Physical and chemical variables of sampling stations
Physical and chemical variables varied among sampling stations and their results are given in Table 2. Streams in the Konya closed river basin had mainly alkali waters and it ranged between 7.5 at Asın Stream (S32) and 8.8 at Gök Stream (S1). The mean EC values ranged from 64 μS/cm at Baldıran Stream (S7) to 723 μS/cm at Anaçay Stream (S2). Sampling stations S1, S2, S10-12, S15, S22, and S23 had EC values more than 500 μS/cm.
Relatively low variations were found in the nutrient gradient of sampling stations. The highest mean TP was found in Asın Stream (S32) with 142 µg/L, followed by Uluçay Stream (S34) with 116 µg/L, whereas several streams (e.g., Avşar, Kurucaova, and Baldıran streams) had TP values smaller than 10 µg/L. NO2-N was not detected in most of sampling stations (see Table 2). Mean TN varied between 1.64 mg/L in Suludere Stream (S30) and 0.28 mg/L in Çarşamba Stream (S25).
Table 2. Mean values of environmental variables of sampling stations in the Konya closed river basin. Abbreviations and full names of stations are given in Table 1. nd is not detected.
|
Temp
|
pH
|
EC
|
DO
|
Sali
|
Alka
|
BOD
|
COD
|
TOC
|
TN
|
NH4
|
NO2
|
NO3
|
TP
|
|
°C
|
|
µS/cm
|
mg/L
|
ppt
|
mg/L
|
mg/L
|
mg/L
|
mg/L
|
mg/L
|
mg/L
|
mg/L
|
mg/L
|
μg/L
|
S01
|
17.0
|
8.8
|
640
|
7.69
|
0.31
|
334
|
4.9
|
26.2
|
8.08
|
0.95
|
0.05
|
0.01
|
0.54
|
13
|
S02
|
16.4
|
8.5
|
723
|
6.01
|
0.35
|
331
|
5.1
|
24.9
|
15.54
|
1.24
|
0.05
|
0.01
|
0.49
|
51
|
S03
|
17.3
|
8.4
|
317
|
8.42
|
0.16
|
129
|
1.9
|
10.1
|
2.18
|
1.37
|
0.08
|
0.02
|
0.48
|
51
|
S04
|
18.9
|
8.6
|
81
|
7.58
|
0.04
|
36
|
1.9
|
9.0
|
0.90
|
1.03
|
0.05
|
nd
|
0.09
|
35
|
S05
|
19.5
|
8.0
|
191
|
7.09
|
0.08
|
73
|
1.9
|
12.0
|
5.47
|
0.59
|
0.05
|
nd
|
0.09
|
18
|
S06
|
21.5
|
8.2
|
78
|
8.66
|
0.03
|
188
|
1.9
|
9.0
|
0.90
|
0.83
|
0.05
|
nd
|
0.09
|
10
|
S07
|
19.4
|
7.8
|
64
|
6.28
|
0.03
|
49
|
1.9
|
9.0
|
0.90
|
0.50
|
0.05
|
nd
|
0.10
|
7
|
S08
|
13.3
|
8.1
|
185
|
7.53
|
0.10
|
97
|
1.9
|
9.0
|
2.90
|
1.05
|
0.05
|
nd
|
0.17
|
43
|
S09
|
13.4
|
8.0
|
255
|
6.96
|
0.12
|
119
|
1.9
|
9.0
|
1.40
|
0.74
|
0.05
|
nd
|
0.21
|
15
|
S10
|
10.0
|
8.2
|
513
|
9.14
|
0.26
|
235
|
2.1
|
13.9
|
4.11
|
0.94
|
0.05
|
nd
|
0.09
|
10
|
S11
|
12.2
