Table 2.

The gully index of Tutujiliangzi and the optimum-fit functions.

Gully Number	A (m2)	L (m)	N	H(N)	Morphology of Longitudinal Profile	Linear Function (R2)	Exponential Function (R2)	Logarithm Function (R2)	Power Function (R2)
T1	16.37	134.71	1.147	0.230	concave	0.983	0.962	0.944	0.995 *
T2	111.17	898.51	1.075	0.212	concave	0.732	0.803	0.477	0.916 *
T3	18.77	154.93	2.384	0.515	concave	0.815	0.636	0.881 *	0.740
T4	30.76	249.00	0.592	0.093	knickpoint	0.406 *	0.298 *	0.283	0.203
T5	18.74	145.47	0.462	0.064	knickpoint	0.989 *	0.996 *	0.977	0.987
T6	10.67	119.46	2.148	0.464	concave	0.964	0.954	0.854	0.999 *
T7	118.44	969.61	1.255	0.257	concave	0.884	0.868	0.733	0.972 *
T8	73.59	616.76	1.309	0.270	concave	0.823	0.933 *	0.671	0.944 *
T9	20.54	171.94	1.491	0.314	concave	0.942	0.992 *	0.846	0.978
T10	30.48	259.75	1.375	0.286	concave	0.999 *	0.989	0.985	0.999 *
T11	25.96	228.24	1.445	0.303	concave	0.970	0.831	0.996 *	0.967
T12	62.45	505.19	1.190	0.240	concave	0.790	0.934 *	0.624	0.856
T13	22.67	190.2	0.700	0.118	convex	0.739 *	0.634	0.529	0.433
T14	15.59	131.33	1.605	0.341	concave	0.998	0.975	0.969	0.999 *
T15	28.24	228.44	1.005	0.194	concave	0.880	0.967 *	0.682	0.905
T16	31.68	254.65	1.865	0.402	concave	0.962	0.971	0.835	0.996 *
T17	23.33	190.72	0.700	0.118	convex	0.423	0.441 *	0.246	0.271
T18	61.80	511.65	1.576	0.335	concave	0.711	0.924 *	0.508	0.920
T19	35.10	301.38	1.543	0.327	concave	0.761	0.898	0.602	0.910 *
T20	34.45	279.67	1.752	0.376	concave	0.925	0.996 *	0.786	0.976
T21	39.34	322.58	1.607	0.342	concave	0.880	0.984 *	0.801	0.945
T22	22.87	184.58	1.024	0.199	concave	0.959	0.981 *	0.853	0.921
T23	25.61	207.11	1.278	0.262	concave	0.954	0.998 *	0.879	0.971
T24	28.76	230.68	1.600	0.340	concave	0.881	0.951 *	0.824	0.911
T25	12.21	100.58	1.287	0.364	concave	0.999 *	0.928	0.970	0.993
Average	36.78	303.49	1.337	0.279

“*” represents optimum-fit functions of longitudinal profile.