Rivers
That is a very good question. If when you say petra you are talking about the narrow gorge or canyon of sandstone walls then yes petra is a landform. The word petra means rock. If you are talking about the tombs and architectural structures like El Dier that were carved out of the rock by ancient civilizations then no petra is not a landform. Landforms are created by various geological forces not by humans.
China
It Creat's Mountains,Dumb people
isthmus
If you want to include all geological features, a Yardang(a sharp-crested ridge carved by wind erosion from soft but coherent deposits) might be considered a "landform".
A landform is a geographic feature of the topography of the Earth's surface. Gas fields are found deep underground and there is usually no direct relationship between the geological structure of the gas field formation and the the surface geology. In other words there is no landform that characterises the presence of gas beneath it. There are however geological conditions/structures that can be identified seismologically that could be likely places to look for gas.
The landform that best describes elevated flat land is a plateau. A plateau is a flat-topped landform elevated above the surrounding area, and it usually covers extensive areas. They are commonly formed by geological processes such as volcanic activity or uplift of the Earth's crust.
That question only makes sense if you mean "long time" in a geological/geomorphological context. ' The slowest rates of landform development are of tectonic processes in the continental crust below the landform in question. The most rapid rates of change are those of erosion of the developed landform. ' However the rates of major geological / geomorphological processes depend on so many variables that really this is a meaningless question - you need to analyse an individual area's own growth and decay in its own right, not make blanket statements as you imply asking for.
What is a landform
no it is not a landform!
Because they realy dont create any prominent geographical or geological feature/landform.
YES! it is landform