prazeres a., rodrigues s., tavares j., morgado o., castelo-branco m.a., gonçalves m.c
DESCRIPTION
Evaluation of the water quality in the Enxoé river – Eutrophization risk?. Prazeres A., Rodrigues S., Tavares J., Morgado O., Castelo-Branco M.A., Gonçalves M.C. Monotoring water from Ribeira do Enxoé (RE) & Vale de Vargo (VV). How. Why. - PowerPoint PPT PresentationTRANSCRIPT
Prazeres A., Rodrigues S., Tavares J., Morgado O., Castelo-Branco M.A., Gonçalves
M.C.
Evaluation of the water quality in the Enxoé river –
Eutrophization risk?
Collecting regulary water samples & using a automatic sampling station
Streamlets RE and VV supply the Enxoé watershed
How Why
•Monotoring water from Ribeira do Monotoring water from Ribeira do Enxoé (RE) Enxoé (RE) & Vale de Vargo (VV)& Vale de Vargo (VV)
•Use a Piper Diagram to classified the types of waters
•Use a statistic tool PCA (Principal Component Analysis) to analyse physico-chemical parameters.
•PCA was applied to the normalized data to compare the compositional patterns between the analyzed water samples and to identify the factors that influence each one of the streamlets.
IntroductionIntroduction
General characteristics
Enxoé River during dry season
•The Enxoé river basin is included in the basin of the Guadiana River and is located in Serpa Municipality, in Beja District.
•The study area, corresponding to the Enxoé catchment area of the reservoir, has 6080 ha, and an average altitude of about 200 m.
• The study site of Enxoé river is located in a rural area, near the small village of Vale do Vargo, at approximately 40 km from Beja city.
Material & Methods Data Presentation Conclusions
Land use
The dominant land uses in Enxoé basin are olive groves (2740 ha), and agro-forestry of holm-oak (2005 ha). Winter crops, maize and pastures (1050 ha), water (205 ha) and urban area (80 ha) are also important land uses to consider.
Hydro-climatic conditions
•The hydrological regime of the catchment is pluvial and is characterized by a strong interannual and intrannual variation of the discharges.
•The Enxoé basin presents drought mediterranean characteristics, with hot summers, high insolation and high evapotranspiration.
•The annual average precipitation in the basin is about 500 mm, being the interannual distribution of precipitation extremely irregular with more than 80% of the annual total of the precipitation concentrated between October and April. During summer time Enxoé river frequently presents no flow.
•The annual average temperature is about 16°C. The annual reference evapotranspiration varies between 1200 mm and 1300 mm.
Soils characteristics
In the Enxoé catchment, the dominant soils are Luvisols covering 45% (Calcic Luvisols 13%), Cambisols 30%, and Calcisols 15% of the area. (FAO, WRB 2006)
IntroductionIntroduction Material & Methods Data Presentation Conclusions
Catchment Enxoé Main catchment Guadiana Area (km2) 60 Altitude max-min (m) 175-300 Dominant geology Granites, Calcareous and Schists Pedology Luvisols, Cambisols and Calcisols (FAO,
WRB 2006) Dominant and secondary soil occupation
Dominant: Olive groves and Oak tree mediterranean woodland “montado” Secondary: winter crops
Rainfall (mm per year) 500 Valley type Gentle ondulating relief River bed length (km) 9 (from the source to Enxoé dam) Hydrological management
Vegetation Olive trees, Oak trees mediterranean woodland
Mean annual discharge (m3 s-1)
Not measured
Mean discharge in low water period (m3 s-1)
Not measured
Bi-annual flood discharge
Not measured
Hydrological regime Pluvial Catchment population 1000 inhabitants Main cities 1 village Vale do Vargo Waste water treatment station
Yes, but the waste waters are pumped outside Enxoé catchment
Typical Landscape
IntroductionIntroduction Material & Methods Data Presentation Conclusions
Introduction Material & Methods Data PresentationData Presentation Conclusions
•Phosphates are not toxic to people or animals unless they are present in very high levels. Digestive problems could occur from extremely high levels of phosphate.
