Analysis of stream water quality and estimation of nutrient load with the aid of Quick Bird remote sensing imagery

Figures & data

Fig. 1 Location of Koise River basin and observation sites for water quality sampling.

Fig. 2 Land cover map generated by Quick Bird remote sensing imagery.

Table 1  Statistical parameters of the studied variables

	Max.	Median	Min.	Mean	SD	CV	Frequency	Number
	(mg/L)	(mg/L)	(mg/L)	(mg/L)
TN	4.42	2.18	0.65	2.28	0.68	29.62	Monthly	12/year
TP	0.85	0.07	0.02	0.09	0.08	81.31	Monthly	12/year
TOC	16.65	2.88	0.67	3.56	2.18	61.44	Monthly	12/year
DTN	4.26	1.96	0.29	2.08	0.73	34.78	Monthly	12/year
DIN	3.77	1.75	0.06	1.82	0.73	39.87	Monthly	12/year
DON	0.66	0.26	(0.00)	0.26	0.13	49.09	Monthly	12/year
PON	1.56	0.12	0.03	0.21	0.23	110.15	Monthly	12/year
DTP	0.16	0.03	0.01	0.04	0.02	50.41	Monthly	12/year
DOC	4.45	1.90	0.47	2.05	0.96	47.04	Monthly	12/year
POC	14.32	0.95	0.20	1.51	1.57	104.08	Monthly	12/year
Note: SD, standard deviation; CV, coefficient of variation.

Table 2  Statistical parameters of the hydrological characteristics of tributaries

	River discharge						Area (km^2)	Land use
	Max.	Median	Min.	Mean	SD	CV		F	A	U	O
	(m^3/s)	(m^3/s)	(m^3/s)	(m^3/s)
Koi-1	2.91	1.82	1.36	1.88	0.36	19.24	17.2	0.62	0.18	0.10	0.10
Koi-2	3.88	1.91	1.32	1.92	0.45	23.57	9.8	0.57	0.21	0.12	0.11
Koi-3	3.50	2.59	1.40	2.59	0.44	16.95	6.4	0.48	0.25	0.14	0.13
Koi-4	4.16	3.06	1.15	2.83	0.71	25.11	9.8	0.47	0.29	0.12	0.12
Koi-5	3.71	2.59	1.67	2.55	0.44	17.40	11.4	0.57	0.20	0.12	0.11
Koi-6	3.02	2.17	1.25	2.13	0.36	16.86	9.5	0.47	0.28	0.13	0.12
Koi-7	4.41	2.83	1.55	2.72	0.54	19.97	33.3	0.52	0.31	0.17	0.01
Koi-8	2.32	1.71	1.39	1.71	0.21	12.36	0.9	0.96	0.01	0.00	0.03
Note: F, forest; A, agricultural land; U, urban; O, other lands.

Fig. 3 Variation of average monthly river discharge in eight tributaries of the Koise River.

Fig. 4 Variation of average monthly TN, TP, and TOC concentration in eight tributaries of the Koise River.

Fig. 5 Comparison between simulated and observed total load for eight tributaries of the Koise River.

Fig. 6 Total phosphorus (TP) load from different sources in eight tributaries of the Koise River.

Fig. 7 Total organic carbon (TOC) load from different sources in eight tributaries of the Koise River.