scholarly journals Estimating annual groundwater recharge coefficient for karst aquifers of the southern Apennines (Italy)

2014 ◽  
Vol 18 (2) ◽  
pp. 803-817 ◽  
Author(s):  
V. Allocca ◽  
F. Manna ◽  
P. De Vita
Keyword(s):  
Land Use ◽  
Time Series ◽  
Groundwater Recharge ◽  
Regional Scale ◽  
Karst Aquifer ◽  
Spring Discharge ◽  
Karst Aquifers ◽  
Southern Apennines ◽  
The Mean ◽  
Groundwater Outflow

Abstract. To assess the mean annual groundwater recharge of the karst aquifers in the southern Apennines (Italy), the estimation of the mean annual groundwater recharge coefficient (AGRC) was conducted by means of an integrated approach based on hydrogeological, hydrological, geomorphological, land use and soil cover analyses. Starting from the hydrological budget equation, the coefficient was conceived as the ratio between the net groundwater outflow and the precipitation minus actual evapotranspiration (P − ETR) for a karst aquifer. A large part of the southern Apennines, which is covered by a meteorological network containing 40 principal karst aquifers, was studied. Using precipitation and air temperature time series gathered through monitoring stations operating in the period 1926–2012, the mean annual P − ETR was estimated, and its distribution was modelled at a regional scale by considering the orographic barrier and rain shadow effects of the Apennine chain, as well as the altitudinal control. Four sample karst aquifers with available long spring discharge time series were identified for estimating the AGRC. The resulting values were correlated with other parameters that control groundwater recharge, such as the extension of outcropping karst rocks, morphological settings, land use and covering soil type. A multiple linear regression between the AGRC, lithology and the summit plateau and endorheic areas was found. This empirical model was used to assess the AGRC and mean annual groundwater recharge in other regional karst aquifers. The coefficient was calculated as ranging between 50 and 79%, thus being comparable with other similar estimations carried out for karst aquifers of European and Mediterranean countries. The mean annual groundwater recharge for karst aquifers of the southern Apennines was assessed by these characterizations and validated by a comparison with available groundwater outflow measurements. These results represent a deeper understanding of an aspect of groundwater hydrology in karst aquifers which is fundamental for the formulation of appropriate management models of groundwater resources at a regional scale, also taking into account mitigation strategies for climate change impacts. Finally, the proposed hydrological characterizations are also supposed to be useful for the assessment of mean annual runoff over carbonate mountains, which is another important topic concerning water management in the southern Apennines.

scholarly journals Estimating annual effective infiltration coefficient and groundwater recharge for karst aquifers of the southern Apennines

2013 ◽  
Vol 10 (8) ◽  
pp. 10127-10159 ◽  
Author(s):  
V. Allocca ◽  
F. Manna ◽  
P. De Vita
Keyword(s):  
Land Use ◽  
Time Series ◽  
Groundwater Recharge ◽  
Groundwater Resources ◽  
Spring Discharge ◽  
Karst Aquifers ◽  
Southern Apennines ◽  
Correlation Relationship ◽  
Mediterranean Countries ◽  
The Mean

Abstract. To assess the mean annual groundwater recharge of the karst aquifers in southern Apennines (Italy), the estimation of the mean annual effective infiltration coefficient (AEIC) was conducted by means of an integrated approach based on hydrogeological, hydrological, geomorphological, land use and soil cover analyses. We studied a large part of the southern Apennines that is covered by a meteorological network and containing 40 principal karst aquifers. Using precipitation and air temperature time series gathered through monitoring stations operating in the period 1926–2012, the annual effective precipitation (AEP) was estimated, and its distribution was modelled, by considering the orographic barrier and rain shadow effects of the Apennines chain, as well as the altitudinal control. Four sample karst aquifers with available long spring discharge time series were identified for estimating the AEIC by means of the hydrological budget equation. The resulting AEIC values were correlated with other parameters that control groundwater recharge, such as the extension of outcropping karst-rock, morphological settings, land use and covering soil type. A simple correlation relationship between AEIC, lithology and the summit flat and endorheic areas was found. This empirical model has been used to estimate AEIC and mean annual groundwater recharge in other regional karst aquifers. The estimated AEIC values ranged between 48% and 78%, thus matching intervals estimated for other karst aquifers in European and Mediterranean countries. These results represent a deeper understanding of an aspect of groundwater hydrology in karst aquifers which is fundamental for the formulation of appropriate management models of groundwater resources, also taking into account mitigation strategies for climate change impacts. Finally, the proposed hydrological characterisations are also perceived as useful for the assessment of mean annual runoff over carbonate mountains, which is another important topic concerning water management in the southern Apennines.

