regarding, the water systems process mentioned by you, is it a natural process?
It is mostly caused by phosphate and nitrogen from various human sources.
Mechanism of eutrophication
According to Ullmann's Encyclopedia, "the primary limiting factor for eutrophication is phosphate." The availability of phosphorus generally promotes excessive plant growth and decay, favouring simple algae and plankton over other more complicated plants, and causes a severe reduction in water quality. Phosphorus is a necessary nutrient for plants to live, and is the limiting factor for plant growth in many freshwater ecosystems. Phosphate adheres tightly to soil, so it is mainly transported by erosion. Once translocated to lakes, the extraction of phosphate into water is slow, hence the difficulty of reversing the effects of eutrophication. However, numerous literature reports that nitrogen is the primary limiting nutrient for the accumulation of algal biomass.

The sources of these excess phosphates are phosphates in detergent, industrial/domestic run-offs, and fertilizers. With the phasing out of phosphate-containing detergents in the 1970s, industrial/domestic run-off and agricultu
the general surface wind circulation associated with the high-pressure center (h) is most likely A high-pressure area, high ,or anticyclone. how is it formed? Winds within high-pressure areas flow outward from the higher pressure areas near their centers towards the lower pressure areas further from their centers. Gravity adds to the forces. The winds are further twisted due to Coriolis effect. could i know more about the effect mentioned above? This is an apparent, but fictitious, force that arises when an observer is in a rotating reference frame, due to the conservation of angular momentum of the air as it moves towards or away from the Earth's axis of rotation. how is it related to the wind conditions? They are associated with light winds at the surface and subsidence through the lower portion of the troposphere. what is the last term used above? It is the lowest layer of earth's atmosphere. what does it consist of? Nitrogrn, oxygen, argon, carbon dioxide and small amounts of other gases. who discovered the former from the list above? Daniel Rutherford. what are its properties? It has seven electrons and one of the highest electronegativities among the elements. what are its uses? Synthetically produced nitrogenous compounds like ammonia and nitrates are key industrial fertilisers, and fertiliser nitrates are key pollutants in the eutrophication of water systems.
Yes, it can also be a natural process, particularly in lakes. Yes. Yes
Eutrophication Eutrophication Eutrophication
Natural eutrophication Introduction Introduction
Although eutrophication is commonly caused by human activities, it can also be a natural process, particularly in lakes. Eutrophy occurs in many lakes in temperate grasslands, for instance. Paleolimnologists now recognise that climate change, geology, and other external influences are critical in regulating the natural productivity of lakes. Some lakes also demonstrate the reverse process (meiotrophication), becoming less nutrient rich with time. The main difference between natural and anthropogenic eutrophication is that the natural process is very slow, occurring on geological time scales. Eutrophication (from Greek "eutrophos", "well-nourished"), dystrophication or hypertrophication, is when a body of water becomes overly enriched with minerals and nutrients which induce excessive growth of algae. This process may result in oxygen depletion of the water body after the bacterial degradation of the algae. One example is an "algal bloom" or great increase of phytoplankton in a pond, lake, river or coastal zone as a response to increased levels of nutrients. Eutrophication is often induced by the discharge of nitrate or phosphate-containing detergents, fertilizers, or sewage into an aquatic system. Lake eutrophication has become a global problem of water pollution. Chlorophyll-a, total nitrogen, total phosphorus, biological or chemical oxygen demand and secchi depth are the main indicators to evaluate lake eutrophication level. Target 14.1 of Sustainable development goal 14 preventing all kinds of marine pollution including nutrient pollution which is eutrophication. Eutrophication (from Greek "eutrophos", "well-nourished"), dystrophication or hypertrophication, is when a body of water becomes overly enriched with minerals and nutrients which induce excessive growth of algae. 
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Eutrophication [SEP] Mechanism of eutrophication
Eutrophication most commonly arises from the oversupply of nutrients, most commonly as nitrogen or phosphorus, which leads to overgrowth of plants and algae in aquatic ecosystems. After such organisms die, bacterial degradation of their biomass results in oxygen consumption, thereby creating the state of hypoxia. According to Ullmann's Encyclopedia, "the primary limiting factor for eutrophication is phosphate." The availability of phosphorus generally promotes excessive plant growth and decay, favouring simple algae and plankton over other more complicated plants, and causes a severe reduction in water quality. Phosphorus is a necessary nutrient for plants to live, and is the limiting factor for plant growth in many freshwater ecosystems.