the system dynamics technique is an object-oriented approach that studies and manages complex feedback systems. its merits include the friendly and easy development and improvement of a model. it is also used as a decision tool for engineering problems. in this paper, the system dynamics technique was used to simulate the performance of a subsurface drainage system in an unsteady state. the mod...

abstract aims: one of the consequences of taking ground water into surface is changing its chemical quality, specially increasing the concentration of dissolved salts. this research was performed in order to analyze growth possibility of heterotrophic bacteria in the membrane of active desalination plants in kashan city, iran. instrument & methods: this descriptive cross-sectional study was don...

tehran has been facing water shortage challenge for decades and it has not hesitated to exploit neighboring watersheds. rising demand and limited resources might make water crisis a strong possibility in the near future. an accurate and applied analysis of tehran's urban water system (uws) would be the first step to be taken to prevent such a crisis. this research is an effort to make an a...