The present study was conducted to investigate the water quality characteristics and nutritional status of the Miankaleh wetland using the Carlson Trophy INDEX (TSI) and TRIX. Measurement of parameters has been done during 6 seasons and 8 sampling periods in 6 stations of Dahane-ye-chopoghli, Bandar-e-Gaz, Gharehsu, Galogah, Ismaeilsay, and Miyan-ghaleh. Based on the results, Dahane-ye-chopoghli, and Gharehsu stations respectively have the highest amounts of phosphate (0.12 mg/l), nitrate (11.04 mg/l), the lowest DO (87 mg/l) and the highest BOD (mg/l 14/77) which indicates the unfavorable condition of the wetland in terms of quality. Calculation of TSI INDEX based on TP shows that Miankaleh wetland is in hypertrophic condition (70-80) in four stations of, Dahane-ye-chopoghli, Gharehsu, Galogah, and Miyan-ghaleh and in eutrophic condition (60-70) in Bandar-e-Gaz and Ismaeilsay stations. On the other hand, based on TN, except for the Galogah station, which is in hypertrophic condition (70-80), the rest of the stations are in acute hypertrophic condition (80-100). Also, based on P/N, all the studied stations of the Miankaleh wetland are in mild mesotrophic conditions (30-40). In general, based on the total TSI INDEX (29.62), the status of the wetland is in the eutrophic range (60-70). The results obtained for TRIX show that the two stations of Dahane-ye-chopoghli, and Galogah are in the mesozotrophic range (4-5) and the rest of the stations are in the oligotrophic range (2-4), which indicates the unfavorable condition of the wetland in terms of tropism. The main cause of these conditions is the discharge of sewage and drains from different units on the edge of the lagoon, which contain large amounts of nitrate and phosphate compounds.

Lake of the Martyrs of the Persian Gulf (also known as the Chitgar Lake) is located in the north-western of Tehran. The construction of this artificial lake was done by Tehran Municipality was filled water of the Kan River in 2012. TN, TP, SD and Chl-a was used to determine trophic levels. Water sampling was performed by Rotner sampler and the water quality was investigated on 5 stations site during 2013-2019. Standard methods were used for Analysis of water parameters. To determine the difference between mean of the studied parameters, the One-way ANOVA variance analysis test and Duncan mean pair test was used, and the confidence level was 95%. Based on the study, the results indicated that during 2013-2019 the mean yearly EC was 432±, 65 µ, s/cm, pH was 7. 79±, 0. 45 and SD was 3. 7±, 0. 9 meter. The mean yearly of dissolve oxygen, total phosphorous, total nitrogen, respectively, were 8. 3±, 1. 4, 0. 041±, 0. 015, 2. 828±, 1. 342 as mg/l and chlorophyll-α,was 5. 2±, 2. 7 µ, g/l. During the months under study, the water temperature varied between 5. 8±, 0. 4 to 28. 9±, 0. 2 as °, C. The ratio of total nitrogen to total phosphorus was more than 30 which indicated phosphorus is limiting factor in the lake Eutrophication. Based on multivariate evaluation method, during 2013-2019 mean of TSI was 40. 6±, 6. 3 with range of 29-50. In the early years, TSI was oltraoligotrogh and during 2016-2017 the eutrophication state close to the mesotrophic state and then it has almost returned to its original level during the downward trend after the summer of 2018. Introducing fishes and refinery performance are two main factors that have contributed to the declining level of eutrophication in the lake.

Kanibarazan wetland is one of the most important satellite wetlands in the South of Lake Urmia, which due to biodiversity; it has been promoted as a wildlife refuge and Ramsar site. In this research, 15 stations were selected in the Kanibrazan wetland of Mahabad for sampling of water quality parameters in 4 seasons of 2015 and a systematic sampling was carried out. Additionally, 6 bed sediment samples were collected to determine the bioavailable phosphorous content of the wetland during the summer season. Water quality parameters in this study included: nitrogen, phosphorus, transparency, chlorophyll a, biological oxygen demand (BOD), chemical oxygen demand (COD) and bacterial load in the wetland determined by standard laboratory methods. The results for BOD and COD showed that in all seasons the values of these parameters were much higher than the standards. The results also showed that TSI (TNs) was high in the first and second seasons and the increase in TSI (TP) and TSI (SD) values in the autumn and winter seasons were compared to the previous seasons. The average bioavailable phosphorous content in sediment samples was 29. 4 mgkg-1 which indicates high risk of the phosphorous release from the bottom sediments to the overlying water and accelerating of the eutrophication process. In addition, the significant (r = 79, P < 0. 01) correlation between Colwell-P of sediments and single-cell algae indicated Colwell-P can be used as a bioavailable phosphorous indicator in Kanibrazan wetland. Finally, based on the trophy indices, it was observed that the conditions of the wetland in the spring, summer, autumn and winter seasons are located in the state of Mild Mesotrophic, Oligotrophic, Mesotrophic and Acute Mesotrophic, respectively, and it can be stated that the status of the wetland is passing to the nutritional stage, due to lack of water supply with quantity and quality, especially in summer. . .

