HR: 1330h
AN: H33A-02    [Abstracts]
TI: Colombian Hydrologic Atlas
AU: * Mesa, O J
EM: ojmesa@unalmed.edu.co
AF: Universidad Nacional de Colombia, Escuela de Geociencias y Medio Ambiente, Medellín, Colombia
AU: Poveda, G
EM: gpoveda@unalmed.edu.co
AF: Universidad Nacional de Colombia, Escuela de Geociencias y Medio Ambiente, Medellín, Colombia
AU: Vélez, J I
EM: jivelezu@unalmed.edu.co
AF: Universidad Nacional de Colombia, Escuela de Geociencias y Medio Ambiente, Medellín, Colombia
AB: Colombia has climatic influences from the Caribbean Sea, the Pacific Ocean and the Atlantic Ocean through the tropical forest of the Amazon basin and the savannas of the Orinoco River. To make things mores complex, the western part is crossed by the Andes Mountains. This work present a systematic effort to estimate the long term averages of the main hydrologic variables using all available information, physical principles and statistical estimation techniques. Topography for instance, is a major control for precipitation, temperature, wind velocity and air humidity. The precipitation field was estimated using a hand made expert map as an input trend for a universal kriging interpolation technique. The estimation of actual evaporation was a major challenge because of the variety of methods and because of conceptual problems related to the long term and regional scale estimation needed, whereas most of the methods are short term point estimation equations of potential evaporation. A careful evaluation of climatic evaporation estimation was carried out, including Turc's, Budyko's and advection aridity methods like Morton's. The results were tested using the long term water balance equation against 200 streamflow gauging stations. Morton's method gave the least estimation error for long term river discharges (average of 20%), with not significant superiority over other methods. Overall, we conclude that the magnitude of errors arises fundamentally from deficiencies in the data and the sparsity of the observations. Besides the long term average fields we estimated floods and low flow fields for different return periods, for the entire river networks of Colombia using scaling ideas and the long-term flow field as the scaling variable. The result is a Hydrologic Atlas of Colombia, in a custom-made geographic information system which extracts basins and integrate the field for any particular site.
UR: http://cancerbero.unalmed.edu.co/~hidrosig/index.php
DE: 1800 HYDROLOGY
DE: 1818 Evapotranspiration
DE: 1821 Floods
DE: 1836 Hydrologic budget (1655)
DE: 1854 Precipitation (3354)
SC: Hydrology [H]
MN: 2005 Joint Assembly