Landsat TM/OLI images of the built-up areas in Chengde City(Shuangqiao District and Shuangluan District) in 2000,2009 and 2014 were adopted,Support Vector Machine(SVM) was applied to classify the images automatically,...Landsat TM/OLI images of the built-up areas in Chengde City(Shuangqiao District and Shuangluan District) in 2000,2009 and 2014 were adopted,Support Vector Machine(SVM) was applied to classify the images automatically,land use/cover map of the study area was obtained after precision test.Through analyzing the land use types in the study area and also applying transfer matrix to monitor the changes,the results showed that human activities and urbanization in the past 14 years have brought the increasing tendency of construction land,and the negative growth of arable land,forest and shrubbery land.It is urgent to adopt corresponding measures to maintain the coverage of forest and shrubbery land in the built-up area of Chengde City,so as to reduce the impact of human activities and improve urban ecological environment.展开更多
[ Objective] The research aimed to analyze variation rule of the precipitation series in Chengde City in recent 58 years. [Method] Mexi- can hat wavelet was used to analyze multi-scale characteristics of the monthly p...[ Objective] The research aimed to analyze variation rule of the precipitation series in Chengde City in recent 58 years. [Method] Mexi- can hat wavelet was used to analyze multi-scale characteristics of the monthly precipitation data in Chengde from 1951 to 2008. We revealed multi- time-scale complex structure of the precipitation change in Chengde, analyzed change cycles and mutation points of the precipitation series under different time scales, and identified primary period in each series. [ Result]There were high/low value centers of the precipitation under interdec- adal scale （more than 10 years）. Under interannual scale （below 10 years）, oscillation was complex and variable, but 4-year scale had obvious high-frequency oscillation. Wavelet variance analysis verified existence of the 4-year precipitation cycle, and M - K test also confirmed conclusions of the wavelet analysis. [ Conclusion] We could judge from alternating wet and dry conditions that the wet year decreased significantly, and the cur- rent Drecioitation was still less than normal.展开更多
Chengde Mountain Resort was the summer residence of emperors dur- ing the Qing Dynasty (1644-1911). Construction of the resort started in 1703, and lasted for 87 years. Chengde City in
基金Sponsored by Program of Hebei Provincial Department of Education(Z2015080)Scientific and Technological Support Program of Chengde City(2015035)Scientific and Technological Research Program of Hebei Normal University for Nationalities(FY201523)
文摘Landsat TM/OLI images of the built-up areas in Chengde City(Shuangqiao District and Shuangluan District) in 2000,2009 and 2014 were adopted,Support Vector Machine(SVM) was applied to classify the images automatically,land use/cover map of the study area was obtained after precision test.Through analyzing the land use types in the study area and also applying transfer matrix to monitor the changes,the results showed that human activities and urbanization in the past 14 years have brought the increasing tendency of construction land,and the negative growth of arable land,forest and shrubbery land.It is urgent to adopt corresponding measures to maintain the coverage of forest and shrubbery land in the built-up area of Chengde City,so as to reduce the impact of human activities and improve urban ecological environment.
基金Supported by Natural Science Research Item of Hebei Higher Institution (Z2009202)
文摘[ Objective] The research aimed to analyze variation rule of the precipitation series in Chengde City in recent 58 years. [Method] Mexi- can hat wavelet was used to analyze multi-scale characteristics of the monthly precipitation data in Chengde from 1951 to 2008. We revealed multi- time-scale complex structure of the precipitation change in Chengde, analyzed change cycles and mutation points of the precipitation series under different time scales, and identified primary period in each series. [ Result]There were high/low value centers of the precipitation under interdec- adal scale （more than 10 years）. Under interannual scale （below 10 years）, oscillation was complex and variable, but 4-year scale had obvious high-frequency oscillation. Wavelet variance analysis verified existence of the 4-year precipitation cycle, and M - K test also confirmed conclusions of the wavelet analysis. [ Conclusion] We could judge from alternating wet and dry conditions that the wet year decreased significantly, and the cur- rent Drecioitation was still less than normal.
文摘Chengde Mountain Resort was the summer residence of emperors dur- ing the Qing Dynasty (1644-1911). Construction of the resort started in 1703, and lasted for 87 years. Chengde City in