The lake’s trophic state can well represent human disturbances on these ecosystems. The present study was conducted seasonally to investigate the trophy status of Bostan Dam Lake (Golestan Province) from spring 2019 to summer 2020 in five study stations. A number of physicochemical parameters were determined such as pH, electrical conductivity, temperature, dissolved oxygen concentration, Secchi disk depth, salinity, dissolved solids, total hardness and turbidity. While nitrate, phosphate, total nitrogen, total phosphorus, ammonia, total alkalinity and chlorophyll evaluated using standard method. Carlson's INDEX, the amount of nutrition in different parts of the lake estimated based on total phosphuros, chlorophyll and transparency. The result of Carlson's INDEX showed different values between 52.44 to 60.46 and eutrophic condition in lake. The present research can provide a decision support system in the future to achieve optimal monitoring and exploitation and water quality management of the reservoir behind the Bostan Dam.

Determining of the wetland trophic condition is the first step at the qualitative assessment. High levels of nitrogen and phosphorus that come with pollutants are one of the major problems affecting on water resources quality. These materials, mainly the results of human activities, are entered to water through the wastewater of agriculture and industry. Eutrophication is one of the effects of increasing nutrients in the aquatic ecosystems that it is most serious environmental threat. Trophic state INDEX (TSI) is a useful tool to ease the expression of water quality and determination of the trophy position, which is presented by Carlsson. Due to importance of Anzali wetland in the region ecosystem, in the present study different models of Carlson INDEX were used to investigate the status of the wetlands Trophy in 2014. For this purpose, 10 stations (brag of Bandar Anzali, Sorkhankal, PirBazar, Siadarvishan, Nokhaleh, Hendkhaleh, East wetlands, output of East wetlands, Abkenar and Mahruzeh) were selected to measure parameters. The data analysis was performed using SPSS 18 software. Normalization and homogeneity of data variances were investigated using Kolmogorov – Smirnov and Leven tests. In order to evaluate differences between sampling stations and stages, one-way ANOVA analysis and Duncan test were performed. Any change in phosphorus concentration of fresh water ecosystems can alter its trophic status (Carvalho and Kirika, 2003). Kleeberg and Dude (1977) also have pointed to the direct role of phosphorus in the eutrophication process. According to 54 percent portion of forest and grassland of the watershed wetlands, the most important external source of Anzali wetland enrichment is forest floor litter and humus that inter into the wetland by raining flows (Darvishsefat et al. 1999). In addition, domestic sewage and adjacent residential areas, food and animal wastewater that inter into rivers without purification have an important role in intensifying of eutrophication process in the Anzali wetland. Moreover, vastness of the wetland areas, diversity of human activities in the basin and consequently entrance of organic and inorganic maters in to the wetland are the main causes of intensifying eutrophication (Sakizadeh, 2003). In this case, the important sources of nutrients material are including: agricultural fertilizer and domestic sewage. Eutrophication condition extends in wetland due to high consumption of dissolved oxygen by animals in the water, at night. So, the amount of dissolved oxygen reduces significantly in the hours of darkness. Kimball (1974) studied the first wetland condition in regard to plant growth in Anzali. Mirzajani et al. (2010) showed trophic status of wetland in the years 1992 to 2002. Based on Darvishsefat et al. (1999) research for the years 1991 to1995 in terms of chlorophyll a, Anzali Wetland appears at the end of mesotroph and transferring to trophic status and according to total phosphate is in trophic and goes toward hypertrophy(Darvishsefatet al. 1999). Nezami (1995) assessed Anzali wetland in trophic status, in case of bacterio-plankton. Solis and Lenard (2009) research on the trophy of three lakes (Piaseczno, Rogó ź no and Krasnein Poland) showed changes in Carlson value due to increased amounts of nitrogen and phosphate. A similar study (Ejankowski and Lenard, 2014) on the lake Czarne and Gł ę bokie observed increasing amount of TSI. The results of variance analysis in Anzali indicated a significant difference (P <0. 05) in the values of the indicators listed in the stations, in different seasons. Assessment of trophy INDEX (TSI) based on total phosphorus (TP) and total nitrogen (TN), showed wetland condition in hypertrophy to severe hypertroph for most stations, in 2014. Based on the phosphate concentration, the maximum and lowest values of INDEX estimated in Pir Bazar and Abkenar in autumn, respectively. According to nitrogen concentration, the maximum value of INDEX was measured in the output wetland in summer and the lowest value was in Sorkhankal in winter. Generally, the trophy has been progress in recent years towards severe hypertrophy. Consequently based on the results of this study, Anzali wetland received large amounts of nitrogen and phosphorus nutrients in recent years which lead to the gradual formation and development of extreme eutrophication phenomena in the wetlands. Nutrients concentration changes and TSI INDEX reflect the exponentially trends of this phenomenon, so that the wetland trophy condition has pushed from trophic level to severe hypertrophy. It is obvious that in these conditions the destruction of wetlands symptoms, including loss of biodiversity and the loss of sensitive species, appear gradually. Therefore, to preserve wetland and protect valuable species, taking appropriate management approaches is suggested. In this regard, comprehensive environmental assessing, controlling of anthropogenic pollutants, reducing the organic load of effluents (industrial, urban and agricultural) are recommended, as well as water quality monitoring during the year.

