ghobad rostamizad; Mojtaba Pakparvar; parviz abdinejhad; Zahra Abdollahi; jafar khalafi
Abstract
Introduction
Evapotranspiration (ET) is one of the most important factors in the hydrological cycle and is a key determinant of energy equations on the earth’s surface. evapotranspiration estimates are important for hydrology, irrigation, forest and rangeland, and water resources management. The ...
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Introduction
Evapotranspiration (ET) is one of the most important factors in the hydrological cycle and is a key determinant of energy equations on the earth’s surface. evapotranspiration estimates are important for hydrology, irrigation, forest and rangeland, and water resources management. The evapotranspiration drives the soil water-energy balance which is largely used in general circulation models and climate modelling. Consequently, river water flow forecasting, crop yield forecasting, irrigation management systems, river/lake water quality are all dependent on evapotranspiration levels. For this reason, it is essential to accurately estimate the water budget. Numerous models have been developed to estimate evapotranspiration using remote sensing methods. The review of recent research shows that remote sensing and the use of satellite images have a high ability to estimate the amount of actual evapotranspiration.
Material and method
The aim of this study is calibrating the METRIC algorithm in estimating evapotranspiration in the Sohrin-Qaracheryan Plain, which is affected by flood spreading. This method has been used by many researchers around the world to estimate evapotranspiration. On the other hand, estimating the actual evapotranspiration is of great importance in the plains affected by the flood, especially in the Sohrin-Qaracherian Plain’s flood spreading. Therefore, in this research was conducted to estimate evapotranspiration using the metric algorithm in the Sohrin-Qaracherian Plain, for the optimization management of water resources in the region and regions with similar conditions. In this research, were used of the daily and hourly meteorological data of Zanjan Airport synoptic station from 2020 to 2021. These the data included minimum and maximum temperature, minimum and maximum humidity, wind speed average, sunshine hours and air pressure. To check the application of metric algorithm, were downloaded Landsat 8 images for 2020-2021 years and were done necessary corrections and preprocessing on them. Landsat images are available at 16-day intervals with a spatial resolution of 30 m and were obtained from the United States Geological Survey website (http://glovis.usgs.gov). After the images processing, is obtained the albedo, surface emissivity, land surface temperature, plant indicators, incoming-outgoing radiation fluxes, net radiation flux and the soil heat flux. Next, the sensible heat flux is calculated by determining the hot and cold pixels. Finally, evapotranspiration maps are plotted. In addition, for a better comparison of the results, were compared of the layers related to vegetation index include soil heat flux and land surface temperature in the different stages of the growth period. After extracting these indices, the evapotranspiration map was extracted using ENVI software.
Result and discussion
Results show that daily evapotranspiration increases is directly related with increase in vegetation density. at the initial of the growth period, the range of evapotranspiration is estimated between 0.08 and 4.97 mm.d-1, while this value in the middle and late of the growing season is estimated in the range of 0.086 to 5.56 and 0.59 to 9.57 mm.d-1 respectively. Based on the results of this research evapotranspiration obtained from the soil water balance model and METRIC model were estimated as 24115 and 25648 m3, respectively. The results validation of evapotranspiration obtained from the metric model was compared with the actual evaporation and transpiration obtained from the soil water balance model, and the error coefficient was obtained equal to 5.97%.
Conclusion
According to the results of this research, it was determined that the use of energy balance models using the science of remote sensing provides the possibility of estimating evaporation and transpiration regionally. On the other hand, the calculation error percentage shows that the metric algorithm is accurate enough to estimate ET in the studied area.
Abstract
Physicochemical properties and the forms of erosion of marl formations as well studied in this experiment within Zanjanrud watershed basin. At first, the distribution and erosion landscape maps for different marl formation were prepared and then by overlying different maps the final map of working units ...