|
8.1
|
707
|
8.08
|
0.35
|
270
|
1.9
|
12.4
|
0.90
|
0.96
|
0.05
|
nd
|
0.39
|
15
|
S12
|
13.9
|
8.2
|
545
|
7.69
|
0.27
|
250
|
1.9
|
9.6
|
0.90
|
0.85
|
0.05
|
nd
|
0.09
|
5
|
S13
|
15.5
|
8.5
|
386
|
8.51
|
0.18
|
242
|
2.3
|
14.8
|
5.51
|
1.16
|
0.50
|
0.01
|
0.34
|
18
|
S14
|
15.3
|
8.7
|
332
|
8.02
|
0.16
|
149
|
1.9
|
10.3
|
3.51
|
1.47
|
0.84
|
0.02
|
0.16
|
68
|
S15
|
14.3
|
8.5
|
546
|
8.58
|
0.26
|
175
|
3.1
|
23.4
|
12.68
|
1.07
|
0.11
|
nd
|
0.09
|
14
|
S16
|
18.5
|
8.4
|
368
|
8.21
|
0.17
|
165
|
1.9
|
9.7
|
0.90
|
0.95
|
0.05
|
nd
|
0.13
|
11
|
S17
|
16.7
|
8.5
|
364
|
8.81
|
0.15
|
168
|
1.9
|
9.0
|
0.90
|
1.02
|
0.05
|
nd
|
0.43
|
11
|
S18
|
16.2
|
7.8
|
328
|
8.12
|
0.15
|
152
|
1.9
|
9.0
|
0.90
|
1.11
|
0.05
|
nd
|
0.51
|
9
|
S19
|
15.0
|
8.2
|
407
|
8.19
|
0.18
|
183
|
2.6
|
163
|
5.35
|
1.22
|
1.51
|
nd
|
0.61
|
20
|
S20
|
16.0
|
8.4
|
341
|
8.55
|
0.16
|
176
|
1.9
|
9.0
|
0.90
|
0.94
|
0.52
|
0.01
|
0.44
|
5
|
S21
|
22.1
|
8.5
|
475
|
7.96
|
0.23
|
191
|
1.9
|
9.0
|
0.90
|
1.98
|
1.20
|
nd
|
0.59
|
48
|
S22
|
16.8
|
8.1
|
577
|
7.41
|
0.28
|
289
|
3.6
|
35.7
|
12.13
|
1.18
|
0.05
|
nd
|
0.48
|
15
|
S23
|
16.9
|
8.3
|
530
|
8.00
|
0.26
|
310
|
1.9
|
22.4
|
16.59
|
0.62
|
0.05
|
nd
|
0.09
|
18
|
S24
|
17.0
|
8.3
|
288
|
8.89
|
0.14
|
145
|
1.9
|
9.0
|
0.90
|
0.39
|
0.05
|
nd
|
0.13
|
7
|
S25
|
18.8
|
8.1
|
272
|
8.64
|
0.14
|
150
|
7.5
|
435.0
|
22.61
|
0.28
|
0.05
|
nd
|
0.09
|
5
|
S26
|
18.9
|
8.2
|
177
|
7.89
|
0.09
|
130
|
1.9
|
9.0
|
0.90
|
0.47
|
0.05
|
nd
|
0.09
|
24
|
S27
|
12.5
|
8.7
|
227
|
8.76
|
0.11
|
113
|
2.1
|
15.3
|
8.21
|
0.56
|
0.05
|
nd
|
0.09
|
5
|
S28
|
14.3
|
8.6
|
178
|
8.93
|
0.08
|
102
|
4.9
|
25.3
|
8.35
|
0.90
|
0.05
|
nd
|
0.09
|
5
|
S29
|
10.9
|
8.2
|
188
|
8.89
|
0.09
|
113
|
5.2
|
30.7
|
1.83
|
0.74
|
0.05
|
nd
|
0.09
|
10
|
S30
|
22.8
|
8.4
|
360
|
6.71
|
0.17
|
85
|
1.9
|
15.6
|
5.49
|
1.64
|
0.70
|
0.05
|
0.53
|
21
|
S31
|
16.3
|
8.3
|
176
|
8.01
|
0.08
|
96
|
3.9
|
19.2
|
11.53
|
0.94
|
0.05
|
nd
|
0.13
|
51
|
S32
|
14.4
|
7.5
|
426
|
8.87
|
0.11
|
312
|
7.2
|
45.6
|
25.48
|
1.50
|
1.00
|
nd
|
0.21
|
142
|
S33
|
14.8
|
8.2
|
98.9
|
8.30
|
0.05
|
55
|
1.9
|
9.0
|
0.90
|
0.58
|
0.05
|
nd
|
0.09
|
18
|
S34
|
17.3
|
8.7
|
243
|
9.01
|
0.12
|
113
|
1.9
|
15.2
|
9.64
|
0.84
|
0.05
|
0.01
