چکیده:
Estimated Effective Precipitation (Pe) in dryland areas is an essential element of water resource management. It represents the amount of precipitation available in the crop root zone to meet the needs of evapotranspiration. The current study compared different approaches for estimating Pe in different climatic zones of Iran. A two-layer soil– water balance (SWB) model was adopted based on the proposed approach in which a portion of the previous day’s precipitation saved between the previous and current root-zone development is added to the Pe of the current day. To
this end, we used three groups of data (meteorological, phenological, and soil characteristics data) related to 21 agrometeorological stations representing arid, semi-arid, semi-humid, and humid regions of the country. The results of this study indicated that, in spite of data limitations, the new procedure performed appropriately in estimating that part of the wheat yield which could be explained by Pe only. Coefficients of determination (R2) between annual precipitation and Pe ranged from 0.50 in the humid climatic zone to 0.82 in the arid climatic zone. Ultimately, using annual precipitation data collected from 181 Iranian synoptic stations and its correlation with Pe, the first annual Pe map of Iran was produced.
خلاصه ماشینی:
"ir Desert 19-2 (2014) 91-98 Estimation of effective precipitation for winter wheat in different regions of Iran using an Extended Soil-Water Balance Model J.
Bazrafshana a Meteorological Division, Irrigation and Reclamation Engineering Department, University of Tehran, Karaj, Iran Received: 2 November 2013; Received in revised form: 28 July 2014; Accepted: 29 September 2014 Abstract Estimated Effective Precipitation (Pe) in dryland areas is an essential element of water resource management.
A two-layer soil– water balance (SWB) model was adopted based on the proposed approach in which a portion of the previous day’s precipitation saved between the previous and current root-zone development is added to the Pe of the current day.
Introduction Estimating effective precipitation (Pe) as a portion of the precipitation stored in the plant root zone to meet evapotranspiration requirements has always been a problem in agricultural water management (Tsai et al.
Since a precise estimation of Pe is necessary for increasing agricultural production, the major objective of the current study was to design a soil- water balance model that provides a more accurate estimation of Pe; in addition, climate zoning of Iran based on Pe is presented.
To this end, three different approaches of soil-water balance model were compared to choose the one that gives a more accurate estimate of Pe for wheat crops.
3. Results and Discussion The authenticity of the proposed soil-water balance model compared with previous approaches was tested using the wheat yield data from different climatic zones of Iran.
A computer model based on soil-water balance for estimating the effective rainfall in rainfed wheat crop (the case study of Fars province)."