Rodrigo Proença de Oliveira

Transcrição

1 Hydrology, environment and water resources 2016 / 2017 Flow and runoff estimation Rodrigo Proença de Oliveira

2 The water cycle IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Precipitação Precipitation Precipitação Evapotranspiration Evapotranspiração Evaporação Água retida em depressões Infiltration Infiltração Interception Intercepção Runoff Escoamento superficial (directo) Evaporation Evaporação Flow volume: For a given water year corresponds to the diference between precipitation and evapotranspiration Escoamento: se for avaliado para um ano hidrológico corresponde à diferença entre a precipitação e a evapotranspiração, e integra o escoamento superficial, o subsuperficial e de base Recarga Recharge Escoamento sub-superficial ou intermédio Intermediate flow Escoamento de base Base flow

3 Discharge, flow and runoff Discharge (or flow): Volume of water that passes through a given crosssection per unit of time: Q (m3/s) Common symbol: Q Units: m 3 /s; l/s Flow volume: Volume of water that passes through a given cross-section in a given time period: Q (m3/s) Common symbol: no standard, Units: hm3, dam3 Flow volume from t1 to t2 = න Runoff / Altura do escoamento: Flow volume per unit of area generating it: Common symbol; H Unit: mm Specific discharge / Caudal específico t2 t1 Q t dt The volume of water that flows through a cross-section per unit of time and unit of area which generated it. / Volume de água que atravessa uma secção de um curso de água por unidade de tempo e por unidade de área geradora do escoamento; Units: m 3 /s/km 2 IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, t t

4 Discharge and flow or runoff IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Flow as average discharge (a ficticious average value that represents the volume over a time period) / É usual definir o escoamento em caudal médio (fictício): Average daily discharge (or flow) / Caudal médio diário Average monthly discharge (or flow) / Caudal médio mensal Average annual discharge (or flow) / Caudal médio anual (módulo anual) Average annual discharge (or flow) for a period / Caudal médio plurianual (módulo) Q (m3/s) Average discharge: a ficticious discharge that leads to the same flow volume. t

5 Discharge measurement Discharge measurement is obtained from flow velocity measurements; One needs to: Measure water heights at different verticals and compute the cross-section area; Measure flow velocity at different points; Estimate the average flow velocity at the cross-section; Compute discharge: Q U A It takes from 1 hour (small creek) to 2-5 days (large rivers) to obtain a single discharge measurement; It is hard (long field work) to measure discharge. IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira,

6 Flow velocity distribution IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Over the cross section: Over the vertical profile: V V V 0,8 V V sup 0, 9 sup V V 0.6 USGS assumes: V 0,5 V V

7 Current meter IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira,

8 Discharge measurement IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Discharge estimation from flow velocity measures is a time consuming task. / A estimativa do caudal a partir de medições é uma tarefa morosa. We routinely estimate discharge by an indirect method / As medições de rotina de caudal são realizadas de forma indirecta: Stage measurement / Mede-se a altura hidrométrica. Estimate discharge through a rating curve that relates stage and discharge / Infere-se o caudal por uma relação entre o escoamento e o caudal (curva de vazão) que se assume estável. h(m) h Q(m/s) The hydrometric networks gathers all stations, i.e. cross-sections where stage is continuously measured and discharge measurements are performed to maintain an updated rating curve / A rede hidrométrica reúne o conjunto das estações hidrométricas, onde são realizadas as medições de rotina do caudal. Q

9 Stage measurement at stage scales IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira,

10 Stage measurement at stage scales IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira,

11 Stage measurement at stage meters IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Types of stage meters: Floating device Pressure. Old recording device now they are digital. Sem-fim

12 Rating curve or stage-discharge curve IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, h(m) medição de caudal Q = a(h-h o ) b h o zero de referência a altura hidrométrica a, b parametros a estimar b ~ 1,5 a 3 h o Q(m/s) Hydrometric station should be located at cross-sections with a stable geometry and where the water level is not affected by backwater from downstream infra-structures; Deve-se procurar secções estáveis não afectadas por regolfos; Em secções de fundo móvel é necessário recalcular a curva de vazão com frequência, ou construir descarregadores que tornar invariável a curva de vazão.

