Ramin Papi; Saeid Hamzeh; Masoud Soleimani
Abstract
The climate change over the past few decades, and consequently decrease in the precipitation, along with the population growth in different regions in Iran have led to an increase in demand for water for domestic agricultural, industrial, etc. consumption. This has led to uncontrolled exploitation of ...
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The climate change over the past few decades, and consequently decrease in the precipitation, along with the population growth in different regions in Iran have led to an increase in demand for water for domestic agricultural, industrial, etc. consumption. This has led to uncontrolled exploitation of groundwater resources, causing severe decrease in the groundwater level. Artificial recharge technique is one of the methods to compensate for the groundwater deficit, especially in arid and semi-arid regions. Selection of suitable sites before artificial recharge can help improve the efficiency of the project and ensure its success. Having in mind the problems related to decrease in groundwater resources in Tehran due to the increasing population and the expansion of industry and agriculture. This study aims to identify and zoning of regions that are suitable for artificial recharge of groundwater in Tehran Province. The GIS can help determine such regions more precisely, faster, and with better results. For this purpose, the present study integrated GIS and Fuzzy AHP to weigh and combine factors that play a positive role in artificial recharge, such as the depth and changes in the groundwater level, precipitation, drainage density, elevation and land slope, distance from fault, distance from river, geological properties, and land use. After investigating the views of experts about the binary comparison of the criteria, and prioritizing them using AHP, it was found that the hydrological properties were the most effective criteria for the subject under study. Results indicated that 6.2% and 15.75% of the entire area of the region under study are very suitable and suitable for artificial recharge of groundwater, respectively. Very suitable regions are mostly located in the east of the province, with suitable geologic formations, short distance from river, and predominant rangeland and agricultural land use. They also, have a very low and decreasing groundwater level.
mohammad mehrabi; Saeid Hamzeh; Seyed Kazem alavipanah; Majid Kiavarz; Ruhollah Ziaee
Abstract
Soil moisture is one of the key parameters in watershed and water resources studies. Field measurement of this parameter is extremely difficult, time-consuming and costly. Hence, in recent years, numerous satellite-based methods for estimating and modeling soil moisture have been developed and presented. ...
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Soil moisture is one of the key parameters in watershed and water resources studies. Field measurement of this parameter is extremely difficult, time-consuming and costly. Hence, in recent years, numerous satellite-based methods for estimating and modeling soil moisture have been developed and presented. Among proposed methods, surface energy models performed better and have a higher degree of accuracy because of their physical nature. But, due to their particular complexity, they have been used rarely. Therefore, this research was carried out to estimate soil moisture using Landsat 8 Satellite imagery and Surface Energy Balance System (SEBS) near the Shadegan Wetland, located in the south-west of Iran. For this purpose, volumetric soil moisture content was measured at 39 points on 27 June 2016, simultaneous with the overpass of Landsat 8 Satellite over the study area. After necessary image processing, the was calculated using the applying the SEBS on satellite image. Then, the evaporation fraction was used as the main input in an experimental model (saturation ratio model) for estimating the soil moisture. Results showed the good ability of the model for estimating soil moisture with the coefficient of determination of 0.69 and the RMSE error value of 0.03 . It can be concluded that combination of remote sensing data, surface energy balance system and the experimental model of soil moisture can be used for modeling soil moisture in a large scale.
Ghazaale Madadi; Saeed Hamzeh; Aliakbar Noroozi
Abstract
Most of drought assessment systems are largely based on rainfall data. Although the short period of data, poor quality of rainfall measurement network and low-dense distribution of stations reduce the ability of detecting drought spatial patterns. Therefore, it is obligatory to detect climate data sources, ...
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Most of drought assessment systems are largely based on rainfall data. Although the short period of data, poor quality of rainfall measurement network and low-dense distribution of stations reduce the ability of detecting drought spatial patterns. Therefore, it is obligatory to detect climate data sources, which would get rid of this problem, then to be used as an alternative option. Accordingly, in this study for monitoring drought in West Frontier Basin (including the Ilam, Kermanshah, Kurdistan and Lorestan provinces), using meteorological data (including 30 climatology and synoptic stations), to assess monthly data satellite TRMM (3B43). Drought indicators using SPI index for time scales of three, six, nine and 12 months in the period of 12 years (2000-2012) were calculated. After evaluating the accuracy and validating of monthly data from satellite images, estimation value of the drought on the determined time scales was done by use of TRMM dataset. The estimated value of the drought (SPI) across the study area using TRMM satellite images and maps of rainfall of ground-stations was calculated in MATLAB software after that for all the pixels continuously SPI value was calculated. The results indicate that, the SPI index from satellite images and ground stations are closely related. According to the statistics of weather and precipitation, year 2008 was introduced as the low rainfall year, besides the results of the study showed that the SPI value of the basin, in 2008 was lowest that determined it as the dry year.
