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Water environment

About: Water environment is a research topic. Over the lifetime, 13384 publications have been published within this topic receiving 125138 citations.


Papers
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Journal ArticleDOI
TL;DR: A theoretical basis for solving the problem of water pollution in the watershed and the contradiction in the development of the watershed, and realizing social equity and harmonious development is provided.

40 citations

Journal ArticleDOI
TL;DR: The intention of this paper was to provide an integrated assessment model, propose potential countermeasures, and achieve sustainable water utilization in the Yellow River basin.
Abstract: Water is a major limiting factor of human survival and social economic development. Water security is also important for the ecological system. In this paper, the water security assessment index system of the Yellow River basin was developed based on three subsystems: the water resources subsystem, the water environment subsystem and the social economic subsystem. The integrated assessment of water security was developed based on the combination of set pair analysis (SPA) and fuzzy analytical hierarchy process (FAHP) as well as technique for order preference by similarity to ideal solution (TOPSIS), gray relational analysis (GRA), vague sets (VS) and matter element (ME) models. First, fuzzy cluster analysis method was used to check the consistency of all the models before and after implementing the integrated assessment. Secondly, the ranking values of four single assessment models (i.e., TOPSIS, GRA, VS and ME models) were analyzed by SPA method to get the consistency connection degree. Then FAHP was constructed to describe the relative importance of the four different single models when determining the weight coefficient in the integrated assessment model. And lastly, the integrated assessment model of water security was developed based on the ranking values and weight coefficients of the selected single assessment models. The conclusion of the developed integrated assessment model which was applied in the Yellow River basin showed that Sichuan province was at security level; Henan, Shandong, Qinghai and Shaanxi provinces were at the threshold security level; Shanxi, Gansu and Inner Mongolia provinces were at the relative insecurity level; Ningxia province was water no secure. The integrated assessment results showed that the improved integrated model presented in this paper had relatively better performance than single assessment models. The intention of this paper was to provide an integrated assessment model, propose potential countermeasures, and achieve sustainable water utilization in the Yellow River basin.

40 citations

Journal ArticleDOI
TL;DR: In this article, the authors designed the scale-based runoff plots of extensive green roofs with different substrate and vegetation types, and investigate whether the studied green roofs act as a sink or source of nutrients and suspended solids in their runoff compared to a conventional roof.

40 citations

Journal ArticleDOI
TL;DR: Generally, it was found that the rate of herbicide release decreased with increasing size of particles, and for smaller particles the kinetics was strongly influenced by an initial burst release.
Abstract: The preemergence chloroacetamide herbicide metazachlor was encapsulated in biodegradable low molecular weight poly(lactic acid) micro- and submicroparticles, and its release to the water environment was investigated. Three series of particles, S, M, and L, varying in their size (from 0.6 to 8 μm) and with various initial amounts of the active agent (5%, 10%, 20%, 30% w/w) were prepared by the oil-in-water solvent evaporation technique with gelatin as biodegradable surfactant. The encapsulation efficiencies reached were about 60% and appeared to be lower for smaller particles. Generally, it was found that the rate of herbicide release decreased with increasing size of particles. After 30 days the portions of the herbicide released for its highest loading (30% w/w) were 92%, 56%, and 34% for about 0.6, 0.8, and 8 μm particles, respectively. The release rates were also lower for lower herbicide loadings. Metazachlor release from larger particles tended to be a diffusion-controlled process, while for smaller ...

40 citations

Journal Article
TL;DR: Feeding fish with optimal nutrients-balanced diets, keeping freshness of feed and raw feed materials, and maintaining a sustainable healthy water environment are the ultimately right measures to prevent fish fatty liver.
Abstract: Fatty liver is a physiological or pathological phenomenon and is commonly seen in farmed fish at present. Severe fatty liver in fish results in reduced growth and feed efficiency,impaired immune response and decreased nutritional quality. However,so far,people still don't know exactly the causes of fatty liver in farmed fish,and also have not found good solutions to eliminate fatty liver. The present article systemically reviews the results of fish fatty liver studies and has put forward some new perspectives to discuss the origins of fish fatty liver in the current aquaculture system. In the present review,five main causes of fatty liver in farmed fish are summarized: nutrition and formulated diet,environmental pollution,physiological process,species difference and genetic mutation. Among them,the unbalanced nutrients composition and excess energy intake,such as overfeeding,excess dietary lipid and carbohydrate contents,deficiency of vitamins which are needed to maintain normal lipid metabolism,are regarded as the principal causes of fish fatty liver.Beside,in some aquaculture regions,high amount of water contaminants,especially heavy metals and persistent organic pollutants( POPs),have been recently reported to contribute to the prevalence of fatty liver in farmed fish. The occurrence of fatty liver is also related to the gender and development of fish. For example,the change of fat content in liver of young and /or female fishes normally is more sensitive to dietary energy content than that in liver of older and /or male fishes. It is also noted that some fish species specifically deposit fat in liver,thus fish species difference should be considered in preventing fatty liver in farmed fish. Through reviewing the above results,the present article brings some new perspectives: 1) Most of fatty liver could be classified as"nutritional fatty liver"and"oxidative fatty liver"depending on the fatty liver symptom caused from nutrient unbalance or oxidative stress; 2) The common occurrence of fatty liver in farmed fish fundamentally correlates with the contradiction between the requirement of high aquaculture production of human and natural physiological features of fish. Therefore,as long as the present fish species have not been genetically modified to adapt to modern high-density aquaculture industry,the common occurrence of fatty liver in farmed fish would last in future for a long time; 3) Fatty liver could not be completely regarded as a pathological symptom. Actually,initial stage of increasing hepatic triglyceride synthesis is a protective mechanism to avoid the lipotoxicity induced by high free fatty acids in circulation. In conclusion,feeding fish with optimal nutrients-balanced diets,keeping freshness of feed and raw feed materials,and maintaining a sustainable healthy water environment are the ultimately right measures to prevent fish fatty liver.

40 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202239
2021932
2020869
2019980
20181,015
2017916