Gran Colombia–Peru War was the kernel of Bolívar's grander scheme to unite the former Spanish colonies in Central and South America. Prior to becoming the titular head of Gran Colombia, Bolívar had been, briefly, the president of the newly independent state of Bolivia, his namesake. Bolivia had formerly been a part of the Viceroyalty of the "Rio de La Plata", known as Upper Peru, and, once Bolívar relinquished the presidency of Bolivia to his revolutionary compatriot, Antonio José de Sucre Alcalá, in 1826, the Peruvians saw an opportunity. Early in 1828, Peru launched a campaign against Bolivia to reclaim its former territory and
Water resources management in Peru upper basins, whereas the southern part of the country is particularly prone to droughts. Aside from natural causes, such as El Niño Southern Oscillation, the effects of droughts and floods have been exacerbated by manmade interventions including soil erosion stemming from poor cropping and grazing practices, deforestation, and poor land use-practices. El Niño hits Peru approximately once every seven years and consists of heavy winds and rainfall associated with devastating floods and landslides. In 1997–1998 the costs of damages reached US$2 billion. Droughts severely affect the southern coast, producing agricultural losses as well as limitations on human water consumption. Preventive