ANN-based mapping of monthly reference crop evapotranspiration by using altitude, latitude and longitude data in Fars province, Iran

The main goal of this study was to evaluate the different feed-forward back-propagation artificial neural networks’ (ANNs) potential to estimate and interpolate the reference crop evapotranspiration (ET₀) in Fars province of Iran. ET₀ was calculated using the FAO-56 Penman–Monteith method over 24 synoptic stations. Then, altitude, latitude, longitude and the month’s number as inputs and the monthly ET₀ as output (target) were used to train the ANNs. In addition, the three-layered ANNs optimized with different training algorithms including gradient descent back-propagation (gd), gradient descent with adaptive learning rate back-propagation (gda), gradient descent with momentum and adaptive learning rate back-propagation (gdx) and scaled conjugate gradient back-propagation (scg). The results indicated that scg algorithm with architecture (4 2 1) had more satisfactory results with the RMSE and R correlation coefficient equal to 18.538 mm and 0.967 in validation phase, respectively. Based on the mentioned architecture of scg algorithm, and input data form different parts of Fars province and surrounding areas, monthly ET₀ maps were produced and annual one achieved by summation of monthly maps. The maps particularly annual one showed that highest values of ET₀ could be found in the southern and especially southeastern regions, while the lowest values of ET₀ could be seen in the northern parts. Contribution of geographic and topographic variables improved the accuracy and spatial details of the resulting maps. It is interesting to note that the fundamental capability of this model is the usage of just a few parameters for ET₀ mapping. Since ET₀ is a key parameter in water demand planning, therefore, the derived maps could be useful and applicable for many purposes mainly irrigation scheduling in Fars province, Iran.     

Comparison of understorey bird species in relation to edge–interior gradient in an isolated tropical rainforest of Malaysia

Forest fragmentation results in a loss of forest interior and an increase in edge habitat. As a result, these changes may affect the bird species distribution and composition. We studied how understorey bird community composition and habitat variables changed along an edge-to-interior gradient in a fragmented lowland rainforest in Peninsular Malaysia. Birds and environmental variables were recorded at each of the 93 sampling points distributed along the 14 parallel transects that were systematically placed across the gradient of distance from the forest edge to the forest interior. Species composition was different along the edge–interior gradient, although only a few species were strictly confined to either edge or interior habitat. Based on bird–habitat associations along the edge–interior gradient, some of these edge-preferred species occurred in high numbers at the matrix surrounding the patch. In contrast, the interior-specialist group, mainly terrestrial insectivores, avoided the forest edge and was positively associated with humidity, canopy cover, the number of dead trees, percentage of litter cover, and depth of the litter layer. Species endemic to the Sunda subregion were more abundant in the interior of the forest. From a conservation perspective, forest remnants in the lowlands of Peninsular Malaysia that have a deep leaf litter layer, dense canopy cover, high number of dead trees, and high relative humidity are able to support understorey bird species that are sensitive to edge effects. The forest has important conservation value even though it is fragmented and isolated.     

Effect of different biochars amendment on soil biological indicators in a calcareous soil

Environmental Science and Pollution Research - Previous studies suggest that biochar has potential to benefit soil when used as an amendment, but only few studies have investigated how the...     

Colloid-Associated Groundwater Contaminant Transport in Homogeneous Saturated Porous Media: Mathematical and Numerical Modeling

During the past two decades, significant efforts have been made to study contaminant transport in the presence of colloids. Several researchers reported that colloidal particles could enhance the migration of contaminants in groundwater by reducing retardation factor. When the colloidal particles are present in the aquifer, the subsurface system can be considered as a three-phase system with two solid phases and an aqueous phase. The interaction between contaminants, colloids, and solid matrix should be considered in assessing the fate and transport of the contaminant in the groundwater flow system. In this study, a one-dimensional numerical model is developed by employing a fully implicit finite difference method. This model is based on mass balance equations and mass partition mechanisms between the carriers and solid matrix, as well as between the carriers and contaminants in a saturated homogeneous porous medium. This phenomenon is presented by two approaches: equilibrium approach and fully kinetic first-order approach. The formulation of the model can be simplified by employing equilibrium partitioning of particles. However, contaminant transport can be predicted more accurately in realistic situations by kinetic modeling. To test the sensitivity of the model, the effect of the various chemical and physical coefficients on the migration of contaminant was investigated. The results of numerical modeling matched favorably with experimental data reported in the literature.     

Should we Leave Nature Unattended or Assist through Enrichment to Foster Climate Change Mitigation? Exclosure Management in the Highlands of Ethiopia

Environmental Management - In order to foster the potential of exclosures to sequester carbon, it is understood that they are increasingly assisted through enrichment planting. To study the impact...     

Effect on herbicide adsorption of organic forestry waste products used for soil remediation

Organic soil amendments can be useful for improving degraded soil, but this increase in organic matter (OM) may influence adsorption of herbicides subsequently applied to the treated soil, even though the particle size of amendments and their nature differ from typical soil OM. In this study, a batch equilibrium method was used to measure adsorption of five herbicides following application to two organic media, wood pulp and sawdust, comparing these with two cropping soils. Herbicide adsorption, quantified by distribution coefficients (k_d), was much higher in the two organic media than in the cropping soils. The increases in adsorption were strongly correlated to the percentage of organic carbon. When the k_d was normalized to adsorption coefficients corrected for OM content (k_oc), variation in results between the media was greatly reduced, indicating that OM is an important factor influencing adsorption in these media. The results of this study suggest that herbicides will be less effective when applied to soils in which sawdust and wood pulp have been added. Using organic amendments to remediate soil will increase adsorption of pesticides, reducing their bio-availability and efficacy, but also reducing their tendency to leach into root zones of deep-rooted crops and into groundwater.     

An attempt to develop ecotourism in an unknown area: the case of Nehbandan County,South Khorasan Province,Iran

Environment, Development and Sustainability - This study is an attempt to develop ecotourism in Nehbandan County, in the South Khorasan Province, Iran, by representing unknown areas that have...     

Isotherm,kinetic, and thermodynamic studies for dynamic adsorption of toluene in gas phase onto porous Fe-MIL-101/OAC composite

Environmental Science and Pollution Research - In the present paper, micro-mesoporous Fe-MIL-101/OAC composite using in situ incorporation of Fe-MIL-101 into oxidized activated carbon was...