الفهرس | Only 14 pages are availabe for public view |
Abstract The country of Libya covers an area of about 1,759,540 square kilometers spanning three climatic zones: the Mediterranean, the semi-desert, and the vast desert zone of the northern Sahara with its sprinkling of oases. The present population in Libya is about 5.6 millions lives mainly in the Mediterranean coastal zone, with a large proportion in its principal Cities Tripoli and Benghazi. The fertile lands of the Jeffara Plain in the northwest of the country, Al Jabal Al-Akhder in the northeast, and the coastal plain east of Sirt, all support a flourishing agriculture, which is dependent upon rainfall. To the south, separated by a strip of semi-desert, the desert is encroaching ever nearer the Gulf of Sirt. Records of rainfall distribution show 500 millimeters falling annually on Al-Jabal Al-Akhder, falling to 150 millimeters in the coastal region around Benghazi and 200-250 millimeters fall annually along the Jebel Nefussa and the western coast. Along the coast of the Gulf of Sirt, the annual rainfall decreases rapidly with distance inland, and south of Jebel Nefussa and Al-Jabel Al- Akhder it similarly diminishes until only a few millimeters are recorded annually at Sarir in the southeast and Sabha in the southwest. In the north of Libya, the demand for water is rapidly increasing, forcing the intense exploitation of groundwater resources, particularly in the fertile lands of the Jeffara Plain in the northwest and Al-Jebel Al-Akhder in the northeast of the country. Al-Jabal Al-Akhdar area is an upland area along the northern coast of north eastern Libya. It is crescent shaped ridge culminating at more than 870 m a.m.s.l, in its central part. The northern flank consisting of step like plateaus bordered by escarpment. The southern flanks are gently dipping towards a depression marked by several large Sebkhas. To the east and mostly to the west, coastal plains are well developed between the foot of the first escarpment and the sea. The development of groundwater has increased rapidly during the past ten years. Most of the water in the Mediterranean coastal zone area in Libya is used for agricultural purposes, which on average accounts for 62% of the groundwater consumption. Domestic water use accounts for 33% of the water supplied, and industrial usage makes up the remaining 5%. However, the rapid increase in groundwater withdrawals has resulted in lowering the piezometric surface, particularly in the north regions of the country. There is suspicion that saline intrusion is occurring along the coast in the north, with upward leakage of poor quality water at points of heavy abstraction elsewhere. In Libya, the situation of water supply has become more problematic, as the population increases rapidly and low rainfall. As a result soon after the discovery of fresh groundwater in the deserts of southern Libya, the local authority adopted and implemented a plan of action to address its water deficit problems, mainly through the implementation of “The Great Manmade River Project” to sustain its economy. The Libyan government began to design and install the hydraulic infrastructure needed to exploit the discovered fresh groundwater to the various demand sites along its Mediterranean coast where the most of the population lives. With the exception of Al- Jabal Al-Akhdar area, which is not considered to be supplied from the Great Manmade River Project, as there is the availability of somewhat water resource. Therefore, there is a need for a comprehensive knowledge and understanding of the 2 groundwater resources in these areas for better strategic water management of such huge projects that underlay the quest for self-sufficiency and national economic prosperity. The quality of groundwater is equally important as the quantity. Assessment of groundwater vulnerability to pollution is necessary for feasibility and development analysis, planning management, and land use decisions. The overall objective of the current study is to evaluate the groundwater quality for agriculture purposes using Geostatistics in selected regions in Al-Jabal Al-Akhdar. The purposes of this assessment are: (1) to evaluate and monitor the status of groundwater quality and assess its suitability for irrigation; (2) to determine the spatial distribution of groundwater quality parameters; (3) to generate a groundwater quality map for the studied area; (4) to proposing of water managements for the low water quality. Also, there is an urgent need to assessment of the groundwater quality for livestock and poultry drinking. |