Modern impacts on an ancient landscape, the piedmont plain in southwest Turkmenistan

The piedmont plain in southwestern Turkmenistan has experienced a millennialong settlement history despite prevailing arid climates. One of the prerequisites for the various agricultural efforts was irrigation. Most of the water used for irrigation measures came from the adjacent Kopet Dag mountain chain. This situation changed with the introduction of the Karakum canal in the middle of the 20th century. The present study evaluates the rich irrigation history of the piedmont plain by investigating two small catchments that drain the eastern ranges of the Kopet Dag. Within their catchments, geomorphological and hydrological analyses were conducted. We present several Optically Stimulated Luminescence and 14-C dating results that add to the understanding of the landscape history from the Pleistocene until modern ages. Moreover, modern climatological and hydrological data were analyzed that show a remarkable drop in runoff from the Kopet Dag since the 1960s. (C) 2017 Wiley Periodicals, Inc.