The study of ecological status of Republic Armenia Rivers is importance both for evaluation of water quality of that objects and for their further rational use. Development of water quality assessment methods using conventional indicators comprehensively taking into account various properties of surface water is an important issue. The complex evaluation is an extremely difficult task that requires a simultaneous consideration of a variety of properties of the water object. For evaluation of water contamination degree the comprehensive indicators are used which take possible to evaluate the contamination of water at the same time on a wide range of quality indicators. Water Contamination Index (WCI), Canadian Water Quality Index (CWQI) and Specific-combinatorial Water Quality Index (SCWQI) are used for evaluation surface water quality in Republic of Armenia [3, 4, 7]. It must be noted that most developed complex characteristics of water object in one way or another connected with the existing maximum permissible concentration (MPC). In the last years we suggest Entropic Water Quality Index (EWQI) and Armenian Water Quality Index (AWQI) for evaluation surface water quality [8, 9].
Monitoring Positions cross-sections of the River Aghstev
The aim of presented paper is evaluation of River Аghstev and it’s tributarу Getik by Armenian Water Quality Index.
River Aghstev is right tributary of the Kura. Aghstev is 133 kilometres long with a drainage basin of 2,589 square kilometres [5]. It rises in the territory of Armenia, on the northwest slope of Mount Tezhler. The following takes place in a wider valley. The largest tributaries – Bldan, Voskepar, Getik. Two monitoring posts located on the river Aghstev: number 15–1,2 km above the city of Dilijan, number 16–0,5 km below the city of Dilijan, number 17–1,0 km above the city of Ijevan, number 18–8 km below the city of Ijevan Getik River – right tributary Aghstev. The river is 63 km [5]. On Getik river located positions: number 19–0,5 km above the city of Chambarak and number 20 – at the mouth of the river.
Determination procedure
In hydroecological systems there can be processes both with increase, and with entropy reduction. The concept of entropy has many interpretations in various fields of human knowledge. The system interacts with the outside world as a whole. An open system can exchange energy, material and, which is not less important, information with environment. The system must it must consume information from the environment and provide information environment for act and interact with environment. Shannon was the first who related concepts of entropy and information [6]. He was suggesting that entropy is the amount of information attributable to one basic message source, generating statistically independent reports. Get any amount of information entropy is equal to the lost. Information entropy for independent random event x with N possible states is calculated by the equation:
where Pi – probability of frequency of occurrence of an event.
Entropy general equation of Shannon was been used at the first time by Maс-Artur in 1955 for evaluation of degree of structuring biogenesis [1]. In 1957, R. Margalef postulated theoretical concept that meets a variety of entropy for a random selection of species from the community [2]. As a result of these works widespread and universal recognition received index Shannon H, sometimes referred to as a Shannon information index of diversity [6]:
Pollution of water systems can be represented as a system of the hydro-chemical parameters (elements), the concentration of which exceeds the MPC. Then in the equation Shannon pi- probability of the number of cases of MPC excess of i-substance or water indicator of total cases of MPC – N, Pi = ni/N.
H = log2N – I;
where I – geoecological syntropy [10].
The following computational algorithm is used for determination I, H, EWQI and AWQI values:
1. Determines the number of cases of MPC excess of i-substance or indicator of water – n.
2. Estimates the total amount of cases the maximum permissible concentration (N) – 
.
3. Computes log2N, nlog2n and 
.
4. Determines geoecological syntropy (I) and entropy (H):
and H = log2N – I.
5. Then EWQI is determined: G = H/I.
6. Further, the total amount multiplicity MAC exceedances is estimated (M) – 
.
