hydrogeology
Mirali Mohammadi; Mahsa Mohtadi
Abstract
The purpose of present research work is to study the hydraulic properties of River Simineh and its process using HEC-RAS model, in a combination with ArcGIS software using HEC-GeoRAS extension to simulate the hydraulic parameters of river having a catchment area of 3726 km2. For that mean, since multi-dimensional ...
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The purpose of present research work is to study the hydraulic properties of River Simineh and its process using HEC-RAS model, in a combination with ArcGIS software using HEC-GeoRAS extension to simulate the hydraulic parameters of river having a catchment area of 3726 km2. For that mean, since multi-dimensional models require long time and high cost in river bends, by using a combination of satellite images and HEC-RAS model a multi-dimensional simulation was prepared. Among those, 58 cross-sections are considered along the river lane that main data required in this research are elevation maps, satellite images, boundary conditions and River Simineh hydrometric stations. The results showed that at the upstream of river, the discharge was 316.3 m3/s and water level was 12.85 m, and at the downstream the flow rate and water level are 313.6 m3/s and 11.52 m, respectively. On the other side of the river bend, the water level variation is around 50 cm and the flow velocity is directly proportion to a distance from the river bank; so that the maximum flow velocity of 2.2 m/s occurred at a distance nearby 1.5 m. To verifying the model, a statistical parameter of NSE coefficient for the water level and flow depth were 0.805 and 0.845, respectively; which shows the accuracy of model. Those results indicate a high accuracy of HEC-RAS model in hydraulic simulation of River Simineh flow. Also, simulations prepared in GIS background have significant impacts on the accuracy of outputs
Mehdi Dini; Abrahim Mohammadi Aydinlo
Volume 5, Issue 15 , October 2018, , Pages 17-35
Abstract
Abstract
Introduction
Due to an intense loss in groundwater level and a high decrease in reservoir capacity, the Marand plain has been banned since 1991. However, since 1994, the groundwater level been dropping year by year. As a result, many wells and qanats have been dried or their discharge capacity ...
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Abstract
Introduction
Due to an intense loss in groundwater level and a high decrease in reservoir capacity, the Marand plain has been banned since 1991. However, since 1994, the groundwater level been dropping year by year. As a result, many wells and qanats have been dried or their discharge capacity has been decreased, which has caused a lot of problems for the operating organizations. In this study, to investigate and manage the groundwater level variation in the Marand plain, three scenarios including supplying all consumption from groundwater resources, supplying drinking and industry consumption from the Aras River, and supplying drinking and industry consumption from the Aras River and applying the optimal management of the consumption for agricultural uses were defined. The water balance equation was used to establish the relationship between input, output, storage in an aquifer, and a variation of groundwater level in the Marand plain was estimated based on the available data (2005-2014). Finally, the zoning of the groundwater level was done for the September 1398 and the results were compared with the September 1393.
Methodology
In this research, the Marand plain with an area of 562.22 km2 in the northwest of East Azerbaijan province was selected as a case study. Investigating the hydrological and meteorological parameters of the Marand plain between the years 1982 and 2013 showed that the average annual precipitation was 283 mm, the average annual temperature was 12.8°C, and the average annual pan evaporation was 104 mm. The aim of this research was to estimate the spatial and temporal variation of the groundwater level of the Marand plain. For this purpose, the water balance estimation was done by using Excel and the zoning of groundwater level variation was done by using ArcGIS. A groundwater level analysis of the Marand plain was carried out based on the 50 observations of wells during 2005 to 2014. In this period, according to the groundwater level data, the aquifer parameters, such as the loss of the groundwater level and the amount of water withdrawal from the aquifer were determined. Then, various scenarios were defined for assessing the status of the aquifer.
Result and Discussion
The analysis of the groundwater level in the Marand Plain in a year statistical period (1982-2013) showed that the groundwater level of the plain had decreased about 16.56 m. Also the average annual groundwater level of the plain decreased about 48 cm between the years 2005 and 2015.
By applying the first scenario, in the next five years, the fall of the groundwater level in the zone 1 will be 2.35 m, in the zone 2 will be 2.25m, in the zone 3 will be 2.6m, and in the zone 4 will be 2.45m.
Also the area of the zone 4 had increased from 246 km2 to 252 km2 which indicated a further fall of the groundwater level in a large area of the plain. By applying the second scenario, in the next five years, the growth of the groundwater level in the zone 1 will be 1.74 m, in the zone 2 will be 1.67 m, in the zone 3 will be 1.93 m, and in the zone 4 will be 1.82 m. Indeed, following this trend, the groundwater level after 14 years will return to the situation of 10 years ago (2005). In addition, after 46 years, it will return to the situation of 32 years ago (1982). By applying the third scenario, in the next five years, the growth of the groundwater level in the zone 1 will be 4.78 m, in the zone 2 will be 4.58 m, in the zone 3 will be 5.29 m, and in the zone 4 will be 4.99 m. Following this trend, the groundwater level after 5 years will return to the situation of 10 years ago (2005). After 17 years, it will return to the situation of 32 years ago (1982).
Conclusion
The aim of this research was to estimate the spatial and temporal variation of the groundwater level in the Marand plain. The results showed that the annual average groundwater level had decreased 48 cm/year between the years 2005 and 2014. Also by applying the first scenario, with an intensified decline in the groundwater level in all zones, the status of the Marand aquifer becomes more critical. For example, in some areas, the groundwater level will decease about 2.6 m. By applying the second scenario, the groundwater level will increase at least 1.67 m and utmost 1.93m and by following this trend, after 14 years, the aquifer will return to the situation of 2005. Also by applying the third scenario, the groundwater level will increase at least 4.78 m and utmost 5.29m and by following this trend, after 5 years, the aquifer will return to the situation of 2005.
