Online) An Open Access

ABSTRACT Soil moisture constitutes an important contribution to the knowledge of a part of the water balance at the global, regional, and local scales. Hence, this information is widely used in hydrological applications helping to quantify the diverse components of the water balance -infiltration, surface runoff, evaporation, deep percolation, and changes in water content. Remote sensing provides researchers and the community with the possibility to monitor changes in land and ocean around the globe, especially where in-situ observations are limited or non-existent. Microwave remote sensing enables satellite to get observations day and night regardless of the lighting conditions, and at selected frequencies, microwave emissions have a good cloud penetration which proves to be an immensely advantage over the oceans, which are on average 70% covered by clouds. We can mention the recent succes

The assessment of groundwater geochemistry of some wells in Rafsanjan plain, Iran

Water quality is the critical factor that influence on human health and quantity and quality of grain production in semi-humid and semi-arid area. Groundwater and irrigation water quality play important roles in main production this crop. For this purpose, 94 well water samples were taken from 25 wells and samples analyzed. The results showed that four main types of water were found: Na-Cl, K-Cl, Na-SO4, and K-SO4. It seems that most wells in terms of water quality (salinity and alkalinity) and based on Wilcox diagram have critical status. The analysis suggested that more than 87% of the well water samples have high values of EC that these values are higher than into critical limit EC value for irrigation water, which may be due to the sandy soils in this area. Most groundwater were relatively unsuitable for irrigation but it could be used by application of correct management such as removing and reducing the ion concentrations of Cl‾, SO42‾, Na+ and total hardness in groundwater and also the concentrated deep groundwater was required treatment to reduce the salinity and sodium hazard. Given that irrigation water quality in this area was relatively unsuitable for most agriculture production but pistachio tree was adapted to this area conditions. The integrated management of groundwater for irrigation is the way to solve water quality issues not only in Rafsanjan area, but also in other arid and semi-arid areas

Evaluating inverse distance weighting and kriging methods in estimation of some physical and chemical properties of soil in Qazvin Plain

Today, the presence of accurate information about variability of soil properties been considered more than ever to apply this information in economic modeling, environmental predictions, accurate farming and natural resources management. The present research was conducted in some lands of Qazvin plain to study variability of some chemical and physical properties of soil by sampling 62 observational points in depth of 20 cm above soil surface. Initial statistical study of data indicated that the studied properties follow normal distribution in the region. Spatial variations of the studied properties showed that spherical model was the best fitted model to semivariogramin other properties than silt percent and bulk densityand total porosity. The highest radius for the studied properties was 21100 m related to bulk density, total porosity and electric conductivity and pH. Spatial dependence class was observed medium to strong in all physcial and chemcial properties. To validate intrapolation methods, three indices of evaluation, R2, MBE, MAE which indicate accuracy of each of the intrapolation methods were used and results showed that the studied properties had spatial structure, their impact range had good variability and kriging estimator better can show variability of the studied properties in the region in comparison to IDW method. At the end, considering the best interpolation method, spatial variability map of each of the properties was prepared in ArcGIS software