Abstract
Since the Caspian seabed is extremely rich in hydrocarbon resources, there arises an urgent problem of dividing the Caspian seabed between the five Caspian littoral states for development and extraction of oil and natural gas. In this paper we provide a final solution to this long-standing problem. It should be said right away that according to the Convention on the Legal Status of the Caspian Sea (Aktau, 2018), the surface and waters of the Caspian are considered common to the ships of all Caspian states, so there is no practical problem of dividing the surface of the Caspian. However, we will still find a (conditional) geometrically fair division of the Caspian Sea surface, not as a purpose but as an intermediate result, and then the orthogonal projection of the obtained division of the sea surface onto the sea bottom will give the desired division of the Caspian Sea bottom. The concept of geometric justice is understood in the sense that a point on the surface ofthe sea belongs, for example, to Iran if and only if this point is closest to the coast of Iran. Thus, although the surface of the Caspian Sea plays a secondary role, we need an algorithm for a geometrically fair division of the sea surface between the five Caspian states. The article presents an algorithm for a geometrically fair division of the Caspian Sea surface between the five Caspian states, using Voronoi – Thiessen polygons. The algorithm is implemented in the QGIS geographic information system. The resulting division of the Caspian Sea is compared with the one officially recognized today. It is pointed out that although geometric justice is basic, superstructural factors (such as economic, natural, financial and geopolitical) are no less important. The geoinformation approach proposed in the paper can be applied to division of any geo-objects.