allocation and removing of excess water from the irrigation and drainage network is one of the most important activities in the management of these networks. side weir is one of the most common structures for this purpose. study on the flow hydraulic characteristics of this structure included two parts, defining the water surface profiles and estimating the discharge coefficient. to estimate th...

salinity is a phenomenon that does not satisfy the crop water requirement and leads reduction vegetation. to control of this phenomenon requires appropriate management and monitoring of spatial and temporal salinity variations from the past to the present in this study the spatial and temporal changes of soil salinity of irrigation and drainage network located in garmsar, iran, is investigated ...

Mass balance analysis and water quality model development for paddy field were performed using field experimental data during 2001-2002. About half (47-62%) of the total outflow was lost by surface drainage, with the remainder (490-530 mm) occurring by evapotranspiration. Most of nutrient inflow and outflow were mediated by fertilization and plant uptake, respectively. Nutrient outflow by surfa...

nesar anticline is located in west of country and in north of kermanshah province. pattern of drainage network at each district is under the effect of various factors which has intensive anomaly in nesar anticline in spite of its low area and this in turn reflects different lithology, tectonic effects and slope changes in anticline. the goal of this research is the recognition of influential fa...

the first step in policy making is describing the objectives and choosing the policy instruments and management strategies and then, analyzing and assessing the impacts of them. in this study, farmers’ responses to selected policy instruments and management strategies were assessed using a semi-distributed planning model in qazvin irrigation and drainage network. the proposed model, simulates t...

Although chronic subdural hematoma (CSDH) is one of the most common entities encountered in neurosurgical practice, optimal surgical treatment for CSDH remains controversial. This study retrospectively compared results for CSDH between burr hole drainage alone and burr hole drainage with irrigation. Ninety-two patients with CSDH underwent surgery at our institution from January 1998 through Dec...

Ethnohistory, genetics and simulation are used to propose a new ‘budding model’ to describe the historical processes by which complex irrigation communities may come into existence. We review two alternative theories, Wittfogel’s top-down state-formation theory and common-pool resource management, and suggest that a budding model would better account for existing archaeological and ethnographic...