Damage assessment within the Kathmandu valley’s World Heritage Monument Zones after 2015 Gorkha Earthquake

Kathmandu, the capital city of Nepal experienced a cultural catastrophe in the aftermath of the 2015 Gorkha Earthquake (Mw=7.8) which destroyed hundreds of historical and cultural monuments. Five out of the seven mountain zones within Kathmandu’s UNESCO World Heritage Sites suffered damage ranging from the complete collapse of several temples near Hanumandhoka’s Durbar Square to partial damage at Changu Narayan. This study presents the results of reconnaissance surveys conducted in December 2017 and June 2018 within the Pashupati and Changu Narayan monument zones investigating the plausible causes of damage incurred. Geotechnical assessment of soils reveals the presence of gravelly sand at Pashupati and clayey silt at Changu Narayan. The soil-water retention characteristics and strength parameters of these soil were also obtained in the laboratory. Evidence of rotation and differential settlements in the foundations of the ancient structures was not observed suggesting that soil liquefaction had not taken place at these locations. Structural damage patterns observed at these sites indicated a lack of periodic maintenance and low bending and shear stiffness of the masonry walls of the temples. This study suggests engineering interventions and monitoring systems that could safeguard these structures in the event of future earthquakes

Holocene settlement shifts and paleoenvironments on the Central Iranian Plateau: investigating linked systems

For thousands of years, humans have inhabited locations that are highly vulnerable to the impacts of climate change, earthquakes, and floods. In order to investigate the extent to which Holocene environmental changes may have impacted on cultural evolution, we present new geologic, geomorphic, and chronologic data from the Qazvin Plain in northwest Iran that provides a backdrop of natural environmental changes for the simultaneous cultural dynamics observed on the Central Iranian Plateau. Well-resolved archaeological data from the neighbouring settlements of Zagheh (7170—6300 yr BP), Ghabristan (6215—4950 yr BP) and Sagzabad (4050—2350 yr BP) indicate that Holocene occupation of the Hajiarab alluvial fan was interrupted by a 900 year settlement hiatus. Multiproxy climate data from nearby lakes in northwest Iran suggest a transition from arid early-Holocene conditions to more humid middle-Holocene conditions from c. 7550 to 6750 yr BP, coinciding with the settlement of Zagheh, and a peak in aridity at c. 4550 yr BP during the settlement hiatus. Palaeoseismic investigations indicate that large active fault systems in close proximity to the tell sites incurred a series of large (MW ~7.1) earthquakes with return periods of ~500—1000 years during human occupation of the tells. Mapping and optically stimulated luminescence (OSL) chronology of the alluvial sequences reveals changes in depositional style from coarse-grained unconfined sheet flow deposits to proximal channel flow and distally prograding alluvial deposits sometime after c. 8830 yr BP, possibly reflecting an increase in moisture following the early-Holocene arid phase. The coincidence of major climate changes, earthquake activity, and varying sedimentation styles with changing patterns of human occupation on the Hajiarab fan indicate links between environmental and anthropogenic systems. However, temporal coincidence does not necessitate a fundamental causative dependency

From human niche construction to imperial power: long-term trends in ancient Iranian water systems

This article summarizes the outcome of a workshop sponsored by the Durham University Centre for Iranian Cultural Studies, where papers were presented on the entire chronological range of water management systems in Iran from around 8000 years bc until around 1000 ad. The primary aim was to recognize major research questions that could be used to create an agenda for future studies of ancient water use in the country. In the Durham meeting, it appeared that although the small-scale prehistoric systems probably constituted an example of ‘human niche construction’, the later imperial systems did not. Despite the recognition of occasional irrigation systems of third millennium bc date in the Deh Luran plain by Neely and Wright, as well as perhaps in Khuzestan, there appears to be a general dearth of evidence of Chalcolithic and Bronze Age systems in Iran. However, by the first millennium bc there was a considerable increase in the construction of major water management systems, some of which were, at least as far as the associated evidence suggests, constructed by imperial authorities. All agreed, however, that just because a system appeared large in scale, it was not necessarily a result of imperial management. For the subject of qanats it was argued that not only were they usually built by small-scale societies, but also that there may have been multiple centres of origin; one primary centre being a broad zone of south-east Iran, Pakistan and south-east Arabia