•In freshwater lakes and rivers, phosphorus is often found to be the growth-limiting nutrient, because it occurs in the least amount relative to the needs of plants.
•If excessive amounts of phosphorus and nitrogen are added to the water, algae and aquatic plants can be produced in large quantities. When these algae die, bacteria decompose them, and use up oxygen.
Eutrophication
IntroductionIntroduction Material & Methods Data Presentation Conclusions
• FertilizersFertilizers Fertilizers generally contain phosphorus in the form of orthophosphate. Phosphate is not very mobile in soil; it tends to remain attached to solid particles rather than dissolving in water. If too much fertilizer is applied, the phosphates are carried into surface waters with storm runoff. Soil erosion of fertilized fields and lawns can also carry a considerable amount of particulate phosphate to streams.
• Animal WasteAnimal Waste Phosphate runoff can be an issue in waters near cattle feedlots, farms, dairies, and barnyards.
• Wastewater and Septic System Effluent Wastewater and Septic System Effluent Organic phosphates are formed primarily by biological processes. They are contributed to sewage by body waste and food residues
• Detergents Detergents Orthophosphates and certain polyphosphates are major constituents of many commercial cleaning preparations
• Forest Fires Forest Fires Forest fires can cause soil erosion, which will release phosphorus bound to soil particles.
• Synthetic Materials Synthetic Materials Organophosphates are commonly used as construction materials, flame retardant and plasticizers. Reduced forms of phosphorus are present in certain synthetic organic chemicals, including some that are used in insecticides.
Factors that can Influence Phosphorus Concentrations in Enxoé Catchment
IntroductionIntroduction Material & Methods Data Presentation Conclusions
Map of Enxoé Catchment
IntroductionIntroduction Material & Methods Data Presentation Conclusions
Monitoring Sites – Ribeira do Enxoé & Vale de Vargo
Sampling and Chemical Analysis (Jan 2010- May 2011)
Photos of different spots of sampling
Samples collect in triplicate
VVRE
REVV
IntroductionIntroduction Material & Methods Data Presentation Conclusions
Automatic Sampling Station
Introduction Material & MethodsMaterial & Methods Data Presentation Conclusions
Parameters Observations
pH •The normal value of pH for sweet waters is between 4 and 9.
Chlorides The sudden change of Chlorine concentrarion in waters is a contamination indicator. The average concentration shoud be comprise between 10 -50 ppm.
Carbonates and hidrogenocarbonates
The hidrogenocarbonate concentration in sweet waters shoud be comprise betwwen 50 e 350 ppm. The carbonates concentration is usually smaller (50ppm).
TSS - total suspended solids
The average values should be situates between 75-300 ppm.
EC- electrical conductivity
Values bigger 2000 microhms/cm should not be use in agricultural
Total P Total phosphorus (TP) is a measure of all the forms of phosphorus, dissolved or particulate, that are found in a sample.
Orthophosphate Orthophosphate is the most stable kind of phosphate, and is the form used by plantstotal phosphate should not exceed 0.05 mg/L (as phosphorus) in a stream at a point where it enters a lake or reservoir, and should not exceed 0.1 mg/L in streams that do not discharge directly into lakes or reservoirs
Introduction Material & MethodsMaterial & Methods Data Presentation Conclusions
Parameters Observations
Ammonium Should not exceeed 10 ppm in waters
Nitrate Should not exceeed 50 ppm in waters
Iron Rivers contain approximately 0.5-1 ppm of iron, and groundwater contains 100 ppm. Drinking water may not contain more than 200 ppb of ironFe+3 + PO4
-3 FePO4 (solid)
Calcium The concentration of the Calcium ion in water should vary between 10-250ppm, but in some cases can achieved 600 ppm.
Mangnesium The concentration of the Magnesium ion in water should vary between 10-100ppm, but in some cases can achieved 600 ppm
Sodium The concentration of the Sodium ion in freshwater should vary between 10-150 ppm, but in some cases can achieved 600 ppm. If the value is superior to 10 ppm it is not not adequate to irrigation waters.