scholarly journals Testing Evapotranspiration Estimates Based on MODIS Satellite Data in the Assessment of the Groundwater Recharge of Karst Aquifers in Southern Italy

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 118
Author(s):  
Giovanni Ruggieri ◽  
Vincenzo Allocca ◽  
Flavio Borfecchia ◽  
Delia Cusano ◽  
Palmira Marsiglia ◽  
...  
Keyword(s):  
Groundwater Recharge ◽  
Air Temperature ◽  
Southern Italy ◽  
Remotely Sensed ◽  
Actual Evapotranspiration ◽  
Annual Rainfall ◽  
Karst Aquifers ◽  
Southern Apennines ◽  
Remotely Sensed Data ◽  
Empirical Formulas

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.

scholarly journals Thresholds definition in MOD13Q1 and VGT-S10 time series for coffee crop area estimation in Triângulo Mineiro/Alto Paranaíba

2019 ◽  
Vol 3 (2) ◽  
pp. 1-10
Author(s):  
Michel Eustáquio Dantas Chaves ◽  
Elizabeth Ferreira ◽  
Antonio Augusto Aguilar Dantas
Keyword(s):  
Land Use ◽  
Time Series ◽  
Large Scale ◽  
Agricultural Research ◽  
Regional Scale ◽  
Vegetation Indices ◽  
Seasonal Development ◽  
Land Use Classification ◽  
Crop Area ◽  
The Time Domain

In the last decades, remote sensing application in agricultural research has intensified to evaluate phenological cycles. Vegetation indices time series have been used to obtain information about the seasonal development of agricultural vegetation on a large scale. The multitemporal approach increases the gain of information coming from orbital images, an important factor for analysis of its spatial distribution. The objective of this study was to test the application of vegetation indices of the MODIS and SPOT-VEGETATION sensors to estimate the areas destined for coffee crops in the Triângulo Mineiro/Alto Paranaíba mesoregion. The results show that the vegetation indices NDVI and EVI of the product MOD13Q1 were more adequate for the estimation of land use over the time domain, especially NDVI. The best minimum threshold varies between 0.39 - 0.42 and the best maximum threshold varies between 0.71 - 0.74. The contribution of this work is that these thresholds can serve as subsidies for land use classification studies on a regional scale and for estimating areas for planting.

scholarly journals Calibration of a semi-distributed lumped karst system model and analysis of its sensitivity to climate conditions: the example of the Qachqouch karst spring (Lebanon)

2020 ◽  
Author(s):  
Emmanuel Dubois ◽  
Joanna Doummar ◽  
Séverin Pistre ◽  
Marie Larocque
Keyword(s):  
Time Series ◽  
Karst Aquifer ◽  
Regulatory Function ◽  
Karst Aquifers ◽  
Karst Spring ◽  
Flow Rates ◽  
Lumped Model ◽  
Climate Conditions ◽  
Time Series Analyses ◽  
Spring Flow