13 Caudal (m3/s) Problems when estimating the rating curve IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, EH de Ponte de Cabouco CV ,5 1 1,5 2 2,5 Nível (m)

14 Caudal (m3/s) Problems when estimating the rating curve IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, EH de Gois / /89 20 PBH VML 15 INAG?? 10 INAG 89/ Nivel (m)

15 Exercise IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, The following table presents stage measurements at a given cross section. Using the cross-section rating curve presented below, compute the volume (in m 3 ) and the average flow (m 3 /s) from day 10, 0:00 h, to day 13, 24:00. Q h Q (m 3 /s) h(m) Day (YYMMDD) Hour h(m) : : : : : : :

16 Exercise IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Obtain the rating curve from the data below, assuming the following generic formula: Q = a(h-h o ) b. Use a linear regression analysis to obtain the parameters a, b e h 0 that minimize the error between observed flow and estimated flow. Numa estação hidrométrica obtiveram-se os seguintes pares de valores para a altura hidrométrica e para o caudal que lhe corresponde. Admitindo que a curva de vazão pode ser representada por uma função do tipo Q = a(h-h o ) b, determine os parâmetros a, b e h 0 que minimizam a soma dos quadrados dos desvios entre o caudal medido e o caudal estimado e o coeficiente de correlação linear entre o caudal medido e o caudal estimado. Date h(m) Qobs(m3/s) Date h(m) Qobs(m3/s) Date h(m) Qobs(m3/s)

17 Exercise resolution IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Two ways: User solver or goal seek in Excel to obtain ho, a and b that minimize the sum of the squared errors between the observations and the rating curve values; Transforming the rating curve and the data to a log-log scale and use simple linear regression: By trial and error, look for h o that maximizes R 2 (Old way when Excel was not available; less accurate); Solution: ho = 0,302: a = b = 2.257

18 Daily flow characterization Flow duration curves

19 Flow average duration curve QMD (m 3 /s) The average duration of a discharge value is the average number of days per year when the discharge exceeds that value For a given water year: flow duration curve Q Discharge that is exceeded, on averge, D days per year O QMD Q é em média excedido D dias por ano For a set of water years: flow average duration curve D Duração (dias) IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira,

20 Average annual flow and semi-permanent flow QMD (m 3 /s) Due to the positive statistical assymetry of discharge: The average annual discharge is higher than median flow. The duration of average annual discharge is lower than 180 days. Average flow volume Average annual discharge Módulo Q mediano O módulo excede o caudal mediano Median discharge / Semi-permanent discharge Average flow volume Duração (dias) IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira,

21 Flow average duration curve IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Get daily flow data; Sort dataset from all water years: from max to min; Assign a frequency value to each value: i th value >> Duration (days) = i / N, where N is the number of years in the dataset QMD Ano vals de QMD Ano vals de QMD.. Ano N 365 vals de QMD N x 365 valores + nº anos bissextos Ordem xN QMD Max Min Duração média 1/N i/n xN/N= Duração média

22 WARNING THIS IS NOT THE WAY TO ESTIMATE THE FLOW AVERAGE DURATION CURVE IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Ano vals de QMD Ano vals de QMD.. Ano N 365 vals de QMD Ordenar 365 vals de QMD QMD Ordenar 365 vals de QMD QMD.. Ordenar 365 vals de QMD QMD Média de QMD Média dos valores de QMD que são excedidos em mais de x dias por anos Duração Duração Duração x days Duração The flow average duration curve is different than the average of annual flow duration curves; A primeira indica o valor médio da duração (em dias) que um valor de QMD é excedido por ano; a segunda indica a média dos valores de QMD que são excedidos em mais de um dado número de dias

