تبیین و تحلیل کارکرد سازه‌های آبی ایالت آسورستان ساسانی و ارتباط آن با فتح اعراب (651-590 م.)

شاهنشاهان ساسانی برای کنترل قلمرو وسیع خود نیازمند منابع مالی ثابت بودند که یکی از روش‌های تامین آن، ساخت‌وسازه‌های آبی و گسترش کشاورزی بود. ایالت آسورستان به‌دلیل وجود رودهای دجله و فرات محل مناسبی برای اجرای طرح‌های توسعه‌طلبانۀ ساسانیان بود. فرمانروایان ساسانی به ناحیۀ جنوب آسورستان به‌دلیل حاصلخیزی و تراکم جمعیت لقبِ «دل ایرانشهر» را داده بودند. زمین‌های حاصلخیز این ایالت با برخورداری از منابع آبی کافی و به‌وسیلۀ سیاست‌های آبرسانی ساسانیان، کشاورزی این منطقه را رونق بخشیده بود. ساخت شهرهای جدید و توسعۀ سازه‌های آبی در این ایالت، موجب افزایش جمعیت و گسترش زمین‌های زیر کشت گردید که افزایش درآمد مالیاتی دولت را درپی دشت. ازسوی دیگر، سازه‌های آبی ساخته شده، مستلزم نظارت و نگه‌داری ویژه‌ای بود که توسط نیروی انسانی انجام می‌شد؛ هرچند دولت در طرح‌های آبرسانی سرمایه‌گذاری‌های فراوانی کرده بود، ولی عدم نگه‌داری و بازسازی آن‌ها به‌دلیل مشغول‌شدن ایرانیان در جنگ‌ها موجب گسترش تالاب‌ها شد. درواقع رونق اقتصادی، نیروی نظامی و دادگستری ساسانیان در حلقه‌ای به‌هم‌پیوسته با یک‌دیگر قرارداشت که زوال یکی از این سه مولفه می‌توانست نظام شاهنشاهی را سرنگون سازد. این پژوهش با بهره‌گیری از منابع کتابخانه‌ای و روش توصیفی -تحلیلی، به‌دنبال یافتن پاسخی برای این پرسش است که ارتباط بین کارکرد سازه‌های آبی آسورستان و فتح آنجا به‌دست اعراب چگونه بوده است؟ یافته‌های پژوهش براساس داده‌های تاریخی نشان می‌دهند که پس از سلطنت «خسرو پرویز»، مشغول‌شدن ایرانیان در اختلافات داخلی و جنگ‌ها و عدم نگه‌داری و بازسازی سازه‌های آبی، موجب گسترش تالاب‌ها در آسورستان گردید و نواحی مهم کشاورزی توسط سیلاب‌های عظیم ویران شد. ایالت آسورستان که روزی بیشترین درآمد مالیاتی را نصیب ساسانیان می‌کرد، در سراشیبی سقوط قرار گرفت. هم‌بستگی رونق اقتصادی با توان نیروی نظامی ساسانیان، باعث‌شد که زوال یکی، فروپاشی دیگری را درپی داشته باشد.

an examination of the significance of hydraulic structures in the sassanid āsōristān and their connection to the arab conquest (590-651 ad)

