Sand dune - a ridge of sand created by the wind; found in deserts or near lakes and oceans Sand dunes
1. Costal Dunes originate from sand thrown up onto the shore by and is blown away by the wind. 2. Inland Dunes usually exist in the form of ridges, small hills, and knolls found on ancestral lake beds and outwash plains. Types of sand dunes
The principle of the dune fixation techniques is based on reducing the threshold velocity of wind at the dune surface by establishing a pre-planting mechanical and biological systems Sand dune fixation is designed to prevent the movement of sand long enough to enable either natural or planted vegetation to become established Sand dune fixations techniques
Using non living material such as wheat, straw, branches of trees, bamboo, reeds, sorghum stalks, clay, cobblestone, petroleum chemicals and soon to set up barriers on the sand dunes or to cover the surface of the sand dunes is called a mechanical measure or engineering measure for sand dune fixation.
Covering dunes with earth 1Functions Covering dunes with mud 2 Completecover Covering dunes with cobblestone 3 Surface barriers Covering dunes with straw 4 To stabilize sand dunes Covering dunes with emulsified asphalt 5 Mechanical barriers Covering dunes with high polimer 6 Belt cover Belt Covering dunes with straw 7 Standing barriers Densestructure Low standing 8 To heap up blown sand Concealed barrier 9 Windproof Clay barrier 10 structure Earth wall 11 Ventilating High standing straw barrier 12 Structure Hedges or sand trap grate 13 The types of mechanical measures and their functions
the farmland local communities irrigation canals reservoirs transport lines mining areas Preserving the dune vegetation Before planting trees, shrubs or growing grass on some sand dunes, Which areas are suitable for mechanical measures?
The localy found materials commonly used for erecting low fences (hedges/microwindbreaks) are classified in to two groups a. Vegetative material: twings from trees,, grass sheaves, reeds, brushes, palm leaves, etc. emulsified asphalt a. Other substances: Clay, cobblestone, damp soil, oil drums, emulsified asphalt, etc.
Rows of such materials inserted in to the ground are called palisade or microwindbreaks Spreading vegetative materials on the surface of sand are called mulching
To reduce sand transporting capacity of sand diriving wind The sand barriers is not to be buried by the dropped sand So the ventilating sand barrier can act on sand control for a long time and can stop a great deal of sand on the leeward side of the sand barrier. High Standing Barriers
To reduce sand transporting capacity of sand diriving wind The reform, the sand carried by the sand bearing wind will heap up around the sand barriers If the sand is very abundant, dropped sand heigt will be rapidly equal to the height of barrier so the service life of a barrier is very short The low windproof or dense structural barriers should be adopted before the planting of vegetation is started between sand barriers
The clay barrier belongs to the low standing type of sand barrier with windproof structure.In many sandy areas, the clay barrier is set up first before the sandy plants. The effectiveneee of the clay sand barrier for sand- control near farmlands and irrigation canals is also very satisfactory. In the general the clay barrier is set up at lower part of the windward slope of sand dunes
The best season for setting up straw sand barriers are the end of autumn and the earlier of winter. Because the sand is moist in these period, alot of labour can be saved. İf the barrier set up summer or spring, they will be easily destroyed by the wind. Installation of straw barriers
The service life of a mechanical measure is about 3-5 years. They should be maintained often after they are set up. In many cases the effectiviness of sand dune kontrol by plant measures alone is not satisfactory. Therefore, various sand holding plant species should be planted after the mechanical measures, especially straw checks, are set up. In the ensuing years, especially the first 5 years, mechanical and biological measures methods can well be complementary in checking wind and controling sand
Choosing indigenous tree or shrub species for which biological and silvicultural knowledge is available Introducing exotic tree or shrub species only if their suitability for the area has been demonstrated by testing Selecting indigenous or introduced tree or shrub species in reference to the following requirements: -ease of obtaining planting stock, -ease of establishment, -İmmunity to insects and disease, -fast growth, -resistant to drought
Understanding the seasonal rainfall patterns that are critical for tree or shrub species to survive and grow As a general rule, a tree or shrub species can be moved successfully from its home range to another areas of same latitude because of similarity in climate Considering the following necessities to ensure suc c es s ful results; site preparation, when to plant, how to plant, the spacing and arrangement of the plantings, and care after planting
Tamarix ramosissima Tamarix austrmongolica Caragana korskinskii Sophora viciifolia Species for biological measures
Hedysarun scoparim Fisch Mey Elaeagnus angustifolia Bge. Amorpha fruticosa Linn Nitraria tangutorum Species for biological measures
Turkey has different ecosistem due to ıts climate, topography and soil characteristics
Annual Average Precipitation of Turkey: 632 mm (Sensoy, S. et al, 2008)
- In Turkey, Approximately there are 21 611 ha. on Mediterranean coast, 7341 hectares on Black Sea coast and in total, 28 952 ha sand dune areas - Sand dunes are formed around the mouth of rivers and ancient lakes - In Turkey;
Sand dune stabilization works were realised in totally 11.000 hectares area in Turkey.
Sand dunes were very destructive by bruying the fertile agricultural lands, cotton fields, orange orchards and vegetable gardens, inhabited areas and water resources. History of sand dune stabilization practices in Turkey
The first studies on stabilization of coastal dunes (an afforestation on sand dunes) started in 1952-1953 by the Turkish Forest Service. -Large-scale reforestation was particularly used in the 1950s and 1980s. 1966 1965 sand dune stabilization practices (in Turkey)
Konya-karapınar Manisa/ Beyoba Terkos Karasu Sinop Iğdır-aralık Sand Dune stabilization project sites in Turkey
First studies on stablization of costal sand dunes in Turkey were started in1955 by Southwest Anatolia Forest Research Institute and Forestry Faculty to determine mechanical and biological tecniques of sand dune stabilization on the mediterranean and black sea region The Researches On Stablization Of Costal Sand Dunes in Turkey