23 Application of flow duration curves Water supply Q (m 3 /s) Consider the flow average duration curve on the left. Is it possible to satisfy the domestic needs of 50,000 people, if the ecological requirements are 0.7 m 3 /s? Cap = 150 l/hab Q dom = x 150 / 3600 / 24 = 90 l/s Q ecol = 0.7 m 3 /s Q = Q dom + Q ecol = 0.79 m 3 /s Duration = 265 days There are 100 days when it is not possible to satisfy the water needs Duration (days) IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira,

24 Application of flow duration curves Energy production Ecological requirement Q ecol = 0.8 m 3 /s Mini hydropower station Q max = 1.3 m 3 /s Consider a water derivation for energy production at a minipower plant where the design flow is 1.3 m 3 /s. Assuming an ecological requirement of 0.8 m 3 /s, what is the volume available for energy production? Q (m 3 /s) Available volume for energy production Q (m3/s) Duration (days) Qturb (m3/s) Vol (dam3) Vtotal dam3 Volume for ecological requirements Duration (days) IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira,

25 Dimensionless flow average duration curve IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Dimensionless flow curves are useful when one wants to transfer information from a gaged watershed to ungaged watershed. One computes the dimensionless flow average duration curve from one watershed and assumes it holds in another watershed where data is missing

26 Flow duration curve transposition Fonte: Quintela IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, The daily flow variability is greater for low annual average flow; The dimensionless flow duration curve is mainly depended on the average annual flow. One can use the dimensionless curve to transpose the flow duration curve. Procedure: Compute H(mm) (avg annual runoff) from the ungauged watershed Select a dimensionless flow duration curve from a nearby watershed which has a similar H value; Use that selected dimensionless flow duration curve to determine the flow duration curve of the ungaged watershed.

27 Exercise IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Using the flow duration curves proposed by Quintela, estimate the average daily flow (m3/s) that is equaled or exceeded on average 40 days per year, in a watershed with a runoff of 410 mm and an area of 320 km2.

28 Exercise IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, QMD/Q mod Consider a watershed with 400 km 2 that generates an annual average stream flow of 4 m 3 /s. Assuming the flow duration curves on the left, determine the semi-permanent flow and the flow value that is exceeded on average 20 days per year. 2 H=600 mm 1 H=300 mm Duração média (dias)

29 Exercise IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, QMD/Q mod Consider a watershed with 2100 km 2 that generates an average annual flow equal to 40 m 3 /s. Knowing that the semi permanent flow is 25 m 3 /s and using the flow duration curves on the left, determine the average number of days that is not possible to satisfy a water abstraction of 5 m 3 /s. 2 1 H=600 mm H=400 mm H=200 mm Duração média (dias)

30 Annual average runoff estimation Annual average runoff maps Flow records Empirical formulas

31 Mean annual flow / Runoff IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira,

32 IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, 2016 Water balance simplification 32 P+ I x = H + E + S s + S v + S u + E x P = Precipitation over the basin H = Flow at the final crossection E = Evapotranspiration S s = Overland storage variation S V = Soil storage variation S u = Deep aquifer storage variation E x = Man mad water exports R = Mad made imports If there are no significant human interventions / Se forem desprezadas as quantidades de água movimentadas pela ação humana: E x = I x = 0 P = H + E + S S = S s + S v + S u When long period with low variation in basin water storage is considered / Para um intervalo de tempo longo e supondo desprezáveis, ou compensadas, os vários tipos de armazenamento: S s + S v + S u = 0 Then P = H + E For an hydrologic year / Para um ano hidrológico : P = H + E

33 Annual water balance Precipitation Precipitação Real evapotranspiration Evapotranspiração real Runoff Escoamento Gerês: P = 2500 mm; ETR = 800 mm; H = = 1700 mm Alentejo interior: P = 500 mm; ETR = 400 mm; H = = 100 mm IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira,

