Water for people.pdf - WHO Thailand Digital Repository

4 6 6 / P I L O T C A S E S T U D I E S : A F O C U S O N R E A L - W O R L D E X A M P L E SLake Titicaca Basin, Bolivia and PeruLAKE TITICACA IS A REGION OF MYSTERY AND LEGEND. Originally inhabitedby the Urus, a race today extinct, it was dominated successively byAymara warlords, Quechuas of the Inca empire and Spanish conquerors.Along its banks flourished the Tihuanacu culture (1500 AC) that left behindimmense megalithic constructions and complex agricultural systems redolent ofan advanced civilization. Before it mysteriously disappeared, its art, culture andreligion had spread throughout the entire Andean region.General ContextLocationAt 14 degrees south, the Andean ridge is divided in two branches:the eastern and western ridges. Between them is a closedhydrological system of approximately 140,000 square kilometres(km 2 ) located between 3,600 and 4,500 metres above sea level(m.a.s.l.). Within that system lie four major basins (see table 21.2):Lake Titicaca (T), Desaguadero River (D), Lake Poopó (P) andCoipasa Salt Lake (S). Desaguadero River is Titicaca’s only outletand flows into Lake Poopó, the overflow from which in turn givesrise to Coipasa Salt Lake. These four basins form the TDPS systemof which the main element, Lake Titicaca, is the largest in SouthAmerica, the highest navigable lake in the world, and, according toInca cosmology, the origin of human life.Major physical characteristicsTopographyThree geographical units can be distinguished in the system:■ the mountain ridge, with altitudes greater than 4,200 m.a.s.l.;■ slopes and intermediate areas, ranging in altitude between4,000 and 4,200 m.a.s.l. with moderate to steep slopes and adense hydrographic network; and■ the high plateau, from 3,657 to 4,000 m.a.s.l., in which Lake Titicacais located. The surrounding area, the most densely populated of thesystem, varies in height from 3,812 to 3,900 m.a.s.l. BetweenTiticaca and Poopó, there is a ridge rising to 1,000 metres abovethe level of the plateau, which is split from west to east by theDesaguadero River. Along the far western edge is a narrow stripTable 21.1: Hydrological characteristics of the Lake Titicaca basinSurface area of the basin 57,293 km 2Annual precipitation702 mm/yearAnnual discharge 281 m 3 /sAnnual potential evapotranspiration652 mm/yearMap 21.2: Basin map5,428 m▲LagunillasLake▲PACIFICOCEAN◆◆▲TiticacabasinTurapata ArapaLake5,640 m▲RamisJuliacaUmayoLakeATacnaCoatalAricaRamsar sitePunotiMap 21.1: Locator mapECUADORPERULakeTiticacabasinPacificOceanCHILEBRAZILBOLIVIAPARAGUAYAtlanticOceanARGENTINASource: Prepared for the World Water Assessment Programme(WWAP) by AFDEC, 2002.LakeTiticacapBiosphere reserveNational parkTDPS systemSub-basinsInternationalboundaryVolcanosSalineCitieslIlaveanoSuchesW e s t e r n M o u n t a i n Rid ge▲◆◆GuaquiDesaguaderobasinMauriAchacachi▲6,520 m▲▲ 6,485 mPucaraniCamataViachaUmalaDesaguaderoCoipasabasinCoipasaLakeCoipasaSalt FlatTuichiZongoLA PAZBeniCoroicoUyuni Salt FlatDoopiEastern MountainLakeUru UruPoópoa PoopóbasinLakePoopóOruroSource: Prepared for the World Water Assessment Programme (WWAP) by AFDEC, 2002.50 kmRidge