نتایج جستجو برای: wind erosion index
تعداد نتایج: 504575 فیلتر نتایج به سال:
Semiarid forests across the western USA and elsewhere are being thinned to reduce risk from fire, restore previous ecological conditions, and/or salvage trees from recently burned areas. Prescriptions and monitoring for thinning generally focus on biotic characteristics of vegetation, like tree density, rather than abiotic characteristics of soils and their loss, which are usually only consider...
In this paper work on image analysis methods extracting field boundaries and wind erosion obstacles from aerial imagery is presented. Describing the objects of interest and additional GIS-data together in an integrated semantic model is essential to get an overview of the numerous relations between the different objects and how to exploit the prior knowledge. The strategy is derived from the mo...
از آنجا که پدیده های واقعی همواره فازی، نادقیق و مبهم هستند. آنچه در ارزیابی این پدیده ها مهم به نظر می رسد امتیازدهی صحیح شاخص ها به منظور دستیابی به نتایج قابل استناد می باشد. فرسایش بادی نیز به عنوان یک پدیده واقعی واجد شاخص هایی هست که ساختار کیفی یا ساختار نامشخصی دارند که نمی توانند به دقت اندازه گیری شوند. در چنین مواردی به منظور دستیابی به ماتریس ارزشیابی می توان از اعداد فازی استفاده ک...
In this paper, we present an integrated wind-erosion modelling system which couples a physically based wind-erosion scheme, a high-resolution atmospheric model and a dust-transport model with a geographic information database. This system can be used to determine the pattern and intensity of wind erosion, in particular, dust emission from the surface and dust concentration in the atmosphere. Th...
To better understand the effects of biological soil crusts (BSCs) on soil moisture and wind erosion and study the necessity and feasibility of disturbance of BSCs in the Mu Us sandland, the effects of four treatments, including moss-dominated crusts alone, Artemisia ordosica alone, bare sand, and Artemisia ordosica combined with moss-dominated crusts, on rainwater infiltration, soil moisture, a...
the majority of iran’s area is covered by arid and semiarid climates. in these areas, wind causes more erosion compared to water. therefore, determination of wind characteristics especially its velocity is very important. one of the simplest methods that can supply researchers with the origin of wind erosion in the shortest time is synthesizing sand rose model and interpretation of aerial photo...
evaluation soil erosion is an important matter to protecting it from destroying in future due to the excessive use of the inherent capacity of soil and also improper management. therefore, in this study land vulnerability related to water and wind erosion of abyek for crops and pasture land has been evaluated, using raizal model as one of the microleis sub-models. morphological and physical and...
the main objective of this study is evaluation and wind statistic analysis, investigation of wind regime role on discharge flow and direction of sediments transferring in the case study. thus, sabzevar station anemometer data duration 10 years statistic period (1996-2005) analyzed. sand drift potential amount of study area is 160.9 v.u and result drift directionâ is west as well as sand flux is...
Histosols (also known as organic soils, mucks, or peats) are soils that are dominated by organic matter (OM > 20%) in half or more of the upper 80 cm. Forty two states have a total of 21 million ha of Histosols in the United States. These soils, when intensively cropped, are subject to wind erosion resulting in loss of crop productivity and degradation of soil, air, and water quality. Estimatin...
A laboratory research program was arranged to study the effect of different factors influencing the stability of fine soils against wind action. For this purpose, a laboratory wind tunnel was stabilized and several soil samples were examined by putting the sample trays inside the wind tunnel for different rates of wind velocities. The tray for soil samples was 20´30 cm2 with the depth of 5 cm, ...
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