Puerto Galera Watersheds

Puerto Galera WatershedsPuerto Galera Watersheds

• Increasing population• Tourism boom

• Increased demand for resources ( e.g. land, water, food)

• Land use / cover change

• More wastes generated

How can watershed How can watershed modeling help modeling help Puerto Galera?Puerto Galera?

• Assessing water supply potential

• Quantifying material fluxes, also from built-up areas

• Assessing the effect of clear-cutting and deforestation

• Evaluating risk of flash flooding

White Beach

forest 2005deforested 2005 (from 2001)

Puerto Galera Watersheds

Balatero Balatero watershedwatershed

Aninuan Aninuan watershedwatershed

SRTM 3” DEM

Balatero WatershedBalatero Watershed

Present Land Cover

21798, 9%

155513.5,63%

67975.6,28%

All Forest

153380.5, 63%

58932.5, 24%

33017, 13%Interception

Infiltration

Discharge

All Bare

0, 0%

143191.9, 58%

102070.9, 42%

Present LCPresent LC All ForestAll ForestAll BareAll Bare

Balatero WatershedBalatero Watershed Hydrographs

0

5

10

15

20

25

0 50 100 150 200 250 300 350 400

minutes

cms

All Forest

All Bare

Present Land Cover

Present LC

Rapid increase in stream dischargeHigh peak discharge

All ForestAll Bare

Gradual increase/decrease

in stream discharge

More gradual increase/decrease in stream dischargeLow peak discharge

Aninuan WatershedAninuan Watershed

All Forest92719.4,

24%

210190.2,54%

83046.3,22%

All Bare

0, 0%

222042.7,58%

163805.8,42%

Interception

Infiltration

Discharge

Aninuan Watershed Hydrographs

0

5

10

15

20

25

30

35

40

0 50 100 150 200 250

minutes

cms

All ForestAll Bare

Aninuan Watershed

Aninuan Watershed

Anin

uan

Wat

ersh

edAn

inua

n W

ater

shed

All BareAll Bare All ForestAll Forest

Conclusions

• Long-term continuous monitoring reveals discharge dynamics not adequately captured by intermittent grab sampling

• Land cover composition and landscape patterns have significant influence on river/stream discharge

• Watershed modeling is a useful tool for understanding effects of land cover change, among other factors, and hence for supporting decision-making in a coastal environment.

Maraming salamat po!Maraming salamat po!