نتایج جستجو برای: land uses of agriculture
تعداد نتایج: 21188402 فیلتر نتایج به سال:
In this study, the effects of three land use categories on runoff quality was investigated using a rainfall simulator, in six sub-catchments in Kakasharaf watershed in Lorestan province. In total, 39 instances of artificial rain with a duration 30 min were created and the amount of phosphorus and potassium in the resulting runoff was measured on three land uses. The results showed that the aver...
Since 1952, U.S. timberland has decreased by about 20 million acres, with about one-quarter of the reduction in the South. Although some of the timberland has been converted to urban and developed uses, larger amounts of land shifted uses between forest and agriculture because of changes in product markets and policy conditions. We summarize area trends for major land uses, examine recent polic...
abstract soil quality is an essential concept for maximum agriculture production without environmental destruction. studying soil physical quality indicators, that express soil structural stability and soil air-water balance in root zone, is one of the most important aspects of soil quality. so determination of optimal range for pore volume distribution is important and this research carried ou...
the runoff generation and soil erosion in the kechik watershed, golestan province, was assessed, using a designed and constructed portable rainfall simulator. treatments were applied on different land-uses, slopes and aspects as the most influential factors. results showed that land-use significantly affected runoff generation (13.35 l, 6.9 l, and 4.12 l, respectively for agriculture, forest an...
Small farmers in many tropical developing countries practice swidden agriculture. A key aspect of swidden agriculture is the time period during which the land is left fallow. This paper uses a new ecological-economic approach to study the fallow period and to determine the optimal length of this period in swidden agriculture. We first construct a theoretical model of a parcel of forest land tha...
using of different systems of soil plough after changing unconsciously and non-scientific of land use, other soil physical and chemical characteristics affected. this fact, especially in marginal lands and mountainous regions is more visible. this research compared with the purpose of studying land use changing on some soil physical and chemical characters like very tiny sand percent, ph, ec, c...
The earth's surface, due to its natural conditions and its structure is always changing and reshaping. One of the created deformations is the land subsidence. This is the most dangerous events which can be seen in most urban areas especially in the agricultural plains today. This study aims at zoning land subsidence and recognition of geometrical factors in southwest of Tehran. To estimate and ...
the ecological footprint as an indicator estimates the effect of population and industrial products process on ecosystem by evaluating and calculating the used energy and materials in a city, region or country. dehgolan county is located in kurdistan province between hamadan and sanandaj cities. dehgolan is one of the important and effective counties of kurdistan in agriculture. however, with t...
Extended abstract Introduction The present study was performed to investigate the effects of slope percentage and land use type on the produced sediment by an artificial rainfall simulator in Kakasharaf watershed, a branch of Karkhe watershed (Lorestan province). Methodology The rainfall simulator used in this research was designed and constructed by the Soil Conservation and...
Karami A, Sefidi K, Feghhi J. 2014. Structure and spatial pattern of land uses patches in the Zagros Mountains region in the west of Iran. Biodiversitas 15: 53-59. Landscape ecology as a new interdisciplinary science, concepts, theories and methods provides for evaluation and management of land. Quantification of landscape patterns has key role in the interpretation and modeling of spatial and ...
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