Ilave Abaroa (R. Mauri) Abaroa (R. Cosapa) Calacoto (R. Mauri) Ulloma (Desaguadero) Chuquiña (Desaguadero)
0.900 0.900 0.900 0.900 0.900 0.900
0.900 0.900 0.170 0.900
Source: Binational Master Plan, 1993.
- Frost and freezing frequency Frost or freezing is a common event over the whole basin, although its frequency is quite irregular. The less affected area is the Lake Titicaca and its surroundings (including the lower valleys of the Rivers Ilave, Coata, Ramis, Huancané and Huaycha), where the number of frost or freezing days is less than 150 per year. Along the coastline of the Lake Titicaca, the frequency is less than 100 days. This frequency increases in all directions starting from the Lake Titicaca, although in the central strip of the basin to the south there are less than 250 days per year with temperatures below zero. Towards the border of the basin, the frequency increases up to 300 – 350 days per year, especially along the western border. There are very few locations with periods that are completely free from frosts/freezes. Among them are: Isla del Sol with 7 months; Copacabana with 4 months; Puno, Huaraya Moho and Puerto Acosta with 2 months – all of them are near the lake – and Calamarca and Chuquiña, located on the Desaguadero River, with 1 month. The station of Huaraya Moho, near the lake, has recorded the longest period without frosts or freezes. The highest frequency of frosts or freezes occurs in winter (June to August, and in general, may be extended to May and September) while the lowest frequency occurs in summer (December to March). The map shows the distribution of the number of frost/freeze days over the whole basin. See figure 15. Map of frosts and freezing periods (Days per year) [Annex, page 95] Human impact on water resources: - Current land use With reference to the current use of the land in the basin, the following is observed: -
Agricultural and livestock-raising uses cover a total of 48% of the basin (including the aquatic areas). In this regard, 4.4% of the basin is used for crops and 21.7% for grazing, 7% for agriculture and livestock raising and 14.9% for agriculture, forestry and grazing. The largest area used for crops is located in Lake Titicaca basin, while grazing is highest in the Ramis Basin.
See figure 16. Map of current land use in Peru-Bolivia TDPS System [Annex, page 95] -
Forestry use covers barely 3% of the basin. Of this, 2.3% is covered by scrubby bushes, most of them spaced, and only 977 km2 are covered by queñoa (Polylepis) forest.
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The rocky outcrops, sandy and stony grounds represent 33%, that is, one-third of the basins area. However, in most of such areas (in 96.2% of rocky outcrops and 96.4% of sandy and stony grounds) crops and/or grazing are observed, where there are bushy or herbaceous vegetation.