[Objective] The aim was to build an optimal leaf area measurement model of E. urophylla and E. grandis×E.urophylla. [Method] The correlation between leaf area and leaf＇s eigenvalue of E. urophylla and E. grandis...[Objective] The aim was to build an optimal leaf area measurement model of E. urophylla and E. grandis×E.urophylla. [Method] The correlation between leaf area and leaf＇s eigenvalue of E. urophylla and E. grandis×E.urophylla were studied. [Result] There was certain difference in leaf characteristics values between the 2 species. The leaf areas of E. urophylla and E. grandis×E.urophylla both had significant correlation with leaf length,leaf width,leaf perimeter,leaf length × leaf width,the ratio of leaf length to leaf width,shape factor,etc.,so the factors could be constructed into a regression model with leaf area. Among them,the best 2 models for leaf area calculation which were built by leaf length × leaf width of E. urophylla and E. grandis×E.urophylla both had relatively high accuracy and practical applications. [Conclusion] The research provides a simple and effective leaf area measurement method for studies on the 2 tree species.展开更多
The problems existing in the development of agriculture-related enterprises in earthquake area are evaluated,as well as the prominent issues existing in the process of developing E-commerce,consequently,the correspond...The problems existing in the development of agriculture-related enterprises in earthquake area are evaluated,as well as the prominent issues existing in the process of developing E-commerce,consequently,the corresponding strategies for developing E-commerce in agriculture-related enterprises are proposed.展开更多
[ Objective] The research aimed to study distribution prediction of suitable growth area for Eucommia ulmoides in China under climatic change background. [ Method] By using the maximum entropy model and many kinds of ...[ Objective] The research aimed to study distribution prediction of suitable growth area for Eucommia ulmoides in China under climatic change background. [ Method] By using the maximum entropy model and many kinds of climate change scenarios, we predicted current and future distribution pattems of suitable growth area for Eucommia ulmoides in China and its change process. [ Result ] At present, highly suitable growth area of E. ulmoides mainly distributed in Sichuan, Shaanxi and Chongqing, Under climate change background, total suitable growth areas in future three decades all drastically reduced when compared with that at present. It was noteworthy that moderately and highly suitable growth areas of wild E. ulmoides all disappeared, and junction between Shaanxi and Gansu and Taibai Mountain would be stable suitable growth area of wild E. ulmoides. [ Condusioa] The research could provide useful reference data for investigation, protection and sustainable development of the wild E. ulmoides resources.展开更多
Rainfall estimate in arid region using passive microwave remote sensing techniques has been a complex issue for some time.The main reason for this difficulty is that the high and variable emissivity of land surfaces g...Rainfall estimate in arid region using passive microwave remote sensing techniques has been a complex issue for some time.The main reason for this difficulty is that the high and variable emissivity of land surfaces greatly aggravates the complexity of the signatures from the rain cloud.The Xinjiang area,located in the northwest of China,holds all the typical characteristics of arid climate.A rainfall algorithm has been developed for this region by using the Advanced Microwave Scanning Radiometer for Earth Observing System(AMSR-E) measurements.The algorithm attempts to use all 12 chan-nels on the AMSR-E instrument and a two-step method calibrated over 11 days of hourly rain-gauge data.First,Stepwise Discriminant Analysis(SDA) used to optimally estimate rain pixels based on all 12 channels,although only three channels were found to be necessary.Next,a rain predicator scattering index was used to estimate rain rates.A linear relationship between the rain rates and the scattering index above the threshold of 3.0K was constructed with a simple approximately linear function.The estimated rain rates were compared with the rain-gauge data used to calibrate the method,and a good relationship was found with a root-mean-square error of 2.1mm/h.The numerical calculations and comparisons show that the algorithm works well in the Xinjiang area.展开更多
In order to provide an objective and scientific theoretical basis for rational distribution of wheat growth in Yunnan Province,according to the relationship between Yunnan weather conditions and wheat growth adaptabil...In order to provide an objective and scientific theoretical basis for rational distribution of wheat growth in Yunnan Province,according to the relationship between Yunnan weather conditions and wheat growth adaptability,a study on eco-climate type regionalization of wheat growing areas in Yunnan was conducted using principal component analysis and GIS technology. The results show that Yunnan Province could be divided into four types,namely southern warm and humid wheat growing area,central semi-arid wheat growing area,central semi-humid wheat growing area and north-central cold wheat growing area.展开更多
In this study,in-situ soil moisture measurements are used to evaluate the accuracy of three AMSR-E soil moisture prod ucts from NASA(National Aeronautics and Space Administration),JAXA(Japanese Aerospace Exploration A...In this study,in-situ soil moisture measurements are used to evaluate the accuracy of three AMSR-E soil moisture prod ucts from NASA(National Aeronautics and Space Administration),JAXA(Japanese Aerospace Exploration Agency)and VUA(Vrije University Amsterdam and NASA)over Maqu County,Source Area of the Yellow River(SAYR),China.Re sults show that the VUA soil moisture product performs the best among the three AMSR-E soil moisture products in the study area,with a minimum RMSE(root mean square error)of 0.08(0.10)m3/m3 and smallest absolute error of 0.07(0.08)m3/m3 at the grassland area with ascending(descending)data.Therefore,the VUA soil moisture product is used to describe the spatial variation of soil moisture during the 2010 growing season over SAYR.The VUA soil moisture product shows that soil moisture presents a declining trend from east south(0.42 m3/m3)to west north(0.23 m3/m3),with good agreement with a general precipitation distribution.The center of SAYR presents extreme wetness(0.60 m3/m3)dur ing the whole study period,especially in July,while the head of SAYR presents a high level soil moisture(0.23 m3/m3)in July,August and September.展开更多
基金Supported by Key Science and Technology Project of Forestry in Guangxi Province for the Eleventh Five-year Plan ([2009] No.8)~~
文摘[Objective] The aim was to build an optimal leaf area measurement model of E. urophylla and E. grandis×E.urophylla. [Method] The correlation between leaf area and leaf＇s eigenvalue of E. urophylla and E. grandis×E.urophylla were studied. [Result] There was certain difference in leaf characteristics values between the 2 species. The leaf areas of E. urophylla and E. grandis×E.urophylla both had significant correlation with leaf length,leaf width,leaf perimeter,leaf length × leaf width,the ratio of leaf length to leaf width,shape factor,etc.,so the factors could be constructed into a regression model with leaf area. Among them,the best 2 models for leaf area calculation which were built by leaf length × leaf width of E. urophylla and E. grandis×E.urophylla both had relatively high accuracy and practical applications. [Conclusion] The research provides a simple and effective leaf area measurement method for studies on the 2 tree species.