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Physicochemical properties and the forms of erosion of marl formations as well studied in this experiment within Zanjanrud watershed basin. At first, the distribution and erosion landscape maps for different marl formation were prepared and then by overlying different maps the final map of working units were produced. Soil samples from selected points within each working unit were collected and after laboratory measurements statistical analyses were applied. The results suggested that surface and sheet erosion were more dominated than other forms of erosion. While gypsum content was concentrated at surface, some elements such as Ca, Mg, and dissolved Na subsided in lower layers. Marl units account for 20% of the total area of the basin, which consists of two types of Marl Pliocene (Plm) (99.75%) and the upper Red marl (Mur) (0.25%). In this basin, there are four superficial erosional facies, surface,rill, badland and gully erosin, with the rill erosion facies having the highest and most expanse of 61%. Toward the deeper layers in marl soils level of salinity, pH and clay percentage increases as the result of leaching of salts and fine material by runoff and transferring them from surface to depth. There is statistical significant difference in the amount of EC, clay, limestone, and gypsum among various forms of erosion, so that the highest and lowest level of EC were found respectively in deep gully and upper layers of surface erosions. Highest content of gypsum was found in badland erosion while the lowest of that was found in surface erosion. Therefore, changes of chemical properties are mostly found in surface and badland erosions. Finally, prevention of these two types of erosion must be prioritized because they can be precursors to other forms of erosion in this type of marl soil.
Parviz Abdinejad; Mohammad Roghani
Abstract
The present research was carried out at a research station in Qarehchryan, located in north-west of Zanjan City, Iran. Rainwater catchment systems had dimensions of 5×8 m, with five treatments of control (withness)(A), without vegetation and gravel with gravelly filter (B),without gravelly filter ...
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The present research was carried out at a research station in Qarehchryan, located in north-west of Zanjan City, Iran. Rainwater catchment systems had dimensions of 5×8 m, with five treatments of control (withness)(A), without vegetation and gravel with gravelly filter (B),without gravelly filter (C), impervious a part of the system with gravelly filter (D) and without gravelly filter (E) in a randomized complete block design with three replications. There were nine daily rainfall events from April until late August 2013, with two times irrigation with an interval of 60 days, 45 liter for every seedling and 33 times of measurement of moisture at depths of 20 and 50 cm. Results showed that spring rainfall had not been able to produce runoff in the control treatments and had no effect on soil moisture. Soil moisture influence has been increased by daily rainfall in both B and C treatments compared to control treatments.. Soil moisture influence from daily precipitation has been increased up to 30 percent in D and E treatments due to insulating surface of existing systems and impervious surface of rainwater catchments. Timeline of the average moisture at the depths of 20 and 50 cm is almost similar in all treatments. This situation indicates that the distribution of moisture in depth of 20 to 50 cm is similar with no significant difference, but, the moisture at the depth of 20 cm is more than 50 cm.
Parviz Abdinezhad; Parviz Moradi
Abstract
In this research, some effective factors on stability and sedimentation of woven-wire check dams within marly areas were studied. For this pupose, data of 380 light-weight metallic dams were collected during field study and Pearson correlation coefficients and regression analysis of variance of SPSS ...
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In this research, some effective factors on stability and sedimentation of woven-wire check dams within marly areas were studied. For this pupose, data of 380 light-weight metallic dams were collected during field study and Pearson correlation coefficients and regression analysis of variance of SPSS statistical software were used in analysis procedures. The results showed that there were significant relation between width, length and volume of dams with stability at confidence level of 99% and according to correlation coefficients, width of dam showed a higher correlation in comparison to two other variables, but length of dam holds the second place. On this respect, dimensions of dams were among the effective factors on their stability. The stability of dams also represents an inversely linear relationship (correlation coefficient of 0.24) with volume of sediment accumulated behind them. The link between length and width to volume of accumulated sediment favors a direct linear relationship, and based on their correlation coefficients (0.69 and 0.23 respectively) the impact of length of dams is greater. In general, to reach a desired stability of these dams, their dimension must be in accordance with standards and must be determined using respective equations.
