Geoinformation Monitoring of the Condition of Rice Fields in An Giang Province (Vietnam) according to Multispectral ERS Data and Field Spectroradiometering

Abstract—The spatial distribution of areas of territory used for agricultural work is of great importance for developing measures for managing territories and planning the rational use of land and water resources. As a result of the high development of land and its use for agricultural production, the timely assessment of both the condition of soils and the growing season of crops in the fields plays an important role. Because under the conditions of the study area it is possible to choose the timing of sowing, growing, and harvesting, spatial data on the location of fields for growing rice can be used to estimate the volume of water consumed for its cultivation and develop a crop rotation model for different volumes of available water based on the level of water reserves of the main crop source. Geoinformation classification of Earth remote sensing data and the use of spectral indices can be used to monitor the dynamics of rice crop formation under existing conditions. The results of geoinformation processing of satellite images is refined using field standardization methods, including photo standardization, showing the real value of reflected energy during large-scale photography and spectroradiometry, which makes it possible to determine the characteristics of the reflected energy by these objects in various spectral ranges. The results make it possible to obtain statistical data on the values of the area of plots based on 4844 measurements; the average values of the area of plots are established—0.447, standard deviation is 0.309, the maximum area is 5.84 ha, and the minimum area is 0.02 ha. The statistical results make it possible to determine on average the estimated number of plots in the territory of An Giang province, which is 442 000 fields. Thus, when deciphering images of rice fields on satellite images, local geoinformation cartographic layers of such fields are developed, taking into account the actual characteristics and stage of plant vegetation, as well as the stage of harvesting and the stage of tillage.