precipitation and air temperature data, only, are often recorded at meteorological stations, with radiation beingmeasured at very few weather stations, especially in developing countries. therefore there arises a need for suitablemodels to estimate solar radiation for a completion of data sets. this paper is about an evaluation of eight models foran estimation of daily solar radiation (q) from ...

soil organic carbon is a key factor in productivity and quality of soil and environment particularly in semi arid regions. in this article, the role of farm soil organic matter management in soil and in land is discussed. the variability of soil organic carbon in drylands is mainly controlled by tillage and crop residue management. results of this study indicated that usage of correct tillage m...

changes in groundwater quality, is caused destruction of other resources, either directly or indirectly, due to bad management of groundwater extractions. considering the importance of groundwater resources, especially in arid and semiarid regions, this research was done to modeling the spatial distribution of some groundwater qualitative factors with emphasis on drinking using geostatistical m...

The ongoing changes in vegetation spring phenology in temperate/cold regions are widely attributed to temperature. However, in arid/semiarid ecosystems, the correlation between spring temperature and phenology is much less clear. We test the hypothesis that precipitation plays an important role in the temperature dependency of phenology in arid/semiarid regions. We therefore investigated the in...

This paper reviews the main methodologies and techniques that have been used to characterize gypsum in soils, especially in gypsiferous soils of semiarid and arid regions and range from the identification of gypsum in soil surveys in the field to the study of gypsum in the laboratory. Many methods of gypsum identification and determination have been developed, each one with its own limitations....

Substantial tracts of land in the southwestern and western U.S. are undergoing or will require ERA. Toxicity bioassays employed in baseline ERAs are, for the most part. representative of mesic systems, and highly standardized test species (e.g., lettuce, earthworm) are generally not relevant to arid system toxicity testing. Conversely, relevant test species are often poorly characterized with r...