Calculation of Solar Radiation on Slopes During Snowmelt
The aim of this work is to calculate the value of heat flux density reaching the slopes of Kama River catchments of different exposition and steepness during snowmelt. Materials and methods. The initial mapping data are layers of vector topographic maps of ROSKAR-TOGRAPHY at a scale of 1:200000. Calculations of solar radiation are made with the construction of digital elevation models for two river catchments of the Perm Kama region, belonging to the plain (the river Kos - Kos village) and foothill (the Vishera River - Ryabinino village) territories. The method of the study is mathematical and geoinformation modeling in ArcGIS 10.4 software. Results and discussion. The patterns of solar radiation distribution over the territory of the studied catchments during the snowmelt period have been obtained. Slope exposure influences the distribution of solar radiation on the catchment area. It is established, that the western, eastern slopes and plain territories receive almost equal quantity of solar radiation, which increases during April and does not depend on a slope angle. The maximum insolation values occur on the southern slopes and the minimum on the northern slopes. Calculations of the daily insolation dynamics during April showed that for the southern slopes the incoming radiation will decrease, while for the northern slopes it will increase relative to the western and eastern slopes. This change is similar in magnitude, but has a different sign. Conclusions. Calculations of insolation based on qualitative digital elevation models allow revealing spatial inhomogeneity of the amount of heat arriving with solar radiation on slopes of different exposition and steepness. The relief has a significant impact on the duration of snowmelt processes. Thus, the amount of incoming solar radiation increases on the southern slopes with an increase in the slope angle, while it decreases on the northern slopes, which leads to a later melting (on average, by 18-20 days) of snow on them.