Abstract. Flow in complex karst aquifers is challenging to conceptualize, therefore to model for better management practices, especially in poorly investigated areas, in semi-arid climates, and under changing climatic conditions. The objective of this work is to propose a calibration approach based on time-series analyses for a karst aquifer and to assess the impact of changing climate conditions on the spring discharge. Based on more than three years of high-resolution continuous monitoring, a semi-distributed lumped model was calibrated and validated for the Qachqouch karst spring, north of Beirut (Lebanon). Time-series analyses and decomposition of spring hydrographs revealed that the system has a high regulatory function, with considerable storage capacity providing stable flow (minimum flow of 0.2 m3/s) during the dry season, and with flow rates exceeding 10 m3/s during the wet season, similar to other karst aquifers in the region. Based on this detailed understanding of the hydrodynamics of the system, the model geometry and parameters were validated. Three linear reservoirs were implemented to reproduce the combined contribution of the different flow components of the system. A satisfactory simulation (Nash–Sutcliffe coefficient = 0.72) of measured spring flow rates was obtained after calibration. Climate change conditions (+1 to +3 °C warming, −10 to −30 % less precipitation annually, and intensification of rain events) were added to a baseline climatic year to produce scenarios of expected spring flow responses. Results show that the Qachqouch karst aquifer is sensitive to decreasing rainfall, which is associated with more pronounced recessions, with flow rates decreasing by 34 % and 1-month longer dry periods. Because of the limited influence of snow on the spring flow rate, a warming climate has less impact on spring flow conditions than a reduction in precipitation. Although the model shows that increasing rainfall intensity induces larger floods, recessions and shorter low flow periods, the real impact of high-intensity precipitation events remains uncertain, since the model does not account for complex unsaturated and epikarst processes. This work shows that calibrating a semi-distributed lumped model using time series analysis can be an efficient approach to improve simulations of complex karst aquifers, thus providing useful models for long-term sustainable water management.

scholarly journals Quantitative and Qualitative Methods for the Characterization of Karst Springs (case study: Lorestan province, Zagros Mountain, Iran)

2022 ◽  
Author(s):  
Fatemeh Geravand ◽  
Seiyed Mossa Hosseini ◽  
Mehran Maghsoudi ◽  
Mojtaba Yamani
Keyword(s):  
Groundwater Resources ◽  
Saturation Index ◽  
Karst Aquifer ◽  
Base Flow ◽  
Spring Discharge ◽  
Karst Aquifers ◽  
Zagros Mountains ◽  
Discharge Data ◽  
Karst Springs

Abstract Karst groundwater resources in the Zagros Mountains are vital for supplying of different demands in the region which need to sustainable management and protection. Quantitative and qualitative characterization of karst aquifers in this region were understudied due to lack of site-specific logging-data and speleological investigations. In this study, a state-of-the-art of the statistical methods developed to characterize karst aquifer based on analyses of the spring recession hydrograph and spring water quality are presented. These methods including Manging’s method for classification of karst aquifers, relationships of precipitation and discharge data, groundwater quality index (GQI), hydrochemical diagrams (Piper, Durov and Gibbs), and Saturation index (SI), Chloro-Alkaline indices (CAI). 42 major karst springs mainly located in folded part of Zagros region (western Iran) are selected for application of the reviewed methods. Results indicated that the saturated zone exerts almost main control over the discharge of 76% of the studied springs. The base-flow contributes as between 80.0% to 100% of total water storage in the study aquifers. 78.5% of the studied aquifers have a high karstification degree. An insignificant lag-time is observed between the precipitation on the karst basin and spring discharge. The hydrochemical diagrams show that the waters are dominated by HCO3 and Ca and the majority of the waters are alkaline, with originate from silicate minerals weathering. Such repeatable methods adopted in this study can provide crucial information of the karst aquifers, especially those suffer scarcity of aquifer hydrodynamic data.

scholarly journals Accumulation studies on Amundsenisen, Dronning Maud Land, Antarctica, by means of tritium, dielectric profiling and stable-isotope measurements: first results from the 1995–96 and 1996–97 field seasons

1999 ◽  
Vol 29 ◽  
pp. 1-9 ◽  
Author(s):  
Hans Oerter ◽  
Wolfgang Graf ◽  
Frank Wilhelms ◽  
Andreas Minikin ◽  
Heinz Miller
Keyword(s):  
Time Series ◽  
Regional Scale ◽  
Significant Trend ◽  
Deuterium Content ◽  
Accumulation Rates ◽  
Electrical Measurements ◽  
First Results ◽  
Dronning Maud Land ◽  
The Mean ◽  
Isotope Content

