Freidoon Soleimani; Mohammad Hossein Mahdian; Majid Heidarizadeh
Abstract
Due to the water resources limitation in the country, subsurface flow of the seasonal rivers has an important role. These water resources can be used when collected by underground dams in locations with appropriate properties. In order to use the subsurface flow, it is necessary to estimate water resources ...
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Due to the water resources limitation in the country, subsurface flow of the seasonal rivers has an important role. These water resources can be used when collected by underground dams in locations with appropriate properties. In order to use the subsurface flow, it is necessary to estimate water resources potential accurately. Therefore, the aim of this study is to estimate the volume of subsurface flow using Salas model based on hydrologic balance. For this reason, the meteorologic and hydrometric information and data of 15 stations were by gathered and two hydrometric stations of Abgelal and Marghab were chosen as suitable ones by assessing and field survey. At these stations, the balance of subsurface flow was estimated using the above mentioned model. The results showed that in Abgelal watershed, 73 and 11 percent of the total rainfall were lost due to evapotranspiration and infiltration respectively, and just 16 percent was outflowed from watershed in the form of surface runoff. Also, most of the rainfall was outflowed through surface runoff in Marghab watershed and the coefficient of runoff was 58.7 percent. In this watershed, 41.2 percent of the total rainfall was infiltrated and 29.9 percent was lost due to evapotranspiration and 27.4 percent was infiltrated. Considering the area of Abgelal watershed of 151.6 km2, about 8.4 million m3 is drained annually as subsurface flows. According to the area of Marghab watershed of 664.3 km2, annually about 250 and 43 million m3 are drained as surface and subsurface flows, respectively. Also, evaluation of the model in both stations using relative root mean square error, Nash-Sutcliffe efficiency and mean absolute error, showed the amounts of 2.53, 0.53 and 10.08 in Marghab and 0.97, 0.32 and 8.9 in Abgelal station.
Majid Heidarzadeh; Seyed Said Moosavi nadooshani; Azadeh Mahdipoor
Volume 2, Issue 4 , January 2011, , Pages 237-249
Abstract
In water resources projects, the maximum instantaneous discharge as well as the maximum average flood discharge and their corresponding volumes in any given durations and return periods are required. In this study a method selected to investigate the Partial Duration Series (PDS) where the sample sizes ...
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In water resources projects, the maximum instantaneous discharge as well as the maximum average flood discharge and their corresponding volumes in any given durations and return periods are required. In this study a method selected to investigate the Partial Duration Series (PDS) where the sample sizes are greater than pre-identified thresholds. In this method, randomly several observations are selected for a given year while some years have no observation greater than the threshold.. Selecting the most appropriate observations as representative for floods is the main characteristic of the PDS method. In contrast, the main advantage of the Maximum Annual Series (MAS) can be referred to the inherent independence of the data. This subject can be validated and examined in the PDS using randomness and stationary tests. The Soltani hydrometric station in Halilrood River located in south-west of Kerman province, Iran was selected as a case study. Comparison of the theoretical results of the PDS and MAS methods indicated that the estimated values of PDS for 10 years and smaller return period are greater than those of MAS. However the results for this study area show this difference is negligible for 27 years data. The PDS method quickly approaches the population for a given data. Therefore the PDS is favorable for hydrometric stations with limited data availability. The required software coherent with Iranian data were prepared and presented in this study.
