Search

Land use/land cover (LULC) significantly affects groundwater quality. This study analyzed the spatial distribution characteristics of groundwater hydrochemical parameters in the Guanzhong Basin and assessed the relationships between the groundwater parameters and LULC using statistical models and a curved streamline searchlight-shaped model (CS-SLM). The results showed that higher groundwater parameter concentrations were observed in the north of the plain than in the south. Forest and water bodies showed a positive effect on most hydrochemical parameters (Na+, Cl−, SO42−, F−, Cr6+), while bare land and cropland revealed a negative effect on them. In addition, the Patch-generating Land Use Simulation (PLUS) model was used to predict the LULC patterns for 2030 and to qualitatively analyze the potential changes in groundwater quality associated with LULC changes. The simulation results highlighted a significant decrease in forest areas in the southern part of Guanzhong Plain by 2030, resulting in potential groundwater quality deterioration. [ABSTRACT FROM AUTHOR]

Statistical analyses, a Piper diagram, the saturation index and the correlations of chemical parameters were used to reveal the hydrogeochemistry and hydrogeochemical evolution of shallow groundwater in the southern part of the Zhongwei section of the Yellow River alluvial plain. The water quality for agricultural and domestic uses was also assessed in the study. The results suggest that the shallow groundwater in the study area is fresh to moderately mineralized water. Higher Ca2+ and HCO3- are observed in the less mineralized water, whereas Na+ and SO42- are common ions in the highly mineralized water. The major hydrochemical facies for groundwater with total dissolved solids (TDS) <1 g/L are HCO3-Ca·Mg and HCO3-Ca·Na·Mg, and for groundwater with TDS > 1 g/L, SO4·Cl-Na and SO4·Cl-Na·Mg·Ca are the predominant hydrochemical types. The main reactions in the groundwater system are the dissolution/precipitation of gypsum, fluorite, halite, calcite and dolomite. Cation exchange is also important in controlling the groundwater chemistry. The water samples assessed in the paper are of acceptable quality for agricultural use, but most of them are not fit for direct human consumption (drinking). TDS, total hardness (TH), Cl- and SO42- are the main indices that result in the poor drinking water quality. [ABSTRACT FROM AUTHOR]

Abstract: The microstructural characterization of the Al–2.24Cu–1.42Mg–0.9Fe–0.9Ni (wt%) alloy were studied using optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and tensile tests. The results indicate that the microstructures of the as-cast alloy consist of α-Al matrix, Al/Al2CuMg eutectic structure, Al7Cu2Fe, Al7Cu4Ni and Al9FeNi compounds. After 16h homogenization at 520°C, the lamellar eutectic phases dissolved into the matrix, and the intermetallics containing Fe or Ni were remained in the microstructure. [Copyright &y& Elsevier]