Abstract

Data on the spatial distribution of calcium carbonates (CaCO₃) in the surface layer and in the profiles of irrigated soils at two key plots of the Svetloyarsk irrigation system in Volgograd oblast are presented. The key plots are located in different natural areas of the dry-steppe zone: the Yergeni Upland and the Caspian Lowland. The fields at both plots are characterized by patchiness on satellite images both for the bare soil surface and for the vegetation cover. One of the main reasons for the patchiness on the image is the different content of carbonates in the surface soil layer. Two mechanisms of the appearance of carbonates near the surface of irrigated soils have been established. The first mechanism is related to the cutting of the soils of arching areas of micro- and mesotopography in the course of surface leveling during the construction of irrigation systems with the exposure of calcareous horizons in the middle part of the soil profile and the movement of the cut material, including carbonates, to neighboring areas. The second mechanism is the ascending migration of soil solutions to the surface layer with the deposition of carbonates during the long period of irrigation in a dry hot climate. The combined use of remote sensing data and ground-based field surveys of soils along transects that intersect areas with different patchiness and spectral brightness of the images makes it possible to identify soils with different contents of carbonates in the plow horizon.

中文翻译：

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伏尔加格勒州干旱草原区灌溉土壤中碳酸盐含量的遥感

摘要

碳酸钙空间分布数据 (CaCO ₃) 在伏尔加格勒州 Svetloyarsk 灌溉系统的两个关键地块的表层和灌溉土壤剖面中。关键地块位于干草原区的不同自然区域：耶尔格尼高地和里海低地。两个地块的田地都以卫星图像上的裸露土壤表面和植被覆盖为特征。图像上出现斑驳的主要原因之一是表层土层中碳酸盐的含量不同。已经确定了灌溉土壤表面附近碳酸盐出现的两种机制。第一个机制与灌溉系统建设过程中表面平整过程中微地形和中地形拱形区域土壤的切割有关，土壤剖面中部钙质层的暴露以及土壤的运动。将材料（包括碳酸盐）切割到邻近区域。第二种机制是在干燥炎热气候下长期灌溉期间，随着碳酸盐的沉积，土壤溶液向上迁移到表层。结合遥感数据和沿线土壤的地面实地调查，这些横断面与图像的不同斑块和光谱亮度相交区域，可以识别耕层中碳酸盐含量不同的土壤。