نتایج جستجو برای: arid regions in each studied system
تعداد نتایج: 17364255 فیلتر نتایج به سال:
Interdependencies of ecologic, hydrologic, and social systems challenge traditional approaches to natural resource management in semi-arid regions. As a complex social-ecological system, water demands in the Sonoran Desert from agricultural and urban users often conflicts with water needs for its ecologically-significant riparian corridors. To explore this system, we developed an agent-based mo...
soil erosion is the most important threat to the soil and water resources among the soil degradation processes in arid and semi-arid regions. this study was conducted in shirin-darreh basin, a semi-arid region in north-eastern iran, to evaluate the performance of erosion potential method (epm) and hydro-physical method (csy) in generating erosion potential and sediment load maps via geographic ...
We investigate the impact of land reform on the destruction of "Bone" and agricultural production in the arid regions in Iran. We employ the agricultural census collected in 1960 (1339) and 1971 (1350)-1974 (1353). Our empirical methodology is difference-in-difference. Results indicate that in regions with bone, the agricultural production has dropped due to the land reform of 1962 (1341)-1966 ...
in this study, a simple, rapid and selective method was developed for the determination of dexamethasone. the proposed method is based on inhibitory effect of dexamethasone on the oxidation of orange-g by bromate in sulfuric acid media. the reaction was followed spectrophotometrically at 478.5 nm (?max). under optimum experimental conditions, (72.6 ?mol l-1 of orange-g, 0.76 mol l-1 of h2so4, 0...
Some endemic shrubs in arid and semiarid ecosystems are in danger of extinction, and yet they can play useful roles in maintaining or restoring these ecosystems, thus practical efforts are needed to conserve them. The shrubs Amygdalus pedunculata Pall., Amygdalus mongolica (Maxim.) Ricker and Ammopiptanthus mongolicus (Maxim. ex Kom.) Cheng f. are endemic species in arid and semiarid regions of...
in the first part of this thesis we explored wetting and its dynamics for small droplets. first, we showed how a simple feature of water droplets on a surface, i.e. laplace pressure, can be exploited to build a micropump. we investigated capillary pumping in microchannels both experimentally and numerically. putting two droplets of different sizes at the in/outlet of a microchannel, will ge...
in this thesis we will present three topics. we define approximate fixed points in fuzzy normed spaces. also we obtain some necessary and sufficient conditions on the existence of? -fixed points for ? > 0. at the continue some results about approximate fixed points for a class of non-expansive maps on g-metric spaces are obtained and we define approximate fixed points in partial metric spa...
Desertification in arid, semi-arid and dry sub-humid regions is a global environmental problem. Considering theincreasing importance of desertification and its complexity, the necessity of giving attention to desertification criteria andindices is essential. Models and methods such as MEDALUS, UNEP-FAO, and others have been proposed on local andnational scales. In this research, IMDPA was selec...
dynamic assessment according to vygotskys sociocultural theory, states that instruction and assessment are interrelated. using static forms of assessment with second and foreign language students could do more harm than good. many teachers neglect to take account of the complexity involved in learning a second or foreign language and often wonder why learning of a language take so long. thi...
analyzing spatial planning system in different countries could help make appropriate decisions to improve functional system of planning in our country. belgium, inspite of its limited area, has a unique planning system which is derived from political and social condition. belgium has a federal system which is composed of three cultural societies and three economic regions. spatial planning is i...
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