Search

【Objective】 Research on remote sensing evaluation of cultivated land quality is of great significance to realize real-time and effective management and protection of cultivated land quality, promote the development of modern and efficient agriculture and ensure national food security.【Method】 The present paper took Conghua area as the study area, the spectral parameters were calculated and obtained from GF-1 image data by using various transformation technologies. And the correlation coefficient and variance inflation factor were used to select the spectral response of the cultivated land quality indicators. The remote sensing spectral response models of cultivated land quality in Conghua district were constructed based on linear（ PLSR） and nonlinear （BPNN, GA-BPNN） models, and the optimal model was used to realize the rapid inversion and spatial mapping of cultivated land quality.【Result】 The crop spectral response indexes of cultivated land quality were FD-3, SD-4, EVI and LR-4, and the correlation coefficients with cultivated land quality were 0.661, 0.663, 0.714 and-0.674, respectively, indicating that red and near infrared in GF-1 image were the crop spectral response bands of cultivated land quality. The PLSR, BPNN and GA-BPNN models were used to retrieve the cultivated land quality respectively. Compared with the inversion accuracy, it was found that the GA-BPNN model could quickly realize the inversion of cultivated land quality（R~2=0.64,NRMSE=10.75%）. Spatial mapping and validation of cultivated land quality using optimal model were conducted, and the results showed that the crop spectral indicators extracted from GF-1 satellite image data based on GA-BPNN model could quickly and accurately retrieve the cultivated land quality at regional scale. 【Conclusion】 The use of remote sensing technology is helpful to quickly understand the quality of cultivated land at the regional scale, improve the existing discipline system of cultivated land quality evaluation, promote the development of the discipline, and provide a theoretical basis for the subsequent spectral inversion of cultivated land quality. [ABSTRACT FROM AUTHOR]

[Objective] In order to comprehensively maintain and improve the production, ecological and living functions of the farmland ecosystem, under the different types of cultivated land, the present paper analyzed the spatial and temporal evolution trajectory and characteristic differences of the quantity and quality of the water and dry land in the cultivated land based on the perspective of the ’trinity’ protection for quantitative and quality ecological development.[Method] Taking the Jiangjin District of the Three Gorges Reservoir as an example, the land use status and cultivated land quality grade evaluation result data, the standard deviation ellipse, landscape pattern index, nearest neighbor index method, etc. were used to study the quantity, the spatial and temporal evolution pattern of quality and ecology. [Result]（i） Quantity, the distribution of flooded and dry land in Jiangjin District had a trend of further expanding to the hinterland of Jiangjin District. The evolution path of dry land changes from northwest to southeast, and the evolution path of paddy field changed from southwest to southeast;（ii） Quality, the overall quality of the paddy field was higher than that of the dry land. The grade of the paddy and dry land was gradually decreasing from the central and western regions to the north and south.（iii） Ecological, the shape of the paddy and dry land was complex and fragmented, with reduced connectivity and significant aggregation.[Conclusion] The implementation of arable land zoning and types of protection measures, to achieve the development momentum of characteristic agriculture according to local conditions, provides reference for the protection of arable land resources in this area, the formulation of ’tri-in-one’ protection policies and the optimization of the layout of arable land. [ABSTRACT FROM AUTHOR]