تركز الأمطار وعلاقته بتدهور الغطاء النباتي الطبيعي في إقليم الجبل الأخضر

Abstract

The most important climate factor in the growth of the natural plant, and determining the degree of their intensity in the Al-Jabil Elkader. And its awareness of the Al-Jabil Elkader. By analyzing some climatic elements in the tow stations of Shhat and Derna in the period (1945-2010), the following results became clear:

1- It emerged from the analysis of the monthly rainfall amounts in the tow stations. Using the vector method, it appears that rainfall is concentrated in the winter season especially in January, which is the coldest month. The percentage of rainfall concentration in this month was (64.1%) in Shhat and Derna it was (65.7%). 2- The period of water surplus that occurs in the winter months, and reaches its maximum in a month with a mount in Shhat (84.3mm) and it reached in Derna (8.9mm). It corresponds to a decrease the temperature reached its lowest level in the same month, which it reached (-1.8 c৹) in Shhat; which corresponded with decreased the sun shining in Shhat (4.7 hour/day). While the period of water deficit had reached to maximum levels during the driest season with a mount to scarcity of (165.2mm) in Shhat and (165.7mm) in Derna. It had also corresponded to higher Temp., with increased a number of shining hours. Plants have a critical to combing activities with unplanned humanity in degradation of natural vegetation cover.

3- It emerged from the application of the (Combier, Ch.) Criterion for the classification of the Mediterranean climate. So, there is an agreement between the increase in the actual value of precipitation, with the amount of monthly rainfall. In Shhat there are cold months, which are December, January, and February are wet months. While the hot, or dry months that start from May to September are very dry months. In Derna, the months of the Winter season, semi-wet months started from July to November and are almost dry, and this corresponds to reduces the actual value of the rainfall and hence reduce vegetation density, which predominates human exploitation with rapid of the degradations occurs.