Modern impacts on an ancient landscape, the piedmont plain in southwest Turkmenistan Berking, J., Beckers, B., Reimann, T., Pollock, S., & Bernbeck, R. This article is made publically available in the institutional repository of Wageningen University and Research, under article 25fa of the Dutch Copyright Act, also known as the Amendment Taverne. Article 25fa states that the author of a short scientific work funded either wholly or partially by Dutch public funds is entitled to make that work publicly available for no consideration following a reasonable period of time after the work was first published, provided that clear reference is made to the source of the first publication of the work. For questions regarding the public availability of this article, please contact [email protected]. Please cite this publication as follows: Berking, J., Beckers, B., Reimann, T., Pollock, S., & Bernbeck, R. (2017). Modern impacts on an ancient landscape, the piedmont plain in southwest Turkmenistan. Wiley Interdisciplinary Reviews: Water, 4(2), [e1202]. https://doi.org/10.1002/wat2.1202 Focus Article Modern impacts on an ancient landscape, the piedmont plain in southwest Turkmenistan Jonas Berking,1* Brian Beckers,1 Tony Reimann,2 Susan Pollock3 and Reinhard Bernbeck3 The piedmont plain in southwestern Turkmenistan has experienced a millennia- long settlement history despite prevailing arid climates. One of the prerequisites for the various agricultural efforts was irrigation. Most of the water used for irri- gation measures came from the adjacent Kopet Dag mountain chain. This situa- tion 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 pied- mont 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 Lumines- cence and 14-C dating results that add to the understanding of the landscape his- tory 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. © 2017 Wiley Periodicals, Inc. How to cite this article: WIREs Water 2017, 4:e1202. doi: 10.1002/wat2.1202 INTRODUCTION possible through irrigation measures. The area is among the earliest ones in Central Asia where agricul- – he piedmont plain in southwest Turkmenistan tural activities, and hence irrigation, took place.1 3 Tis an arid and nowadays remote area. How- As in many arid environments, agricultural suc- ever, numerous settlement remains in the shape of cess was mainly controlled by the highly variable small mounds (locally called depes) indicate that spatial and temporal availability of water. Despite the area flourished in history and prehistory. For subsistence, these settlements relied on agriculture, these challenges, vast drylands have been culturally raising of animals, and hunting, the first being only highly dynamic areas in which the inhabitants have developed multiple ways to cope with these uncer- 4,5 *Correspondence to: [email protected] tainties. The art of managing drylands and mitigat- 1 ing their risks is of significant interest to many Department of Earth Sciences, Physical Geography, Freie Univer- – sität Berlin, Berlin, Germany studies and applications.6 9 2Netherlands Centre for Luminescence Dating, Soil Geography The special character of the area in focus is its and Landscape group, Wageningen University, Wageningen, The very long and quasi-continuous settlement history Netherlands coupled with its irrigation strategies. Moreover, it is 3Institute for Ancient Near Eastern Archaeology, Freie Universität Berlin, Berlin, Germany a good example of the numerous central Asian riv- erine or oasis landscapes which have been nuclei of Conflict of interest: The authors have declared no conflicts of inter- 10 est for this article. human settlement activities throughout history. This changed during the last century when the fi [Correction added on 16 February 2017, after rst online publica- Soviet regime built the Karakum Canal in the tion: Appendices have been added at the end of the article as these were initially published as Supporting Information.] region, which detaches regional irrigation measures Volume4,March/April2017 ©2017WileyPeriodicals,Inc. 1of20 Focus Article wires.wiley.com/water FIGURE 1 | General climatic setting of Turkmenistan and the surrounding countries. Gray layers depict the annual mean precipitation (data from 1950 to 2000, worldclim.org database). Indicated in italic bold letters are the Koeppen–Geiger climate zones. The red box delineates the area of interest, see also Figure 2. from the dependency on natural water availability the region. The hydrology of these two rivers, the and supply. Meana [Meana (loc. Miana) = name of settlement The study area is characterized by low precipi- and river] and Chacha [Chacha (loc. Çaaça or Chaa- tation and a high amount of insolation (Figure 1). cha) = name of settlement and river], are assumed to Even without any human impact, these dryland eco- be representative for the problems stated above. systems with their sparse or initial vegetation and soil