Author name:
زينب ضمد حسن
Supervisor name:
ثائر مظهر فهمي العزاوي | هالة محمد عبد الرحمن
Abstract:
Remote sensing techniques and Geographic information system (GIS) proved the installation of the bands (3,4,7) is the best in the discrimination of Sebkha and their moisture content, which gives the Sebkha dark gray inclined to brown, and gray indicating least moisture; salts take blue color and installation of (3,4,5) is associated with distinguishing the crescent lakes, with installation of (2,3,4) is associated with river islands. The merging between these channels has an advantage in differentiating these phenomena and their geo - morphological relationship with Sebkha.A relationship between the Sebkha areas and the rainy seasons prior to the summer is established which works on assembling salts from the high surrounding areas and its concentration in low basin areas within these plain Lands. This explains the increased marsh spaces in 2013 in each of the Baghdad, Babil, and Wasit governorates with increasing amount of rain during the rainy season 2012 - 2013. The increase of Sabcka areas in Diwanya, Theeqar and Basrah governorates with the increase in rain quantity during the rainy season (2012 - 2013). In addition, corresponding spatial visualization space is performed to indicate the effect on the tectonic shift mechanism on rivers change together with identifying geomorphological processes affecting the increase of Sebkha and crescent lakes and river islands.The results of change detection and calculation of changing spaces in these phenomena declared that the alluvial plain is characterized by the positive change in 2013 by the increase in vegetation cover, water area and positive decrease for each of the Sebkha saline crust area and soil Sebkha, also all the provinces within the alluvial plain have been distinguished to undergo positive change in significant increase of vegetation and water plains in 2013 except the province of Karbala where water area decreased, and as for the Sebkha of salt crust, it underwent a marked negative increase for each of the province of Baghdad in which the changing area, Maysan, and Wasit an area. The large increase in the salt crust Sebkha included Wasit province, followed by Maysan, and then Baghdad. As to the other provinces, the results indicated positive change revealing less spaces of salt crust Sebkha in the summer of 2013. In regard to the Sabcka soil, the change was negative as noticed by the increase in the province of Baghdad, Basra, Karbala, Maysan, and Wasit. As to the other provinces, the Sabcka soil has decreased in varying sizes compared with 2002.The field study proved the accuracy of the results, that have been obtained via geographical techniques, in determining the spatial distribution of the Sebkha sites, which gathered by deled observations with interpretation and statistical digital classification), their locations were identified through a Global Positioning system GPS, in addition to description of geo - morphological phenomena and their interpretation, besides determining the field variables toincrease reliability. Samples of soil, surface and ground water carefully selected were obtained in a fashion to be distributed over a wide geographical area. The field study has shown forms of Sabcka, which has taken local distribution dispersed in the alluvial plain in the low basin areas of the plain, whose level is close from ground water and on both sides of the river, around the temporary and permanent plains, and dried areas. It started to extend near populated areas and planted depressions. The Sabkha dimensions varied from governorate to another, which varied almost from 1 - 15km, and in most cases extends in an intermittent and continuous form in between populated and all agricultural areas along the roads between governorates.The exact geo - morphological forms associated of Sebkha formats have been all determined, such as : Alnbaka, lakes, salt flats, and others of small forms : bridges with brine, mud cracks, salt ponds etc…together with determining vegetation cover associated with Sebkha of Holophyte with their classification and importance, in detail and accurately documented with terrestrial field Photographs. These are to be compared with the levels and standards of the varieties that have been carefully selected to be acquainted with their characteristics and to determine their locations using the Global Positioning System(GPS). Furthermore, geomorphological map related to sabkha is to be prepared.Following the recognition of the properties of the sedimentary and geochemical properties of recent sediments in the sedimentary basin through, analysis of the positive and negative of basic elements and heavy elements of surface and ground water was performed, besides the soil with regard to its distribution and its classification according to maps. These maps indicated that the pollution of the area under study by negative and positive ions of Sodium, Calcium, Magnesium, Sulfates, and Chlorine, rare and heavy ions represented by Nickel, Cobalt, Cadmium, Copper, Lead and Zinc. The chemical analyses indicated that the soil increase in their concentration by amount exceeds Iraqi and international limits. Best method to simulate soil elements concentration was found in the Arc GIS V.10, which is the IDW (Inverse Distance Weighted Spatial analyst interpolate). Laboratory analyses have shown that the water quality is poor due to increased salinity, dispersed small quantities of polluting elements, besides determination of most important environmental traces that cause increase in Sabkha by loss of agricultural land, in addition to loss of pasture areas and animals. Further degradation is in water quality and increased desertification phenomenon and its impact on urban sprawl and deterioration of construction quality, loss of biological varieties and crop structure due to high salinity
