نتایج جستجو برای: are used to reduce soil erosion
تعداد نتایج: 11167584 فیلتر نتایج به سال:
abstract: in the paper of black and scholes (1973) a closed form solution for the price of a european option is derived . as extension to the black and scholes model with constant volatility, option pricing model with time varying volatility have been suggested within the frame work of generalized autoregressive conditional heteroskedasticity (garch) . these processes can explain a number of em...
abstract: literature is said beautiful words of poetry or prose that excites reader’s or listener’s feel. certainly, to be effective, such a text should have certain characteristics. the four elements of the literature: thought, imagination, emotion and style make a text to be literary and effective. emotion and imagination are specific elements of literary texts, while thought and style a...
wireless sensor networks (wsns) are one of the most interesting consequences of innovations in different areas of technology including wireless and mobile communications, networking, and sensor design. these networks are considered as a class of wireless networks which are constructed by a set of sensors. a large number of applications have been proposed for wsns. besides having numerous applic...
maintaining soil productivity is one of the key factors in sustainable agriculture. soil erosion reduces soil productivity over a long-term period of time. therefore, determining soil erosion tolerance is necessary for sustainable agriculture production. in this study, the long-term effects of erosion on soil productivity in the typical kohin watershed were evaluated. the soil productivity inde...
Extended abstract 1- Introduction Climate change is one of the problems human is facing today, and most of the scientific societies know that it is rooted in the distribution of greenhouse gases. Distribution of greenhouse gases with large volumes and in large spans has been affecting the energy budget and consequently has caused earth rapid temperature increase during the last deca...
in this study, the process-based watershed model, soil and water assessment tool (swat), was used for simulating hydrology and sediment transport in the gharesou watershed and for identifying critical areas of soil erosion and water pollution. after model calibration and uncertainty analysis using sufi-2 (sequential uncertainty fitting, ver. 2) method, the outputs of the calibrated model were u...
1- INTRODUCTION Soil as one of the most important inputs in agricultural production process plays an important role in the quality of production operation, food security and sustainable development. On the other hand, soil erosion as one of the environmental agriculture issues has been intensified with increasing population and transforming to intensive forms of agriculture in recent years. Mi...
A series of biopolymers added to irrigation water were tested for their efficacy in reducing shear-induced erosion in a laboratory-scale mini-furrow. Suspensions of chitosan, starch xanthate, cellulose xanthate, and acid-hydrolyzed cellulose microfibrils, at concentrations of 20, 80, 80, and 120 ppm, respectively, reduced suspended solids by more than 80%. None of these biopolymers, however, ex...
بررسی تنوع ژنتیکی ژنوتیپهای بومی پیاز ایرانی در مقایسه با انواع خارجی چکیده: برنامه های اصلاحی گیاهان بر اساس تنوع و انتخاب صفات برتر کمی و کیفی صورت می گیرد. لذا، ارزیابی تنوع ژنتیکی، اولین مرحله در برنامه های اصلاحی است. در این راستا، استفاده از روش های جدید مطالعهی تنوع ژنتیکی ضروری به نظر می رسد. در این بررسی تعیین تنوع ژنتیکی سیزده ژنوتیپ پیاز ایرانی در مقایسه با دو ژنوتیپ خارجی با است...
soil conservation and control of erosion is a basic problem in all countries. the goal of this research is to estimate erosion and sediment yield in ekbatan dam drainage basin by erosion potential method (epm), using geographic information system (gis). the basin is located in hamedan province, west of iran, in a cold and semi- arid region, with an average annual rainfall of 334mm. the study ar...
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