نتایج جستجو برای: Arid and semi-arid basins
تعداد نتایج: 16850415 فیلتر نتایج به سال:
abstract erosion and sedimentation are the most complicated problems in hydrodynamic which are very important in water-related projects of arid and semi-arid basins. for this reason, the presence of suitable methods for good estimation of suspended sediment load of rivers is very valuable. solving hydrodynamic equations related to these phenomenons and access to a mathematical-conceptual model ...
plant biomass is an important factor for determining arid and semi-aridrangelands capacity. due to the lack of proper and annual sampling of rangelands, there areno suitable data to determine biomass, range condition and proper range managementoperations. plant biomass is one of the measurable attributes that can be assessed inrangeland studies. since the clip and weight method is destructive a...
the purpose of this study was to evaluate the species-environment relationships in arid and semi-arid rangelandsof nodushan, yazd. the plant species cover and the environmental variables were measured at 9 sites. soil sampleswere taken for measurement of 12 attributes in 0-10 cm and 10-80 cm layers. vegetation was classified using twowayindicator species analysis (twinspan). data was analyzed u...
Land degradation impacts on several critical environmental issues such as food security, diminishing quality and quantity of fresh water resources, preservation of natural resources, loss of biodiversity, and global climate change. Land degradation is responsible for soil erosion and can eventually lead to desertification. The International Convention to Combat Desertification (CCD) defines des...
the objective of this research was to investigate the effects of deficit irrigation on physiological and agronomic terms of eggplant to maximize the water use efficiency (wue) without affecting the final yield and fruit quality parameters under arid environment. therefore, two field experiments were conducted at two different sites: ghor al-safi, jordan valley and sail al-karak, karak valley, ka...
Nitrate contamination in rivers has raised widespread concern in the world, particularly in arid/semi-arid river basins lacking qualified water. Understanding the nitrate pollution levels and sources is critical to control the nitrogen input and promote a more sustainable water management in those basins. Water samples were collected from a typical semi-arid river basin, the Weihe River watersh...
soil compaction has become a widespread problem in the world and is one of the factors involved in land degradation and declining crop yields, especially in the arid and semi-arid agriculture. the purpose of this study was to investigate the effects of subsoil compaction on morphological, physiological and agronomic aspects of wheat .the research was carried out in the experimental farms of anb...
The world’s arid lands are some of the most beautiful landscapes on Earth, and their paucity of vegetation often makes it possible to see landforms and structures with great clarity (Figure 1.1). In addition, they have many characteristics both in terms of landforms and geomorphological processes that render them different from other major environments (see, for example, Laity, 2008; Parsons an...
at the beginning of twenty-first century, the water crisis in the priority policy andmanagement is inside and outside of the country as principle thoroughly human, social,economic and political rulers of the country is considered abundant. the world bank hasannounced that during 1960 and 2025, water resources in middle east, from 3430 m3 for theeach person in year reach to 667 m3 because of pop...
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