How to calculate TWI & SPI in ArcGIS

[@nisrina6369]

How to get slope in radian?

[@hejarshahabi114]

thank you for video on SPI, however there is question I'd like to ask. why the range of SPI is so high? can we use Ln tool in raster calculator to reduce it ?

[@lemhuwang44]

What is. 001 in the TWI formula?

[@sriharsha_10]

how did you make it small?

[@tanveerulhaq733]

why we use C+0.001?

[@kosmatification]

bro, spi value range looking weird, isn't it?

[@tutorials987]

can I ask a question

[@vinhhoangduc]

Yes, please sir

[@lemhuwang44]

What is C=.001 in the in the TWI formula?

[@giang2u]

C = 0.001 is a tip to avoid the denominator = 0 (which make the formula becomes infinitive)

[@tanveerulhaq733]

what is C+0.001 can you explain please?

[@vinhhoangduc]

0.001 is very small, it is a tip to avoid the denominator = 0

[@giang2u]

Second formula for SPI should be Ln(...)
Cellsize should be 30x30 !?

[@tanveerulhaq733]

tại sao chúng tôi sử dụng C + 0,001

[@phanvantho699]

Cách xác định TWI and SPI của bạn có vấn đề =)

[@vinhhoangduc]

Cảm ơn bạn, bạn có thể chỉ cho tôi vấn đề gì ko ạ?