Analysis of soil organic matter influencing factors in the Huangshui River Basin by using the optimal parameter-based geographical detector model

Figures & data

Figure 1. The geographical location of the study area and distribution of sample points.

Figure 2. Spatial distribution of influential factors.

Figure 3. Methodology flowchart.

Table 1. Type of interaction results.

Results	Interaction
q(x1∩x2) > q(x1) + q(x2)	Nonlinear-enhance
q(x1∩x2) = q(x1) + q(x2)	Independent
q(x1∩x2) > max[q(x1), q(x2)]	Bi-enhance
min[q(x1), q(x2)]<q(x1∩x2)<max[q(x1), q(x2)]	Uni-weaken
q(x1∩x2) < min[q(x1), q(x2)]	Nonlinear-weaken

Note: q(x₁∩x₂) denotes the explanatory power (q-value) of the SOM when factors x₁ and x₂ interact. q(x₁) and q(x₂) denote the explanatory power of the spatial distribution of the SOM when factors x₁ and x₂ act independently.

Table 2. Descriptive statistical analysis of SOM in the study area.

Name	Number	Max/g·kg^−1	Min/g·kg^−1	Mean/g·kg^−1	CV/%	K-S test
						p
SOM	107	59.79	4.31	28.38	39.36%	0.20

Note: p < 0.05, indicates that the data presents significance.

Figure 4. Spatial distribution of SOM content.

Figure 5. Continuous variable q-statistics change.

Figure 6. Factor detection results.

Table 3. Interaction detection and ecological detection results.

	X1	X2	X3	X4	X5	X6	X7	X8	X9	X10	X11	X12	X13
X1	0.004	0.174	0.175	0.162	0.332	0.230	0.069	0.340	0.187	0.083	0.135	0.087	0.074
X2	Y	0.128	0.275	0.285	0.359	0.268	0.158	0.282	0.256	0.231	0.361	0.182	0.163
X3	Y	Y	0.059	0.231	0.477	0.287	0.180	0.399	0.223	0.359	0.231	0.227	0.127
X4	Y	N	Y	0.127	0.440	0.329	0.227	0.448	0.293	0.341	0.355	0.245	0.257
X5	Y	Y	Y	Y	0.309	0.492	0.375	0.382	0.492	0.532	0.542	0.442	0.423
X6	Y	Y	Y	Y	Y	0.169	0.330	0.547	0.312	0.479	0.298	0.298	0.322
X7	Y	Y	Y	Y	Y	Y	0.095	0.404	0.236	0.277	0.130	0.097	0.141
X8	Y	Y	Y	Y	N	Y	Y	0.251	0.471	0.591	0.463	0.384	0.444
X9	Y	N	Y	N	Y	N	Y	Y	0.142	0.357	0.193	0.233	0.153
X10	Y	N	Y	N	Y	N	Y	Y	N	0.119	0.308	0.142	0.201
X11	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	0.044	0.237	0.203
X12	Y	N	Y	N	Y	N	Y	Y	N	N	Y	0.094	0.063
X13	Y	N	Y	N	Y	N	Y	Y	N	N	Y	N	0.132

Note: X1, landuse type; X2, soil type; X3, aspect; X4, precipitation; X5, temperature; X6, pH; X7, slope; X8, elevation; X9, profile curvature; X10, plan curvature; X11, TWI (Topographic Wetness Index); X12, RDLS (Relief Degree of Land Surface); X13, NDVI (Normalized Difference Vegetation Index).

Figure 7. Comparison of Pearson and geographic probe analysis of organic matter and impact factor correlation results.

Data availability statement

All data can be obtained from the authors on reasonable request.