Potassium Rivers generally contains about 2-3 ppm potassium
Dissolved Organic Carbon (DOC)
Concentrations of DOC in undisturbed watersheds generally range from approximately 1 to 20 mg/L carbon
Introduction Material & Methods Data PresentationData Presentation Conclusions
Vale de Vargos
Ribeira do Enxoé
Waters collected in ER and VV are identical, being characterized as calcium or magnesium bicarbonate waters.
Diagrama de Piper
Introduction Material & Methods DataData PresentationPresentation Conclusions
Vale de VargosRibeira do Enxoé
PCA-Principal Component Analysis
•Given a data set described by a set of numerical variables {x1, x2 , ..., xp}, the goal of Principal Components Analysis is to describe this data set with a smaller set of new, synthetic variables. These variables will be linear combinations of the original variables, and are called Principal Components.Quite generally, reducing the number of variables used to describe data will lead to some loss of information. PCA operates in a way that makes this loss minimal, in a sense that will be given a precise meaning.Therefore, PCA may be regarded as a dimensionality reduction technique.SOURCE-www.princeton.edu/~aspremon/OptSPCA.pdf
Introduction Material & MethodsMaterial & Methods Data Presentation Conclusions
•The year was divided in three trimesters (Jan-Feb-Mar, Apr-May-Jun, and Sept-Oct-Nov) and for each trimester was carried out, a Principal Components Analysis (PCA). Using this analysis it was possible to reduce the number of parameters determinant of the behaviour of water quality. •PCA evolved 3 PCs with eigenvalues >1 explaining about 80% total variance.
Introduction Material & Methods Data PresentationData Presentation Conclusions
Rib
eir
a d
o E
nxoé
Rib
eir
a d
o E
nxoé
Projection of the variables on the factor-plane ( 1 x 2)
Active
pH
EC TSS
ALC POC
DOC
Norg
NO3
NH4
NTotal dis
P total
P-PO4
Cl
Ca
Mg Na
K
F e
-1,0 -0,5 0,0 0,5 1,0
Factor 1 : 41,50%
-1,0
-0,5
0,0
0,5
1,0
Factor 2 : 14,98%
1º trimester
Factor 1 Factor 2
pH 0,749504
EC 0,906646
TSS -0,845190
ALC 0,715074
POC -0,862224
DOC 0,708488
Norg
NO3 0,648458
NH4
Ntot diss 0,768605
P total -
P-PO4
Cl
Ca 0,802576
Mg 0,771614
Na 0,754235
K
Fe -0,849477
Projection of the variables on the factor-plane ( 1 x 2)
Active
pH CE
SST
ALC.
COP
COD
Norg. NO3
NH4
NTotal dissol
P total P-PO4
Cl
Ca Mg
Na K
Fe
-1,0 -0,5 0,0 0,5 1,0
Factor 1 : 51,36%
-1,0
-0,5
0,0
0,5
1,0
Fa
cto
r 2
: 1
7,9
1%
Vale
de V
arg
os
Vale
de V
arg
os
Factor 1 Factor 2
pH 0,790803
EC 0,951348
TSS -0,953656
ALC 0,803283
POC -0,947869
DOC 0,847739
Norg
NO3
NH4
Ntot diss 0,840559
P total
P-PO4
Cl 0,845859
Ca 0,951401
Mg 0,936189
Na 0,888367
K
Fe -0,917555
Introduction Material & Methods Data PresentationData Presentation Conclusions
Rib
eir
a d
o E
nxoé
Rib
eir
a d
o E
nxoé Projection of the variables on the factor-plane ( 1 x 2)
Active
pH
EC
TSS
ALC
POC
DOC
Norg
NO3
NH4
NTotal dis
P total
P-PO4
Cl
Ca
Mg
Na
K
F e
-1,0 -0,5 0,0 0,5 1,0
Factor 1 : 35,13%
-1,0
-0,5
0,0
0,5
1,0
Factor 2 : 18,99%
2º trimester
Factor 1 Factor 2
pH 0,835795
EC -0,840030
TSS
ALC -0,788159
POC
DOC
Norg -0,705111
NO3
NH4 -0,716897
Ntot diss 0,801144
P total -0,743783
P-PO4 -0,764558
Cl 0,767565
Ca
Mg 0,752577
Na
K -0,859279
Fe -0,798025
Projection of the variables on the factor-plane ( 1 x 2)
Active
pH
EC
SST
ALC.