|
0.23
|
116
|
S35
|
16.2
|
8.1
|
218
|
7.53
|
0.10
|
102
|
1.9
|
12.9
|
5.40
|
0.61
|
0.05
|
nd
|
0.09
|
51
|
S36
|
12.8
|
8.0
|
475
|
8.33
|
0.23
|
254
|
8.5
|
36.3
|
12.75
|
1.00
|
0.05
|
nd
|
0.09
|
25
|
S37
|
11.6
|
8.4
|
322
|
9.06
|
0.15
|
164
|
4.5
|
24.3
|
8.22
|
0.56
|
0.05
|
nd
|
0.09
|
5
|
S38
|
12.5
|
8.4
|
411
|
8.49
|
0.20
|
223
|
1.9
|
12.8
|
7.27
|
0.54
|
0.05
|
nd
|
0.09
|
5
|
S39
|
13.0
|
8.4
|
374
|
8.62
|
0.18
|
192
|
1.9
|
13.6
|
7.36
|
1.21
|
0.05
|
0.01
|
0.41
|
5
|
Table 2 continued
|
Al
|
Sb
|
As
|
Cu
|
B
|
Zn
|
Fe
|
Co
|
Ti
|
V
|
Sn
|
Ni
|
|
mg/L
|
µg/L
|
µg/L
|
µg/L
|
µg/L
|
µg/L
|
µg/L
|
µg/L
|
µg/L
|
µg/L
|
µg/L
|
µg/L
|
S01
|
0.10
|
0.15
|
0.46
|
1.94
|
27.3
|
8.88
|
132.5
|
0.10
|
0.45
|
1.12
|
0.45
|
7.81
|
S02
|
0.35
|
0.15
|
0.81
|
1.47
|
92.4
|
0.89
|
448.4
|
0.62
|
11.39
|
4.02
|
0.45
|
11.03
|
S03
|
1.16
|
0.15
|
9.24
|
1.71
|
601.7
|
29.54
|
632.1
|
0.57
|
8.18
|
10.74
|
12.33
|
1.60
|
S04
|
0.21
|
0.15
|
0.46
|
1.68
|
9.5
|
7.43
|
122.7
|
0.03
|
7.89
|
1.92
|
0.45
|
11.67
|
S05
|
0.07
|
0.15
|
1.19
|
1.57
|
208.9
|
3.95
|
501.7
|
0.08
|
2.57
|
1.95
|
35.79
|
4.81
|
S06
|
0.04
|
7.52
|
0.71
|
0.96
|
309.5
|
7.25
|
22.7
|
0.20
|
4.29
|
9.13
|
47.75
|
1.60
|
S07
|
nd
|
0.15
|
0.45
|
0.96
|
170.5
|
4.48
|
215.2
|
0.03
|
0.45
|
1.92
|
58.33
|
1.60
|
S08
|
0.17
|
0.15
|
0.64
|
1.40
|
9.5
|
18.29
|
107.2
|
0.12
|
3.37
|
3.38
|
0.45
|
11.00
|
S09
|
0.10
|
0.15
|
2.51
|
2.55
|
42.1
|
15.99
|
372.0
|
0.29
|
0.74
|
0.64
|
0.45
|
13.10
|
S10
|
0.06
|
0.15
|
2.67
|
0.96
|
9.5
|
0.89
|
41.3
|
0.03
|
0.45
|
1.09
|
0.45
|
5.92
|
S11
|
0.05
|
0.15
|
0.46
|
1.25
|
64.4
|
0.89
|
48.5
|
0.03
|
0.45
|
2.11
|
0.45
|
4.21
|
S12
|
0.01
|
0.15
|
0.46
|
3.19
|
9.5
|
5.82
|
33.2
|
0.03
|
0.45
|
5.84
|
0.45
|
4.53
|
S13
|
0.06
|
0.15
|
0.45
|
2.85
|
77.1
|
11.33
|
187.0
|
0.18
|
0.67
|
1.57
|
12.07
|
5.29
|
S14
|
0.41
|
1.21
|
1.98
|
5.59
|
9.5
|
22.53
|
417.8
|
1.58
|
1.32
|
2.06
|
0.45
|
9.15
|
S15
|
0.08
|
0.15
|
0.66
|
3.64
|
9.5
|
5.38
|
104
|
0.11
|
4.77
|
3.63
|
0.45
|
7.00
|
S16
|
0.12
|
0.15
|
0.72
|
2.04
|
64.1
|
2.91
|
73.4
|
0.18
|
1.65
|
1.86
|
11.00
|
3.35
|
S17
|
0.11
|
0.15
|
0.61
|
0.96
|
79.1
|
0.89
|
90.8
|
0.06
|
0.45
|
1.22
|
11.97
|
2.74
|
S18
|
nd
|
0.15
|
0.45
|
0.96
|
139.9
|
0.89
|
4.5
|
0.03
|
0.45
|