During the fieldwork and informal interviews cover are vulnerable to the impacts of climate with locals in the region in 2011 and 2012, we were change, earthquakes, or floods.9 told that these rivers became ever dryer and their The main question tackled in this study is: how runoff behavior changed within the last decades. In irrigation and management of water supply changed the living memories of local residents, they were once through the long history of the study region, including perennially flowing streams, which at the time con- the major shift that occurred with the construction of tributed the majority of water available for irrigation the Karakum canal. In this sense, the scope of the and drinking purposes. Such a perennial, rather than present study is to combine and discuss data from the current ephemeral, river regime would offer an (1) sediment chronologies, (2) archeological investiga- explanation for the long history of irrigation in the tions, and (3) modern climatic and hydrological data. area. However, in the modern situation the rivers are Much of the analysis and results presented dry for much of the year and deep wells (more than focus on the discharge history of two small rivers in 15 m) no longer reach the groundwater. 2of20 ©2017WileyPeriodicals,Inc. Volume4,March/April2017 WIREs Water Modern impacts on piedmont plain 60°20′E 60°40′E Physical Loess hills Alluvial fan (active) 37°N Alluvial fan (innactive) 37°N Catchment Main streams Elevation (m asl) 0–250 250–500 500–750 750–1000 >1 000 Other N ′ N Sampling site ′ 36°50 Ancient settlements 36°50 Modern settlements Border Street Kilometers 0 5 10 60°20′E 60°40′E FIGURE 2 | Study site map with the main landscape features. Historical Background Kopet Dag.12,13 In some of the excavated settlements, Turkmenistan´s agricultural sector depends on irriga- cereals such as barley or einkorn have been found, tion, as is the case for most of central Asia. Conse- pointing to the earliest agricultural endeavors (Ref 14; quently, access to water plays a major role in its Miller in Ref 15). The earliest approach to irrigation political, economic and social history. The longue may have combined naturally favorable locations durée history of irrigation in the region spans more such as the floodplains of the rivers that emerge from than 8000 years, from its beginnings in the Neolithic the Kopet Dag, with simple ditch and canal construc- 1,3,16–18 through the Tsarist and later Soviet Union rule, tions to raise the soil water content. before the modern state of Turkmenistan emerged in Settlement activity during the Aeneolithic and 1991.11 later Bronze Age is evidenced by sites on the pied- Since more than 90% of Turkmenistan is virtu- mont plain that most probably utilized the same ally uninhabitable desert, major settlements are— schemes of floodwater irrigation, but with increasing today as in the past—bound to locations of water scales. From the fourth millennium onward, these surplus. These locations are the strips along the major settlements grew significantly in size, and large urban rivers and the piedmont region at the Kopet Dag centers such as Altyn Depe and Gonur Depe emerged footslopes, the latter of which is the focus here. The (for the location of Altyn Depe, see Figure 2). Later, earliest examples of settlements date to the Neolithic from the first millennium BCE to the first millennium to early Aeneolithic periods of the late seventh CE, Iron age, Achaemenid, Seleucid, Parthian, and through fifth millennia BCE, the remains of which are Sasanian settlement systems emerged. At least since dispersed over much of the piedmont region of the Sasanian time, the ever growing importance of the Volume4,March/April2017 ©2017WileyPeriodicals,Inc. 3of20 Focus Article wires.wiley.com/water Silk Road, which passed through the plains north of The two rivers in the focus of this study, the the Kopet Dag, must have boosted the local Meana and Chacha, are small dryland rivers, repre- economy.19 sentative of many small streams that emerge from the The last two centuries brought a distinct change higher Kopet Dag Mountains. They show a sharp in irrigation schemes, because the distant and centra- decrease in their velocity when flowing through the lized governments of the Russian Tsarist and later piedmont plain and later into in the Karakum Desert Soviet rule introduced and installed modes and where they desiccate.25 The two streams are each means of water management and large-scale irriga- characterized by a set of conically shaped active and tion plus agricultural planning. This culminated in inactive alluvial fans. Today they are ephemeral and the construction of the longest canal in the world, only carry water during and after the rainy season or the Karakum canal, between 1954 and 1988, which snow melt.1 Their recent wadi beds are several annually redirects approximately 13 km3 of water meters deep and up to 20 m wide.