flow in natural river bends is a complex and turbulent phenomenon which affects the scour and sedimentations and causes an irregular bed topography on the bed. for the reason, the flow hydralics and the parameters which affect the flow to be studied and understand. in this study the effect of bed and wall roughness using the software fluent discussed in a sharp 90-degree flume bend with 40.3cm ...

in this study, scour of mashkid bridge pier located in mashkid river of saravan county has been studied and to measure the scour rate, the numerical model hec-ras 4.0 has been used. upon selection of mashkid river as the case study and whereas the studied zone is important with respect to the climatic conditions and showery monsoon raining and flowing the great and destructive floodwaters, ther...

This study was conducted in oak forests of Ilam province in order to evaluate the morphological characteristics of old trees including diameter at breast height, trunk height, whole tree height, minimum and maximum crown diameter, crown health, crown vitality, crown symmetry, health and form of the trunk, Was investigated. Selection of old trees was performed based on the criteria of DBH and wi...

  In order to Study the quality of diameter at breast height distribution, height and height till the beginning of the crown of Oak trees in un-even aged stands from the collected data of the forestation plan in Shanderman Siyahkesh Guilan province, 367 trees were randomly selected as samples and the diameter, height and the height till the beginning of the crown were analyzed. According to the...

Tree marking can cause changes in forest. This study aimed to assess tree marking operation and to predict its effect on stand structure of Persian ironwood-hornbeam stands at Bahramnia forestry plan, north of Iran. Therefore 98 trees that were marked in compartment 9 of the mentioned forest in 2017 based on selection system and according to the recent laws of Forests, Range and Watershed Manag...

The present investigation was aimed to study the qualitative and quantitative characteristics of Lebanon Oak (Quercus libani Olive.) in Marivan city-kordistan. To investigate the effect of altitude on the qualitative and quantitative characteristics of Lebanon Oak, 108 circular plots of 1000 m2 on three elevation classes of 1400-1600, 1600-1800 and 1800-2000 m were designated. Within each plot,...

Knowledge about the relationship between tree height (H) and diameter at breast height (D) is crucial for forest planning, monitoring, biomass estimation, and forest stands dynamics description. In this study, 20 different height-diameter models were evaluated to estimate accurately the height of the trees of Pinus brutia and Cupressus sempervirens var. horizontalis species in Arabdagh region (...