for 160 observation stations in China during 1951 -2000 by the utilization of empirical orthogonal function （EOF）, and characteristics of interannual and interdecadal variability were analyzed. [Result] The summer precipitation mainly distributes in eastern part of China; The 1 st, 2nd and 3rd EOF modes of spatial distribution are especially remarkable as well consistent with the results of previous reports about three rainfall patterns from analysis on the percentages of precipitation anomaly of summer. [Conclusion] There exists interannual and interdecadal variability for summer precipitation in China.展开更多
蓝绿水评价可为流域水资源的全面管理提供科学参考,以地形复杂的乌江流域为例,基于SWAT(Soil and Water Assessment Tool)水文模型,通过年径流距平百分率法确定不同降水年型,利用曼-肯德尔M-K检验法(Mann-Kendall Trend Method)和线性...蓝绿水评价可为流域水资源的全面管理提供科学参考,以地形复杂的乌江流域为例,基于SWAT(Soil and Water Assessment Tool)水文模型,通过年径流距平百分率法确定不同降水年型,利用曼-肯德尔M-K检验法(Mann-Kendall Trend Method)和线性回归趋势分析法分析评估乌江流域1992-2019年蓝绿水资源量时空特征和不同降水年型蓝绿水年内分配和空间分布差异。结果表明:(1)SWAT模型模拟效果较好,可以准确描述乌江流域水循环过程;(2)流域多年平均降水量、蓝水资源量和绿水资源量分别为1126mm、549mm和589mm,降水量和蓝水资源量总体呈下降趋势,绿水资源量总体呈上升趋势;(3)丰水年、平水年和枯水年绿水系数分别为46%、52%和58%,绿水资源量有所变化,对生态系统维持起重要作用;(4)从流域上游到下游,降水量和蓝水资源量均呈现出先增加再减少的趋势,绿水资源量呈现出先增加再减少最后增加的趋势;(5)蓝水资源量时空分布差异主要受降水量变化影响,绿水资源量时空分布受到降水量、气温和土地利用覆被变化的影响。展开更多
This study has revealed spatial-temporal changes in Recreational Business Dis- tricts （RBDs） in Beijing and examined the relationship between the location of urban RBDs and traffic conditions, resident and tourist d...This study has revealed spatial-temporal changes in Recreational Business Dis- tricts （RBDs） in Beijing and examined the relationship between the location of urban RBDs and traffic conditions, resident and tourist density, scenic spots, and land prices. A more reasonable classification of urban RBDs （LSC, CPS, and ULA） is also proposed. Quantitative methods such as Gini Coefficient, Spatial Interpolation, Kernel Density Estimation, and Geographical Detector were employed to collect and analyze the data from three types of urban RBDs in Beijing in 1990, 2000, and 2014, respectively, and the spatial-temporal pat- terns as well as the distribution characteristics of urban RBDs were analyzed using ArcGIS software. It was concluded that （1） both the number and scale of urban RBDs in Beijing have been expanding and the trend for all types of urban RBDs in Beijing to be spatially agglom- erated is continuing; （2） the spatial-temporal evolution pattern of urban RBDs in Beijing is ＂single-core agglomeration-dual-core agglomeration-multi-core diffusion＂; and （3） urban RBDs were always located in areas with low traffic density, tourist attractions, high resident and tourist population density, and relatively high land valuations; these factors also affect the scale size of RBDs.展开更多
基金National Natural Science Foundation of China(41271541)
文摘Here,we quantitatively determine temporal and spatial distribution characteristics of main grain crops in the West Liaohe River basin,Inner Mongolia,China,from 2000 to 2010 based on MODIS remote sensing data and NDVI time series information for the years 2000,2005 and 2010.Phenological calendars and a decisionmaking tree extraction model were also used to obtain spatial distribution information of spring maize,spring wheat and soybean.We found that in 2010,the sown area of the main grain crops in the West Liaohe River basin was 11 965.08km2,of which,the sown area for spring maize accounted for 92.28%and was concentrated in the lower reaches of the region.Spring wheat accounted for 3.14% and was mainly in the middle reaches.Soybean accounted for 4.58% and was predominantly in the upper reaches.From 2000 to 2005,the sown area of these grain crops in the West Liaohe River basin grew by 29.77%,mainly in the lower reaches： spring maize grew by 38.99%,spring wheat by 39.04% and soybean by 21.27%.From 2005 to 2010,growth in the sown area of these crops was slow（5.18% growth） and mainly in the lower reaches of the basin.The sown area of spring maize increased,but decreased for both spring wheat and soybean.
文摘[Objective] Study on the spatial distribution of summer precipitation patterns and interannual and interdecadal variability. [Method] The summer precipitation patterns were obtained from standard field of summer precipitation data for 160 observation stations in China during 1951 -2000 by the utilization of empirical orthogonal function （EOF）, and characteristics of interannual and interdecadal variability were analyzed. [Result] The summer precipitation mainly distributes in eastern part of China; The 1 st, 2nd and 3rd EOF modes of spatial distribution are especially remarkable as well consistent with the results of previous reports about three rainfall patterns from analysis on the percentages of precipitation anomaly of summer. [Conclusion] There exists interannual and interdecadal variability for summer precipitation in China.
文摘蓝绿水评价可为流域水资源的全面管理提供科学参考,以地形复杂的乌江流域为例,基于SWAT(Soil and Water Assessment Tool)水文模型,通过年径流距平百分率法确定不同降水年型,利用曼-肯德尔M-K检验法(Mann-Kendall Trend Method)和线性回归趋势分析法分析评估乌江流域1992-2019年蓝绿水资源量时空特征和不同降水年型蓝绿水年内分配和空间分布差异。结果表明:(1)SWAT模型模拟效果较好,可以准确描述乌江流域水循环过程;(2)流域多年平均降水量、蓝水资源量和绿水资源量分别为1126mm、549mm和589mm,降水量和蓝水资源量总体呈下降趋势,绿水资源量总体呈上升趋势;(3)丰水年、平水年和枯水年绿水系数分别为46%、52%和58%,绿水资源量有所变化,对生态系统维持起重要作用;(4)从流域上游到下游,降水量和蓝水资源量均呈现出先增加再减少的趋势,绿水资源量呈现出先增加再减少最后增加的趋势;(5)蓝水资源量时空分布差异主要受降水量变化影响,绿水资源量时空分布受到降水量、气温和土地利用覆被变化的影响。
基金Foundation： National Natural Science Foundation of China, No.41071110
文摘This study has revealed spatial-temporal changes in Recreational Business Dis- tricts （RBDs） in Beijing and examined the relationship between the location of urban RBDs and traffic conditions, resident and tourist density, scenic spots, and land prices. A more reasonable classification of urban RBDs （LSC, CPS, and ULA） is also proposed. Quantitative methods such as Gini Coefficient, Spatial Interpolation, Kernel Density Estimation, and Geographical Detector were employed to collect and analyze the data from three types of urban RBDs in Beijing in 1990, 2000, and 2014, respectively, and the spatial-temporal pat- terns as well as the distribution characteristics of urban RBDs were analyzed using ArcGIS software. It was concluded that （1） both the number and scale of urban RBDs in Beijing have been expanding and the trend for all types of urban RBDs in Beijing to be spatially agglom- erated is continuing; （2） the spatial-temporal evolution pattern of urban RBDs in Beijing is ＂single-core agglomeration-dual-core agglomeration-multi-core diffusion＂; and （3） urban RBDs were always located in areas with low traffic density, tourist attractions, high resident and tourist population density, and relatively high land valuations; these factors also affect the scale size of RBDs.
