Predicting Land Use Impacts on Regional Scale Groundwater Recharge and Discharge

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.

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A pilot regional scale model of land use impacts on groundwater quality

Management of Environmental Quality An International Journal ◽

10.1108/14777830510591651 ◽

2005 ◽

Vol 16 (3) ◽

pp. 220-234 ◽

Cited By ~ 10

Author(s):

H.J. Di ◽

K.C. Cameron ◽

V.J. Bidwell ◽

M.J. Morgan ◽

C. Hanson

Keyword(s):

Land Use ◽

Groundwater Quality ◽

Regional Scale ◽

Scale Model ◽

Land Use Impacts

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A PYTHON TOOL TO ESTIMATE LAND-USE IMPACTS ON GROUNDWATER NITRATE CONCENTRATIONS OBSERVED AT HIGH-CAPACITY PUMPING WELLS IN AN UNCONFINED GLACIAL AQUIFER

10.1130/abs/2020am-349317 ◽

2020 ◽

Author(s):

Stephanie Lynn DeVries ◽

◽

William Garrett Hooten ◽

William Garrett Hooten

Keyword(s):

Land Use ◽

High Capacity ◽

Land Use Impacts ◽

Pumping Wells ◽

Nitrate Concentrations

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Changing Land Use and Population Density Are Degrading Water Quality in the Lower Mekong Basin

Water ◽

10.3390/w13141948 ◽

2021 ◽

Vol 13 (14) ◽

pp. 1948

Author(s):

Flavia Tromboni ◽

Thomas E. Dilts ◽

Sarah E. Null ◽

Sapana Lohani ◽

Peng Bun Ngor ◽

...

Keyword(s):

Water Quality ◽

Land Use ◽

Population Density ◽

Local Population ◽

Reference Conditions ◽

Mekong River ◽

Land Use Impacts ◽

Wet Season ◽

Mekong Basin ◽

Lower Mekong Basin

Establishing reference conditions in rivers is important to understand environmental change and protect ecosystem integrity. Ranked third globally for fish biodiversity, the Mekong River has the world’s largest inland fishery providing livelihoods, food security, and protein to the local population. It is therefore of paramount importance to maintain the water quality and biotic integrity of this ecosystem. We analyzed land use impacts on water quality constituents (TSS, TN, TP, DO, NO3−, NH4+, PO43−) in the Lower Mekong Basin. We then used a best-model regression approach with anthropogenic land-use as independent variables and water quality parameters as the dependent variables, to define reference conditions in the absence of human activities (corresponding to the intercept value). From 2000–2017, the population and the percentage of crop, rice, and plantation land cover increased, while there was a decrease in upland forest and flooded forest. Agriculture, urbanization, and population density were associated with decreasing water quality health in the Lower Mekong Basin. In several sites, Thailand and Laos had higher TN, NO3−, and NH4+ concentrations compared to reference conditions, while Cambodia had higher TP values than reference conditions, showing water quality degradation. TSS was higher than reference conditions in the dry season in Cambodia, but was lower than reference values in the wet season in Thailand and Laos. This study shows how deforestation from agriculture conversion and increasing urbanization pressure causes water quality decline in the Lower Mekong Basin, and provides a first characterization of reference water quality conditions for the Lower Mekong River and its tributaries.

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