34 Runoff maps IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Assume a watershed with 200 km 2 marked in the map. What is the average annual runoff generated in the watershed and the annual flow volume in hm 3? H = 150 mm Flow volume = 0.15 x 200 x 10 6 = 30 hm 3

35 Using a nearby stream flow gage (hydrometric station) record IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Flow depends on the watershed characteristics: Area; Precipitation pattern; Topography; Watershed shape and river network characteristics; Soil type; Land use. If we assume that all properties except the area are similar, i.e. the average specific flow (or runoff) is equal in both watersheds, then Q???? B EH A Specific flow (m 3 /s/km 2 ) = Avg discharge / Area of the watershed Runoff (mm) = Flow volume / Area of the watershed AvgFlow B = AvgFlow A x A B / A A

36 Keller, Wundt e Langbein formulas IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Keller (1906): Wundt (1937): H Langbein (1949): b 1 P Keller eq. for central Europe : 2 H b P 2 H b 3 a 1 H 0,942 P a 2 (P 2 P0) 405 H Runoff D Flow deficit, i.e. loss to evapotranspiration. D = P H H (mm) The parameters a 1, a 2, b 1, b 2 and b 3 are dependent on temperature. D P (mm)

37 Turc formula IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Turc (1951; 1954/55) Data from Europa, América, África e Java D L 2 P 0,9 2 P L T 2 P 2 L 0,1 3 0,05 T lim P D L T in ºC and P in mm

38 Quintela regional curves for Portugal IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira,

39 Exercise IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Estimate the annual runoff (in mm and dam 3 ) generated in a watershed in continental Portugal, where soils have low infiltration capacity, the average annual temperature is 12ºC and the average annual precipitation is 850 mm. Use Quintela s regional formulas and the Turc method. The area of the watershed is 280 km 2. Estime o escoamento anual médio (mm) numa bacia hidrográfica de Portugal Continental, com solos dando origem a escoamento elevado, onde a temperatura média anual é 12 ºC e a precipitação anual média é 850 mm. Utilize as relações regionais de Quintela e o método de Turc.

40 Water balance at monthly or daily time step

41 IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, 2016 Water balance simplification 41 P+ I x = H + E + S s + S v + S u + E x P = Precipitation over the basin H = Flow at the final crossection E = Evapotranspiration S s = Overland storage variation S V = Soil storage variation S u = Deep aquifer storage variation E x = Man mad water exports R = Mad made imports If there are no significant human interventions / Se forem desprezadas as quantidades de água movimentadas pela ação humana: E x = I x = 0 P = H + E + S S = S s + S v + S u When long period with low variation in basin water storage is considered / Para um intervalo de tempo longo e supondo desprezáveis, ou compensadas, os vários tipos de armazenamento: S s + S v + S u = 0 Then P = H + E For an hydrologic year / Para um ano hidrológico : P = H + E

42 Water balance simplification given the analysis time step 42 Flow = Prec ET - S Annual analysis S ~ 0 Flow = Prec ET Monthly or daily analysis Flow = Prec ET S Hourly analysis (rainfall event) ET ~ 0 S = Inf, Inf can be estimated by simplified models Flow = Prec Inf

43 Water cycle Land component Precipitação Evaporação Transpiração Escoamento superficial Zona não saturada Zona saturada Infiltração Recarga Escoamento sub-superficial Natural regime: E x -R = 0 P = H + E + S s + S v + S u Evaporação Evaporação Escoamento subterrâneo S = S a + S v + S u P = H + E + S

44 IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, 2016 Hydrologic modeling 44 Types of models Physical models Mathematical models Types of mathematical models Empiric vs conceptual Event vs continuous Lumped vs distributed Deterministic vs stochastic Examples of hydrological models: Thorthwaite-Matter (conceptual, continuous, lumped) Stanford Watershed Model (Linsley, 1960) (conceptual, continuous, lumped) MIKE11 and MIKE-SHE (DHI) (conceptual, continuous, distributed) SWAT (conceptual, continuous pseudo-distributed HEC-HMS (ex HEC1) (conceptual, event, lumped)

