Hyper-Nutrient Enrichment Status in the Sabalan Lake, Iran
| Autor: | Sayed M. Bateni, Saber Aradpour, Majid Hosseinzadeh, Elmira Ansari, Mohsen Maghrebi, Yongwook Jeong, Roohollah Noori |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Hydrology
Limiting factor Carlson trophic state index Watershed fertilizers Water supply for domestic and industrial purposes limiting factor Geography Planning and Development dam reservoir Hydraulic engineering Aquatic Science Iran Biochemistry Nutrient Epilimnion Environmental science Total phosphorus Eutrophication TC1-978 Thermocline TD201-500 Water Science and Technology Trophic level |
| Zdroj: | Water, Vol 13, Iss 2874, p 2874 (2021) Water Volume 13 Issue 20 |
| ISSN: | 2073-4441 |
| Popis: | Lakes/reservoirs are rapidly deteriorating from cultural eutrophication due to anthropogenic factors. In this study, we aimed to (1) explore nutrient levels in the Sabalan dam reservoir (SDR) of northwest Iran, (2) determine the reservoir water fertility using the total phosphorus (TP) based and total nitrogen (TN) based Carlson trophic state indices, and (3) specify primary limiting factors for the reservoir eutrophication. Our field observations showed a state of hyper-nutrient enrichment in the SDR. The highest variation of TN in the reservoir water column happened when the reservoir was severely stratified (in August) while the highest variation of TP took place when the thermocline was attenuated with the deepening of the epilimnion (in October). Both TP and TN based trophic indicators classified the SDR as a hypereutrophic lake. TN:TP molar ratio averaged at the epilimnion indicated a P–deficiency in the reservoir during warm months whilst it suggested a co–deficiency of P and N in cold months. Given the hyper-nutrient enrichment state in the reservoir, other drivers such as water residence time (WRT) can also act as the main contributor of eutrophication in the SDR. We found that WRT in the SDR varied from hundreds to thousands of days, which was much longer than that of other reservoirs/lakes with the same and even much greater storage capacity. Therefore, both hyper-nutrient enrichment and WRT mainly controlled eutrophication in the reservoir. Given time consuming and expensive management practices for reducing nutrients in the watershed, changes in the SDR operation are suggested to somewhat recover its hypereutrophic state in the short-term. However, strategic long-term recovery plans are required to reduce the transition of nutrients from the watershed to the SDR. |
| Databáze: | OpenAIRE |
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