The reconstruction of an abandoned historical reservoir network in a continental temperate climate region using a multi-method approach

Reservoirs represent a specific environmental component in many parts of the Earth, especially where water supply is limited. As is the case of the Moldavian hilly area, due to its dryness, the inhabitants created an extensive network of reservoirs since the medieval period, in the proximity of the settlement network. Over time, many dams were abandoned, while others have been relocated with impressive dynamics at a historical scale. In this paper, by analyzing old maps, LiDAR high-res DEMs, ERT surveys, and sediments, we have reconstructed the reservoir network's expansion in the last century at a regional scale and investigated the main geomorphologic characteristics of dams and associated landforms. In Jijia catchment (3386 km2) we found a total number of 1351 dams, of which 832 abandoned. 495 reservoirs were recognized on different topo maps dating from the 20th century, while 337 have been identified on DEMs. Two reservoirs were investigated in detail by field surveys, ERT surveys, profile digging, sediment analysis, and micro-sedimentological study, confirming lacustrine deposits according to the topographic reconstructions based on high-resolution LiDAR DEMs. These sedimentary lacustrine archives can substantially contribute to detailed paleoclimatic, paleohydrologic, and paleovegetation reconstruction in the study area.

Automated summary

Reservoirs serve as an essential environmental component in regions with limited water supply, such as the Moldavian hilly area where an extensive network of reservoirs was established near settlement networks since medieval times. Old maps, LiDAR high-res DEMs, ERT surveys, and sediment analyses were used to study the expansion and geomorphological characteristics of dams in the region. Field surveys and sedimentological studies confirmed lacustrine deposits in two reservoirs, contributing valuable information for paleoclimatic, paleohydrologic, and paleovegetation reconstructions in the study area.