Usefulness of Soil Moisture and Actual Evapotranspiration Data for Constraining Potential Groundwater Recharge in Semiarid Regions

In many Italian regions, and particularly in southern Italy, karst aquifers are the main sources of drinking water and play a crucial role in the socio-economic development of the territory. Hence, estimating the groundwater recharge of these aquifers is a fundamental task for the proper management of water resources, while also considering the impacts of climate changes. In the southern Apennines, the assessment of hydrological parameters that is needed for the estimation of groundwater recharge is a challenging issue, especially for the spatial and temporal inhomogeneity of networks of rain and air temperature stations, as well as the variable geomorphological features and land use across mountainous karst areas. In such a framework, the integration of terrestrial and remotely sensed data is a promising approach to limit these uncertainties. In this research, estimations of actual evapotranspiration and groundwater recharge using remotely sensed data gathered by the Moderate Resolution Imaging Spectrometer (MODIS) satellite in the period 2000–2014 are shown for karst aquifers of the southern Apennines. To assess the uncertainties affecting conventional methods based on empirical formulas, the values estimated by the MODIS dataset were compared with those calculated by Coutagne, Turc, and Thornthwaite classical empirical formulas, which were based on the recordings of meteorological stations. The annual rainfall time series of 266 rain gauges and 150 air temperature stations, recorded using meteorological networks managed by public agencies in the period 2000–2014, were considered for reconstructing the regional distributed models of actual evapotranspiration (AET) and groundwater recharge. Considering the MODIS AET, the mean annual groundwater recharge for karst aquifers was estimated to be about 448 mm·year−1. In contrast, using the Turc, Coutagne, and Thornthwaite methods, it was estimated as being 494, 533, and 437 mm·year−1, respectively. The obtained results open a new methodological perspective for the assessment of the groundwater recharge of karst aquifers at the regional and mean annual scales, allowing for limiting uncertainties and taking into account a spatial resolution greater than that of the existing meteorological networks. Among the most relevant results obtained via the comparison of classical approaches used for estimating evapotranspiration is the good matching of the actual evapotranspiration estimated using MODIS data with the potential evapotranspiration estimated using the Thornthwaite formula. This result was considered linked to the availability of soil moisture for the evapotranspiration demand due to the relevant precipitation in the area, the general occurrence of soils covering karst aquifers, and the dense vegetation.

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Estimating surface runoff and groundwater recharge in an urban catchment using a water balance approach

Hydrogeology Journal ◽

10.1007/s10040-021-02385-1 ◽

2021 ◽

Vol 29 (7) ◽

pp. 2411-2428

Author(s):

Robin K. Weatherl ◽

Maria J. Henao Salgado ◽

Maximilian Ramgraber ◽

Christian Moeck ◽

Mario Schirmer

Keyword(s):

Soil Moisture ◽

Water Balance ◽

Groundwater Recharge ◽

Surface Runoff ◽

Urban Areas ◽

Water Cycle ◽

Land Use Changes ◽

Curve Number ◽

Hydrograph Separation ◽

Balance Approach

AbstractLand-use changes often have significant impact on the water cycle, including changing groundwater/surface-water interactions, modifying groundwater recharge zones, and increasing risk of contamination. Surface runoff in particular is significantly impacted by land cover. As surface runoff can act as a carrier for contaminants found at the surface, it is important to characterize runoff dynamics in anthropogenic environments. In this study, the relationship between surface runoff and groundwater recharge in urban areas is explored using a top-down water balance approach. Two empirical models were used to estimate runoff: (1) an updated, advanced method based on curve number, followed by (2) bivariate hydrograph separation. Modifications were added to each method in an attempt to better capture continuous soil-moisture processes and explicitly account for runoff from impervious surfaces. Differences between the resulting runoff estimates shed light on the complexity of the rainfall–runoff relationship, and highlight the importance of understanding soil-moisture dynamics and their control on hydro(geo)logical responses. These results were then used as input in a water balance to calculate groundwater recharge. Two approaches were used to assess the accuracy of these groundwater balance estimates: (1) comparison to calculations of groundwater recharge using the calibrated conceptual HBV Light model, and (2) comparison to groundwater recharge estimates from physically similar catchments in Switzerland that are found in the literature. In all cases, recharge is estimated at approximately 40–45% of annual precipitation. These conditions were found to closely echo those results from Swiss catchments of similar characteristics.