45 Hydrologic modeling IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Continuous model vs event model: Escoamento Caudal Evento 1 Evento 2 Evento 3 Evento 4 Simulação contínua Tempo Simulação de eventos Lumped model vs distributed model: Lumped model Novas condições iniciais Novas condições iniciais Distributed model Novas condições iniciais Pseudo-distributed model

46 Hydrologic Mathematical modeling Input variables: Precipitation Potential evapotranspiration Model parameters Output variables HYDROLOGIC MODEL Streamflow Real evapotranspiration Infiltration Why modeling: To study processes; To complete or to validate data; To evaluate situations which cannot be studied in the field. Modeling steps: Calibration; Validation; Application.

47 Modeling steps IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Calibration CALIBRAÇÃO Conjunto de observações 1 Parâmetros do modelo Valores dos parametros Conjunto de observações 1 Variáveis de entrada MODELO Variáveis de saída Validation VALIDAÇÃO Conjunto de observações 2 Valores dos parametros Parâmetros do modelo Variáveis de entrada MODELO Variáveis de saída Aplication APLICAÇÃO Resultados 2 Conjunto de observações 2 Valores dos parametros Parâmetros do modelo Conjunto de observações 3 Variáveis de entrada MODELO Variáveis de saída Resultados 3

48 Conceptual model (Haan, 1972) IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira,

49 Thornthwaite Mather model A single parameter: U max Original sugestion =150 mm, For instance, it requires a soil depth of 5 m and porosity of 0,3 m. Smaller values are expected in PT. U t av = min ETP t P t U t 1 U max ; U t 1) ETP t ETR t = disp P t + U t No need to compute if ETP t P t + U t av if ETP t P t + U t av if P t ETP t if P t ETP t U av Water available in the soil for evapo transpiration; it depends on the water available in the soil (U t-1 ) and on the difference bewteen ETP - P; Real evapotranspiration during timestep t. U max U t = ቊ U t 1 + P t ETR t if P t ETR t U max U t 1 if P t ETR t U max U t 1 Water available in the soil at time t X t = P t ETR t U t U t 1 T t = 0,5 X t + 0,5 X t 1 Hydropower Proença de Oliveira 2016 Excess water at time t, available for aquifer recharge and superficial runoff. The original formulation of the Thorhthwaite-Matter model assumes that the excess water X is evenly distributed between the current time period and the next time period.

50 Hydropower Proença de Oliveira 2016 Thornthwaite Mather model How does U av changes with U t-1 and ETP? U t av = min ETP t P t U t 1 U max ; U t 1) No need to compute if P t ETP t if P t ETP t U av U av vs ETP-P for U max = 150 mm ETP-P U(t-1)=0 mm U(t-1)=40 mm U(t-1)=80 mm U(t-1)=120 mm U(t-1)=150 mm A part of ETP is satisfied by precipitation; The rest of ETP, namely ETP- P is satisfied by the water available in the soil, if possible; The water available in the soil for evapotranspiration, U av, cannot be larger than the soil maximum capacity Umax nor than the soil initial storage.

51 IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Why not assume that X is not evenly distributed between two time steps? Distributed between two time steps, but not evenly T t = α X t + 1 α X t 1 Distributed between an infinite number of time steps T t = α X t + α 1 α X t 1 + α 1 α 2 X t α 1 α n X t n + 1 α n+1 X t n 1 T t = α X t + 1 α T t 1 An alternative formulation for the Thornthwaite-Matter model L is the potential water loss to the soil; equal to the difference (a negative value) between the cumulative precipitation and cumulative evapotranspiration, since the beginning of a dry period (period during which (P-ETP)<0). The higher the L the harder it is to extract water from the soil. L t = ቊ L t 1 + P t ETP t se L t < 0 0 se L t 0 U t = ቐ min U t 1 + P t ETP t ; U max L i Umax e U max se P i ETP i se P i < ETP i