基金Supported by Rural Development Research Center of Sichuan Province
文摘The problems existing in the development of agriculture-related enterprises in earthquake area are evaluated,as well as the prominent issues existing in the process of developing E-commerce,consequently,the corresponding strategies for developing E-commerce in agriculture-related enterprises are proposed.
基金Supported by National Basic Science Talent Culture Fund Item,China(J1103511)
文摘[ Objective] The research aimed to study distribution prediction of suitable growth area for Eucommia ulmoides in China under climatic change background. [ Method] By using the maximum entropy model and many kinds of climate change scenarios, we predicted current and future distribution pattems of suitable growth area for Eucommia ulmoides in China and its change process. [ Result ] At present, highly suitable growth area of E. ulmoides mainly distributed in Sichuan, Shaanxi and Chongqing, Under climate change background, total suitable growth areas in future three decades all drastically reduced when compared with that at present. It was noteworthy that moderately and highly suitable growth areas of wild E. ulmoides all disappeared, and junction between Shaanxi and Gansu and Taibai Mountain would be stable suitable growth area of wild E. ulmoides. [ Condusioa] The research could provide useful reference data for investigation, protection and sustainable development of the wild E. ulmoides resources.
基金supported by Innovation Project of the Chinese Academy of Sciences (KZCX3-SW-229)the National Basic Research Program of China (Grant No.2006CB400504)
文摘Rainfall estimate in arid region using passive microwave remote sensing techniques has been a complex issue for some time.The main reason for this difficulty is that the high and variable emissivity of land surfaces greatly aggravates the complexity of the signatures from the rain cloud.The Xinjiang area,located in the northwest of China,holds all the typical characteristics of arid climate.A rainfall algorithm has been developed for this region by using the Advanced Microwave Scanning Radiometer for Earth Observing System(AMSR-E) measurements.The algorithm attempts to use all 12 chan-nels on the AMSR-E instrument and a two-step method calibrated over 11 days of hourly rain-gauge data.First,Stepwise Discriminant Analysis(SDA) used to optimally estimate rain pixels based on all 12 channels,although only three channels were found to be necessary.Next,a rain predicator scattering index was used to estimate rain rates.A linear relationship between the rain rates and the scattering index above the threshold of 3.0K was constructed with a simple approximately linear function.The estimated rain rates were compared with the rain-gauge data used to calibrate the method,and a good relationship was found with a root-mean-square error of 2.1mm/h.The numerical calculations and comparisons show that the algorithm works well in the Xinjiang area.
基金Supported by the National Special Founds for the Construction of Modern Agricultural Industrial Technology System (MATS)(CARS-3-2-45)Founds for Selection and Promotion of New High-quality Beer-feed Barley in Yunnan
文摘In order to provide an objective and scientific theoretical basis for rational distribution of wheat growth in Yunnan Province,according to the relationship between Yunnan weather conditions and wheat growth adaptability,a study on eco-climate type regionalization of wheat growing areas in Yunnan was conducted using principal component analysis and GIS technology. The results show that Yunnan Province could be divided into four types,namely southern warm and humid wheat growing area,central semi-arid wheat growing area,central semi-humid wheat growing area and north-central cold wheat growing area.
基金supported in part by the Programs of National Natural Science Foundation of China (41675157, 91537212)
文摘In this study,in-situ soil moisture measurements are used to evaluate the accuracy of three AMSR-E soil moisture prod ucts from NASA(National Aeronautics and Space Administration),JAXA(Japanese Aerospace Exploration Agency)and VUA(Vrije University Amsterdam and NASA)over Maqu County,Source Area of the Yellow River(SAYR),China.Re sults show that the VUA soil moisture product performs the best among the three AMSR-E soil moisture products in the study area,with a minimum RMSE(root mean square error)of 0.08(0.10)m3/m3 and smallest absolute error of 0.07(0.08)m3/m3 at the grassland area with ascending(descending)data.Therefore,the VUA soil moisture product is used to describe the spatial variation of soil moisture during the 2010 growing season over SAYR.The VUA soil moisture product shows that soil moisture presents a declining trend from east south(0.42 m3/m3)to west north(0.23 m3/m3),with good agreement with a general precipitation distribution.The center of SAYR presents extreme wetness(0.60 m3/m3)dur ing the whole study period,especially in July,while the head of SAYR presents a high level soil moisture(0.23 m3/m3)in July,August and September.
