Validation of soil moisture simulation with a distributed hydrologic model (WetSpa)

The objective of this paper is to test the ability of a spatially distributed hydrologic model (WetSpa) to simulate soil moisture. The test is conducted in the Baron Fork river basin (Oklahoma, USA), where soil moisture has been recorded on a daily basis at the WEST site soil moisture monitoring station of the Oklahoma Mesonet. The model is calibrated by comparing hourly simulated and observed river flows at Eldon gaging station from October 1, 1995 to December 31, 1996. The model performance to predict hourly river flows is verified by comparing model estimates and observations from January 1, 1997 to December 31, 2000. Next, the model predictions of soil moisture are compared with observations of WEST site soil moisture monitoring station for the same validation period. The observations are well reproduced by the model with errors that are within range of the observation accuracy, although the predictions show somewhat more abrupt temporal fluctuations as the whole root zone is considered to react instantaneously to precipitation events. The good performance compared to other studies is especially attributed to the quality of the rainfall data provided by weather radars. It is concluded that the performance of the model to predict soils moisture is promising, although spatial patterns still have to be verified.     

Effects of cations and anions on iron and manganese sorption and desorption capacity in calcareous soils from Iran

This study investigated the effect of cations and anions on the sorption and desorption of iron (Fe) and manganese (Mn) in six surface calcareous soil samples from Western Iran. Six 10 mM electrolyte background solutions were used in the study, i.e., KCl, KNO₃, KH₂PO₄, Ca(NO₃)₂, NaNO₃, and NH₄NO₃. NH₄NO₃ and NaNO₃ increased the soil retention of Fe and Mn, whereas Ca(NO₃)₂ decreased the soil retention of Fe and Mn. Iron and Mn sorption was decreased by NO₃ ^? compared with H₂PO₄ ^? or Cl^?. The Freundlich equation adequately described Fe and Mn adsorption, with all background electrolytes. The Freundlich distribution coefficient (K _F) decreased in the order H₂PO₄ ^? > Cl^? > NO₃ ^? for Mn and H₂PO₄ ^? > NO₃ ^? > Cl^? for Fe. The highest sorption reversibility was for Fe and Mn in competition with a Ca²⁺ background, indicating the high mobility of these two cations. A MINTEQ speciation solubility model showed that Fe and Mn speciation was considerably affected by the electrolyte background used. Saturation indices indicated that all ion background solutions were saturated with respect to siderite and vivianite at low and high Fe concentrations. All ion background solutions were saturated with respect to MnCO_3(am), MnHPO₄, and rhodochrosite at low and high Mn concentrations. The hysteresis indices (HI) obtained for the different ion backgrounds were regressed on soil properties indicating that silt, clay, sand, and electrical conductivity (EC) were the most important soil properties influencing Fe adsorption, while cation exchange capacity (CEC), organic matter (OM), and Mn-DTPA affected Mn adsorption in these soils.     

Geochemistry of Triassic Carbonates: Exploration Guide to Pb–Zn Mineralization in North Tunisia

The Triassic carbonate rocks in Northern Tunisia (Nappes, Domes, Jurassic Mountains zones), consist of massive carbonates, clays and gypsum with authigenic minerals. These are associated with several Pb–Zn deposits and occurrences. At Jebel Ichkeul, Bechateur and Oum Edeboua, these Triassic carbonates exhibit enrichment in Pb (0.32 to 228 ppm), Zn (17 to 261 ppm), Cd (5 to 6 ppm) and Co (0.3 to 89.5 ppm), with respect to their average contents in crustal carbonates. The enrichment is more pronounced at Oum Edeboua (near the ore zone). Permeability is one of the most effective factors of dispersion of metallic trace elements, causing the development of geochemical halos. The genetic relationship of the Triassic carbonate rocks with the ore deposits was controlled by diapirism and tectonic movements, which favored mineralization along the Triassic‐cover contact as well as the remobilization of metals from the mineralized rocks. Analysis of metallic trace elements in Triassic rocks provides clues to the presence of possible mineral deposits. These could be effectively used for both geochemical interpretation and mineral exploration. Carbon and O‐isotope data (– 9.3‰ < δ¹³C < +3‰; +21.9 < δ¹⁸O < +31‰) suggest that the Triassic carbonates of all study areas have marine carbonates as their origin; some of them show significantly lower δ¹⁸O values indicating some exchange with hydrothermal fluids. Calcites associated with mineralization at Oum Edeboua have δ¹³C of –6.2‰ to –8.22‰ and δ¹⁸O of +24.88‰ to +25‰. The C‐isotope compositions of these calcites are ¹³C depleted, indicating an organic origin.     

Statistic and genetic investigation of faults in North Tehran tectonic wedge (South Central Alborz)

In this research, we have focused on the geometrical characteristics of young faults in North Tehran tectonic wedge which is confined with the Mosha and North Tehran faults, the most outstanding active faults in Alborz fold-thrust belt. The statistical, genetic, and kinematic relationships between internal faults, boundary faults, and the stress regime in the area (at the finite state of deformation path) are considered in detail with the help of rose diagrams and Riedel??s model. On this basis, all faults with diverse mechanisms have been classified into different Riedel fractures and their orders of formation are identified. Pattern of faults implies a more or less N?CS compression at the period of faulting. Consideration of geometry and tectonic setting of abundant normal faults have led to propose folding and listric faulting model to explain the origin of normal faults in a compressional tectonic region. These structural models represent the mechanism of normal faulting in response to compression in crustal and upper crustal scales, respectively.     

