Publicação
A recarga no Sistema Aquífero Condeixa-Alfarelos(O31): processos, zonografia e quantificação
| Resumo: | This dissertation’s main objective is the characterization of the recharge in the Condeixa-Alfarelos Aquifer System (O31) knowing the main recharge processes occurring in the area, designation of the direct recharge areas of the aquifer system and their quantification. It was also carried out a study regarding the superior suspended and unconfined aquifer units overlying the Condeixa-Alfarelos aquifer system, to contribute to the description of the aquifer system and promote sustainable management of local water resources. The quantification of the aquifer recharge was carried out using different estimation methods, which allowed the comparison between different final values. Four different methods were used to estimate the recharge value in the study area: 1) the method of fluctuation of the water table 2) the method of the hole hydrograph; 3) the water balance method, according to Thornthwaite and Mather (1955) or through mathematical operations between maps in ArcGIS 10.2.2. and 4) the chloride balance method. Different recharge estimates were obtained through the application of these different methods. From the groundwater fluctuation method, in an area of similar characteristics and near the study area, a value of 150 to 190 mm per year was obtained for the direct recharge of the upper (suspended and unconfined) aquifer units. From the use of the borehole hydrograph method to identify the most unfavourable and favourable conditions to the aquifer recharge for this specific Condeixa-Alfarelos aquifer system, were obtained values between 1 and 329 mm annually respectively. After obtaining these values, the water balance method was applied according to Thornthwaite and Mather (1955) with final findings of 170 and 210 mm annually for the same aquifer, depending on the type of soils in the area and its capacity of usable water by plants. The gross recharge results obtained by the water balance method through mathematical operations performed in identical grids for the attributes of precipitation, evapotranspiration and surface flow, were between 100 and 200 mm per year. Finally, through the use of the chloride balance method and the chloride analysis data in 4 groundwater quality monitoring stations, values of 80 and 230 mm per year were obtained. |
|---|---|
| Autores principais: | Simões, Rita Isabel Santos |
| Assunto: | Hidrogeologia Recarga Aquífera Sistema aquífero Condeixa-Alfarelos Hidrogeology Aquifer Recharge Aquifer System Condeixa-Alfarelos |
| Ano: | 2018 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso embargado |
| Instituição associada: | Universidade de Coimbra |
| Idioma: | português |
| Origem: | Estudo Geral - Universidade de Coimbra |
| Resumo: | This dissertation’s main objective is the characterization of the recharge in the Condeixa-Alfarelos Aquifer System (O31) knowing the main recharge processes occurring in the area, designation of the direct recharge areas of the aquifer system and their quantification. It was also carried out a study regarding the superior suspended and unconfined aquifer units overlying the Condeixa-Alfarelos aquifer system, to contribute to the description of the aquifer system and promote sustainable management of local water resources. The quantification of the aquifer recharge was carried out using different estimation methods, which allowed the comparison between different final values. Four different methods were used to estimate the recharge value in the study area: 1) the method of fluctuation of the water table 2) the method of the hole hydrograph; 3) the water balance method, according to Thornthwaite and Mather (1955) or through mathematical operations between maps in ArcGIS 10.2.2. and 4) the chloride balance method. Different recharge estimates were obtained through the application of these different methods. From the groundwater fluctuation method, in an area of similar characteristics and near the study area, a value of 150 to 190 mm per year was obtained for the direct recharge of the upper (suspended and unconfined) aquifer units. From the use of the borehole hydrograph method to identify the most unfavourable and favourable conditions to the aquifer recharge for this specific Condeixa-Alfarelos aquifer system, were obtained values between 1 and 329 mm annually respectively. After obtaining these values, the water balance method was applied according to Thornthwaite and Mather (1955) with final findings of 170 and 210 mm annually for the same aquifer, depending on the type of soils in the area and its capacity of usable water by plants. The gross recharge results obtained by the water balance method through mathematical operations performed in identical grids for the attributes of precipitation, evapotranspiration and surface flow, were between 100 and 200 mm per year. Finally, through the use of the chloride balance method and the chloride analysis data in 4 groundwater quality monitoring stations, values of 80 and 230 mm per year were obtained. |
|---|