1.82
|
37.84
|
3.19
|
S19
|
nd
|
0.15
|
0.53
|
0.96
|
51.2
|
0.89
|
6.4
|
0.03
|
0.45
|
1.37
|
10.40
|
2.86
|
S20
|
0.01
|
0.15
|
0.70
|
0.96
|
9.5
|
0.89
|
13.4
|
0.03
|
0.45
|
1.00
|
0.45
|
5.22
|
S21
|
nd
|
0.15
|
0.46
|
0.96
|
9.5
|
0.89
|
4.5
|
0.03
|
0.45
|
0.62
|
0.45
|
7.00
|
S22
|
0.15
|
0.15
|
0.46
|
0.96
|
9.5
|
0.89
|
74.7
|
0.03
|
8.82
|
1.70
|
0.45
|
6.02
|
S23
|
0.10
|
1.21
|
0.51
|
4.36
|
93.5
|
16.25
|
73.7
|
0.17
|
1.77
|
1.49
|
0.45
|
2.80
|
S24
|
0.07
|
0.15
|
0.45
|
3.12
|
21.2
|
8.44
|
56.7
|
0.07
|
1.65
|
0.45
|
0.45
|
1.60
|
S25
|
0.14
|
0.15
|
0.45
|
0.96
|
31.7
|
6.28
|
148.9
|
0.03
|
2.82
|
0.45
|
0.45
|
1.60
|
S26
|
0.16
|
0.99
|
0.56
|
2.76
|
24.8
|
13.33
|
227.3
|
0.44
|
1.20
|
0.96
|
0.45
|
3.29
|
S27
|
nd
|
0.15
|
0.46
|
0.96
|
9.5
|
0.89
|
4.5
|
0.03
|
0.45
|
0.45
|
0.45
|
1.60
|
S28
|
nd
|
0.15
|
0.46
|
0.96
|
9.5
|
0.89
|
4.5
|
0.03
|
0.45
|
0.45
|
0.45
|
1.60
|
S29
|
0.07
|
0.58
|
0.56
|
0.96
|
75.8
|
6.29
|
97.3
|
0.08
|
0.45
|
0.45
|
0.45
|
1.60
|
S30
|
0.26
|
0.15
|
0.59
|
6.66
|
14.3
|
27.91
|
362.7
|
0.54
|
3.52
|
3.02
|
0.45
|
1.60
|
S31
|
0.12
|
0.68
|
1.89
|
1.66
|
31.7
|
17.47
|
298.7
|
0.10
|
3.63
|
3.67
|
0.45
|
1.60
|
S32
|
0.11
|
1.72
|
1.88
|
4.43
|
39.0
|
21.82
|
231.2
|
0.26
|
3.51
|
5.00
|
0.45
|
1.60
|
S33
|
0.14
|
1.78
|
0.46
|
19.28
|
34.07
|
26.97
|
250.6
|
0.28
|
5.74
|
1.56
|
0.45
|
2.13
|
S34
|
0.18
|
0.15
|
1.45
|
3.91
|
17.5
|
17.31
|
279.0
|
0.24
|
4.21
|
4.65
|
0.45
|
1.60
|
S35
|
0.15
|
0.15
|
2.80
|
2.87
|
139.5
|
57.15
|
207.7
|
0.11
|
1.86
|
3.03
|
10.83
|
1.60
|
S36
|
nd
|
0.15
|
0.46
|
0.96
|
9.5
|
0.89
|
4.5
|
0.03
|
0.45
|
0.45
|
0.45
|
1.60
|
S37
|
nd
|
0.15
|
0.46
|
0.96
|
9.5
|
0.89
|
4.5
|
0.03
|
0.45
|
0.45
|
0.45
|
1.60
|
S38
|
nd
|
0.15
|
0.46
|
0.96
|
9.5
|
0.89
|
4.5
|
0.03
|
0.45
|
0.45
|
0.45
|
1.60
|
S39
|
nd
|
0.15
|
0.46
|
0.96
|
9.5
|
0.89
|
4.5
|
0.03
|
0.45
|
0.45
|
0.45
|
1.60
|
Temp–Temperature, EC-electrical conductivity, DO–dissolved oxygen, BOD–biological oxygen demand, COD-chemical oxygen demand, TOC-total organic carbon, TN–total nitrogen, N-NO2–nitrite, N-NO3–nitrate, TP–total phosphorus, CaCO3–calcium carbonate, Al-Aluminum, Sb-Antimon, As-Arsenic, Cu-Copper, Co-Cobalt, B-Boron, Zn-Zinc, Fe-iron, Ti-Titanium, V-Vanadium, Sn–Tin, and Ni–Nickel.
