Assessing Impacts of Caspian Sea Level Catastrophic Rise
on Land Degradation in Gorgan Bay Region, Iran

M. Ownegh

Department of Arid Zone Management
Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
e-mail: mownegh@yahoo.com

Abstract

Abnormal and rapid rise of the Caspian Sea level is a pervasive and complex hazard and threats all coastal vulnerable elements at regional scale. It has been recognized to be an intrinsic part of the coupled process and self-induced hazard, leading to soil salinization and further land degradation. As a result of rapid sea level rise by 2.5 m (-26.5m) during 1978-1995, the extensive areas of the Caspian coasts were flooded and serious ecological and economic damages have been caused to coastal environments and human societies. In this long and continuous cycle of transgression the very low rate  natural desalinization process of ancient sea beds has changed to rapid and complex desertification and caused to intense land degradation through flooding ,ponding, salt water intrusion, water table rising, salinization and affected all coastal zone land use plans by different radius and intensity. In spite of critical uncertainties and eustatic paradox, one of the long term prediction is sea level catastrophic rise up to -22m in 2050, that will threat by high risk all coastal zone environmental elements and projects. Direct and indirect, partial and total risk perspective of gradual or sudden transgression of sea water up to -22 m in the low coastal plain of Gorgan Bay will be diverse and tremendous and cause to a new geo-eco-disaster of dark nature. Relative to sea level of -29 m in 1977, during the recent period of rapid rising (1978-1995) the sea water penetrated more than 5 km in coastal plain and submerged all lands and elements, and triggered the land degradation intensity by 1 to 2 classes. At -22 m as  a high risk scenario  in coming decades, vast area with different human and geo-ecological elements will submerge and sea salt water  frontal desertified area (class IV) extent up to 15 km especially along the Gorgan-Rud and Qara-Su rivers and surrounding low lands. The only logic strategy to solving the chronic and bi-hazard (both sea level rise and fall) problem of the Caspian Sea level mysterious fluctuations and its related physical ,ecological and cultural risks lies on the "Stabilization Strategy" at appropriate level for littoral countries (as -27.5 m) via "Engineering solution" as" Caspian Surgery".