background and purpose: water is the most important limiting factor of sustainable development. poor quality of water sources and lack of appropriate management in some regions are the main reasons of water crises in the country. this study was conducted to assess water sources quality and the trend of their change in rural area of sabzevar county in a five year period. materials and methods: i...

karkhe watershed (kw) with more than 5 million hectares recently encountered many problems in the natural, social and man-made habitats. unsuitable use of land, soil erosion and lack of rainfall are the most destructive factors in this watershed affecting the whole region fundamentally. as expected, these problems have caused a considerable fall in biodiversity in fauna and flora, a decrease in...

sensitivity analysis might be considered as one of inevitable steps in modelling since it would help to determine the behaviour of model, which was developed for further application. sensitivity analysis was not paid much attention in studies that have been conducted for modelling the relationship between stream water quality and land cover except machine learning techniques such as artificial ...

conclusions according to the average of wqi index, quality of water was good in station number one, medium in station number two, and bad in the rest of stations. according to the wilcox index, qualities of water in third station were medium and in the rest were good. results by using wqi, the best water quality was reported in station number one with the scalar quantity of 71.11 (water with be...

Employing a unique and rich data set of water quality attributes in conjunction with detailed household characteristics and trip information, we develop a mixed logit model of recreational lake usage. Our empirical analysis shows that individuals are responsive to the full set of water quality measures used by biologists to identify the impaired status of lakes. WTP estimates are reported based...

groundwater contamination is a serious problem facing the countries. because groundwater is vulnerable to contamination from a variety of sources, and, once contaminated, it is very difficult to restore to its original quality. the main objective of this study was evaluation of groundwater quality in shahrekord aquifer and finding the source of the groundwater contamination. some of the chemica...

a study was carried out in a strip of a river and in a nearby well in the rainy and dry seasons to assess the impact of tobacco waste disposal on the roadsides. there were significant seasonal variations in the concentration of nicotine being higher (p