abstractthe sasanian emperors heavily relied on a steady stream of financial resources to effectively govern their vast overseas territories. one of the ways they achieved this was through the construction of hydraulic structures and the promotion of agricultural development. the region of āsōristān, situated along the tigris and euphrates rivers, proved to be a strategic area for the sasanian expansionist plans. the rulers of the sasanian empire referred to the southern part of āsōristān as the heart of iranshahr due to its fertile land and high population density. the state’s abundant arable lands, coupled with the implementation of effective irrigation policies by the sasanian rulers, led to a prosperous agricultural sector in the region. the establishment of new cities and the improvement of hydraulic structures further contributed to the growth of the population and the development of arable land, consequently resulting in increased tax revenues for the state. however, man-made water structures necessitated specialized oversight and upkeep by labor. despite significant investments by the government in irrigation projects, these structures tended to deteriorate without proper maintenance, and the absence of enough workers due to chronic wars and failure to rebuild led to the development of the wetlands. the economic prosperity and military might of the sasanian empire were interconnected, and the collapse of either could spell doom for the imperial system. this study aims to explore the relationship between the āsōristān hydraulic structures and the arab conquest using library resources and a descriptive-analytical approach. according to historical records, the research findings indicate that following the rule of khosrow parviz, the participation of iranians in internal conflicts, coupled with the neglect and failure to repair hydraulic systems, led to the expansion of wetlands in āsōristān and the devastation of crucial agricultural areas due to massive floods. the āsōristān region, which used to generate the highest tax revenue for the sasanian empire, experienced a decline. the economic prosperity of the empire was closely tied to its military might, which contributed to the downfall of one aspect that was interconnected with the collapse of another aspect.keywords: the sasanian empire, assyria, ctesiphon, hydraulic constructions, tigris river, the arabs. introductionthe sassanid aimed to establish a strong centralized government to assert their political control over the diverse regions of great iran, which possessed a wide range of climates and geological features. this ambitious goal necessitated a well-organized and stable army supported by crucial financial resources. the economy of the sassanid state heavily relied on agriculture, and the government’s focus on agricultural initiatives and the utilization of excess crops emphasized the importance of hydraulic infrastructure such as bridges, dams, waterways, and aqueducts (gyselen 1997). numerous scholars have highlighted the significant density and abundance of population found in major settlements, along with indications of sophisticated hydraulic systems in mesopotamia. they have also noted that the surplus agricultural output and food resources in this area led to increased financial gains for the state through taxation, ultimately impacting the sassanid economy (simpson 2016: 34–35). the economic prosperity, military power, and legal system of the sassanid empire were interrelated, with the decline of each result in the downfall of the imperial system (morony 1984: 28). special maintenance and surveillance were necessary for the hydraulic plans, and regular dredging of streams was essential to prevent them from filling up (bruner 2014: 175). occasionally, these structures themselves caused damage, such as a dam in the lower kaskar that broke during the reign of qobad (kavad), resulting in the submerge of many arable lands (blazari 1988: 414). water conservation measures were put in place in water-tethered civilizations such as the assyria state to prevent river flooding and ensure provisions (wittfogel 2012: 50. the study aimed to assess the impact of water structures in the sassanid assyrian state and their connection to the muslim arab conquest, considering the disrupted maintenance of the irrigation system during the invasion. questions and research methods: the study question is that what are the effects of both water structures in assyrian state capitalized in ctesiphon and the consequent requirement to maintenance services on the conquest there by arabs? data collection for this study involved extensive use of library resources and followed a descriptive-analytical research approach.importance of researchthe analysis of the sassanid assyrian region is of utmost importance as it served as the iranian imperial capital for a considerable time, encompassing the mesopotamian floodplain and the cities of ctesiphon and seleucia. however, there is a dearth of recorded information regarding the arab conquest of assyria, particularly in relation to irrigation systems and their connection to this event. therefore, researchers from the fields of archaeology and history can explore the use of archaeological data to elucidate the unexplored aspects of this historical period.economic and social conditions in assyriathe southern region of assyria was referred to as the heart of iranshahr by the sassanid rulers due to its land fertility and high population density (christensen 2016: 47). according to adams, there is no doubt that assyria had the highest population during that period (adams 1981: 209). the state’s fertile lands, coupled with ample water resources and effective irrigation policies implemented by the sassanids, contributed to the prosperity of agriculture in the region (daryaee and rezakhani 2018: 79). despite the significant investment made by the state in irrigation projects, these infrastructures tended to deteriorate due to lack of maintenance. the participation of iranians in wars, coupled with the failure to reconstruct these structures, led to the development of wetlands (simpson 2016: 43). additionally, the short reign of shirviyeh (kavad ii) was marked by political and economic turmoil, and the cities of assyria were devastated by the plague, causing the disappearance of more than half or one third of the population, as per another historical account (masoudi 2003, vol. 1: 274). thus, the association of environment and humans for water structures and agriculture was rendered futile (christensen 2016: 81-83). the region’s economy, previously centered around agriculture, suffered significant setbacks prior to the arab invasions (adams 1981: 252). when the first islamic armies arrived in 633 ad, the sassanid empire was already financially weakened due to prolonged wars and the destruction of key agricultural regions by byzantine forces and flooding (donner 1981:172). indeed, the sassanid’s economic prosperity, military might, and legal system were intricately linked and hende, any disruption or weakening of one element within this triad had the potential to lead to the downfall of the entire imperial system (morony, 1984: 28).conclusionsfollowing the reign of khosrow parviz, the involvement of iranians in internal conflicts and the neglect of maintaining and reconstructing water structures resulted in the development of wetlands in assyria and a decline in agricultural production. the once prosperous assyrian state, which used to generate the highest tax revenue for the sassanid empire, experienced a decline. the arab invasion of ctesiphon coincided with this decline, and subsequent events such as wars, floods, and plagues further weakened the iranian resistance. many