| Signatura:||Non available. |
| Tít.Analit.:|| Climate and water: transboundary challenges in the Americas. Díaz, H.F, Morehouse, B.J. (eds.).|
| Autor:|| Amador-Astúa, Jorge A; Chacón-Bolaños, R.E; Laporte, S. |
| Dirección:|| Universidad de Costa Rica, Centro de Investigaciones Geofísicas y Escuela de Física, San José, CR E-mail: firstname.lastname@example.org. |
| Título: ||
Book Series, Advances in Global Change Research. Climate and climate variability in the Arenal River Basin of Costa Rica. Clima y variabilidad del clima en la Cuenca del Río Arenal de Costa Rica. (ISBN 1-4020-1529-1.)|
| P.imprenta: || p. 317-349. Año 2003. Editorial Dordrecht, Kluwer Academic Publ., NL. |
| Descriptores:|| INTERANNUAL VARIABILITY; EL NI&NTILDE;O SOUTHERN OSCILLATION; ENSO; PRECIPITATION; RAIN; CLIMATE VARIABILITY; CLIMATE; PROJECTS; SOCIOECONOMICS; TOPOGRAPHY; VARIANTS; WATER MANAGEMENT; WATERSHEDS. |
COSTA RICA; CENTRAL AMERICA.
ARENAL WATERSHED; AREA DE CONSERVACION ARENAL TEMPISQUE.
| Resumen: ||This work examines some of the effects of climate and climate variability in the Arenal River Basin of Costa Rica, the site of the largest hydropower complex in the country. The Arenal system, which drains part of the north-central portion of Costa Rica, covers a total area of approximately 493 kmý; it is managed mainly for electric power generation and produces nearly a quarter of the electricity in Costa Rica. Monthly, pentad (5-day means), and daily precipitation data are used to study signals associated with climate and shorter-term atmospheric disruptions in the basin. Although the study area is relatively small, strong spatial and temporal contrasts are found in the precipitation patterns there. A clear distinction in the seasonal distribution of precipitation is observed over short distances (similar to 30-40 km), between the northwestern (NW) lowlands of the basin compared to the southeastern (SE) sector. The former region exhibits a bimodal precipitation distribution, with maxima in June and September-October, and relative minima in July and December-April. The July minimum suggests a weak midsummer drought, or "veranillo," signal. The latter region has practically no dry season, with the highest precipitation values occurring during thesecond part of the calendar year. As is determined by principal component analysis (PCA) of anomalies in monthly precipitation data, the main disruption of the normal pattern of precipitation appears to be related to the El Niño/Southern Oscillation (ENSO) signal in the northwest region, whereas the southeast sector shows a positive correlation with Caribbean low-level wind changes. Some of the latter changes are associated with warm or cold ENSO episodes, which seem to modulate wind intensities of the low-level jet over the Caribbean. Precipitation effects in the basin for selected extreme cases, such as those of Hurricane Mitch and other so-called "temporales," are also analyzed. The importance of these systems as fundamental components of the basin's hydrological cycle is well established. ENSO-related variability of the regional summer circulation (such as that of the low-level jet in the western Caribbean), and the appearance of cases of extremely strong trade winds during the winter circulation,are also important forcing mechanisms for precipitation variability in the basin. In these cases, the interaction between the basin's complex topography, and changes in the flow pattern and intensity, seem to be of fundamental importance for precipitation variance. Some socioeconomic impacts of precipitation variability, as well as a discussion about the potential use of climate variability information for water management in the basin, are presented|