Sand Mining Pool Eutrophication (Vale do Paraíba, São Paulo, Brazil): Preliminary Assessment

M.R. Aquino-Silva (1), P.R. C. Leone (2), E.J.B.Bastos (1)(1) Instituto de Pesquisa e Desenvolvimento, Univap, Shishima Hifumi Av., 2911 - São José dos Campos, SP, Brazil

(2) Faculdade de Engenharias, Arquitetura e Urbanismo, Univap, Shishima Hifumi Av., 2911São José dos Campos, SP, Brazil (+55) 12 39471101 – mregina@univap.br; prcleone@gmail.com; ebbastos@univap.br

Introduction The historical process of land occupation has been considered a predatory nature that resulted in the destruction of much of the original vegetation of most

regions in the state of Sao Paulo and Brazil [1]. The extraction of sand although necessary, move the regional economy and it is very important for growth in

relation to the needs of construction inputs, is an extremely degrading as regards the change of landscape quality, soil formation and exposure of the

groundwater. After the extraction, the region inherits immense excavations flooded with little or no biodiversity. The water founded inside may suffer process

of eutrophication. This process occurs mainly by enrichment of water with nutrients, which include the nitrogen and phosphorus. The aim of this study is to

identify the main parameters that determine the eutrophication of sand mining pool and propose actions to minimize this process.

Results

The water samples collection points The soil samples collection points

Water physical chemical parameters

Parameters

A1 A2 A3 A4

pH 6,0 6,1 7,0 6,1

OD (mg/L) 0,13 0,18 0,17 0,18

Temp (ºC) 17 19 19 19

Nitrite (mg/l)

5,43 6,83 10,86 22,84

Phosphate (mg/l)

530,33 447,67 112,33 303,00

Amostras de solo

Topographic maps - Drainage area

Climatological water balance

Water analyzes: pH, dissolved oxygen

temperature, nitrite and

phosphate

Soil analyzes: pH, M.O., phosphate and

potassium

Methods

São José dos Campos and Jacarei (SP-Brazil)(S 23° 12" 54' e W 45° 57" 47') - Sand mining pool area - General view

Relationship between rainfall (P), water stored in soil (S) and runoff (Esc)

Changes in concentrations of dissolved oxygen and nitrite in the collection points

Changes in concentrations of phosphate and nitrite in the collection points

Variation of soil chemical parameters in the two sampling points

0

0,020,04

0,06

0,080,1

0,12

0,140,16

0,18

A1 A2 A3 A4

0

5

10

15

20

25

OD (mg/L) Nitrite (mg/l)

0

5

10

15

20

25

0

100

200

300

400

500

600

Nitrite (mg/l) Phosphate (mg/l)

0

10

20

30

40

50

60

70

80

Mo g/dm³ P mg/dm³ K mmolc/dm³ pH CaCl2

S1 S2

0

50

100

150

200

250

Jan Feb Mar April May Jun July Aug Sept Octob Nov Dec

P (mm) Stocking (mm) Esc. (mm)

Water availability in the soil for much of the year (6 months) combined with planaltimetric letter indicates that the area of reforestation is a unit ecologic with

potential instability seen between low to moderate. Thus, some basic precautions to protect the soil, with efficient management of vegetation are essential to

not worsening the current conditions of the area as the exposure to extensive erosion. The water analysis indicated that the floodplain area has a strong

influence in the process of eutrophication through the subsurface infiltration of water retained in this area toward the pit of sand. The main factors contributing

to the lowland area is rich in nutrients are runoff and use the area for grazing

213m

557

557, 50

558

558,80

559

559,50

560

557,20

557,60

561,60

564

Check the drag of organic matter by surface runoff

Topographic map indicating the flow of runoff

Final Considerations

References[1] Hahn, C. M., Silva, A. N.; Oliveira, C.; Amaral, E. M.; Soares, P. V.; Manara, M. Recuperação Florestal: da muda a floresta. Fundação Florestal, 112p., 2004.

Supported by: Fundação Valeparaibana de Ensino

FACULDADE DE ENGENHARIASARQUITETURA E URBANISMO