Este estudo visa à estimativa dos fluxos de calor à superfície a partir de imagens orbitais, com os modelos SEBAL/METRIC e aplicação na modelagem hidrológica, com o modelo SWAT. Para isso, foram utilizados os dados da torre micrometeorológica da Ilha do Bananal, coletados durante os Experimentos do LBA, e os dados pluviométricos e fluviométricos. Os dados utilizados compreendem o período de outubro de 2003 a dezembro de 2006 da sub-bacia do rio Lajeado, localizada na bacia do rio Tocantins- Araguaia no estado do Tocantins. O clima na área de estudo tem sazonalidade bem definida, com períodos chuvosos de outubro a março e secos de abril a setembro. As estimativas a partir dos modelos SEBAL/METRIC variaram em função do tipo de solo, com estimativas coerentes dos fluxos de calor à superfície. Em geral, as estimativas dos fluxos de calor representam uma subestimativa de 10% para todo o período estudado. No entanto, sazonalmente observou-se subestimativas de 17% no período chuvoso e de 35% no período seco. De maneira geral, os resultados da utilização da evapotranspiração estimada por sensores remotos no modelo SWAT foi satisfatória. A assimilação da evapotranspiração a partir de imagens orbitais resultou em valores de COE que variaram de 0,57 a 0,84 com os dados diários e de 0,69 a 0,77 com os dados mensais de vazão. Isto indica melhoria no ajuste do modelo, devido a uma melhoria de 0,27 de COE no dado diário e de 0,08 no mensal. Observou-se ainda, que em termos percentuais a vazão simulada pelo modelo SWAT na bacia do rio Lajeado, após a assimilação dos dados de evapotranspiração, apresentou uma redução no erro, de 13% (superestimativa) para 3% (subestimativa) na vazão diária e de 9% para 7% (subestimativa) na vazão mensal. / This study presents estimate of the heat flow to the surface from orbital images with the models SEBAL / METRIC for use in hydrological modeling with the SWAT model. For this, we used data from micrometeorological tower of Island Bananal, collected during the experiments the LBA, rainfall and hydrological data. The data used is defined for the period October 2003 to December 2006, in the State Tocantins of catchments river Tocantins- Araguaia of the basin river Lajeado. We observed that the climate in the study area is seasonally well-defined with the rainy season from October to March and the dry are from April to September. Estimates from the models SEBAL / METRIC, varied according to soil type, are consistent with estimates of heat fluxes to the surface. In general, estimates of heat fluxes indicated underestimate of 10% for the period studied. However, seasonally there was an underestimates of 17% in the rainy season and of 35% in the dry season. The results of the hydrologic model can be judged satisfactory by the COE values which vary from 0.57 to 0.84 when comparing the streamflow daily data and from 0.69 to 0.77 with streamflow monthly data, with assimilation of evapotranspiration. This indicates benefits to the model, because was observed an improvement of 0.27 in the COE as daily and of 0.08 as monthly. It was also observed that in percentage terms the streamflow simulated by the SWAT model in the basin river Lajeado after the assimilation of evapotranspiration data showed a reduction error of 13% (overestimation) to 3% (underestimate) to the daily flow and from 9% to 7% (underestimate) to the monthly flow.