Determining the trophy status is one of the assessment and analysis methods of the ecological balance of wetland ecosystems, because the sustainability and continuity of productivity based on these unique ecosystems requires proper monitoring management and control their environmental conditions because increasing nutrients affect all levels of aquatic ecosystems, including changes in species abundance, migration, reduction of biodiversity, and changes in the structure and composition of communities. Therefore, a suitable method should be used to determine the trophy status, or in other words, the production capacity of an ecosystem. Conventional methods for determining the amount of trophy are based on three physical, chemical and biological parameters. Lorestan province due to its unique construction has unique wetlands, including 11 Poldokhtar wetlands with an area of 142. 7 hectares, Bishe Dalan wetland with 913. 5 hectares and Tanodar wetland with an area of 1000 hectares. In this study, to evaluate the trophy status, sampling of phosphorus (TP), total nitrogen (TN) concentration or Carlson trophy INDEX (TSI) was used in Poldokhtar, Bishe Dalan and Tanodar for summer and winter of 2019. Based on the annual average of Carlson INDEX, Poldakhtar and Bishe Delan wetlands are in mild mesotrophic trophy conditions and Tanodar wetland is in the eutrophic category. In the wetlands of Lorestan province, the sediment load of suspended solids and water turbidity have been exceeded these wetlands limits and has had destructive effects on the unstable wetlands` body due to the annual entry of large amounts of sediment from the catchment, development of gardens, various recreational withdrawals in Boroujerd and Doroud, increasing the level of river water pollution caused by municipal and industrial wastewater, also, wastes from city and rural recreation centers and wastes from point sources of pollution such as warm water fish breeding ponds.

There are different mathematic methods to analyze and interpretation of water quality characters but the water quality INDEX is a simple method and has application. Zarivar Lake is the most important aquatic ecosystem and unique water area in Kurdistan province, which is important in terms of providing suitable conditions for aquatic species and amphibians. The aim of this study was to evaluate the water quality of Zarivar Lake in the west of Iran. In this study, according to the available parameters, three indices of TLI TSI, and WQINSF were used to determine the quality of water of Zarivar Lake. Different parameters of lake water were analyzed for 18 months in different seasons. Based on the TLI INDEX, the Zarivar Lake was identified with a numerical value of 25. 26 as the hypertrophy ecosystem. The value of the TSI INDEX is 64. 06, which is in the third class (Eutrophic) of the category. Based on the WQINSF INDEX, Zarivar Lake has a moderate status with a numerical value of 55. 7 and is classified in the third class. According to the calculated indicators, Zarivar Lake has a eutrophic condition and so water quality in Zarivar Lake was not suitable during the study period. Therefore, it is necessary to take strict instructions, especially for domestic, agricultural and wastewater, to protect the water supply from hazardous wastes.

In this paper, we propose a new numerical algorithm for the approximate solution of non-homogeneous fractional di, erential equation. Using this algorithm the fractional di, erential equations are transformed into a system of algebraic linear equations by operational matrices of block-pulse and hybrid functions. Based on our new algorithm, this system of algebraic linear equations can be solved by a proposed (TSI) method. Further, some numerical examples are given to illustrate and establish the accuracy and reliability of the proposed algorithm.