Sharif Digital Repository

The interaction between a lake and groundwater has important implications to the quantity and quality of water in both environments. Quantification of lake-groundwater interaction (LGI) has been challenging in regions with limited in-situ data. LGI can be quantified by physically-based models, direct measurement of seepage, measurements of conservative chemical or isotopic tracers, and lake water balance. Despite the accuracy of the methods based on hydrochemical or isotopic measurements and analysis, they require extensive field data that are costly to collect in large lakes. Instead, the data required to quantify LGI by the lake water budget method can be obtained via typical ground... 

In this paper we examine how exchange flow in Urmia Lake plays a crucial role in dynamics of the lake. Urmia Lake, a very large hyper-saline lake of high ecological significance, is located in northwest of Iran with a 15-km causeway dividing it into north and south lakes. A 1250-m opening in the causeway near the east coast links the two lakes. The differences in mean water levels and densities of the two lakes increase in spring due to large freshwater inflows into the south lake. High evaporation dominates the lake in summer. By incorporating the results of a two-layer hydraulics theory into a mixing model of the lake, we show that the exchange flow through the opening diminishes the water... 

Knowing the rate of evaporation from surface water resources such as channels and reservoirs is essential for precise management of the water balance. Few detailed evaporation studies exist for small lakes or reservoirs in arid regions of the world. In this study, monthly evaporation was determined by Bowen Ratio Energy Budget technique (BREB) for Alghadir reservoir (Saveh, Iran) from 1995-2007 and compared with class-A pan. Daily data were obtained from IMO (Iran Meteorological Organization) weather station, located near the reservoir, for all of these years. Some variations have been observed on the estimated evaporation of the energy budget at different years, ranging from 151 cm for 1997... 

The large heterogeneity in soil surface conditions makes it impracticable to obtain reliable estimates of soil hydraulic parameters for areas larger than few squared kilometers. However, identifying these parameters on a global scale is essential for many hydrological and climatic applications. In this study, a new approach named Drainage from Drydown (DfD) is proposed to estimate the coefficients of drainage using soil moisture observations. DfD firstly selects multiple drydown events when surface runoff and evapotranspiration rates are negligible compared to the drainage rate. Secondly, by inverting the soil water balance equation, the drainage coefficients are obtained. Synthetic... 

Utilizing ground-based measurements to obtain water budget components, especially in large scale basins, is challenging due to the limitation in the spatiotemporal availability of in-situ data. In this paper, we propose a probabilistic framework for estimating water budgets in low runoff regions using remote sensing products. By studying water budgets in the Central Basin of Iran (CBI) over 8 years period (2009–2016), we investigate the locations and time scales at which the water budget calculated from satellite products provides most closure. To this end, we use precipitation from the Tropical Rainfall Measuring Mission (TRMM), evapotranspiration from the Water Productivity Open Access... 

This study investigated the lake–aquifer hydraulic interactions in Lake Urmia (LU) as the second largest hypersaline lake in the world. Due to the scarcity of hydrogeological data required for modelling, a method based on Darcy’s Law and lake water budget was used to quantify the lake–aquifer interaction. Long-term ground- and satellite-based hydrological datasets over the time frame 2001–2019 were used. Results indicate that the groundwater flux between LU and the aquifers controls 18.74 ± 1.67% of the lake’s water storage. While 10 out of 14 adjacent aquifers recharge LU at a rate of less than 180 m3/m.month, one phreatic aquifer recharges the LU up to 1400 m3/m.month. Two aquifers are... 

Remote sensing is an effective tool for capturing spatial and temporal variations of water surface temperature (WST) in large lakes. The WST of Urmia Lake in northwestern Iran was examined from 2007 to 2010, using MODIS land surface temperature (LST) products. Spatial and temporal (diurnal, monthly, seasonal and inter-annual) variations of Urmia Lake WST were also investigated. Results indicate that the MODIS-derived WSTs are in a good agreement with the in situ data (R2=0.92 and bias=-0.27). Spatial analysis of WST revealed that there are three thermal zones along the lake: the shallow region in barriers of the causeway, islands and the shoreline; the south part; and the deep north parts.... 

Urmia Lake in the northwest of Iran is the second largest hyper-saline lake worldwide. During the past two decades, a significant water level decline has occurred in the lake. The existing estimations for the lake water balance are widely variable because the lake bathymetry is unknown. The main focus of this study is to extract the volume-area-elevation (V-A-L) characteristics of Urmia Lake utilizing remote sensing data and analytical models. V-A-L equations of the lake were determined using radar altimetry data and their concurrent satellite-derived surface data. Next, two approximate models, a power model (PM) and a truncated pyramid model (TPM), were parameterized for Urmia Lake and... 

A simple conceptual rainfall–runoff model is proposed for the estimation of groundwater balance components in complex karst aquifers. In the proposed model the effects of memory length of different karst flow systems of base-flow, intermediate-flow, and quick-flow and also time variation of recharge area (RA) during a hydrological year were investigated. The model consists of three sub-models: soil moisture balance (SMB), epikarst balance (EPB), and groundwater balance (GWB) to simulate the daily spring discharge. The SMB and EPB sub-models utilize the mass conservation equation to compute the variation of moisture storages in the soil cover and epikarst, respectively. The GWB sub-model... 

In this study, two conceptual models, the classic reservoir (CR) model and exchange reservoirs model embedded by dual porosity approach (DPR) are developed for simulation of karst aquifer functioning drained by multiple outlets. The performances of two developed models are demonstrated at a less developed karstic aquifer with three spring outlets located in Zagros Mountain in the south-west of Iran using 22-years of daily data. During the surface recharge, a production function based on water mass balance is implemented for computing the time series of surface recharge to the karst formations. The efficiency of both models has been assessed for simulation of daily spring discharge during the...