{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,25]],"date-time":"2026-06-25T20:02:19Z","timestamp":1782417739792,"version":"3.54.5"},"reference-count":2,"publisher":"STEF92 Technology","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,8,15]]},"abstract":"<jats:p>Hydrological droughts are formed by different processes, but how strong and heterogeneous they are, leading to different hydrological droughts characteristics and propagation. Droughts have no distinct starting date, but different methods gives a course of action that may help to identify dry signals and possible, drought conditions for drought early warning and predict to some certain level the magnitude and water required for hydrological drought recovery. We choose hydrological drought indices system that are applicable for Bulgarian economic conjuncture conditions, because of no special expensive licensed software need. Using daily variable threshold method for derive deficit and spatial drought characteristics allow us to identify vulnerable river basins, drought frequency, intensity and hydrological drought duration in the observed catchments. By doing that evaluation and characterization, more effective mitigation schemes can be recommend to benefit hydrological drought management, as well as maps for highlight regional variations and similarities in low flow regimes, drought hazards, vulnerability and risk for local communities and stakeholders (for recovery measures). The central region of our investigation is upper Yantra river basin and its main tributaries.<\/jats:p>","DOI":"10.5593\/sgem2025\/3.1\/s11.16","type":"proceedings-article","created":{"date-parts":[[2025,11,22]],"date-time":"2025-11-22T09:43:57Z","timestamp":1763804637000},"page":"123-132","source":"Crossref","is-referenced-by-count":0,"title":["HYDROLOGICAL DROUGHT FREQUENCY AND CHARACTERIZATION OF THE BULGARIAN YANTRA RIVER HEADWATERS"],"prefix":"10.5593","volume":"25","author":[{"given":"Yordan","family":"Dimitrov","sequence":"first","affiliation":[{"name":"National Institute of Meteorology and Hydrology - Department of Hydrology","place":["Bulgaria"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"3602","reference":[{"key":"ref=1","unstructured":"[1] Tallaksen, L.M., van Lanen H. A. J. (Eds.) 2004. Hydrological Drought. Processes and Estimation Methods for Streamflow and Groundwater. Hydrology and Environmental Hydraulics WIMEK. Development of Water Science, Vol. 48 Elsevier."},{"key":"ref=2","unstructured":"[2] Rossi, G. 2011. Drought Risk for Water Supply Systems Based on Low-flow Regionalisation. \ufffd Ph.D. Thesis, Department of Architecture, Civil Engineering and 130\nSection Hydrology, Water Resources, and Climate Resilience\nhttps:\/\/doi.org\/10.5593\/sgem2025\/3.1\/s11.16\nEnvironmental Sciences University of Braunschweig, Institute of Technology and University of Florence and Faculty of Engineering."}],"event":{"name":"25th SGEM International Multidisciplinary Scientific GeoConference 2025","theme":"Earth and Planetary Sciences","location":"Albena, Bulgaria","acronym":"SGEM2025","number":"25","sponsor":["SGEM WORLD SCIENCE (SWS) Scholarly Society, Austria"],"start":{"date-parts":[[2025,6,29]]},"end":{"date-parts":[[2025,7,6]]}},"container-title":["SGEM International Multidisciplinary Scientific GeoConference\ufffd EXPO Proceedings","25th International Multidisciplinary Scientific GeoConference Proceedings SGEM 2025, Water Resources, Forest, Marine, and Ocean Ecosystems, Vol25, Issue 3.1"],"original-title":[],"deposited":{"date-parts":[[2026,6,25]],"date-time":"2026-06-25T19:29:57Z","timestamp":1782415797000},"score":1,"resource":{"primary":{"URL":"https:\/\/epslibrary.at\/items\/7ae6af04-1c6d-4ab0-90c3-e4ce45d5a37d\/hydrological-drought-frequency-and-characterization-of-the-bulgarian-yantra-river-headwate"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,8,15]]},"references-count":2,"URL":"https:\/\/doi.org\/10.5593\/sgem2025\/3.1\/s11.16","relation":{},"ISSN":["1314-2704"],"issn-type":[{"value":"1314-2704","type":"print"}],"subject":[],"published":{"date-parts":[[2025,8,15]]}}}