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shadman veysi; Milad Nouri; Anahita Jabbari
Abstract
To compensate for the lack, or inadequacy, of weather stations data, one of the most reliable ways is to use the remote sensing and re-analysis dataset, which provides a suitable model for such areas. In this study, the performance of two data sources, namely, WaPOR and ERA5, was evaluated in estimating ...
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To compensate for the lack, or inadequacy, of weather stations data, one of the most reliable ways is to use the remote sensing and re-analysis dataset, which provides a suitable model for such areas. In this study, the performance of two data sources, namely, WaPOR and ERA5, was evaluated in estimating reference evapotranspiration at 64 synoptic stations in the Caspian coastal region in Iran, on a daily and monthly basis. To this end, meteorological data of 64 synoptic stations with a 10-year statistical period (2011-2021) was obtained daily from the Iran Meteorological Organization. The field data used included minimum and maximum temperature, relative humidity, wind speed, and solar radiation intensity. Then, evapotranspiration and reference evapotranspiration were calculated using the Penman-Monteith equation and REF-ET software. Finally, the results were compared with the results from the WaPOR and ERA5 data bases. The results showed that, on average, the nRMSE values of the WaPOR and ERA5 datasets compared to the calculated meteorological station data were 29.6% and 29%, respectively, on a daily basis. Also, on a monthly time scale, in more than 85% of the stations, both datasets provided acceptable results. On a monthly scale, the average nRMSE value for both WaPOR and ERA5 sensors in the catchment area was 19%. The rMBE value showed that the ERA5 dataset underestimated the reference evapotranspiration in most of the stations, while the WaPOR dataset overestimated. Given that the error rate of the two sensors is different in over 30 percent of the stations, a suitable estimate of reference evapotranspiration in the Caspian Sea basin area can be obtained by combining the data from these two datasets. The results showed that in the Caspian Sea coastal areas, 34 stations in the WaPOR dataset and 28 stations in the ERA5 dataset showed the minimum error, with two stations showing the same error. Thus, both WaPOR and ERA5 are suitable databases that can be used for hydrological purposes, including estimation of reference evapotranspiration.
6
Bagher Hoseinpour; Anahita Jabbari; Hassan Alipour
Abstract
The current study aimed to identify and analyze the factors influencing acceptance or rejection of irrigation system in apple orchards of Urmia city, as the center of apple production in West Azerbaijan Province, by applying survey research method and Rogers' Diffusion of Innovations Model. Based ...
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The current study aimed to identify and analyze the factors influencing acceptance or rejection of irrigation system in apple orchards of Urmia city, as the center of apple production in West Azerbaijan Province, by applying survey research method and Rogers' Diffusion of Innovations Model. Based on the results, 57% of the respondents believed that implementation of drip irrigation using a common source of water (well) had many problems, 63% of them also considered the system unsuitable for old orchards. About 64% of the respondents believed that, in current situation, the relative profitability of the system was in the range of medium to low. 77% believed that drip irrigation systems did not have high performance due to various reasons. According to 81.5% of the respondent’s opinion, applicability of these systems is complex compared to traditional methods, because of design, performance, employment, and administrative bureaucracy, obtaining facilities, repair and maintenance. According to the Cox-Nell and Nagelkerke statistics, the variables included in the model are able to explain, respectively, 0.50 and 0.68 of the variance of the drip irrigation acceptance variable. According to the obtained results, the most important recommendations applicable in the region, are using successful models and reference groups to provide practical trainings on irrigation systems, increasing the relative benefit and reducing the risk of investing in drip irrigation, reviewing the process of designing, implementing, the workflow and the quality of equipment in drip irrigation systems, solving problems related to issuing the necessary permits for orchards that do not have ownership documents and, finally, avoiding the use of drip irrigation in old traditional orchards.