Este estudo visa à estimativa dos fluxos de calor à superfície a partir de imagens orbitais, com os modelos SEBAL/METRIC e aplicação na modelagem hidrológica, com o modelo SWAT. Para isso, foram utilizados os dados da torre micrometeorológica da Ilha do Bananal, coletados durante os Experimentos do LBA, e os dados pluviométricos e fluviométricos. Os dados utilizados compreendem o período de outubro de 2003 a dezembro de 2006 da sub-bacia do rio Lajeado, localizada na bacia do rio Tocantins- Araguaia no estado do Tocantins. O clima na área de estudo tem sazonalidade bem definida, com períodos chuvosos de outubro a março e secos de abril a setembro. As estimativas a partir dos modelos SEBAL/METRIC variaram em função do tipo de solo, com estimativas coerentes dos fluxos de calor à superfície. Em geral, as estimativas dos fluxos de calor representam uma subestimativa de 10% para todo o período estudado. No entanto, sazonalmente observou-se subestimativas de 17% no período chuvoso e de 35% no período seco. De maneira geral, os resultados da utilização da evapotranspiração estimada por sensores remotos no modelo SWAT foi satisfatória. A assimilação da evapotranspiração a partir de imagens orbitais resultou em valores de COE que variaram de 0,57 a 0,84 com os dados diários e de 0,69 a 0,77 com os dados mensais de vazão. Isto indica melhoria no ajuste do modelo, devido a uma melhoria de 0,27 de COE no dado diário e de 0,08 no mensal. Observou-se ainda, que em termos percentuais a vazão simulada pelo modelo SWAT na bacia do rio Lajeado, após a assimilação dos dados de evapotranspiração, apresentou uma redução no erro, de 13% (superestimativa) para 3% (subestimativa) na vazão diária e de 9% para 7% (subestimativa) na vazão mensal. / This study presents estimate of the heat flow to the surface from orbital images with the models SEBAL / METRIC for use in hydrological modeling with the SWAT model. For this, we used data from micrometeorological tower of Island Bananal, collected during the experiments the LBA, rainfall and hydrological data. The data used is defined for the period October 2003 to December 2006, in the State Tocantins of catchments river Tocantins- Araguaia of the basin river Lajeado. We observed that the climate in the study area is seasonally well-defined with the rainy season from October to March and the dry are from April to September. Estimates from the models SEBAL / METRIC, varied according to soil type, are consistent with estimates of heat fluxes to the surface. In general, estimates of heat fluxes indicated underestimate of 10% for the period studied. However, seasonally there was an underestimates of 17% in the rainy season and of 35% in the dry season. The results of the hydrologic model can be judged satisfactory by the COE values which vary from 0.57 to 0.84 when comparing the streamflow daily data and from 0.69 to 0.77 with streamflow monthly data, with assimilation of evapotranspiration. This indicates benefits to the model, because was observed an improvement of 0.27 in the COE as daily and of 0.08 as monthly. It was also observed that in percentage terms the streamflow simulated by the SWAT model in the basin river Lajeado after the assimilation of evapotranspiration data showed a reduction error of 13% (overestimation) to 3% (underestimate) to the daily flow and from 9% to 7% (underestimate) to the monthly flow.

Este estudo visa à estimativa dos fluxos de calor à superfície a partir de imagens orbitais, com os modelos SEBAL/METRIC e aplicação na modelagem hidrológica, com o modelo SWAT. Para isso, foram utilizados os dados da torre micrometeorológica da Ilha do Bananal, coletados durante os Experimentos do LBA, e os dados pluviométricos e fluviométricos. Os dados utilizados compreendem o período de outubro de 2003 a dezembro de 2006 da sub-bacia do rio Lajeado, localizada na bacia do rio Tocantins- Araguaia no estado do Tocantins. O clima na área de estudo tem sazonalidade bem definida, com períodos chuvosos de outubro a março e secos de abril a setembro. As estimativas a partir dos modelos SEBAL/METRIC variaram em função do tipo de solo, com estimativas coerentes dos fluxos de calor à superfície. Em geral, as estimativas dos fluxos de calor representam uma subestimativa de 10% para todo o período estudado. No entanto, sazonalmente observou-se subestimativas de 17% no período chuvoso e de 35% no período seco. De maneira geral, os resultados da utilização da evapotranspiração estimada por sensores remotos no modelo SWAT foi satisfatória. A assimilação da evapotranspiração a partir de imagens orbitais resultou em valores de COE que variaram de 0,57 a 0,84 com os dados diários e de 0,69 a 0,77 com os dados mensais de vazão. Isto indica melhoria no ajuste do modelo, devido a uma melhoria de 0,27 de COE no dado diário e de 0,08 no mensal. Observou-se ainda, que em termos percentuais a vazão simulada pelo modelo SWAT na bacia do rio Lajeado, após a assimilação dos dados de evapotranspiração, apresentou uma redução no erro, de 13% (superestimativa) para 3% (subestimativa) na vazão diária e de 9% para 7% (subestimativa) na vazão mensal. / This study presents estimate of the heat flow to the surface from orbital images with the models SEBAL / METRIC for use in hydrological modeling with the SWAT model. For this, we used data from micrometeorological tower of Island Bananal, collected during the experiments the LBA, rainfall and hydrological data. The data used is defined for the period October 2003 to December 2006, in the State Tocantins of catchments river Tocantins- Araguaia of the basin river Lajeado. We observed that the climate in the study area is seasonally well-defined with the rainy season from October to March and the dry are from April to September. Estimates from the models SEBAL / METRIC, varied according to soil type, are consistent with estimates of heat fluxes to the surface. In general, estimates of heat fluxes indicated underestimate of 10% for the period studied. However, seasonally there was an underestimates of 17% in the rainy season and of 35% in the dry season. The results of the hydrologic model can be judged satisfactory by the COE values which vary from 0.57 to 0.84 when comparing the streamflow daily data and from 0.69 to 0.77 with streamflow monthly data, with assimilation of evapotranspiration. This indicates benefits to the model, because was observed an improvement of 0.27 in the COE as daily and of 0.08 as monthly. It was also observed that in percentage terms the streamflow simulated by the SWAT model in the basin river Lajeado after the assimilation of evapotranspiration data showed a reduction error of 13% (overestimation) to 3% (underestimate) to the daily flow and from 9% to 7% (underestimate) to the monthly flow.

