Hi, i’ve just learned how to use this function (NDR) in invest.But i can’t find the data about the crit_len_p(or n) on the internet about my research area. Meanwhile I found that the sample data is 150 for all of the lulc,why this data is 150 for all of the lulc, isn’t it shall be different for lulc? Could anyone give me some empirical values about it ？
Thanks a lot !
Hi @liang -
Ideally yes, the critical length would be different based on LULC type. But this is a parameter that’s harder to obtain (as you are finding). The User Guide Data sources section for NDR gives a bit of guidance about how to look for these values. Based on studies of riparian buffer retention, a value of 150m is suggested as one starting point, in the absence of more specific data.
~ Stacie
thank you stacie! It really helps a lot!