AbstractThe paper focuses on studies of snow-pit samples and shallow firn cores taken during the 1995-96 and 1996-97 field seasons at Amundsenisen, Dronning Maud Land, Antarctica. The dating of the firn is based on the artificial tritium distribution in the snow cover and on several reference horizons identified by electrical measurements. The early 1964 through 1965 horizon is marked by the deposition of sulfate released to the atmosphere during the eruption of the Agung volcano in March 1963; this horizon was detected by dielectric profiling and electrical conductivity measurements: the proof by chemical analysis has still to be seen. At the ten investigated sites on Amundsenisen the 1964-65 horizon was identified 4.1-5.7 m below the surface. The accumulation rates on Amundsenisen are 41-91kg m-2 a−1 The cores are up to 100 years old A relationship between isotope content and the mean air temperature on a regional scale can be based on measurements of firn temperature at 10 m depth at the drilling sites Between Neumayer station at the coast and Heimefrontfiella, the temperature gradient of the deuterium content is 9.6%0 K−1. South of Heimefrontfiella, on the Amundsenisen plateau, it is only 5.5‰ K−1. Time series of yearly accumulation rates show no significant trend For the isotope records a significant trend to higher values with gradients of 0.1-0.2 δ2H‰a−1 can be seen in five of the ten time series

Estimating Land Use Impacts on Regional Scale Urban Water Balance and Groundwater Recharge

2008 ◽  
Vol 23 (9) ◽  
pp. 1863-1873 ◽  
Author(s):  
Bin He ◽  
Yi Wang ◽  
Keiji Takase ◽  
Goro Mouri ◽  
Bam H. N. Razafindrabe
Keyword(s):  
Land Use ◽  
Water Balance ◽  
Groundwater Recharge ◽  
Regional Scale ◽  
Urban Water ◽  
Land Use Impacts ◽  
Urban Water Balance

scholarly journals Analisis MRC untuk Karakterisasi Akuifer Karst di Mataair Mudal, Kabupaten Kuloprogo

2020 ◽  
Vol 33 (2) ◽  
Author(s):  
Afid Nurkholis ◽  
Tjahyo Nugroho Adji ◽  
Eko Haryono ◽  
Ahmad Cahyadi ◽  
Wisnu Agung Waskito ◽  
...  
Keyword(s):  
Karst Aquifer ◽  
Spring Discharge ◽  
Karst Aquifers ◽  
Diffuse Type ◽  
Time Intervals ◽  
Time To Peak ◽  
Recession Curve ◽  
Master Recession Curve ◽  
Discharge Regime ◽  
Karstification Degree

Akuifer karst memiliki triple porosity yang membuat karakterisasinya sulit dilakukan. Tujuan dari penelitian ini adalah menganalisis komponen hidrograf banjir dan membuat Master Recession Curve (MRC) pada akuifer karst yang mengimbuh Mataair Mudal. Data yang digunakan adalah debit aliran dan curah hujan yang tercatat setiap 30 menit pada November 2017 hingga Mei 2018 (6 bulan). Hasil penelitian menunjukkan bahwa Mataair Mudal memiliki complex discharge regime dengan derajat karstifikasi pada kelas 5,5. Analisis komponen hidrograf banjir menguatkan hasil perhitungan derajat karstifikasi. Waktu menuju puncak banjir (Tlag) yang tergolong cepat (2,5 jam) menunjukkan telah adanya aliran conduit. Perhitungan waktu menuju aliran dasar (Tb) baik secara manual (hidrograf banjir) maupun automatis (MRC) memiliki rerata sekitar 40 jam yang mencerminkan bahwa akuifer karst yang mengimbunya masih baik dalam menyimpan airtanah. Secara keseluruhan, akuifer karst di Mataair Mudal masih didominasi oleh retakan bertipe diffuse, meskipun sudah memiliki retakan bertipe conduit yang cukup berkembangThe objective of this research was to analyze the nature of the flood hydrograph components and create a Master Recession Curve (MRC) to estimate the degree of karstification in Mudal Spring. Discharge and rainfall data were recorded every 30 minutes at time intervals between November 2017 and May 2018. The results show that Mudal Spring has a complex discharge regime with a karstification degree in the class of 5.5. Meanwhile, the time to peak flood (Tlag) which is relatively fast (2.5 hours) shows the existence of conduit flow in the flood event. Calculation of time to baseflow (Tb) has an average of 40 hours which reflects that the karst aquifer was still good in storing groundwater. Overall, karst aquifers in Mudal Spring are still dominated by diffuse type voids, although they already have conduit type voids that are quite developed.

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