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Spatial downscaling methods are widely used for the production of bioclimatic variables(e.g. temperature and precipitation) in studies related to species ecological niche and drainage basin management and planning. This study applied three different statistical methods, i.e. the moving window regression(MWR), nonparametric multiplicative regression(NPMR), and generalized linear model(GLM), to downscale the annual mean temperature(Bio1) and annual precipitation(Bio12) in central Iran from coarse scale(1 km × 1 km) to fine scale(250 m ×250 m). Elevation, aspect, distance from sea and normalized difference vegetation index(NDVI) were used as covariates to create downscaled bioclimatic variables. Model assessment was performed by comparing model outcomes with observational data from weather stations. Coefficients of determination(R2), bias, and root-mean-square error(RMSE) were used to evaluate models and covariates. The elevation could effectively justify the changes in bioclimatic factors related to temperature and precipitation. Allthree models could downscale the mean annual temperature data with similar R2, RMSE, and bias values. The MWR had the best performance and highest accuracy in downscaling annual precipitation(R2=0.70; RMSE=123.44). In general, the two nonparametric models, i.e. MWR and NPMR, can be reliably used for the downscaling of bioclimatic variables which have wide applications in species distribution modeling. 相似文献
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Effects of biochar and bio-fertilizer on yield and qualitative properties of soybean and some chemical properties of soil 总被引：1，自引：0，他引：1
Zahra Arabi Hasan Eghtedaey Bahman Gharehchmaghloo Abolfazl Faraji 《Arabian Journal of Geosciences》2018,11(21):672
This study attempted to examine the effects of biochar amendment together with bio-fertilizer on soybean yield and its qualitative properties, as well as a few chemical properties of soil through a factorial randomized complete block design at three replications in east of Golestan Province (Iran) during 2014. The two factors under study included the following: (1) biochar amendment (in four levels of 0, 2.5, 8, and 16 tons per hectare), (2) bio-fertilizer containing phosphorus and sulfur growth-promoting rhizobacteria (in two levels of inoculation and non-inoculation) applied through foliar feeding. The results of analysis of variance indicated that interactions of biochar amendment and bio-fertilizer on harvest index and grain yield were significant (p ≤?0.01). According to the results of this study, the highest harvest index and oil content were 56.9, and 17.7%, respectively, in the treatment of 8 tons per hectare biochar and inoculation with bio-fertilizer. The lowest harvest index and the lowest oil content were in the control treatment. The interaction of biochar and bio-fertilizer on bulk density and cation exchange capacity was significant (p ≤?0.01). The results of this study demonstrated that biochar affected the amount of residual nitrogen in the soil after harvest, cation exchange capacity (CEC), acidity (pH), and electrical conductivity (EC). The highest grain yield (3440 kg/ha) was in the 8-ton biochar treatment with inoculated bio-fertilizer. Our study concludes that the biochar and bio-fertilizers can improve grain yield of soybean till 51% relative to the control. 相似文献
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Water Resources - Monitoring and reviewing vegetation changes are one of the important strategies for multi-year planning in an area regarding the environmental problems of the last decade. The... 相似文献
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Zahra BONYADI 《《地质学报》英文版》2022,96(6):2040-2055
Although the Mehdiabad zinc-lead deposit is one of the most well-known deposits in the central Iran structural zone, the genesis of the deposit remains controversial. The host rock of the ore is a dolomitic limestone of the Lower Cretaceous Taft Formation. In the two main orebodies of the deposit, which includes the Black Hill and East Ridge ore zones, the oxide and sulfide ores are observed at the surface and at depth, respectively. The elements Zn, Fe, Mn and Mg are more abundant in the East Ridge ore zone (in both sulfide and oxide ores), with Ba, Pb, Ag and Cu being more abundant in the Black Hill oxide ore. Based on the distribution of elements and their correlation with each other in these ore zones, the elements are divided into three general groups, that of terrigenous elements, chemically-deposited elements and ore-forming (hydrothermally deposited) elements, a division that is supported by the results of factor analyses. The spatial distribution of elements is jointly affected by contact with host rocks, the boundary of oxide-sulfide ores and fault zones. The main factors governing the distribution of elements are the mechanical transfer of detrital sediments, chemical sedimentation, transfer by hydrothermal fluids, oxidation and surface dissolution, all of which affected the spatial distribution of elements. The ore-forming elements are mostly affected by hydrothermal fluids and oxidation. This study not only provides additional information about the genesis of the Mehdiabad deposit, but also could assist in the exploitation of ore and further exploration purposes. The results of this study can aid in the exploration and exploitation of the Mehdiabad deposit and similar deposits in the region. 相似文献
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International Journal of Earth Sciences - Quantitative vorticity analyses in orogenic belts are essential for studying the kinematics of deformation and can be performed using a range of methods.... 相似文献
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In this work, we study static spherically symmetric wormhole solutions in f(R) gravity. We explore wormhole solutions for anisotropic and isotropic fluids as well as barotropic equation of state with radial pressure. The behavior of weak and null energy conditions is investigated in each case. It is found that these energy conditions are violated for both the anisotropic and isotropic case but are satisfied for barotropic fluids in particular regions. This confirms the existence of wormholes obeying the energy conditions in these regions. 相似文献
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The purpose of this study is to analyze the dynamical role of a radiation field on the growth rate of the unstable Kelvin-Helmholtz (KH) perturbations. As a first step toward this purpose, the analyze is done in a general way, irrespective of applying the model to a specific astronomical system. The transition zone between the two layers of the fluid is ignored. Then, we perform a linear analysis and by imposing suitable boundary conditions and considering a radiation field, we obtain appropriate dispersion relation. Unstable modes are studied by solving the dispersion equation numerically, and then growth rates of them are obtained. By analyzing our dispersion relation, we show that for a wide range of the input parameters, the radiation field has a destabilizing effect on KH instability. In eruptions of the galaxies or supermassive stars, the radiation field is dynamically important and because of the enhanced KH growth rates in the presence of the radiation; these eruptions can inject more momentum and energy into their environment and excite more turbulent motions. 相似文献