Ali A. Almabruk

Articles

Estimation of Evapotranspiration in Libya under the Impact of Plausible Global Climate Change

Ali A. Almabruk

Geographia Polonica (1997) vol. 70, pp. 25-41 | Full text

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Abstract:

The effects of global warming on reference évapotranspiration are investigated and discussed in this report. There are numerous methods for estimating évapotranspiration in the literature. However, we chose to use two acceptable methods for an arid climate: the "Penman method" proposed by the Food and Agriculture Organisation of the United Nations (FAO), and the second one after Budyko-Zubenok, for the purpose of comparison.The amount of water needed for agriculture with and without climate change is estimated and discussed. A computer program based on Penman's method is used, with the necessary data, provided by a separate computer program. To compare results of different models, two climate scenarios were used in these analyses. The results show that the évapotranspiration will increase from north to south, due to an increase in temperature which is the result of the increase in the content of CO2, as well as of other greenhouse gases in the Earth's atmosphere.

Keywords: water scarcity, climate change, évapotranspiration, Libyan case study

Ali A. Almabruk, Institute of Geophysics, Polish Academy of Sciences ul. Księcia Janusza 64, 01-452 Warszawa, Poland

Reflections on climate variability within selected monthly mean time series in Libya and neighboring countries

Ali A. Almabruk

Geographia Polonica (1995) vol. 65, pp. 51-62 | Full text

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Abstract:

This paper contains some results of long-time series analysis with respect to climate variability and change. The data are the mean monthly air temperature, precipitation and humidity at different stations located in Libya and neighbouring countries. At our disposal were 26 time series of monthly and annual mean values with an average length of ca. 51 years. It is to be hoped that the data are free from any anthropogenic influences.The hypothesis that the mean values or variances are homogeneous has been subject to the falsification procedure of non-parametric tests: the runs test, the Mann-Kendall test for trends in the mean or the variance, Lombard's test of the number of change-points, and the Pettitt change-point test.Appropriate statistical computations led the author to conclude that the climate characterized by the investigated processes of monthly and annual values should be considered unstable.

Keywords: Statistical non-parametric tests, climate change — Libyan case

Ali A. Almabruk, Institute of Geophysics, Polish Academy of Sciences ul. Księcia Janusza 64, 01-452 Warszawa, Poland