7. Computes log2M.
8. Armenian Water Quality Index was obtained: AWQI = G + 0,1•log2M.
Results of research and their discussion
It was established that the water of the Rivers Agstеv and Getik regularly exceeded the value of BOD5 and concentrations of nitrite and ammonium ions, due to water pollution by domestic wastewater. It was shown that water of Rivers Agstrv and Getik is also contaminated by some metals. Thus, in the river water is regularly increased MPC of copper, vanadium, aluminum, cobalt, manganese and selenium (Tables 1–4). For example, in 2012 year in the position № 16 of River Agstеv BOD5, 
V, Cu, Al and Mn number of MPC increasing cases is 4, 5, 6, 11, 11, 9 and 7 times, respectively. The amount of excess cases of MPC – N = 53, 
I = 159,309/53 = 3,005; H = log253 – 3,005 = 2,72, G = 2,720/3,005 = 0,900. The total amount of the multiplicity of MPC exceedances – 
log2M = 3,7; А = 0,90 + 0,37 = 1,270 (Table 3)
Table 1
Entropic and Armenian Water Quality Indexes for River Aghstev and Getik (2009)
|
Positions |
15 |
16 |
17 |
18 |
19 |
20 |
||||||
|
Indicator |
n |
nlog2n |
n |
nlog2n |
n |
nlog2n |
n |
nlog2n |
n |
nlog2n |
n |
nlog2n |
|
|
0 |
0 |
6 |
15,5 |
0 |
0 |
0 |
0 |
7 |
19,64 |
0 |
0 |
|
Cu |
7 |
19,64 |
12 |
43 |
11 |
38,0 |
12 |
43,0 |
5 |
11,6 |
11 |
38,0 |
|
V |
8 |
24 |
10 |
33,2 |
10 |
33,2 |
10 |
33,2 |
11 |
38,0 |
8 |
24 |
|
Al |
12 |
43,0 |
12 |
43 |
12 |
43,0 |
12 |
43,0 |
11 |
38,0 |
11 |
38,0 |
|
Mn |
0 |
0 |
5 |
11,6 |
9 |
28,5 |
6 |
15,5 |
4 |
8 |
0 |
0 |
|
N |
27 |
45 |
42 |
40 |
38 |
30 |
||||||
|
|
86,64 |
146,3 |
142,7 |
134,7 |
115,24 |
100 |
||||||
|
I |
3,201 |
3,251 |
3,398 |
3,367 |
3,032 |
3,333 |
||||||
|
H |
1,551 |
2,238 |
2,00 |
1,95 |
2,213 |
1,571 |
||||||
|
G |
0,4845 |
0,688 |
0,5886 |
0,5796 |
0,7300 |
0,471 |
||||||
|
|
10,9 |
17,4 |
18 |
19 |
20,2 |
16,1 |
||||||
|
log2M |
3,44 |
4,12 |
4,167 |
4,254 |
4,333 |
4,006 |
||||||
|
AWQI |
0,8285 |
1,109 |
1,0053 |
1,005 |
1,161 |
0,871 |
||||||
Table 2
Entropic and Armenian Water Quality Indexes for River Aghstev and Getik (2010)
|
Positions |
15 |
16 |
17 |
18 |
19 |
20 |
||||||
|
Indicator |
n |
nlog2n |
n |
nlog2n |
n |
nlog2n |
n |
nlog2n |
n |
nlog2n |
n |
nlog2n |
|
|
0 |
0 |
4 |
8 |
0 |
0 |
0 |
0 |
4 |
8 |
0 |
0 |
|
|
0 |
0 |
5 |
11,6 |
0 |
0 |
0 |
0 |
3 |
4,75 |
0 |
0 |
|
Cu |
6 |
15,5 |
10 |
33,2 |
10 |
33,2 |
10 |
33,2 |
6 |
15,5 |
11 |
38,0 |
|
V |
9 |
28,5 |
12 |
43 |
10 |
33,2 |
11 |
38,0 |
9 |
28,5 |
11 |
38,0 |
|
Al |
10 |
33,2 |
8 |
24 |
9 |
28,5 |
10 |
33,2 |
8 |
24 |
11 |
38,0 |
|
Mn |
0 |
0 |
5 |
11,6 |
7 |
19,64 |
0 |
0 |
4 |
8 |
0 |
0 |
|
Se |
3 |
4,75 |
4 |
8 |
4 |
8 |
3 |
4,75 |
0 |
0 |
3 |
4,75 |
|
N |
28 |
48 |
40 |
34 |
34 |
36 |
||||||
|
|
81,96 |
139,17 |
122,547 |
109,18 |
88,75 |
118,75 |
||||||
|
I |
2,927 |
2,903 |
3,063 |
3,211 |
2,610 |
3,300 |
||||||
|
H |
1,877 |
2,678 |
2,555 |
1,873 |
2,474 |
