In order to provide some preliminary recommendations for the sustainable use and management of croplands, land suitability evaluation for crops was carried out in Shouyang County which partly locates on the Loess Plat...
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In order to provide some preliminary recommendations for the sustainable use and management of croplands, land suitability evaluation for crops was carried out in Shouyang County which partly locates on the Loess Plateau suffering severe soil and water erosion and is characterized by ecological vulnerability and semi-arid climate. Here, land suitability for 4 local crops of maize, wheat, sorghum and millet under 2 cultivation senarios of tradition and mechanization was evaluated by a upscaling approach. The upscaling was implemented in a land form hierarchy which was composed of land unit, land facet and land site at 3 spatial levels. The IAO land suitability evaluation model for crops was revised by applying a meteorological revision index. Rresults showed that a polarized phenomenon occurred, which means that the most suitable class (S1) and the most unsuitable class (N2) were predominant in acreage percentage for all the 4 crops. Maize, millet and wheat were relatively more adaptive to be grown and should be ploughed in the traditional mode. Hence, future cropland use policy should pay more attention to the conversion of arable land to forestland and grassland in unsuitable areas and to more investment for agricultural production in suitable regions, and it is necessary to balance the relationship between the livelihood of local farmers and environmental protection to maintain a healthy and stable ecosystem.
提出利用RM(radiance transfer model)模型MODTRAN4和动态学习神经网络(neural network)从MODIS数据中反演近地表空气温度。 MODTRAN4被用来模拟不同地面辐射状况下(包括不同的地表温度,近地表空气温度,发射率和大气水汽含量)卫星...
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提出利用RM(radiance transfer model)模型MODTRAN4和动态学习神经网络(neural network)从MODIS数据中反演近地表空气温度。
MODTRAN4被用来模拟不同地面辐射状况下(包括不同的地表温度,近地表空气温度,发射率和大气水汽含量)卫星高度获得的辐射强度数据集。动态学习神经网络被用来反演计算,反演分析结果表明近地表空气温度不能直接精确地从MODIS数据中反演计算得到。如果能把地表温度和发射率以及大气水汽含量作为先验知识,则能够比较精确地反演近地表空气温度,模拟分析表明平均误差和标准偏差分别大约是0.8 K和0.9 K。如果考虑地表温度和发射率的误差,平均误差和标准偏差为1.5 K and 1.8 K。反演结果和地面气象站点数据比较表明合理地利用先验知识使得RM-NN能够从MODIS数据中比较精确地反演近地表空气温度。
[Objective] To provide a theoretical basis for high-yield breeding of broom sorghum.[Method] Using 11 kinds of broom sorghum collected at home as research objects, the differences in morphological characteristics of b...
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[Objective] To provide a theoretical basis for high-yield breeding of broom sorghum.[Method] Using 11 kinds of broom sorghum collected at home as research objects, the differences in morphological characteristics of broom sorghum were compared through the survey of some indicators, such as plant height, tillering, inflorescence, stem node, stem-leaf ratio, yield, and so on. [Result] The 11 kinds of broom sorghum were different in morphological characteristics with large amplitude of plant height; zygl-1, zygl-6, zygl-8 and zygl-9 were appropriate for fixed broom type; zygl-9 had the highest integrated production. [Condusion] The study laid the foundation for further exploring breeding, cultivation and promotion of broom sorghum.
Since the increasing demand for arable land and low efficient and disordered use of rural residential land,land consolidation for rural settlement has become a hot issue in *** Chinese scientists studied the topic fro...
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Since the increasing demand for arable land and low efficient and disordered use of rural residential land,land consolidation for rural settlement has become a hot issue in *** Chinese scientists studied the topic from different ***,there is no reference systematically summarizing and discussing feasibility of consolidating rural residential land into arable *** authors listed and analyzed the calculation methods of consolidating rural residential land into arable land,and discussed the feasibility and reasonability of those ***,this paper put forward the study orientation in this regard for providing references for relevant researches.
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