کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8849354 1618550 2018 25 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Long-term change in the trophic status and mixing regime of a deep volcanic lake (Lake Bolsena, Central Italy)
ترجمه فارسی عنوان
تغییر طولانی مدت وضعیت غله و مخلوط کردن رژیم یک دریاچه آتشفشانی عمیق (دریاچه بلسنا، ایتالیا مرکزی)
کلمات کلیدی
یوتروفیزیک، مخلوط دریاچه، تغییر آب و هوا، دریاچه های آتشفشانی
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم آبزیان
چکیده انگلیسی
Lake Bolsena, the fourth Italian lake for volume (9.2 × 109 m3), must be considered as highly sensitive to eutrophication for its extremely long water renewal time. In this paper, temperature and chemical characteristics of the lake measured in the period 2003-2017 are used to discuss the mixing pattern and the variation in the oxygen and algal nutrient concentrations, as indicators of the trophic level. In the analysed period the lake showed oligomictic characteristics, reaching the full overturn, with homogenization of the chemical profile over the whole water column, only in 4 out of the 15 considered years. A regular decrease of oxygen and increase of phosphorus concentrations in the deepest layers has been observed in the non-circulating multi-year periods. The mean total phosphorus concentration showed a regular increase, reaching values close to 16 μg P L−1 in early spring 2017, mostly because of the urban discharge from the watershed, not adequately collected from an existing sewage pipe. Chemical and mixing patterns are discussed in relation with a previous study, carried out in 1966-1971, confirming the recent increase of phosphorus concentrations and the lower frequency of full circulation. The progressive deterioration of lake water quality indicates the need of prompt actions to reduce the external nutrient load and of further studies on the physical and biological characteristics of the lake, still strongly missing.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Limnologica - Volume 72, September 2018, Pages 1-9
نویسندگان
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