Environmental changes in large river basins are subject to forces external to the water and to biological issues. Before 1960, the Plata River Basin was almost undeveloped. The regulation of the Parana for hydroelectricity has been increasing since the early 1970s. Water in reservoirs of the upper Parana Basin currently comprises more than 70 percent of the mean annual discharge at its confluen...

water resources are limited in most parts of the country, including isfahan,where cotton is cultivated but it’s planting time coincides with the sensitive stage of cereal grain growth. therefore, developing and adopting techniques that could maximize use of the existing resources is needed. to study the effect of basin and furrow irrigation methods on yield and some yield components of cotton  ...

global warming has brought about changes in meteorological variable time series. these changes, accompanied with serious human intervention in nature, has resulted in hydrological changes. so the effects can be tracked down by the trend of the time series. the purpose of this study is to analyze and compare the monthly and annual trends of temperature, precipitation as well as stream flow time ...

inappropriate patterns and drastic changes in land-use have caused the severe environmental crisis. therefore, it is necessary to accomplish any plan in relation to establishment of different activities with respect to land capabilities and land-use evaluation thought. in this study, ecological capabilities and the site selection of land uses in babolrood basin, mazandaran province were evaluat...

this experiment was performed based on split plot in rcbd with three replications in minab agricultural research station during two successive years. main plots were allocated to planting method (basin and furrow) and sub plot to four onion cultivars (‘primavera’, ‘white early grano 502’, ‘ht3544’ and ‘ht3560’). nursering was done in october and the transplants were transferred to main land in ...

Introduction: The South Pole-Aitken (SPA) Basin is the largest, oldest basin on the Moon. The extreme size of the basin, ≤2,500 km in diameter and a present depth of up to 13km [1,2], suggests that much of the upper crust would have been excavated during the formation/impact event, exposing the lower crust or upper mantle. Also, a large volume of impact melt breccia containing extensive lower c...

identifying sediment sources is one of important factors in selecting of appropriate method of erosion control and soil conservation. the main objective of this study is to estimateuncertainty and contribution of forest roads to sediment yield in ziarat drainage basin, gorgan city using geochemical tracers. for this purpose, 47 soil samples were collected from different sources with different l...

the systematics, morphology, distribution, biology, economic importance and conservation of the perches of iran are described, the species are illustrated, and a bibliography on these fishes in iran is provided. there are three species, perca fluviatilis , sander lucioperca and s. marinus , found naturally in the caspian sea basin, with s. lucioperca translocated.