Hi Sultan,   I checked ...

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Hi Sultan,

 

I checked your file.

You should download the HWSD Viewer and install it. Add your soil layer polygon in shapefile format clipped based on your basin.

For each polygon read its SMU table data and copy and paste them in excel.

 

Each polygon usually consists of 1 to 7 different soils. Their number and share are shown in the first and second rows of the SMU table, respectively.

 

Then, roll down to Top Soil (30cm) section. Just in the forth row of this section, the soil texture in USDA system is given.

 

For each soil texture, from soil or hydrology text books, you may find the average saturated hydraulic conductivity. if you want to be more accurate, you may consider the minimum and maximum saturated hydraulic conductivity for each soil texture.

 

Then, make a weighted average of these saturated hydraulic conductivity values based on the share of the soil texture in the soil polygon (second row of the SMU table) which you will gain the mean saturated hydraulic conductivity for that polygon. Based on this mean saturated hydraulic conductivity, you may identify the hydrologic soil group of that polygon.

 

Best Regards

Shahab