Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Acta Geophysica

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Multiscale computation of different plan curvature forms to enhance the prediction of soil properties in a low-relief watershed

Khanifar Javad, Khademalrasoul Ataallah

Acta Geophysica

2024

Vol. 72, no. 2

933--944

This study focuses on the multiscale calculation of different plan curvature forms to enhance the modeling of soil penetration resistance and gravimetric soil water content utilizing the classification and regression trees algorithm in a low-relief watershed. To that end, three forms of plan curvature were derived using the Wood method from a two-meter digital elevation model on six neighborhood sizes. The results showed that the neighborhood size influenced the plan curvature values and there was little difference between the utilization of three forms of plan curvature in the landform determination. The modeling results indicated that the three forms of plan curvature on most neighborhood scales have different contributions to each other in modeling the spatial variability of each soil property. The neighborhood scale was a critical factor in soil modeling because it controls the smoothing rate of plan curvature. The overall results suggest that soil models with poor performance could be constructed if the plan curvature forms and the neighborhood size are not considered in the geomor-phometric analysis. Therefore, it is recommended to use the procedure implemented in this study for digital soil mapping in various regions.

Multiscale comparison of LS factor calculation methods based on diferent fow direction algorithms in Susa Ancient landscape

Khanifar Javad, Khademalrasoul Ataallah

Acta Geophysica

2020

Vol. 68, no. 3

783--793

Topography (LS factor) is one of the most important controlling factors of soil characteristics and geomorphic processes in the landscape. This study was performed in the Susa Ancient site and aimed to compare the estimation of three diferent LS factor calculation methods in which the catchment area was calculated based on seven types of fow direction algorithms using DEM with fve spatial resolutions. For calculating the LS factor, the catchment area attribute was used to calculate the slope length based on the fow direction. Results showed that the catchment area is an entirely scale-dependent attribute and with decreasing the spatial resolution, the statistical values of catchment area increased. At high spatial resolution, the diferent fow direction algorithms despite the diference in the fow distribution to the neighboring cells, but the catchment area attributes calculated based on them, are statistically slightly diferent. By upscaling, the LS factor values calculated in Boehner and Selige and Moore et al. methods increase, whereas in Desmet and Govers method decrease and this change rate indicates that the LS factors calculated by these three methods have the lowest sensitivity to the slope length. At a same scale, the statistics of LS factors calculated based on diferent fow direction algorithms depicted no considerable diferent. The single fow direction algorithms of Rh and D8 cause to calculate the lowest mean values of LS factors at all spatial resolutions. The diference between frequency distributions of the LS factors calculated by these three methods increases with decreasing spatial resolution. The statistical analysis of this study confrms that estimating the LS factor scale and calculation method are more important than the type of fow direction algorithm.