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Environmental sustainability of the Chitgar Lake construction project in Tehran, Iran, was evaluated by a life cycle assessment (LCA) method in two phases of construction and operation using SimaPro 8.2.3 software. The results of analysis by Centre voor Milieukunde Leiden (CML) and IMPACT methods demonstrated that during the construction and operation (assuming 80 years of operation) phases of the lake 0.102 and 0.141 Mt of CO2eq (affects global warming), 0.015 and 0.021 Mt of 1,4‐dichlorobenzene (DB)eq (results in toxicity for humans), 657.155 and 807.425 tons of SO2eq (leads to acidification), 150.123 and 69.374 tons of PO4−3 eq (causes eutrophication), 1597 and 2265 terajoules of primary energy (damages the resources), 0.1 and 0.138 Mt of CO2eq (impacts on climate change), 18205330.45 and 11424387.32 potentially disappeared function (PDF) × m2 × yr (harms the quality of the ecosystem), and 165.37 and 104.94 disability‐adjusted life year (DALY) (threats the human health) are caused, respectively. Electricity consumption has the greatest environmental impact on the operation phase of the lake. Furthermore, the operation phase of the lake is more harmful to the environment and human health compared to the construction phase. [ABSTRACT FROM AUTHOR]

Silver carp, Hypophthalmichthys molitrix, is a plankton filter feeder fish and introduced to Chitgar Lake since 9 years ago. In this study, the effect of silver carp stocking was evaluated on the phytoplankton structure of Chitgar Lake at different seasons in 2018. Samples were caught with gill-net, beach seine and cast-net gears. The results obtained from 51 individuals with a total length of 111-473 (average total length of 325.8±134.6) mm showed that coefficient of vacuity, averages of relative gut length and feeding intensity were 0.00%, 5.91±1.65 and 628.4±274.7, respectively and therefore it showed over eating, herbivory and good feeding intensity in this fish. Silver carp fed on 32 phytoplankton and 11 zooplankton genera and phytoplankton and zooplankton were observed in 100% and 88% of studied specimens, respectively. Synedra, Navicula, Staurastrum and Cyclotella were the dominant phytoplankton genera (30.0, 22.2, 13.8 and 12.1%, respectively) and Bosmina and Alona were the dominant genera of zooplankton (84.0 and 7.2%, respectively). There were no seasonal changes in feeding intensity but there were seasonal changes in food items dominance. Releasing of 20000-30000 individuals of silver carp with a weight 50-100 g is suggested in order to protect water quality of Chitgar lake annually.

To find answers to the challenges linked with ecological well-being, policymakers and authorities now prefer the ecosystem-based approach, as the solutions inspired by nature may deflect from ecological collapse. Nature-based solutions (NBS) are rhapsodized both in practice and academia as a means to achieve sustainable development. However, NBS, which inherently is supposed to bring forth positive outcomes, may also lead to unsustainable turmoil. On the other hand, the majority of the studies about NBS are from Western countries and studies focusing on the paradoxical functionality of NBS are scant, especially in the Middle East. In an attempt to bridge this gap, the current study uses one of the largest blue artificial infrastructures in the Middle East as a case. Following the phenomenological interpretive approach, the authors argue that NBS may fabricate unintended problems when the complexity of the supra systems are overlooked. Theoretical and practical contributions are discussed. [ABSTRACT FROM AUTHOR]

Bayat J, Hashemi SH, Nikzad MF, Talakesh SMR. 2021. Necessity of water treatment to meet lake water quality goals in Chitgar Lake. Lake Reserv Manage. 37:160–169. Managing urban lake water quality to prevent algae blooms is important for tourism at Chitgar Lake, which is a shallow artificial lake created for recreation in northwest Tehran City, Iran. Its water quality is influenced by the Kan River as its water source, as well as by peripheral activities and bird excrement. This study investigates the effectiveness of different water quality management practices including restricted water intake rules and water treatment from April 2013 to April 2020 to improve the water quality of the lake in order to limit algae blooms. The nonparametric Mann–Kendall method and the Sen function were applied to decipher trends and assess impacts of the practices. Despite intake water control, the trend analysis showed that chlorophyll-a and total phosphorus had increased after the opening of the lake in 2013. However, this incremental trend was greatly reduced after commissioning a treatment plant for improving water quality. The treatment system improves the quality of diverted Kan River water during winter lake refill and is used to treat lake water during the rest of the year. The specific characteristics of the lake and the Kan River prevent achievement of target water quality without water treatment. [ABSTRACT FROM AUTHOR]

This study focused on zooplankton structure, biodiversity, relationship between a biotic parameters and zooplankton variation, and trophy state of the Persian Gulf Martyrs Lake (Chitgar-Tehran). Based on the lake condition, samples were collected by Juday net at the 5 stations between 2013 and 2014. This study identified 36 zooplankton taxa comprised of Arthropoda (6 genus), Protozoa (6 genus), Rotatoria (20 genus), Nematoda (1 genus), Gastrotricha (2 genus) and Oligochaeta (1 genus). Furthermore, the first record of the freshwater jellyfish Craspedacusta sp. in Iran, with size group of 15-20 mm in diameter in September is reported in the Chitgar lake. The Rotatoria abundance average was measured 61 ±18 ind.l-1 in the lake. The Nematoda, Gastrotricha and Oligochaeta taxa were measured the lowest abundance (< 1 ind.l-1) in this study. The annual average zooplankton abundance was measured as 72±18 ind.l-1. The PCA displayed, the Rotatoria Trichocerca sp. and Polyarthera sp. were dominated with high components loading, low variance and high abundance. The CCA showed, there was no correlation between Rotatoria abundance and a biotic parameters. Based on the zooplankton structure and bio-indicator, the lake situation is in the meso-oligotrophic category. Thus, it is might be increased eutrophication trend due to no management and no aquatic control in this ecosystem.

