The erosion of the Sphinx & its surrounding trench show the result of regular heavy rains, not flooding, not wind, not sand. Egypt has not had that kind of climate since 7,000 BC & with the possibility of the Sphinx being buried in sand for much of the time (as it was till recently excavated) it may very well be many thousands of years older than that.
From a detailed study of the highly-weathered limestone rock and the enclosure in which it sits, Robert Schoch, a geologist from Boston University, also concluded that the Sphinx was exposed to prolonged heavy rainfall.
At some point and or currently there is a fourteen-foot layer of silt sediment around the base of the Great Pyramid, a layer which also contained many seashells, and the fossil of a sea cow, all of which were dated by radiocarbon methods to 11,600 B.P. (Before Present) plus or minus 300 years. Records also speak of the fact that before the Pyramid’s outer casing stones were removed, one could see water marks on the stones halfway up the Pyramid’s height, in about the 240-foot level, which is roughly 400 feet above the present Nile level.
As for all three Giza pyramids: Khufu, first on the scene, would naturally have laid claim to the largest pyramid for himself, or the Great Pyramid. His successor, Khafre, now left with only two pyramids to choose from, would have taken possession of the second largest. Menkhare, the last to reign, would have had to be content with the last pyramid available, the smallest of the three. This suggests the Giza pyramids came first, then the Pharaohs ruled, not the other way around.
The relationship of the 3 Giza pyramids & the Nile to the stars of Orions Belt is exact - provided you 'wind back the clock' to circa 10,400BC. The pattern of temples at Ankor Wat makes a match for the layout of the constellation Draco - provided you 'wind back the clock' to circa 10,400BC.
It has also been proven in the past (although not accepted by the mainstream obviously) that painted hieroglyphic inscriptions found in the air space chambers inside the Great Pyramid which include the name of Pharaoh Khufu were forged by Col. Richard Howard-Vyse in 1837. You can read the detailed article regarding this information here: http://www.atlantisrising.com/issue8/ar8pyramids.html
Pharaoh Khufu himself that he only did repair work on the Great Pyramid. The Inventory Stele, found in 1857 by Auguste Mariette just to the east of the Pyramid, dates to about 1500 B.C., but according to Maspero and other experts, shows evidence of having been copied from a far older stele contemporaneous with the Fourth Dynasty. In the Stele, Khufu himself tells of his discoveries made while clearing away the sands from the Pyramid and Sphinx.
The Stele describes how Pharaoh Khufu, "gave to her (Isis) an offering anew, and he built again (to restore, renovate, reconstruct) her temple of stone." From there, the Pharaoh inspected the Sphinx, according to the text, and related the story of how in his time both the monument and a nearby sycamore tree had been struck by lightning. The bolt had knocked off part of the headdress of the Sphinx, which Khufu carefully restored. Egyptologist Selim Hassan, who dug out the Sphinx from the surrounding sands in the 1930's, observed there is indeed evidence that portions of the Sphinx were damaged by lightning, and the mark of ancient repairs is very apparent. Also, he noted, sycamore trees once grew to the south of the monument, which had been dated to a great age.
The Stele then ends with the story of how Khufu built small pyramids for himself and his daughters, wife and family, next to the Great Pyramid. Today, the ruins of three small pyramids are indeed situated on the east side of the monument. Archaeologists have found independent evidence that the southernmost of the three small pyramids flanking the Great Pyramid was in fact dedicated to Henutsen, a wife of Khufu. Everything in the inscription thus matches the known facts.
This negates the theory that Khufu’s son Khafre built the Sphinx. Moreover, the Inventory Steele fails to make any claim that Khufu built the Sphinx or the Great Pyramid, and these unsurprising omissions offers more support to the actual ages of the various structures.