Impact of Land Use changes on Runoff in a Representative ...Impact of Land Use changes on Runoff in...

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Impact of Land Use changes on Runoff in a Representative Basin in the Semiarid of

Pernambuco State Using the SWAT Model

Authors:Robertson V. P. Fontes Júnior PPGEA - UFRPEAbelardo A. A. A. Montenegro PPGEA - UFRPE

• Water scarcity in semi-arid regions of northeastern Brazil is a limiting factor for economic and social development factor.

Semiarid vegetation

Wet season Dry season

Alluvial Valleys

• Irrigation

Objective

• The objective of this work is to investigate theimpact of land use and land cover changes onthe catchment scale using the SWAT model, mainly the desforestation impacts on wateravaliability.

Figure 1. Location Alto Ipanema Basin in Ipanema Basin in the state of Pernambuco

Ipanema watershed

MIMOSO SUB-BASIN

AREA - 194 km²

(SILVA, 2010)

Figura 2. Equipaments installed: weather station(A), Rain gauges HOBO(Onset) (B),

Manual raingages (C), Data logger for levelogger and raingage (D) e Manual Ville de

Paris raingage (E).

A.

B.

C.

D.

E.

• Piezometers• 6 and 10 meters depth• 1 inch (diameters)• Leveloggers – 5 m depth• 10 years manual montlhy• 2 years automatic sub-daily

Climate info

• BSsh (very hot, semiarid) - Köppen, com

• Precipitation – 730 mm total year

• Evapotranspiration – 1683 mm total year

– (MONTENEGRO & MONTENEGRO, 2006)

Climate info

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R (1961-1999) R (2002-2007) PE

MODELLING STUDY

ArcSWAT 2009

SWAT-CUP

WATERSHED DELINIATION

38 sub-basins

270 ha

SRTM – 90 X 90(EMBRAPA – site)

Area - 125 km²

Landuse

WATER-> Açudes (Reservatórios)ARGL -> AgriculturaFRSD -> Mata GaleriaRNGB -> Mata arbustivaSWRN -> Caatinga Arb. AbertaPAST -> PastoFRST – > Caartinga Arb. FechadaURBN – > Áreas Urbanas e Areial

Soils

EMBRAPA (1: 250,000)

•Red argisol•Red-yellow argisol•Cambisol•Regolithic neosol•Litholic neosol•Fluvic neosol•Planosol

• Climate data

– Weather data - Estimate

– Precipitation – raingage – 2000 -> 2012

• SLOPE –

– 2, 5, 10 e 15 %

Parameters

Observed data

• FLOW ALL SUB-BASINS (m²/s)

Hydrology(MONTENEGRO and RAGAB (2010)

Add Parameters

Hydrology

DiCasM – SWAT (ET / PET)

• DiCasM – (Montenegro & Ragab, 2010)

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ET / PET

DiCasM SWAT

Conclusions

• SWAT simulations presented promissingresults;

• Additional efforts are still required for calibration and validation ;

• Evapotranspiration is one of the key variablecontrols hydrologic processes in the basin.

•CNPq

• FINEP

•UFRPE

Thank you!

• DEAGRI - UFRPE

• E-mail : rr_fontes@hotmail.com

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