Soil erosion is a serious threat to soil and water resources in semi-arid regions. Modified Pacific South-west Inter Agency Committee (MPSIAC) and Erosion Potential Method (EPM), as two well-known models, have shown their performance in many case studies. The goal of present study is to assess the efficiency of these methods for estimating the sediments yield and erosion intensity within short-term and long-term timeframes over two sub-basins of Dez watershed, west of Iran. The results showed that the study area can be categorized into slight, moderate, high and very high erosion zones. Almost half of the study area is highly susceptible to erosion due to the geological formations and land cover. Moreover, the long-term (i.e. 30 years) sediment yield of 387 and 615 (kton) y−1 estimated by MPSIAC and EPM models demonstrated the superiority of EPM. Compared to the measured value of 612 (kton) y−1, the performance of EPM was astonishing. By splitting the dataset into six periods of five years, the sediment yield was predicted in short-term periods by both aforementioned methods. Such segmentation provides the opportunity to evaluate the impact of extreme flooding events on the models performances. The results showed that both models failed in estimation of sediment load during flood conditions. Nevertheless, the correlation coefficients for estimating the sediment yield were found to be R=0.93 and R=0.85 for EPM and MPSIAC models respectively, for short-term simulations.

10.1016/j.iswcr.2016.06.001

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Citations (53)

Simulating tropical storms in the Gulf of Mexico using analytical models

Oceanologia (2019)

Mehdi Yaghoobi Kalourazi Seyed Mostafa Siadatmousavi Abbas Yeganeh‐Bakhtiary Felix Jose

Different analytical models have been evaluated for estimating wind speed of the tropical storm, where the storm-induced wind velocity is calculated as a function of distance from the center of the hurricane. For these models, different parameters such as maximum wind speed, a radius of the maximum wind, hurricane shape parameter, hurricane translation speed and the orientation of the trajectory, etc., affect the shape of a hurricane. Hurricanes Lili (2002), Ivan (2004), Katrina (2005), Gustav (2008) and Ike (2008) from the Gulf of Mexico were used for skill assessment. The maximum wind radius was calculated using significant wind radii (R34, R50 and R64) reported by the National Hurricane Center. Different formulas for calculating the radius of maximum wind speed were evaluated. The asymmetric wind field for each hurricane was generated using analytic methods and compared with in situ data from buoys in the Gulf of Mexico and the H*Wind data. Analytical models were able to predict high wind speed under tropical cyclone conditions with relatively high precision. Among the analytical models evaluated in this research, the model proposed by Holland et al. (2010) showed excellent results. Dynamical wind models such as NCEP/NARR provide wind speed with the coarse spatial resolution which is acceptable for far-field locations away from the hurricane eye. In contrast, analytical models were able to produce sufficiently reliable wind speed within a particular radius from the center of the hurricane. Therefore blending of dynamical and analytical models can be used to provide accurate wind data during hurricane passage in the Gulf of Mexico.

Maximum sustained wind

10.1016/j.oceano.2019.11.001

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Citations (26)

Transitions between different estuarine states in a low-inflow estuary of arid coasts (Mond Estuary, Persian Gulf) with a focus on freshwater lenses

Regional Studies in Marine Science (2024)

Seyed Taleb Hosseini Seyed Mostafa Siadatmousavi Emil V. Stanev Johannes Pein Corinna Schrum

This study shows that the Mond Estuary, Persian Gulf experiences notable time-dependent longitudinal salinity. Monthly-seasonal variability in salinity changes from a positive estuarine system in wintertime to inverse and salt-plug estuaries during summertime. A highly unsteady state (time scale of hours-days) occurs in the wintertime named the freshwater lens estuary (FLE), in which a low-salinity water mass (lens) is confined by both marine and riverine saltwater sources. Here, FLE dynamics is investigated using realistic and idealized numerical models and two 25-hour data sets collected immediately before a hypersaline runoff (weak FLE condition) and during another one (strong FLE condition). The Péclet Number (Pe) reveals a much stronger advective transports than diffusive one (Pe>5.7) throughout the estuary. An exception from this behavior (stronger mixing with Pe=0.8) is observed at the estuary downstream, where a significant amount of freshwater mixes with seawater during the weak FLE conditions. Also, the minimum hypersaline runoff of ~400 m3/s estimated by the numerical model can dampen tidal waves at the head of the estuary. In an idealized basin, the model shows that FLE longitudinal flows form two cells of positive estuarine circulation separated by a maximum mixing zone (the potential energy anomaly <0.75 J/m3). In the Mond Estuary, a sea-level rise of 20 cm increases salinity in the FLE state and the positive estuary during winter. Conversely, it decreases salinity in the inverse and salt-plug estuaries in summer.

Freshwater inflow

Estuarine water circulation

10.1016/j.rsma.2024.103525

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Citations (1)

Numerical simulation of waves in the Caspian Sea: calibration and verification of the observation-based source terms

Ocean Dynamics (2021)

Atefeh Alipour Seyed Mostafa Siadatmousavi Felix Jose

10.1007/s10236-021-01465-w

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Citations (6)

Winter storm-induced hydrodynamics and morphological response of a shallow transgressive shoal complex: Northern Gulf of Mexico