Magnetothermal condensation modes including the effects of charged dust particles

We study thermal instability in a magnetized and partially ionized plasma with charged dust particles. Our linear analysis shows that the growth rate of the unstable modes in the presence of dust particles strongly depends on the ratio of the cooling rate and the modified dust-cyclotron frequency. If the cooling rate is less than the modified dust-cyclotron frequency, then the growth rate of the condensation modes does not modify due to the existence of the charged dust particles. But, when the cooling rate is greater than (or comparable to) the modified dust-cyclotron frequency, the growth rate of unstable modes increases because of the dust particles. Also, the wavenumber of the perturbations corresponding to the maximum growth rate shifts to the smaller values (larger wavelengths) as the cooling rate becomes larger than the modified dust-cyclotron frequency. We show that the growth rate of the condensation modes increases with the electrical charge of the dust particles.     

Fracture Toughness and Fracture Roughness in Anisotropic Granitic Rocks

In this paper we present an experimental approach aimed at assessing the correlation between fracture toughness (K _IC) and fracture roughness of two granitic rocks (Barre and Stanstead granites) exhibiting significant fracture toughness anisotropy. Roughness values have been estimated for fractured surfaces obtained from Chevron Cracked Notch Brazilian Disc samples failed under mode I along three orthogonal planes with respect to their microstructural fabrics. There exists a clear correlation between roughness and toughness within each rock examined along the three planes. Specific orientation of micro-crack alignment could result in preferred out-of-plane propagation of the test-crack irrespective of grain-size distribution. These experimental observations reinforce the hypothesis of the existence of a link among pre-existing petrofabric anisotropy, fracture toughness, fracture roughness, and the evolution and extent of the associated induced fractures within the process zone of granitic rocks along specific directions. This study also highlights the need for employment of pre-failure and advanced post-failure diagnostic techniques in quantifying these inter-relationships.     

Bayesian Spatial Prediction for Discrete Closed Skew Gaussian Random Field

Most approaches in statistical spatial prediction assume that the spatial data are realizations of a Gaussian random field. However, this assumption is hard to justify for most applications. When the distribution of data is skewed but otherwise has similar properties to the normal distribution, a closed skew normal distribution can be used for modeling their skewness. Closed skew normal distribution is an extension of the multivariate skew normal distribution and has the advantage of being closed under marginalization and conditioning. In this paper, we generalize Bayesian prediction methods using closed skew normal distributions. A simulation study is performed to check the validity of the model and performance of the Bayesian spatial predictor. Finally, our prediction method is applied to Bayesian spatial prediction on the strain data near Semnan, Iran. The mean-square error of cross-validation is improved by the closed skew Gaussian model on the strain data.     

Strategies for improving land delivery for residential development: a case of the north-west metropolitan Melbourne

One of the factors affecting the housing supply is closely linked to the time taken to complete the land development assessment approval. Delays in completing the development process on time often results in difficulties of increasing housing supply. In parallel, housing demand continues to increase with increasing net population in Australian urban areas. This research aims to identify the current issues and challenges of releasing land for housing development in the established suburbs of Melbourne north-west area (involving six local government areas: Brimbank, Maribyrnong, Moreland, Moonee Valley, Hume and Melton). An application of multi-criteria decision making (MCDM) using the strategic residential potential assessment (SRPA) method is considered. This is designed to improve the method of land administration strategies for housing development. The analysis is set within the context of investigating land preparation processes and their impacts on land availability for housing supply. The research adopts interview techniques to gain insight into the processes of land release through the activities of town planners in the selected local council areas. The proposed SRPA methods are based on a land-use assessment approach that is underpinned by the current residential land-use schemes legislated by the Department of Transport Planning and Local Infrastructure.¹ The results of applying the proposed model reveal the associated spatial pattern of areas with potential for residential development relative to the public transport and public service locations.     

Seismic expression and inferred depositional environments of Plio-Pleistocene sedimentary sequences in the southwestern Caspian Sea

Eight seismic profiles from the southwestern Caspian Sea were analyzed to establish the sedimentary environments and depositional history in the South Caspian Basin since Pliocene times. Based on reflection terminations, nine sequence boundaries (S1 to S9) were identified and traced across the study area. Consequently, nine depositional sequences (S1–S9) were defined on the basis of seismic facies analysis. The results suggest a transition from non-marine sedimentation in the Lower Pliocene to marine-dominated conditions in the Upper Pliocene (S1–S4). Marine conditions then continued to the present time; however, several sea-level changes led to the formation of sequences S5 to S9. Although no local sea-level curve is available due to a lack of well data, there is good agreement between the seismic stratigraphy of the study area and a published regional sea-level curve.