POC
DOC
Norg.
NO3
NH4 NTot. dissol
P total
P-PO4
Cl
Ca
Mg
Na
K
Fe
-1,0 -0,5 0,0 0,5 1,0
Factor 1 : 49,84%
-1,0
-0,5
0,0
0,5
1,0
Fa
cto
r 2 : 1
6,5
8%
Vale
de V
arg
os
Vale
de V
arg
os
Factor 1 Factor 2
pH 0,940278
EC -0,872873
TSS 0,923134
ALC
POC
DOC
Norg -0,771963
NO3
NH4 -0,777218
Ntot diss 0,874679
P total -0,851823
P-PO4 -0,915901
Cl
Ca -0,778568
Mg -0,975825
Na
K -0,958703
Fe -0,930680
Introduction Material & Methods Data PresentationData Presentation ConclusionsR
ibeir
a d
o E
nxoé
Rib
eir
a d
o E
nxoé
Projection of the variables on the factor-plane ( 1 x 2)
Active
pH
EC TSS
ALC POC
DOC
Norg
NO3
NH4
NTotal dis
P total
P-PO4
Cl
Ca
Mg Na
K
F e
-1,0 -0,5 0,0 0,5 1,0
Factor 1 : 41,50%
-1,0
-0,5
0,0
0,5
1,0
Factor 2 : 14,98%
3º trimester
Factor 1 Factor 2
pH 0,749504
EC 0,906646
TSS -0,845190
ALC 0,715074
POC -0,862224
DOC 0,708488
Norg
NO3 0,648458
NH4
Ntot diss 0,768605
P total -
P-PO4
Cl
Ca 0,802576
Mg 0,771614
Na 0,754235
K
Fe -0,849477
Projection of the variables on the factor-plane ( 1 x 2)
Active
pH
EC
TSS
ALC.
POC
DOC
Norg.
NO3
NH4
NTot. dissol
P total
P-PO4
Cl
Ca
Mg
Na K
Fe
-1,0 -0,5 0,0 0,5 1,0
Factor 1 : 37,26%
-1,0
-0,5
0,0
0,5
1,0
Fa
cto
r 2 : 1
8,3
7%
Vale
de V
arg
oV
ale
de V
arg
o
Factor 1 Factor 2
pH
EC 0,876281
TSS
ALC 0,907233
POC
DOC
Norg 0,790008
NO3 -0,750137
NH4
Ntot diss 0,746716
P total
P-PO4
Cl 0,961097
Ca
Mg 0,935107
Na 0,947262
K
Fe
Introduction Material & Methods Data Presentation ConclusionsConclusions
•1st trimester - Results were identical in both places PC1 showed high positive loading (>0,70) on EC, Ca, Mg, Na, and Alc, as well as on Fe, POC and the TSS. •PC2 (DOC and Ntdiss) contributes on average with 15.5% of the total variance.
•2nd trimester - Results were identical in both places PC 1accounts for 35.5% and 49.4% respectively of the total variance with high positive loadings between EC, NH4, Norg, Ptotal, P-PO4, K, Fe.•PC2 accounts for 18.9% and 16.6% of total variance, showed moderate loadings between pH and Ntdiss.
•3rd trimester –Results were identical in both places PC1 loading superiors then 80% for EC, Mg, Na e Cl.• PC2 (Norg and Ntdiss).
Observed identical results in RE and VV
•P is the most important parameter in the eutrophization control. •Only in the 2nd trimester its influence was significant. •This was probably owed to stream change due to precipitation.