Die Karte „Hydrographische Übersicht“ 1:750 000 im „Atlas DDR“

Summary

This article presents the map "Hydrographische Übersicht" at 1:750,000 scale, which is plate 10 of the "Atlas DDR". The map is part of a comprehensive national atlas and was compiled in coordination with the hydrological map (plate 11). The author describes the map elements: watersheds and drainage basins (up to 4th order, covering areas >500 km² with mean discharge >2 m³/s), river network (all perennial streams longer than 2 km, derived from 1:200,000 map), still waters (lakes >100 ha, reservoirs >1 hm³), and a novel element: drainage network density shown as area colors with a seven-class scale, with thresholds from 0.05 to 3.80 km/km². The map also shows canals and water transfers. The article then provides an overview of hydrographic conditions in the GDR. The drainage network reflects the recent water balance and paleogeographic conditions. Subsurface water transit through ancient valley sediments, karst, and fault zones causes deviations between surface and groundwater divides. The network exhibits a duality: southwest of the Baruth urstromtal, it is hierarchically organized; northeast, in young moraine areas, it is irregular with lakes and internal drainage basins. The development of the drainage system is traced from Tertiary to Quaternary, influenced by tectonics, salt dissolution, and glaciation. Ice sheets blocked rivers, creating ice-marginal valleys and new drainage patterns. The final part discusses anthropogenic changes: land drainage, river straightening, mill dams, and modifications for navigation and mining. Examples include the Jäglitz river diversion, draining of wetlands such as Wische and Friedländer Große Wiese, and modern melioration with groundwater regulation.