| dc.description.sponsorship | Abstract
In this study we carried out one of the most important features of the earth declines which accused by the water erosion from the geographical view that the dried and semidried areas suffered from .and this leads to the losses of large areas of lands which is called the (gully erosion) in Wadi Tanmlow basins in the southern submountain of Al-Jabal Al-Akhdar that located between the two north latitudes (32: 36. 32:02) and the tow east longtitudes (22:03. 21:38) that measures about (431 km2).
To reveal this reasearch object the study involved six chapters, where the practical and methodical frameworks included a general introduction about the farm and pastoral Inds in the dried ad semidried areas and how it is affected by the danger of erosion, in addition to the problems of the study and its assumptions also its importance, and the study area with the justifications of choosing this subject, then the procedures and methodology of the study and finally the related studies of this project.
Also the study sheds the light on the naturanal environmental and human characteristics in the area from the geological and geomorphological aspects and the climate, soil and the plant cover and its geographical distribution in the area and the availabe water sources.
Then the study moved to the most important morphometric characteristic in Wadi Tanmlow basin from its length and formation features and how is the soil formation effected on the natural and chemical characteristics of the soil and made it more amenable to the erosion in that area.
Also the study carried out a general study of the erosion from its kinds and the geographical distribution in the area, where it found that the water erosion is more concentrated and distributed in the declined areas and in the high average rainfall areas which is in the north, but the windy arosion is more concentrated and distributed in the tabulated area and the less average of rainfall as in the south, the different types of the erosions affected badly in the soil in many differant areas of the world
And from the studying of the different agents that effects on the area we found that the location of the area under the shadow of the Al-Jabal Al-Akdar submountain played an important role in giving the area many of the natural features which made it more amanable and effection to the erosion as the rains in its storшу occasionly nature and the declined features and also the soil nature and the plant cover m but these aspects beaing at balance untill the arrival of the human being to the area and using it unsuitably and in a different way against the nature of thr natural plant cover which exaplified in the expanding of the fanm areas in the marginal lands and the early pastoral which leads to decrease the plant cover fisat caused the fast gully erosion in the area, and doesn't use the scientifi methods in making the roads and in setteling the water instriments leads to the gully erosion after removing the plant cover, these gallies continued in in activity by the virtical and lateral fallback which measures about (1.10-1.17m/year), and the most affected suvironments was in the soil losses per year (996.3- 44619 m) and average loss per year (24.9-1115.46 mm/year)
The results of this reosion leads to the depsitions in the building of the water supplies in the area which decrences its stowage rate that reached to (75%) as the study pointed to the necessity of concomitance of keeping and saving and restore the soil and water supplies and also using it at the nature of each area also it is suggested some recommendations that could contribute in solving and decrease this problem in this area. | en |