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Effects of preferential flow on snowmelt partitioning and groundwater recharge in frozen soils

Hydrology and Earth System Sciences ◽

10.5194/hess-23-5017-2019 ◽

2019 ◽

Vol 23 (12) ◽

pp. 5017-5031 ◽

Cited By ~ 4

Author(s):

Aaron A. Mohammed ◽

Igor Pavlovskii ◽

Edwin E. Cey ◽

Masaki Hayashi

Keyword(s):

Soil Moisture ◽

Groundwater Recharge ◽

Preferential Flow ◽

Frozen Soil ◽

Time Lags ◽

Runoff Generation ◽

Frozen Ground ◽

Soil Matrix ◽

Frozen Soils ◽

Flow Through

Abstract. Snowmelt is a major source of groundwater recharge in cold regions. Throughout many landscapes snowmelt occurs when the ground is still frozen; thus frozen soil processes play an important role in snowmelt routing, and, by extension, the timing and magnitude of recharge. This study investigated the vadose zone dynamics governing snowmelt infiltration and groundwater recharge at three grassland sites in the Canadian Prairies over the winter and spring of 2017. The region is characterized by numerous topographic depressions where the ponding of snowmelt runoff results in focused infiltration and recharge. Water balance estimates showed infiltration was the dominant sink (35 %–85 %) of snowmelt under uplands (i.e. areas outside of depressions), even when the ground was frozen, with soil moisture responses indicating flow through the frozen layer. The refreezing of infiltrated meltwater during winter melt events enhanced runoff generation in subsequent melt events. At one site, time lags of up to 3 d between snow cover depletion on uplands and ponding in depressions demonstrated the role of a shallow subsurface transmission pathway or interflow through frozen soil in routing snowmelt from uplands to depressions. At all sites, depression-focused infiltration and recharge began before complete ground thaw and a significant portion (45 %–100 %) occurred while the ground was partially frozen. Relatively rapid infiltration rates and non-sequential soil moisture and groundwater responses, observed prior to ground thaw, indicated preferential flow through frozen soils. The preferential flow dynamics are attributed to macropore networks within the grassland soils, which allow infiltrated meltwater to bypass portions of the frozen soil matrix and facilitate both the lateral transport of meltwater between topographic positions and groundwater recharge through frozen ground. Both of these flow paths may facilitate preferential mass transport to groundwater.

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Open-Source Software Application for Hydrogeological Delineation of Potential Groundwater Recharge Zones in the Singida Semi-Arid, Fractured Aquifer, Central Tanzania

Hydrology ◽

10.3390/hydrology7020028 ◽

2020 ◽

Vol 7 (2) ◽

pp. 28

Author(s):

Kassim Ramadhani Mussa ◽

Ibrahimu Chikira Mjemah ◽

Revocatus Lazaro Machunda

Keyword(s):

Open Source ◽

Groundwater Recharge ◽

Rainwater Harvesting ◽

Drainage Density ◽

Suitability Analysis ◽

Lineament Density ◽

Fractured Aquifer ◽

Starting Point ◽

Potential Groundwater ◽

Semi Arid

This study attempted to delineate and map potential groundwater recharge zones of the Singida, semi-arid, fractured crystalline basement aquifer using open source remote sensing and GIS software. Various thematic maps such as lithology/hydrogeology, soil, land-cover/use, slope, lineament density, drainage density and rainfall distribution were integrated in QGIS software. Vector input layers were rasterized and resampled using QGIS wrap projection function to make sure that the grid cells are of the same size. Reclassification using SAGA and GRASS reclass algorithms in QGIS was carried out to realign the factor classes in a consistent scale, and reclassification to a scale of 1 to 5 was carried out to harmonize the results. The study identified a number of potential areas for groundwater recharge, groundwater exploration, groundwater development and potential areas for artificial groundwater recharge. Potential groundwater recharge zones for the Singida semi-arid fractured aquifer are restricted to areas with high lineament density, cultivated areas, grassland and flat to gentle slopes. The potential of groundwater recharge is also observed in areas with low drainage density. The delineated zones provide a good understanding of the potential recharge zones, which are a starting point for recharge zone protection. This blended approach can be utilized for carrying out suitability analysis using the weighted overlay analysis approach. Areas designated good and very good are recommended for artificial recharging structures as an alternative technique for enhancing groundwater recharge through rainwater harvesting. This will help to augment groundwater storage in this semi-arid environment.

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Application of grey correlation method to evaluate potential groundwater recharge sites

Stochastic Environmental Research and Risk Assessment ◽

10.1007/s00477-006-0034-9 ◽

2006 ◽

Vol 20 (6) ◽

pp. 407-421 ◽

Cited By ~ 29

Author(s):

H. S. Gau ◽

C. Y. Hsieh ◽

C. W. Liu

Keyword(s):

Groundwater Recharge ◽

Correlation Method ◽

Grey Correlation ◽

Potential Groundwater

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Groundwater recharge and groundwater water resources under present and future climate over the Pyrenees (France, Spain, Andorre)

10.5194/egusphere-egu21-16471 ◽

2021 ◽

Author(s):

Yvan Caballero ◽

Sandra Lanini ◽

Pierre Le Cointe ◽

Stéphanie Pinson ◽

Guillaume Hevin ◽

...

