عنوان مقاله [English]
The main features of river ecosystem are that they are dynamic, consistent, organized from the river source to the estuary. This integrated system changes river into a varied, complex and unique system. Critical river ecosystems create a dynamic balance between variables like material, energy, space, time and variability in accordance with their environment.
Extracting too much alluvial materials (more than what can be renewed) results in destruction and collapse of river systems. It destroy their ecological unity in different ways and ultimately transfer its negative effects to the surrounding ecosystems.
Golpaygan River has been the most important resource providing sand for its surroundings for about half a century. Because of many different reasons such as limited flood current, small basin, construction of a dam, the river cannot restore even a small portion of its despoiled resources of sand and gravel.
Therefore, the river is facing irrecoverable morphologic, hydrologic and geomorphologic changes in a vast part of its central basin. This can have negative influence on groundwater resources, vegetation, soil resources, erosion and other environmental elements.
The present article endeavors to study and investigate the effects of mismanagement in the area, hoping that perhaps this results in paying more attention to the environment. To do so, it applies field study, hydrological and geomorphodynamic studies and calculates the volume of erosional sources in the river.