52 Excel setup IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, Data External computation Parameter to calibrate Umax, Hmaxα P T ETP ETR Udisp L UH X QT Qobs Tobs Monthly values: 12 x Number of years Compairison

53 Modelo Thornthwaite Mather: Calibration IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira,

54 Model calibration Parameters: U max, a Which values should we atribute to the parameters? Que valores devem assumir os parâmetros? Reasonable values that lead to a good fit between the model results and the observed results / Valores verosímeis que conduzam a um bom ajustamento dos valores de escoamento calculados e observados. Q, Escoamento Observado Simulação 1 Simulação 2 Auxiliary indicators /Indicadores auxiliares: IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, 2016 tempo MSE 1 N N obs cal T t T t t

55 Model calibration RMS Fix P1, P2 and P3 and vary P4 until a minimum is reached Fixar P1, P2 e P3 e variar P4 até encontrar o mínimo Fix P2, P3 and P4 and vary P1 until a minimum is reached Fixar P2, P3 e P4 e variar P1 até encontrar o mínimo Fix P3, P4 and P1 and vary P2 until a minimum is reached Fixar P3, P4 e P1 e variar P2 até encontrar o mínimo Fix P1, P2 and P4 and vary P3 until a minimum is reached Fixar P1, P2 e P4 e variar P3 até encontrar o mínimo P2 P1 Importante recommendations / Cuidados a ter: To repeat the proccess from diferent starting values / Repetir o processo de calibração a partir de vários pontos iniciais distintos; To assess the physical meaning of the final parameter values / Avaliar o significado físico dos valores obtidos; When possible to estimate parameter values by alternatibe methods / Tentar estimar o máximo número de parâmetros por processos alternativos (e.g. estimar a pela curva de recessão do hidrograma) IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira,

56 Exercise IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, The monthly hydrologic balance of a given watershed shows that for a particular month the precipitation and potential evapotranspiration is 100 mm and 80 mm, respectively. Assuming that the water available for infiltration and runoff is evenly split between these two flow components, compute for that particular month the real evapotranspiration and the infiltration.

57 Exercise IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, The table shows the results of an application of the Thornthwaite-Matter model to a given watershed. Compute the missing values, explaining your reasoning. Mês Prec (mm) ETP (mm) U (t-1) (mm) ETR (mm) T (mm) 1 60 A B C D

58 Water balance at a monthly or daily time step Other models

59 Temez model Conceptual model

60 IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira, 2016 SWAT model 60 SWAT (Soil Water Assessment Tool): Permite a avaliação à escala de uma bacia do impacto das alterações do uso do solo na água, sedimentos e produção agrícola. Modelo contínuo; Modelo fisicamente baseado Modelo distribuído: Bacia; Sub-bacia; HRU. Antecedentes: SWRBB, CREAMS GLEAMS EPIC Inclui QUAL2E

61 SWAT main water fluxes IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira,

62 SWAT model Rainfall, R Evapotranspiration, E a Layer l-1 Lateral flow, Q lat,l-1 Percolation, w Soil water content, SW l-1 perc,l-1 Layer l Lateral flow, Q lat,l Soil water content, SW l Percolation, w perc,l Layer l+1 Lateral flow, Q lat,l+1 Soil water content, SW l+1 Percolation, w perc,l+1... Bottom layer Lateral flow, Q lat,n Root zone / Soil profile Vadose zone w seep Surface runoff, Q surf Recharge, w rchrg w seep Lateral flow Shallow aquifer w revap Return flow, Q gw Pumping, w sh Soil water content, aq sh Deep aquifer Recharge of the aquifer, w deep Pumping, w dp Soil water content, aq dp IST:Hydrology, environment and water resources Rodrigo Proença de Oliveira,