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Showing 3 results for Hoshmand

S. M. Mousavi, A. Hoshmand, S. Bromandnasab, M. Yazdani,
Volume 16, Issue 60 (Summer 2012)
Abstract

The common method of irrigating rice in paddy fields of Iran, like most countries, is flooded irrigation. The water required in this method is too much. However, because of water shortage in recent years, and malfunctioning of irrigation systems, it is needed to use water in a reasonable way and increase water use efficiency. Therefore, it is necessary to know water loss amounts at the paddy fields. The deep percolation (DP) was measured by closed- and open-bottom rings in 4 locations, and 7 sites at each location, of paddy fields in Somae-Sara city, Guilan province. These locations were selected on the base of different physiographic units. The average DP of these locations was also monitored during plant growth season. The measurements were performed twice a week. Results showed that the rate of DP varied during the season, and could take a positive or negative value. The most important factors of these variations were the lateral seepage (from surrounding rice fields) and the high perched groundwater table in paddy fields.
N. Nourmahnad, H. Tabatabaei, A. R. Hoshmand, M. R. Nouri Emamzadei, Sh. Ghorbani Dashtaki,
Volume 18, Issue 68 (summer 2014)
Abstract

Usually, dry soil readily absorbs water .However, not all soils display such characteristics. Some soils (hydrophobic soils) show resistance to wetting. Because of the importance of this subject and lack of research, we evaluated the effect of heating on water repellency and some of soil physical and chemical characteristics. So soil was combined with compost and heated at deferent temperatures, 100, 200, 300, 400 and 500 °C for 30 minutes in an oven or muffle furnace. The results showed that control treatment and heated soil at 300 °C had WDPT and MED 45 (s), 17% and 80 (s), 23% respectively. So, little water repellency was present prior to heating the soil. When soil was heated up to 300°C, intense water repellency resulted, but it was abruptly eliminated by increasing the heating. The soil texture was changed from loam to sandy loam at high temperatures (400 & 500 °C) and the sand percentage was increased. Organic matter decreased by increasing the temperature. Amount of pH decreased up to 200 °C and then increased at 500°C because of increasing ash in soils. Diminution of mineral and organic matter caused EC to decline in all the heated soils.
F. Naeimi Hoshmand, F. Ahmadzadeh Kaleybar,
Volume 26, Issue 3 (Fall 2022)
Abstract

Hydrological models for evaluating and predicting the amount of available water in basins, flood frequency analysis, and developing strategies to deal with destructive floods are expanding daily. In this study, HEC-GeoHMS and Arc Hydro extensions in ArcGIS software and the HEC-HMS model were used to simulate design flood hydrographs in the Aydooghmush basin in the northwest of Iran. SCS-CN, SCS-UH, Maskingham, and monthly fixed methods were used to calculate rainfall losses, rainfall-runoff transformation, flood routing, and base flow, respectively. In model calibration with two real flood events, the average of absolute values of the residuals, the sum of the remaining squares, and the weight of the peak mean the error squares for the flood volume were 2.75, 5.91, and 5.32, respectively and for peak discharge were 8.9, 8.0, and 8.0, respectively. Model validation was evaluated as acceptable with a one percent error rate in the peak of discharge and a 19 percent in the flood volume. For maximum 24-hour precipitation, the log-Pearson type 3 was determined as the most suitable distribution in the SMADA model and design precipitation was extracted in different return periods. Thus, for the return period of 2 to 1000 years, the peak discharge and volume of the design flood were simulated equally to 18.8 to 415.6 m3 s-1 and 5.7 to 87.9 MCM, respectively.


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