This research was aimed to evaluate the possibility of using satellite precipitation products (SPPs) and Numerical Weather Prediction (NWP) of precipitation for better hydrologic simulations and flood forecasting in the trans-boundary Chenab River Basin (CRB) in Pakistan. This research was divided into three parts. In the first part, two renowned SPPs, i.e., global precipitation mission (GPM) IMERG-F v6 and tropical rainfall measuring mission (TRMM) 3B42 v7, were incorporated in a semidistributed hydrological model, i.e., the soil and water assessment tool (SWAT), to assess the daily and monthly runoff pattern in Chenab River at the Marala Barrage gauging site in Pakistan. The results exhibit higher correlation between observed and simulated discharges at monthly timescale simulations rather than daily timescale simulations. Moreover, results show that IMERG-F is superior to 3B42 by indicating higher R2, higher Nash–Sutcliffe efficiency (NSE), and lower percent bias (PBIAS) at both monthly and daily timescale. In the second part, three latest half-hourly (HH) and daily (D) SPPs, i.e., 'IMERG-E', 'IMERGL', and 'IMERG-F', were evaluated for daily and monthly flow simulations in the SWAT model. The study revealed that monthly flow simulation performance is better than daily flow simulation in all sub-daily and daily SPPs-based models. Results depict that IMERGHHF and IMERG-DF yield the best performance among the other latency levels of SPPs. However, the IMERG-HHF based model has a reasonably higher daily correlation coefficient (R) and lower daily root mean square error (RMSE) than IMERG-DF. IMERG-HHF displays the lowest PBIAS for daily and monthly flow validations and it also represents relatively higher values of R2 and NSE than any other model for daily and monthly model validation. Moreover, the sub-daily IMERG based model outperformed the daily IMERG based model for all calibration and validation scenarios. IMERG-DL based model demonstrates poor performance among all of the SPPs, in daily and monthly flow validation, with low R2, low NSE, and high PBIAS. Additionally, the IMERG-HHE model outperformed IMERG-HHL. In the third and last part of this research, coupled hydro-meteorological precipitation information was used to forecast the 2016 flood event in the Chenab River Basin. The gaugecalibrated SPP, i.e., Global Satellite Mapping of Precipitation (GSMaP_Gauge), was selected to calibrate the Integrated Flood Analysis System (IFAS) model for the 2016 flood event. Precipitation from the Global Forecast System (GFS) NWP, with nine different lead times up to 4 days, was used in the calibrated IFAS model. This study revealed that the hydrologic simulations in IFAS, with global GFS forecasts, were unable to predict the flood peak for all lead times. Later, the Weather Research and Forecasting (WRF) model was used to downscale the precipitation forecasts with one-way and two-way nesting approaches. It was found in this study that the simulated hydrographs in the IFAS model, at different lead times, from the precipitation of two-way WRF nesting exhibited superior performance with the highest R2, NSE and the lowest PBIAS compared with one-way nesting. Moreover, it was concluded that the combination of GFS forecast and two-way WRF nesting can provide high-quality precipitation prediction to simulate flood hydrographs with a remarkable lead time of 96 h when applying coupled hydrometeorological flow simulation.