Evaluating the Risks of Groundwater Extraction in an Agricultural Landscape under Different Climate Projections

Abstract

Groundwater resources worldwide are being depleted at alarming rates since 1960 to support agriculture, industry, and domestic water demand. Water harvesting and the implementation of reduced application or more efficient irrigation technologies were identified as two of the most efficient practices to mitigate the declining patterns on groundwater resources. However, prior to implementing these practices, understanding how groundwater interacts with surface water and responds to natural and anthropogenic stressors is crucial. Integrated modeling tools that are able to exchange fluxes in both domains are needed to assess how conservation practices will affect our water resources under different projected climate and land use scenarios. This study aimed to evaluate the most likely impacts of current land management practices under the most severe projections of future climate and quantify the potential mitigation effects of three conservation scenarios on the water resources of the Fort Cobb Reservoir Experimental Watershed (FCREW) in western Oklahoma. The semicoupled SWAT-MODFLOW (SWATmf) model was used to simulate the hydrologic responses of the FCREW to a 50% reduction in the irrigation depths and the transition of 50% and 75% of croplands to rangelands under 32 distinct climate projections. Results showed that future climate can drive a reduction in the streamflow (−18%) and an increase to the depth of the water table (99%–120%) in the western part of the FCREW by the end of the century. The Fort Cobb Reservoir was expected to reduce its release after the mid-2060s to maintain its current target level. All the scenarios, aimed at decreasing groundwater extractions or implementing conservation measures, signaled a full recovery response in the groundwater levels 7–10 years after the year the conservation practices were implemented. The 50% reduction in the irrigation depths was found to elicit faster hydrologic systemic responses than the two that implemented conservation measures, which contravene tradition and would imply cessation of agricultural activities. This study can enable stakeholders to formulate timely adaptation and mitigating strategies to adopt to land use changes.

Groundwater sustainability under land-use and land-cover changes

“…Water stress is among the greatest issues affecting many societies on a global scale. Water de cit is mainly caused by groundwater extraction for irrigation, which can deplete aquifers(Acero Triana et al, 2020;Dalin et al, 2017). As a result of extensive groundwater extraction in the second half of the 20th century for agriculture, industry, and domestic water supply, groundwater resources are depleting at an alarming rate worldwide (Bartolino, 2003).…”

“…As a result of extensive groundwater extraction in the second half of the 20th century for agriculture, industry, and domestic water supply, groundwater resources are depleting at an alarming rate worldwide (Bartolino, 2003). For instance, excessive groundwater depletion and water stress have been reported in northern and southern Africa, the central United States, northeastern China, Australia, and south and central Asia (Acero Triana et al, 2020). This decline causes disparities and complications in different areas, which can be avoided by implementing an integrated water resources management strategy.…”

“…Understanding the impact of groundwater recharge on land cover is critical to pursuing accurate policies to ensure groundwater sustainability under LULC change (Gyam et al, 2017). In this regard, the water table is expected to improve with the conversion of crops to pasture as the consumption of irrigation water and groundwater extraction is reduced (Acero Triana et al, 2020). The present study aims to revitalize the aquifer by changing the cultivated area.…”

Surface Runoff and Diffuse Nitrogen Loss Dynamics in a Mixed Land Use Watershed with a Subtropical Monsoon Climate

“…Among the soil parameters that could lead to watershed diffuse nitrogen pollution changes, the antecedent soil water content (ASW) is one of the most critical factors that affects soil water storage and infiltration capacity, thereby influencing diffuse pollution mechanisms [18]. Land use changes such as changes in crop types, land management practices, land use distributions, and riverbank buffers could affect watershed diffuse nitrogen pollution distribution behaviors [19][20][21][22][23]. Hou et al found that a decrease of nearly 10% in the nitrogen load in surface runoff could be achieved by redistributing land uses within the experimental watershed without any changes in any types of land management practices [24].…”

Spatially distributed impacts of climate change and groundwater demand on the water resources in a wadi system

“…Moreover, hydrological changes caused by climate change and population growth are not only limited to groundwater, but also extend to surface water resources, where changes in runoff timing, seasonality, peak rates, and volumes of surface water have been reported for different arid parts of Iran (Ashraf et al, 2019) and other countries, e.g., in the United States (Caldwell et al, 2012), Algeria (Achite and Ouillon, 2016), China (Xue et al, 2017), and Jordan (Al Qatarneh et al, 2018). Alterations of the streamflow regime can result in negative environmental consequences, as e.g., in China, where decreases in water resources had a negative effect on the semi-arid wetland ecosystem of western Jilin (Moiwo et al, 2010).…”