Keyword(s):

Climate Change ◽

Water Resources ◽

Land Cover ◽

Groundwater Recharge ◽

Hot Spot ◽

Infiltration Capacity ◽

Mountain Areas ◽

Development Fund ◽

Effective Precipitation ◽

Potential Groundwater

Climate change is expected to have a significant impact on water resources in mountain areas, as it is the case of the Pyrenees range between France, Spain and Andorre. Independently of future changes on rainfall patterns, global temperature rise is likely to provoke larger and earlier snowmelt, and enhanced precipitation deficits during the dry summer season. Exploring the impacts of this future situation on groundwater is essential, as this resource is often important for drinking water, irrigation and breeding uses in mountain regions. However, studies on groundwater recharge in the context of climate change are relatively scarce, as compared to studies focusing on surface water resources.We assessed potential groundwater recharge (part of effective precipitation that infiltrates and potentially reach the aquifers) over the Pyrenean range in the framework of the PIRAGUA project, a collaborative multi-national effort funded by the EU&#8217;s Interreg POCTEFA program. Based on a gridded (5x5 km&#178;) meteorological dataset derived from observational data by the CLIMPY project, we estimated effective precipitation for each grid cell using a conceptual water balance scheme. The effect of the seasonal change of land cover / land use (based on the Corine Land Cover dataset) on the water budget model has been assessed, and showed the need to include this component for a more accurate simulation. Based on a spatial characterization of the land infiltration capacity, the potential groundwater recharge has been computed for homogeneous groundwater bodies. Results have been compared to the outputs of groundwater models applied on selected karstic catchments using the BALAN code, and to a general knowledge of groundwater recharge rates for different regions within the study zone. Finally, climate change impacts on future IDPR have been explored using scenarios provided by the CLIMPY project.The Pyrenees range is a hot-spot for water resources with a tremendous impact over a much broader region in SW Europe, as Pyrenean rivers are fundamental contributors to large systems such as those of the Adour and Garonne (France) or Ebro (Spain), as well as smaller systems in the western and eastern sectors such as the Bidasoa (Spanish Basque Country), Llobregat-Ter-Muga (Catalonia), or T&#234;t-Tech-Aude (France). Our results are relevant for the planning and management of water resources for this important transboundary region in the future, as changes in groundwater recharge will also affect water resources availability.Acknowledgments: the project PIRAGUA, is funded by the European Regional Development Fund (ERDF) through the Interreg V-A Spain France Andorra programme (POCTEFA 2014-2020).

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Optimisation of Irrigation Regime for Early Potatoes, Late Cauliflower, Early Cabbage and Celery

Soil and Water Research ◽

10.17221/6515-swr ◽

2013 ◽

Vol 1 (No. 4) ◽

pp. 139-152

Author(s):

Zavadil Josef

Keyword(s):

Soil Moisture ◽

Soil Water ◽

Field Experiments ◽

Actual Evapotranspiration ◽

Suction Pressure ◽

Irrigation Regime ◽

Marketable Yield ◽

Moisture Balance ◽

Seasonal Irrigation ◽

Soil Moisture Balance

The paper deals with optimisation of threshold suction pressure of soil water on light soils for early potatoes, early cabbage, late cauliflower and celery on the basis of results of small-plot field experiments with differentiated irrigation regime. Experiments were conducted in 2003–2005. Threshold suction pressures of soil water were identical for all crops: 15 kPa in treatment I, 30 kPa in treatment II, 60 kPa in treatment III, and 120 kPa in treatment IV. Precipitation, air temperature and relative humidity, global solar radiation, wind speed and direction were measured by an automated meteorological station. Reference and actual evapotranspiration was determined for the experimental crops according to FAO Paper No. 56 and by means of a biological curve (BC) in 2003–2005. To compare these two methods of calculation of actual evapotranspiration the soil moisture balance was found out. Based on the influence on marketable yield and proportion of the crop quality grades it is possible to determine the optimum threshold suction pressure on light loamy-sand soils in early potatoes, late cauliflower and cabbage 30 kPa and in celery 15 kPa. 80% of available soil water capacity (ASWC) corresponds to the threshold suction pressure 30 kPa, and as much as 96% of ASWC corresponds to 15 kPa. The seasonal irrigation depths determined on the basis of soil moisture balance, in which the crop evapotranspiration (ETc) is calculated either according to FAO 56 or by the BC, are substantially different from the really achieved irrigation depths in the treatments where optimal suction pressure is maintained. For potatoes, the really achieved values of seasonal irrigation depths are nearer to the depths calculated by the BC, while for the other vegetables (cauliflower, cabbage and celery) they are more similar to the depths calculated by FAO 56 methodology. The theoretical irrigation depths calculated by the BC method sometimes differ substantially from those based on FAO 56. These differences are at maximum for cauliflower and celery and at minimum for cabbage and decrease with the decreasing irrigation depths.

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Partitioning of Water Between Differently Sized Shrubs and Potential Groundwater Recharge in a Semiarid Savanna in Namibia

Frontiers in Plant Science ◽

10.3389/fpls.2019.01411 ◽

2019 ◽

Vol 10 ◽

Cited By ~ 1

Author(s):

Katja Geißler ◽

Jessica Heblack ◽

Shoopala Uugulu ◽

Heike Wanke ◽

Niels Blaum

Keyword(s):

Groundwater Recharge ◽

Potential Groundwater

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