Juan León

The Andes basins: biophysical and developmental diversity in a climate of change

To understand how agriculture and poverty interact, we analysed water availability, productivity and institutions for the Andes basins. Water limits agricultural productivity in the southern basins but is plentiful in the northern basins where steep slopes or poor land and water management limit productivity. The dominance of small, steep basins results in important upstream–downstream linkages. The greatest challenge to improving the productivity of water in the Andes basins is to regulate water quality better for multiple uses and to negotiate fair and transparent compensation for upstream providers of water-based ecosystem services for the benefits that they provide to downstream users.

Surface Freshwater Storage Variations in the Orinoco Floodplains Using Multi-Satellite Observations

Variations in surface water extent and storage are poorly characterized from regional to global scales. In this study, a multi-satellite approach is proposed to estimate the water stored in the floodplains of the Orinoco Basin at a monthly time-scale using remotely-sensed observations of surface water from the Global Inundation Extent Multi-Satellite (GIEMS) and stages from Envisat radar altimetry. Surface water storage variations over 2003-2007 exhibit large interannual variability and a strong seasonal signal, peaking during summer, and associated with the flood pulse. The volume of surface water storage in the Orinoco Basin was highly correlated with the river discharge at Ciudad Bolivar (R = 0.95), the closest station to the mouth where discharge was estimated, although discharge lagged one month behind storage. The correlation remained high (R = 0.73) after removing seasonal effects. Mean annual variations in surface water volume represented similar to 170 km(3), contributing to similar to 45% of the Gravity Recovery and Climate Experiment (GRACE)-derived total water storage variations and representing similar to 13% of the total volume of water that flowed out of the Orinoco Basin to the Atlantic Ocean.