CAPPSPredicting monthly streamflows and their variability from limited historic records in the Tárcoles watershed, Costa Rica

Holli Nicole Capps

Article first published online: 01 NOV 2018 Journal of Undergraduate Research

DOI: 10.32473/uf%20jur.v20i1.106980

ABSTRACT: Lack of instrumentation in many developing nations makes it difficult to gauge available water resources, an essential part of national socioeconomic wellbeing. Costa Rica is a developing country that has considerable hydrologic data. This study establishes a simple model from limited data to predicted mean monthly flows and their interannual variability at unmonitored locations, within the densely populated Tárcoles watershed of Costa Rica. Relationships between basin area and percentiles of historic flows are derived as a matrix of monthly flow percentiles and averages that can be transformed into potential flows. The station used to validate the model has limited records and contains apparently abnormal flows, nonetheless results indicate considerable success of the model. It could further be refined and tested with more discharge stations. In turn, the modelling approach could be used to predict monthly flows and their variability within the Tárcoles basin as well as other countries where information may be lacking.

Read the full publication at the Journal of Undergraduate Research






KEATINGE – Assessing air temperature trends in Mesoamerica and their implications for the future of horticulture

J.D.H. Keatinge, P. Imbach, D.R. Ledesma, J. d’A. Hughes, F.J.D. Keatinge, J. Nienhuis, P. Hanson, A.W Ebert and S. Kumar

Article first published online: 25 APR 2016 European Journal of Horticultural Science

DOI: 10.17660/eJHS.2016/81.2.1

ABSTRACT: Average air temperature variation in the period 1975–2011 was analyzed across 34 locations from a broad range of Mesoamerican countries with the view to better inform agricultural scientists of what changes to expect up to, and including, the year 2025. Such changes are likely to influence a range of constraints to agricultural and horticultural productivity and therefore ensuring such estimates are as robust as possible is critical to guide breeders, pathologists, entomologists and agronomists in the region effectively. A surprising variability in temperature trends were elicited for the region with increases ranging from the equivalent of 0 to >4°C per hundred years but these trends were not associated with either the geographical positioning of the locations with reference to the Central Cordillera nor were they associated with surface elevation which ranged across sites from 0 to around 2,000 m. In Guatemala, Honduras, El Salvador, Costa Rica and Panama there were sites in each country showing both increases in average air temperature and also sites showing no apparent change over the period 1975–2011. AVRDC and CATIE are promulgating the concept of ‘healthy landscapes’ in Mesoamerica and as such both Centers seek to ensure the greater local production and consumption of nutrient-dense fruit and vegetables which are required to play an important role in combating the pervasive malnutrition still found amongst disadvantaged populations in the region. In addition, the most common vegetable crops of the region presently have yields that are seriously impaired by viruses, diseases and insects. All of these constraints are likely to be further exacerbated by increases in air temperature by 2025. Farmers respond to these growing challenges by spraying increasing amounts of pesticides, often in excessive amounts. Thus to create a more healthy environment for farm families, with less need for spraying, and to relieve crops of the unnecessary burden of diseases and insects which are compromising their natural yield potential – much more investment will be needed into horticultural research and development extension in the region, particularly in building the capacity of regional vegetable scientists in both the public and private sectors. Lines with better heat and drought tolerance and with improved resistance to the common viruses and diseases are already available from AVRDC’s breeders and CATIE’s horticulturalists. More consistent and extensive field testing and seed production of this material at regional hotspot locations will be required to tailor these appropriately to Mesoamerican countries. The means to make such improved seed widely available from local sources to poor farming communities across the region must also be a first priority as current imported seed is both expensive and often ill-adapted.

Read the full publication at European Journal of Horticultural Science.