1 / 13

Prof. Agim Selenica Institute of Hydrometeorology of Albania

Prof. Agim Selenica Institute of Hydrometeorology of Albania. Flood Potential in Albania. ● Floods are a natural phenomenon in Albania. ● Paradoxically, flood is both feared (destructive) and valued. (for the ecosystem of Western Plain of Albania, flood is vital in many respects.

javelar
Download Presentation

Prof. Agim Selenica Institute of Hydrometeorology of Albania

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Prof. Agim SelenicaInstitute of Hydrometeorology of Albania Flood Potential in Albania

  2. ● Floods are a natural phenomenon in Albania ● Paradoxically, flood is both feared (destructive) and valued. (for the ecosystem of Western Plain of Albania, flood is vital in many respects 1. Introduction ● The disadvantages of structural approach and advantages of non-structural approach ● The only long-term solution consists of keeping flood-vulnerable development and uses out of the floodplain ● Maping of flood potential an important non structural measures, which serves also as an inex of the “risk of inundation” of a given territory

  3. ● The hydrographic basin of the rivers of Albania : 43,305 km2 from which 28,748 km2 situated within the state territory of Albania. The rest, which belongs to the catchments of the rivers Drini and Vjosa, is situated in Greece, FYR of Macedonia and Serbia and Montenegro. Annual discharge of this basin 1308 m3/s, or 30l/s.km2 , one of the highest in Europe (fig. 1) 2. Flood potential based on historical records ● The climate of Albania, in general, is Mediterranean. with some degree of continentality. Average annual rainfall:1485 mm,the highest 24 h precipitation oscilate from100 to 420 mm (fig.2)

  4. Fig.2

  5. ● The floods, in general, have a pluvial origin and so they are observed during the period of November-March, when it flows 80-85% of the annual runoff. They are flashy and in the main rivers they traverses the hydrographic network in 8-10 hours ● Based on the information of historical records peak discharges and the volumes of the floods are computed for different return periods. The best fiting is for Pearson III distribution (table 1)

  6. No River – Station Peak discharges Volumes of the floods • (m3/s)(millions m3) • Return period (years) Return period (years) • 50 100 50 100 • Mati – Milot27003400267.393 308.445 • Ishmi - Sukth Vendas1230138077.22083.655 • Erzeni - Ndroq1250 140080.43790.090 • Shkumbini - Rogozhine1900 2200192.146 222.485 • Semani – Ura e Kucit26003000348.488 402.101 • Vjosa - Mifol43505000 768.353 883.164 Table 1 Peak discharges and volumes of the floods with different return periods

  7. ● The specific discharge of the peak - an indicator of the flood potential, which could serve also as a certain “risk of inundation” ● A study was carried out in country scale, in order to estimate the parameters of floods I 54 hydrological stations ● Using these parameters and the floods factors, a multiple regional correlation between them is estimated. The regression equation for the rivers with rain floods: Qm= 0.017 A 0.68 R1.2 H 0.032 I 0.69 where:Qm - mean maximum discharge of the peak in m³/s.km2 A - surface of the catchment area in km , R- maximum 24 h rainfall in mm H - mean altitude of the catchment area in m,I - mean slope of the catchment

  8. ● Using these relations, the specific discharge of the peak (module) is calculated for 50 other rivers of the country, with the surface from 100 to 400 km2 ● With these values of the peak specific discharges a map of the flood potential for the country is designed (fig.3) As an index of the flood potential the standard specific discharge of the peak (module) is chosen, which corresponds to a return period of 100 years and a surface of the catchment area of 100 km2 ● The standard module is calculated by the formula 3, established for the Albanian territory: q(100, 1% ) = q(A, 1% ) (A/100)-0.355 where: q(100, 1% ) is the module for a standard catchment surface of 100 km2 and an exceeding probability of 1% and q(A, 1% ) the module of a certain catchment area with a surface of A and the exceeding probability of 1%. (Fig.4)

  9. Fig. 3

  10. Flood Zone Low Moderate Considerable High Extreme Fig.4 Flood Potential Map 100 Years Return Period

  11. 3. Main conclusions ● The highest 24 h precipitation oscilate from 100 to 420 mm the highest 24 h precipitation oscilate from 100 to 420 mm ● The best fiting was found for Pearson III distribution ● The map of flood potential shows that the values of the maximum module varie too much in Albania (from 2 to 10 m³/s.km2) ● The highest risk of inundation is for Western Plain of Albania (fig. 5)

  12. Rivers Lakes Flooded Area Fig. 5 Flood Risk Map 100 Years Return Period

More Related