Grand Erg Occidental The mean elevation of the Grand Erg Occidental is about 500 m, on average higher than the elevation of the Grand Erg Oriental, but not as high as the neighboring Tademaït to the southwest. This desolate region is a practically uninhabited area; there are no permanent villages and there are no roads crossing it. Grand Erg Occidental The Grand Erg Occidental (, al-ʿIrq al-Gharbī al-Kabīr), (also known as the Western Sand Sea) is the second largest erg in northern Algeria after the Grand Erg Oriental. It covers an area of approximately . The sand dunes in the erg are formed
ERG theory ERG theory ERG theory is a theory in psychology proposed by Clayton Alderfer. Alderfer further developed Maslow's hierarchy of needs by categorizing the hierarchy into his ERG theory (Existence, Relatedness and Growth). The existence group is concerned with providing the basic material existence requirements of humans. They include the items that Maslow considered to be physiological and safety needs. The second group of needs is those of relatedness – the desire people have for maintaining important interpersonal relationships. These social and status desires require interaction with others if they are to be satisfied, and they align with Maslow's social need