Landscape Investigations Using the Kriging Estimator (A Case Study of Hormozabad in Rafsanjan, Kerman Province)

As natural land features, landscapes ranging in size from large plains and mountains to small hills are regarded as morphological formations characteristic of the earth's surface. The objective of the present study was to determine the physiographic unit boundaries in Hormozabad, Rafsanjan, using the ordinary kriging estimator. For this purpose, 77 observation points at distances of 500 m from each other were selected over a regular sampling grid and soil samples were collected from depths of 0–40, 40–80, and 80–120 cm at the specified locations. Similar to the findings reported elsewhere and based on model efficiency estimates, the results obtained showed that ordinary kriging served as a good estimator in zoning the properties of the study area. Additionally, geostatistical results indicated that a sampling distance of 1800 m could be used as a criterion for future surveys in areas similar to the present study one. Comparison of the kriging and topographic maps of the area demonstrated that the kriging estimator used was superior to topographic maps in representing physiographic units. This was evidenced by the more accurate unit boundaries detected by the estimator despite the high variations in soil properties depicted in the respective variograms for intervals above 1800 meters. It is, therefore, recommended that modern techniques such as geostatistics should be employed for detailed soil studies as required for preparing more adequately detained maps with precise data.