1,867 |
||||||
|
G |
0,641 |
0,922 |
0,736 |
0,583 |
0,948 |
0,566 |
||||||
|
|
15,6 |
21,8 |
15,9 |
18,5 |
22 |
17,2 |
||||||
|
log2M |
3,96 |
4,44 |
3,98 |
4,200 |
4,46 |
4,10 |
||||||
|
AWQI |
1,037 |
1,366 |
1,134 |
1,003 |
1,394 |
0,979 |
||||||
Table 3
Entropic and Armenian Water Quality Indexes for River Aghstev and Getik (2011)
|
Positions |
15 |
16 |
17 |
18 |
19 |
20 |
||||||
|
Indicator |
n |
nlog2n |
n |
nlog2n |
n |
nlog2n |
n |
nlog2n |
n |
nlog2n |
n |
nlog2n |
|
BOD5 |
0 |
0 |
4 |
8 |
6 |
15,5 |
0 |
0 |
0 |
0 |
8 |
24 |
|
|
0 |
0 |
5 |
11,6 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
|
0 |
0 |
6 |
15,5 |
0 |
0 |
5 |
11,6 |
0 |
0 |
0 |
0 |
|
Cu |
0 |
0 |
11 |
38,0 |
9 |
28,5 |
10 |
33,2 |
0 |
0 |
10 |
33,2 |
|
V |
10 |
33,2 |
11 |
38,0 |
10 |
33,2 |
11 |
38,0 |
7 |
19,64 |
0 |
0 |
|
Al |
10 |
33,2 |
9 |
28,5 |
9 |
28,5 |
9 |
28,5 |
7 |
19,64 |
12 |
43,0 |
|
Mn |
6 |
15,5 |
7 |
19,64 |
9 |
28,5 |
0 |
0 |
0 |
0 |
0 |
0 |
|
N |
26 |
53 |
43 |
35 |
14 |
30 |
||||||
|
|
81,9 |
159,309 |
134,236 |
111,344 |
39,28 |
100,18 |
||||||
|
I |
3,15 |
3,005 |
3,121 |
3,181 |
2,80 |
3,339 |
||||||
|
H |
1,547 |
2,72 |
2,302 |
1,945 |
1,005 |
1,565 |
||||||
|
G |
0,491 |
0,900 |
0,737 |
0,611 |
0,358 |
0,468 |
||||||
|
|
6,9 |
13,2 |
10,7 |
10,2 |
4,4 |
10 |
||||||
|
log2M |
2,78 |
3,7 |
3,4 |
3,34 |
2,14 |
3,32 |
||||||
|
AWQI |
0,769 |
1,270 |
1,077 |
0,945 |
0,572 |
0,800 |
||||||
Table 4
Entropic and Armenian Water Quality Indexes for River Aghstev and Getik (2012)
|
Positions |
15 |
16 |
17 |
18 |
19 |
20 |
||||||
|
Indicator |
n |
nlog2n |
n |
nlog2n |
n |
nlog2n |
n |
nlog2n |
n |
nlog2n |
n |
nlog2n |
|
BOD5 |
0 |
0 |
0 |
0 |
10 |
33,2 |
8 |
24 |
0 |
0 |
0 |
0 |
|
|
0 |
0 |
9 |
28,5 |
0 |
0 |
7 |
19,64 |
0 |
0 |
0 |
0 |
|
|
0 |
0 |
8 |
24 |
5 |
11,6 |
9 |
28,5 |
0 |
0 |
0 |
0 |
|
Cu |
12 |
43,0 |
12 |
43 |
11 |
38,0 |
11 |
38,0 |
7 |
19,64 |
12 |
43 |
|
V |
10 |
33,2 |
10 |
33,2 |
10 |
33,2 |
10 |
33,2 |
8 |
24 |
10 |
33,2 |
|
Al |
11 |
38,0 |
10 |
33,2 |
10 |
33,2 |
10 |
33,2 |
8 |
24 |
10 |
33,2 |
|
Mn |
8 |
24 |
8 |
24 |
10 |
33,2 |
8 |
24 |
4 |
8 |
0 |
0 |
|
Cr |
0 |
0 |
4 |
8 |
6 |
15,5 |
6 |
15,5 |
5 |
11,6 |
5 |
11,6 |
|
Se |
2 |
2 |
2 |
2 |
2 |
2 |
3 |
4,75 |
0 |
0 |
0 |
0 |
|
N |
43 |
63 |
64 |
72 |
32 |
37 |
||||||
|
|
140,2 |
195,9 |
199,90 |
220,79 |
87,24 |
121,0 |
||||||
|
I |
3,256 |
3,109 |
3,123 |
3,066 |
2,726 |
3,270 |
||||||
|
H |
2,167 |
2,864 |
2,873 |
3,100 |
2,274 |
1,936 |
||||||
|
G |
0,666 |
0,921 |
0,919 |
1,011 |
0,834 |
0,592 |
||||||
|
|
13,5 |
21 |
17,6 |
19,7 |
27,3 |
14,6 |
||||||
|
log2M |
3,752 |
4,390 |
4,135 |
4,298 |
4,768 |
3,865 |
||||||
|
AWQI |
1,041 |
1,351 |
1,3325 |
1,4408 |
1,311 |
0,9785 |
||||||
Table 5
Entropic and Armenian Water Quality Indexes for Rivers Aghstev and Getic (2009-2012)
|
Positions |
2009 |
2010 |
2011 |
2012 |
||||
|
EWQI |
AWQI |
EWQI |
AWQI |
EWQI |