Concerning heavy metals variations, the highest mean Nickel (Ni) concentration was determined in Kovalık Stream (S9) with 13.10 µg/L, followed with 11.67 µg/L in Güvercinlik Stream (S4), whereas the lowest mean concentration equals to 1.6 µg/L Ni were found in 17 sampling stations (Table 2). Some metals were measured in a few regions such as relatively high iron (Fe) values were found in S30-S34 (>231.0 µg/L) at Erenler Mountain, S3 (632.1 µg/L) and S5 (501.7 µg/L) at Melendiz Mountains, and S14 (417.8 µg/L) at Taurus Mountains. The highest mean boron (B) value was found in Ilısu Stream (S3) with 601.7 µg/L, following by Yağıl Stream (S6) with 309.5 µg/L and Okçu Stream (S5) with 208.9 µg/L. Ilısu Stream also had relatively high concentrations of metals like Arsenic-As, Boron-B, Iron-Fe, Ti, and V (see Table 2).
Diatom composition
A total of 201 diatom taxa were identified in sampling stations in Konya closed river basin (Supplementary 1). Threat status and ecological attributes of diatom species were determined according to Hofmann et al (2018). Biological condition gradient (BCG) attributes of species are given in Supplementary 1 according to Hausman et al (2016). Achnanthidium minutissimum, Cocconeis euglypta, Cocconeis placentula, Cymbella excisa, Fragilaria capucina, Encyonopsis minuta, Gomphonema parvulum, Meridion circulare, Navicula tripunctata, Reimeria sinuata, and Ulnaria ulna were commonly encountered species during the study. Among species in the present study, Achnanthidium subatomus, Gomphonema calcifugum, Gomphonema exilissimum, Gomphonema lateripunctatum, Hannaea arcus, Pinnularia microstauron, and Stauroneis anceps are listed in Red-List (RL) threat-category data. Diatom species, Brachysira exilis, Cymbella (C. cymbiformis C. excisiformis, C. laevis, and C. subhelvetica) are endangered, while Gomphonema stauroneiforme, Navicula dealpina, Navicula leptostriata, and Nitzschia gessneri are in the serious danger list. Of the species, Achnanthidium atomoides, Cocconeis pseudolineata, Fragilaria pectinalis, Gomphonema cuneolus, Navicula dealpina, Pinnularia isselana, Planothidium biporomum, Psammothidium bioretii, Staurosirella ovata, and Surirella terricola were new records for diatom database of Turkey.
ANOSIM indicated that differences between spring and autumn (p<0.01) and between spring and summer (p<0.01) groups are significant, when the difference (p=0.70) between autumn and summer is not. SIMPER revealed that the dissimilarity between the spring and autumn groups was 94.1% with contributions of C. excisa (8.0%), C. euglypta (7.9%), A. minutissimum (5.5%) C. placentula (5.4%), Achnanthidium pyrenaicum (4.5%), and Cocconeis euglyptoides (3.0%). The spring-summer dissimilarity as 92.2% was contributed by C. euglypta (9.8%), C. excisa (8.1%), C. placentula (5.5%), Cocconeis lineata (4.2%), A. minutissimum (3.2%), Nitzschia costei (3.1%), and Gomphonema minutum (3.0%). An 87.4% difference between autumn and summer groups was provided by C. euglypta (12.8%), C. placentula (6.6%), A. pyrenaicum (5.2%), C. euglypotides (4.2%), and C. lineata (4.2%).
In Konya closed river basin, within-group similarity was found as 14.9%, 14.4%, and 11.0% for the spring, summer, and fall seasons, respectively. Cymbella excisa (43.7%), C. euglypotides (41.3%), and C. euglypotides (39.0%) were the most contributing species for the spring, summer, and fall seasons, respectively.
