نتایج جستجو برای: degradation indicators
تعداد نتایج: 258369 فیلتر نتایج به سال:
one of the indicators of management and sustainability control of forest resources is the definition deforestation and degradation types. these factors hazard quantitative and qualitative of the iranian forests. in this study with integrated approach, different forms of forest degradation identified in the forest areas with a reviews of library resources and then investigation the degree of sta...
Algal communities possess many attributes as biological indicators of spatial and temporal environmental changes. Algal parameters, especially the community structural and functional variables that have been used in biological monitoring programs, are highlighted in this document. Biological indicators like algae have only recently been included in water quality assessments in some areas of Mal...
Background and objectives: Mountain habitats, due to their climatic conditions, are considered to be very sensitive areas and generally have less plant diversity compared to the lower elevations. Unfortunately, in the past years, due to human attacks, parts of these areas have been destroyed and now some areas are either devoid of vegetation or have very little vegetation. Since Crataegus and B...
Conservation prioritization usually focuses on conservation of rare species or biodiversity, rather than ecological processes. This is partially due to a lack of informative indicators of ecosystem function. Biological soil crusts (BSCs) trap and retain soil and water resources in arid ecosystems and function as major carbon and nitrogen fixers; thus, they may be informative indicators of ecosy...
Study of land use effects on soil quality indicators leads to sustainable management and preventing progressive land degradation. The TM (1987) and ETM+ (2000 and 2005) data were used to study land use change effects in Mahan-Joopar area on soil quality indicators. Fifty random soil samples from 0-30 cm depth of each land use were taken using provided maps. Organic matter, microbial respiration...
In this study, to study the status of water resources degradation in Kashan region, Isfahan Province, eight indices including: drop in groundwater, water salinity, irrigation efficiency, Well-to-Qanat development ratio, the pumping time, shortage of water supplies for animals and humans and the water negative balance were selected according to previous studies conducted on desertification in Ir...
Elevated water temperatures, a decrease in ocean pH, and an increasing prevalence of severe storms have lead to bleaching and death of the hard corals that underpin coral reef ecosystems. As coral cover declines, fish diversity and abundance declines. How degradation of coral reefs affects behavior of reef inhabitants is unknown. Here, we demonstrate that risk assessment behaviors of prey are s...
Railway maintenance planners require a predictive model that can assess the railway track geometry degradation. The present paper uses a hierarchical Bayesian model as a tool to model the main two quality indicators related to railway track geometry degradation: the standard deviation of longitudinal level defects and the standard deviation of horizontal alignment defects. Hierarchical Bayesian...
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