نتایج جستجو برای: severe erosion of near lands

تعداد نتایج: 21215634  

ژورنال: علوم آب و خاک 2013
آیدا طالبی, , امیرحسین چرخابی, , حسین مصدق, , حمیدرضا پیروان, , علی‌اصغر هاشمی, ,

The Marls are unstable sedimentary formations that contain chemical materials and destructive particles. Marls Erosion processes are very intensive, so different forms of erosion on the marls as badlands are of specific characteristics in marl lands. Hence, recognition of effective characteristics in marls erodibility is necessary to adopt corrective measures and methods. In this research, for ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی - دانشکده ادبیات و زبانهای خارجی 1392

while performance-based language assessment has led to an increased authenticity and content validity in the practice of writing assessment, the reliability of ratings has become a major issue. research findings have shown different reactions by native english speaker (nes) and non-native english speaker (nns) teachers to students’ writings. the focus of this study is on investigating whether i...

More than one-third of the earth is characterized by arid and semi-arid climate and desertification phenomenon in these areas has been intensified in recent decades. This study aims to investigate the trend of desertification using vegetation indices and Iranian Model of Desertification Potential Assessment (IMDPA) in Abarkooh Plain, Yazd province, Iran. The satellite images (Landsat images in ...

2001
J. D. Opsomer Z. Wu R. Cruse T. Isenhart V. Sitzmann T. J. Jacobsen J. Y. Kim C. Botts

This article describes the sampling design, survey methodology and findings of a natural resources survey conducted in the Rathbun Lake Watershed in Southern Iowa in 1999-2000. The goal of the survey was to quantify the erosion from all sources on agricultural lands and the ecological health of streams for each of 61 subwatersheds in the area. A total of 183 plots of approximately 160 acres in ...

2009
Masoud Nasri Sadat Feiznia Mohammad Jafari Hasan Ahmadi

Today, incorrect use of lands and land use changes, excessive grazing, no suitable using of agricultural farms, plowing on steep slopes, road construct, building construct, mine excavation etc have been caused increasing of soil erosion and sediment yield. For erosion and sediment estimation one can use statistical and empirical methods. This needs to identify land unit map and the map of effec...

2004
F. Lynn Carpenter J. Doland Nichols Eduer Sandi

11 12 Abstract 13 14 Our goal was to assess the potential of two exotic and five native tree species in reestablishing trees to degraded land in the 15 humid tropics of southern Costa Rica. Our study site was deforested in the 1950s. Steep topography and high rainfall led 16 subsequently to severe erosion, which exposed nutrient-poor, acid, unproductive subsoil. Our site is typical of many trop...

2007
T. A. QUINE D. E. WALLING X. ZHANG Y. WANG D. E. Walling

Much of the agricultural land in the Central Hills area of the Sichuan Basin is at risk from soil erosion by water. An investigation of rates and patterns of soil erosion on agricultural land near Yanting was undertaken using the caesium-137 technique. Erosion of the upper parts of sloping fields was found to be severe, with rates of the order of 20 to 50 t ha" year". However, infield depositio...

ژورنال: مرتع 2021
Ghoreyshi, Roghayeh, Mofidi Chelan, Morteza, Sheidai Karkaj, Esmaeil,

In this study, the economic evaluation of carbon sequestration in plant biomass and soil under three types of livestock grazing intensity was investigated. Three area under light, medium and high grazing intensities in the Inchehbrun salt lands of Golestan province were selected. Soil and plant samples were taken in a systematic-random method. Three 100 meters length parallel transects were ins...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علوم پایه دامغان 1389

in this thesis, ‎‎using‎‎ ‎concept‎s‎ ‎of‎ ‎wavelet‎s‎ ‎theory ‎‎‎som‎e‎ ‎methods‎‎ ‎of‎ ‎th‎e ‎solving‎‎ ‎optimal‎‎ ‎‎con‎tr‎ol‎ problems ‎(ocps)‎‎. ‎g‎overned by time-delay systems is investigated. ‎th‎is‎ thesis contains ‎tw‎o parts. ‎‎first, the method of obtaining ‎o‎f ‎the‎ ‎‎ocps‎ in time delay systems by linear legendre multiwavelets is ‎ ‎presented‎.‎‎‎‎ the main advantage of the meth...

Gully erosion is the most important water erosion which causes land degradation and imbalance in lands. Land degradation, broken ecological balance of landscapes and sensitive condition of biological resources are among reasons of gully erosion study. This study performed with the goal of determining the topographical threshold of gully erosion and expansion and also predicting sensitive areas ...

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