Concerning altitude (A2 800-<1600 and A3≥1600 m), there was a significant difference between A2 and A3 groups (p=0.012) according to ANOSIM. Results of SIMPER indicated that the dissimilarity between A2 and A3 groups was 90.9%, which was presented by C. euglypta (14.6%), C. excisa (6.6%), A. minutissimum (4.7%) C. placentula (4.7%), C. lineata (4.0%), Epithemia sorex (3.9%), R. sinuata (3.4%), Gomphonema cuneolus (2.8%), G. parvulum (2.5%), G. minutum (2.4%), Fragilaria capucina (2.3%), and C. euglypotides (2.2%). Cocconeis euglypotides (54.1%), R. sinuata (11.7%), and G. parvulum (5.1%) were the most contributing species to 16.4% within-A2 similarity, while within-A3 similarity as 12.2% were contributed by C. excisa (30.9%), C. placentula (18,6%), F. capucina (7.9%), and A. minutissimum (5.7%).
Diatom assemblages-environment relationship
The first two axes of the CCA diagram elucidated 82.8% of the species-environment correlation. Diatom species have distinct responses to environmental variables in the basin system (Figure 2) and they were significantly affected by EC, Ni, Cu, B, and altitude (F= 1.802 and p = 0.008). The close relationship between EC and Zorlak (S11), Doğuca (S23), Asın (S32), and Seydihasan (S21) streams was characterized by some diatom species (e.g., Navicula dealpina, Geissleria schoenfeldii, Cymbella cymbiformis, Gomphonema augur, Gomphonema angustius, Caloneis silicula, Diploneis oblongella, Cocconeis pseudolineata Nitzschia dissipata, Navicula cari, and Stauroneis anceps). Relatively high EC preferences of these species were approved by results of WA regression (Figure 3a). S1, S8, S9, S14, S15 showed the relation to Nickel (Ni), which is associated with Navicula veneta, Nitzschia palea, Cymbella neocistula, Gomphonema angustatum, Surirella ovalis, Nitzschia parvula, and Amphora ovalis (Figure 2). WA indicated that mentioned species had Ni optima higher than 75th percentile (Figure 3b). CCA diagram indicated that G. angustatum, N. veneta, N. parvula, and A. ovalis preferred Copper (Cu), which are associated to Genge (S33), Ulu (S14), and Geleri (S15) streams. This assignment was also confirmed by WA (Figure 3c). Close integration between Ilısu (S3) and Boron (B) was found in the CCA ordination, and it was also characterized by Nitzschia flexa, Navicula gregaria, Hantzschia amphioxys, and Rhoicosphenia abbreviata, in agreement with findings of WA (Figure 3d). Some stations (S24 and S27-S29) are located at opposite of EC variable and are associated to Hannaea arcus, Diatoma ehrenbergii, Odontidium mesodon, Encyonema minutum, Encyonema silesiacum, and Achnanthidium subatomus.
Bio-assessment of sampling stations
Dia-assessments of sampling stations in the Konya closed river basin are given in Table 3. Ecological assessment from a high ecological status to a bad environmental condition was found in the Konya closed river system according to responses of different ecoregional diatom indices. Percentages of ecological quality status of diatom indices are provided in Figure 4. The highest percentage of high ecological status with 30.8% was determined by the TIT, following by EPI-D (23.1%), DEQI (20.1%), and IPS (10.8%) (Figure 4). DSIAR and DDI could not separate the ecological status of sampling stations.
Diatom indices showed different ecological status for sampling stations (Table 3). For instance, S32 had five different environmental conditions such as a bad status due to TIT and TWQI; a poor condition according to TI; a moderate status after evaluated by EPI-D, IPS, and TDI; and a good status after assessed by DEQI. Likely, four different ecological conditions are found in S33. European indices displayed that S9 had a good status, whereas it was assigned as a bad condition according to DEQI. European diatom indices except DDI mainly displayed similar behavior in eco-assessment of sampling stations in the Konya closed river basin (Table 3 and Figure 4). European diatom indices indicated that the least disturbed areas are S16, S20, S24, S25, S27-29, S37, and 39 with high ecological status in the Konya closed river system.