This study focused on phytoplankton structure, a biotic limiting factors in phytoplankton bloom at the 5 stations between 2013 and 2014 in the Chitgar Lake. This study identified 35 phytoplankton taxa comprised of Diatoms (12 genus), Chlorophyta (15 genus), Cyanophyta (4 genus), dinoflagellates (2 genus) and chrysophytes (1 genus) in the lake. The finding showed, the Diatom abundance dominate (average of 2060000 ± 230000 cells.l-1) in the Chitgar Lake. The annual average phytoplankton abundance was calculated as 2550000± 304000, with the maximum value recorded in February 2013 (4400000 ± 450000 cell. l-1). The PCA analysis displayed, the Diatoms Cyclotella sp., Achnanthes sp. and Chrysophta Dinobryon sp. were dominated in the study period. Based on the CCA analyses, total nitrogen and water temperature were the significant parameters to increase Cyanophyta and Dinoflagellata abundance in the Chitgar Lake. In overall, the lowest phytoplankton abundance recorded in the Chitgar Lake as compared with other lakes which is an Oligotrophic with the latest trophy state lake.

This study focused on population structure, species diversity and abundance of the Chitgar Lake fishes in October 2014. Based on the lake location fish samples were collected at 34 stations in water body. In this study , 8 families belonging to 18 species comprised of Cyprinidae (11 species), Cichlidae (one species), Loricariidae (one species), Pangasiidae (one species), Serrasalmidae (one species), Poeciliidea (one species), Salmonidae (one species), and Scaridae (one species) were identified. Among the fishes just one native fish from Capoeta bohsei species observed during the study. The dominant lake fishes were invasive species Hemiculter leucisculus, Alburnus hohenackeri, Carassius auratus, Carassius gibelio and Pseudorasbora parva. The highest abundance of fishes were H. leucisculus 62 % and A. hohenackeri 35 % by Seine net. Furthermore, those were dominant abundance (69 and 12 % respectively) in Gill net method. Finally, in Cast net method A. hohenackeri 38 %, Pseudorasbora parva 21 % and H. leucisculus 17 % were dominated in the shore region. The lowest fishes abundance were P. hypophthalmus and Parrotfish. Overall more than 90 % of the fish population were invasive and alien species. Thus, the presence of invasive fishes and lack of predator fishes in the Chitgar Lake might be reason for increasing of trophic level.

Chitgar Lake is an artificial urban lake located in northwestern of Tehran, the capital city of Iran. It is estimated that the lake becomes highly eutrophic in the near future. In this paper, a methodology is presented for evaluating different water supply and water quality management policies proposed for this lake by utilizing evidential reasoning (ER) and fuzzy social choice (FSC) methods. The ER method can handle different kinds of uncertainties, such as fuzziness and ignorance, involved in analyzing lake water management alternatives. Since the ER method, as a multi-criteria single decision making technique, does not directly consider utilities of multiple stakeholders involved in the system, we also utilize a FSC method to reevaluate various lake water management alternatives. A set of 15 alternatives, rather than existing pattern of water supply for the lake, are proposed for the lake water quantity and quality management. Six assessment criteria are also considered for crisp or fuzzy evaluating the lake management alternatives. To evaluate the alternatives, the results of simulating the lake watershed using the storm water management model (SWMM) and model for urban stormwater improvement conceptualization (MUSIC) have been used. The application of the proposed methodology to the Chitgar Lake problem shows that using multi-criteria single decision making and multi-criteria multi-decision making methods can lead to different rankings for the same set of alternatives. Based on our evaluation, results of the FSC method, which directly incorporates the utility functions of stakeholders, look more promising. [ABSTRACT FROM AUTHOR]

As one of the metropolitan project in the north west of Tehran, Chitgar Lake was built with an aim to make the weather fine and attract tourists. The idea behind the construction of the lake in this area is linked to the first urban programs for Tehran expansion; it was finally opened in 2010. Environmental experts have serious critical comments about it. The view of Landscape has also some serious comments about lack of a landscape strategy for the city of Tehran in offering the suggestion. Due to some reasons including the unique integration of recreational activities around the lake and its large dimension in the first years after the construction, the lake has failed to appeal to anyone. On a large scale, the disparate elements of the lake in the landscape and environment have caused a break in the foothill landscape. Based on large, modest and small scales, the study of Chitgar Lake Project represents managerial and professional gaps in the definition, design, and implementation of the project. In each of the three dimensions, lack of interest in problems concerning the natural context and project subject has caused the failure to achieve the goals of the project and productivity of citizens. On the large scale, an obsolete modernist view and lack of sufficient expert in evaluating previous projects have led to a break in the landscape of the region. On average scale, a professional view on landscape, natural capabilities, and project outlook have been disregarded, and on small scale the multiplicity of ideas and interfering preferences, lack of consistent management from design through implementation and decorative look at landscape elements that arise from lack of landscape view, some consequences on comfort, aesthetics, and natural identity of the complex have ensued. It seems that the entire above matters which arise from order-based and nonprofessional management in an expert project at an upstream glance would have given rise to the results in this project. [ABSTRACT FROM AUTHOR]