AWQI |
EWQI |
AWQI |
|
|
15 |
0,485 |
0,828 |
0,641 |
1,037 |
0,491 |
0,769 |
0,666 |
1,041 |
|
16 |
0,688 |
1,109 |
0,922 |
1,366 |
0,900 |
1,270 |
0,921 |
1,351 |
|
17 |
0,588 |
1,005 |
0,736 |
1,134 |
0,737 |
1,077 |
0,919 |
1,3325 |
|
18 |
0,580 |
1,006 |
0,583 |
1,003 |
0,611 |
0,945 |
1,011 |
1,4408 |
|
19 |
0,733 |
1,161 |
0,948 |
1,394 |
0,358 |
0,572 |
0,834 |
1,311 |
|
20 |
0,476 |
0,871 |
0,565 |
0,979 |
0,468 |
0,800 |
0,592 |
0,9787 |
AWQI = (0,271 ± 0,065) + (1,227 ± 0,108)•EWQI; R = 0,98481; N = 6 (2009 year);
AWQI = (0,351 ± 0,033) + (1,094 ± 0,044)•EWQI; R = 0,99676; N = 6 (2009 year);
AWQI = (0,172 ± 0,049) + (1,235 ± 0,079)•EWQI; R = 0,99191; N = 6 (2009 year);
AWQI = (0,309 ± 0,075) + (1,133 ± 0,090)•EWQI; R = 0,98765; N = 6 (2009 year)/
Analysis of obtained data indicate that AWQI has liner dependence with EWQI (Table 5).
The obtained data indicate that along the source to the mouth of the river water quality decreases. After the cities of Dilijan and Ijevan AWQI increases, this indicates a decline in water quality of River Voghji caused by water pollution by domestic wastewater.
Quality of Rivers Aghstev and Getik water also comprehensively evaluate by other indexes: WCI, EWQI, CWQI, SCWQI (Table 6).
Table 6
Water Quality Indexes for Rivers Aghstev and Getik (2009)
|
Index |
AWQI |
EWQI |
WCI |
CWQI |
SCWQI |
|
15 |
0,828 |
0,485 |
0,97 |
81,61 |
1,56 |
|
16 |
1,109 |
0,688 |
1,59 |
73,13 |
2,33 |
|
17 |
1,005 |
0,588 |
1,42 |
74,17 |
2,06 |
|
18 |
1,006 |
0,580 |
1,46 |
72,23 |
2,40 |
|
19 |
1,161 |
0,733 |
1,5 |
71,52 |
2,11 |
|
20 |
0,871 |
0,476 |
1,4 |
72,15 |
1,95 |
Analysis of obtained data indicate that AWQI has liner dependence with WCI, SCWQI, EWQI and an inverse dependence with CWQI:
AWQI = (0,338 ± 0,257) + (0,474 ± 0,183)•WCI; R = 0,79116; N = 6;
AWQI = (0,358 ± 0,313) + (0,309 ± 0,150)•SCWQI; R = 0,71722; N = 6;
AWQI = (0,271 ± 0,065) + (1,227 ± 0,108)•EWQI; R = 0,98481; N = 6;
AWQI = (2,631 ± 0,977) – (0,022 ± 0,013)•CWQI; R = 0,64206; N = 6.
For river Aghstev excellent correlation,
AWQI = (0,408 ± 0,074) + (0,426 ± 0,053)•WCI; R = 0,98468; N = 4;
AWQI = (0,417 ± 0,207) + (0,273 ± 0,098)•SCWQI; R = 0,89146; N = 4;
AWQI = (0,181 ± 0,119) + (1,377 ± 0,203)•EWQI; R = 0,97886; N = 4;
AWQI = (2,823 ± 0,642) – (0,024 ± 0,009)•CWQI; R = 0,89661; N = 4.
Conclusion
Thus, for the first time using AWQI the quality of Rivers Aghstev and Getic water evaluate. It was shown that from the source to the mouth of the river there is an increase in the value of the AWQI, which indicates the decline in the quality of water of the rivers from the first to the second class of pollution. After the cities Dilijan and Ijevan of AWQI increases, indicating a decrease in water quality due to pollution of water River Aghstev by domestic wastewaters. It was established the correlation between AWQI and other water quality indexes.