Table 3. Different ecoregional diatom indices’ scores of the sampling stations. Trophic index Turkey (TIT), Trophic Index (TI), Eutrophication and/or Pollution Index-Diatom (EPI-D), Trophic Diatom Index for Lakes (TDIL), Trophic Water Quality Index (TWOI), Diatom Ecological Quality Index (DEQI), Duero Diatom Index (DDI), Pollution Sensitivity Index (IPS), Trophic Diatom Index (TDI), and Diatom Species Index Australian Rivers (DSIAR). The meaning of different colors used in the table is as follows: blue–high quality, green–good quality, yellow– moderate quality, orange–poor quality, red–bad quality. nd-not detected scores.
Correlations between diatom indices and environmental variables are represented in Table 4. IPS, DSIAR, and DDI showed inverse correlation with environmental pollution while others indicated direct correlations. A few diatom indices such as TIT (p<0.01 r=0.506), TI (p<0.01 r= 0.386), EPI-D (p<0.01 r = 0.367) had significant positive correlations with TP gradient, whereas IPS (p<0.01 r= -0.477) and DDI (p<0.05 r= -0.304) displays significantly negative correlations with TP (see more in Table 4).
Table 4. Spearman’s rank correlations between diatom indices and environmental factors. Abbreviations of diatom indices are given in Table 3.
|
TIT
|
TI
|
EPI-D
|
IPS
|
TDI
|
DSIAR
|
DEQI
|
TWQI
|
DDI
|
Temp.
|
0.164
|
.302*
|
0.223
|
-.349**
|
0.122
|
-.258*
|
0.017
|
0.168
|
-0.139
|
pH
|
-0.126
|
-.350**
|
-0.149
|
0.114
|
-0.028
|
0.072
|
-0.035
|
-0.164
|
0.216
|
NO2
|
-0.065
|
-0.137
|
-0.007
|
0.025
|
-.285*
|
0.154
|
-0.229
|
-.282*
|
0.122
|
NO3
|
0.066
|
0.029
|
0.154
|
0.006
|
-0.044
|
-0.053
|
-.296*
|
-.278*
|
-0.098
|
TP
|
.506**
|
.386**
|
.367**
|
-.477**
|
0.159
|
-0.147
|
0.188
|
0.181
|
-.304*
|
Ni
|
-0.086
|
-.278*
|
-0.237
|
0.017
|
-0.123
|
.319**
|
0.073
|
-0.116
|
-0.007
|
Cu
|
0.021
|
-0.070
|
-0.088
|
-0.145
|
-0.098
|
.339**
|
0.139
|
-0.068
|
0.053
|
B
|
.340**
|
.473**
|
.495**
|
-.277*
|
.257*
|
-0.230
|
0.031
|
0.110
|
-.301*
|
Sb
|
0.039
|
0.165
|
0.210
|
-.332**
|
0.123
|
0.102
|
0.082
|
.254*
|
-0.156
|
As
|
0.144
|
0.138
|
0.212
|
-.340**
|
-0.002
|
-0.042
|
0.119
|
0.172
|
-0.083
|
Ti
|
0.026
|
0.110
|
0.060
|
-.290*
|
0.147
|
0.067
|
.258*
|
0.197
|
-0.126
|
V
|
.351**
|
.389**
|
.334**
|
-.450**
|
.326**
|
-0.158
|
0.147
|
0.129
|
-.301*
|
Sn
|
0.081
|
.335**
|
.278*
|
-0.175
|
0.137
|
-0.217
|
0.027
|
0.096
|
-0.207
|
TIT
|
|
.531**
|
.649**
|
-.499**
|
.487**
|
-0.222
|
.293*
|
.427**
|
-.507**
|
TI
|
|
|
.666**
|
-.722**
|
.417**
|
-.342**
|
0.191
|
.432**
|
-.612**
|
EPI-D
|
|
|
|
-.563**
|
.456**
|
-.299*
|
0.184
|
.320**
|
-.548**
|
IPS
|
|
|
|
|
-.314*
|
0.050
|
-.407**
|
-.454**
|
.548**
|
TDI
|
|
|
|
|
|
-.360**
|
0.136
|
0.223
|
-.508**
|
DSIAR
|
|
|
|
|
|
|
0.121
|
0.068
|
0.230
|
DEQI
|
|
|
|
|
|
|
|
0.135
|
-0.074
|
TWQI
|
|
|
|
|
|
|
|
|
-.422**
|
DDI
|
|
|
|
|
|
|
|
|
|
* and ** show significant levels at 0.05 and 0.01, respectively.