نتایج جستجو برای: agricultural used land

تعداد نتایج: 2401809  

Journal: :مرتع و آبخیزداری 0
کامران کریمی دانشجوی دکتری بیابان زدایی، دانشگاه کشاورزی و منابع طبیعی گرگان، ایران غلامرضا زهتابیان استاد دانشکده منابع طبیعی، دانشگاه تهران، ایران مرزبان فرامرزی استادیار گروه مرتع و آبخیزداری، دانشگاه ایلام، ایران حسن خسروی استادیار دانشکده منابع طبیعی، دانشگاه تهران، ایران

remote sensing is a key technology for assessing expansion and rate of land cover changes that awareness of these changes as the basic information has a special importance for various programs. in this study, land use changes were examined over the past 24 years, and the feasibility of predicting it in the future was evaluated by using the markov chain model of the abbas plain. landsat tm, etm+...

2016
Zhiwei Wang Shengtian Yang Changsen Zhao Juan Bai Hezhen Lou Ke Chen Linna Wu Guotao Dong Qiuwen Zhou Mustafa M. Aral

The transport characteristics of phosphorus in soil and the assessment of its environmental risk have become hot topics in the environmental and agricultural fields. The Sanjiang Plain is an important grain production base in China, and it is characterised by serious land use change caused by large-scale agricultural exploitation. Agricultural inputs and tillage management have destroyed the so...

2012
John W. Recha Johannes Lehmann M. Todd Walter Alice Pell Louis Verchot Mark Johnson

Tropical Africa is affected by intense land-use change, particularly forest conversion to agricultural land. In this study, the stream discharge of four small headwater catchments located within an area of 6 km in western Kenya was examined for 2 years (2007 and 2008). The four catchments cover a degradation gradient ranging from intact forest to agricultural land under maize cultivation for 5,...

2002
L. Brown B. Syed S. C. Jarvis R. W. Sneath V. R. Phillips C. Li

A mechanistic model of N2O emission from agricultural soil (DeNitrification-DeCompositionFDNDC) was modified for application to the UK, and was used as the basis of an inventory of N2O emission from UK agriculture in 1990. UK-specific input data were added to DNDC’s database and the ability to simulate daily C and N inputs from grazing animals and applied animal waste was added to the model. Th...

Journal: :پژوهش های جغرافیای انسانی 0
فریبا جهان رمضان کارشناس ارشد توسعۀ روستایی دانشگاه رازی کرمانشاه کیومرث زرافشانی دانشیار دانشکدۀ کشاورزی دانشگاه رازی کرمانشاه فرحناز رستمی استادیار دانشکدۀ کشاورزی دانشگاه رازی کرمانشاه

introduction food security over the past decade was one of the main objectives of rural development policies in many countries. agricultural policies such as productive improvement, conservation and utilization of water and land resources are being considered in the heart of development projects. among these initiatives to achieve improved quality of infrastructure, environment and welfare is t...

2006
M. Voss

Nitrate input to a river is largely controlled by land use in its catchment. We compared the information carried by the isotopic signatures of nitrate in 12 Baltic rivers, in relation to the vegetation cover, land use, and fertilization of agricultural land of their catchments. We found isotope values in nitrate ranging from −2 to 14‰ for δ15N and 8 to 25‰ for δ18O. The annual variability of ri...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2010
Allison M Thomson Katherine V Calvin Louise P Chini George Hurtt James A Edmonds Ben Bond-Lamberty Steve Frolking Marshall A Wise Anthony C Janetos

Land-use change to meet 21st-century demands for food, fuel, and fiber will depend on many interactive factors, including global policies limiting anthropogenic climate change and realized improvements in agricultural productivity. Climate-change mitigation policies will alter the decision-making environment for land management, and changes in agricultural productivity will influence cultivated...

2006

Despite the apparent abundance of land, agricultural land with a dependable growing period represents a fraction of the total land area in Ethiopia. Moreover, land degradation is extensive and severe, particularly in the highlands above 1500 meters above sea level, which account for about 40 percent of the total land area but home for 90 percent of the total population and 70 percent of livesto...

2012
Stella O. Odebode

Agricultural development has been a major concern to most developing countries within the last two decades. It represents a cluster of six related but separate concepts; agricultural expansion; increased production per acre of cropped land or per head of livestock; agricultural growth; a situation characterized with agricultural products per agricultural worker, rising income per person employe...

2001
K. S. Rajan Ryosuke Shibasaki

Land use and land cover is an important component in understanding the interactions of the human activities with the environment and thus it is necessary to be able to simulate such changes. The authors have developed a national scale, integrated, dynamic time-series simulation model called the ‘Anthropogenically Engineered Transformations of Land Use and Land Cover’ (AGENT-LUC) Model, which si...

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