Table 2. Formula for calculating major ecological indices

Index Formula Index Formula
BMI BMI = ( 4 i = 1 n s i h i g i i = 1 n h i g i ) × 25 si : Unit pollution index of i specieshi = Appearance of i speciesgi = Indicator weight of i species H’ H = i = 1 S ( p i × log 2 p i ) , ( p i = N i N ) Ni : Population of i speciesN : Total appearing population
DI DI = N 1 + N 2 N N1 : First dominant species populationN2 : Second dominant species populationN : Total appearing population R1 R 1 = S 1 ln N S : Total number of speciesN : Total appearing population