Fig. 1. Distribution of sampling points (a) and land types (b)

Fig. 2. P fractions concentration distribution and the pollution evaluation in water samples
P: Pihe River (Area P), S: Shiting River (Area S)

Fig. 3. N fractions concentration distribution and the pollution evaluation in water samples
P: Pihe River (Area P), S: Shiting River (Area S)

Fig. 4. P fractions concentration distribution and the pollution evaluation in surface sediments
P: Pihe River (Area P), S: Shiting River (Area S)

Fig. 5. N fractions concentration distribution and the pollution evaluation in surface sediments
P: Pihe River (Area P), S:Shiting River (Area S)

Fig. 6. Contribution of different pollution sources in different water periods of Pihe River and Shiting River based on APCS-MLR receptor model
1: DP; 2: PP; 3: WTP; 4: STP; 5: IP; 6: Ex-P; 7: BD-P; 8: NaOH-P; 9: HCl-P; 10: OP; 11: $\mathrm {NO^{-}_{3}}-N$; 12: $\mathrm {NH^{+}_{4}}-N$;13: $\mathrm {NO^{-}_{2}}-N$; 14: WTN; 15: $\mathrm {EN-NO^{-}_{3}}-N$; 16: $\mathrm {EN-NH^{+}_{4}}-N$; 17: $\mathrm {EN-NO^{-}_{2}}-N$; 18: HN; 19: STN