Groundwater Decline Research Articles

Ensemble modeling of the hydrological impacts of climate change: a case study of the Baro River Sub-basin, Ethiopia

ABSTRACT Given the Baro River basin's high climatic variability and frequent flooding, climate change is expected to exacerbate the existing issues in the region. Three best-performing climate models from Coupled Model Intercomparison Project phase 6 (CMIP6) were used to examine the potential impact of climate change on the hydrology of the Baro River Basin. The ensemble of the climate models were bias-corrected for the climate change analysis and a calibrated and validated Soil and Water Assessment Tool (SWAT) model was used to examine the impact of the climate changes under two shared socioeconomic pathways (SSP2-4.5 and SSP5-8.5) in the future (2031–2060). The climate change scenarios projected an increase in precipitation and temperature under all scenarios. Consequently, annual increase in surface runoff, water yield, and potential evapotranspiration (PET) was reported by 30.33% (44.67%), 6% (18.1%,), and 4.49% (6.63%) and decline in groundwater by 13.17% (2.64%) under shared socioeconomic pathway, SSP2-4.5 (SSP5-8.5), respectively. The rise in temperature and PET could be responsible for the decline in groundwater, while the projected increase in precipitation is expected to enhance surface runoff, perhaps leading to flooding. This requires an improved water management policy that involves all sectors and takes into account the equity for different users.

Subsidence and Uplift in Active and Closed Lignite Mines: Impacts of Energy Transition and Climate Change

This study examines the combined effects of decommissioning lignite mining operations and long-term climate trends on groundwater systems and land surface movements in the Konin region of Poland, which is characterised by extensive open-pit lignite extraction. The findings reveal subsidence rates ranging from −26 to 14 mm per year within mining zones, while land uplift of a few millimetres per year occurred in closed mining areas between 2015 and 2022. Groundwater levels in shallow Quaternary and deeper Paleogene–Neogene aquifers have declined significantly, with drops of up to 26 m observed near active mining, particularly between 2009 and 2019. A smaller groundwater decline of around a few metres was observed outside areas influenced by mining. Meteorological data show an average annual temperature of 8.9 °C from 1991 to 2023, with a clear warming trend of 0.0050 °C per year since 2009. Although precipitation patterns show a slight increase from 512 mm to 520 mm, a shift towards drier conditions has emerged since 2009, characterised by more frequent dry spells. These climatic trends, combined with mining activities, highlight the need for adaptive groundwater management strategies. Future research should focus on enhanced monitoring of groundwater recovery and sustainable practices in post-mining landscapes.

Advanced machine learning for predicting groundwater decline and drought in the Rabat–Salé–Kénitra region, Morocco

Advanced machine learning for predicting groundwater decline and drought in the Rabat–Salé–Kénitra region, Morocco

Social‐ecological systems modeling for drought‐food security nexus

AbstractDroughts pose severe threats to social systems, particularly to food security which is one of the priority targets in the UN's sustainable development goals (SDG 2). The drought‐food insecurity nexus entails the complex social‐ecological systems (SES) relationships (e.g., feedback) that underpin food insecurity, leading to disastrous consequence to society. To advance the knowledge on capturing the SES relationships of the drought‐food insecurity nexus, an SES model was employed (first attempt) to simulate these relationships to inform policies on food security in the context of climate change in Bangladesh. Different “what if” scenarios were examined determining the possible future trajectories of the system under socio‐economic and climate scenarios. Findings revealed that (i) with business‐as‐usual scenario, crop production and food security continue to increase at the expense of declining water resources over the simulation period; (ii) temperature changes (3.5–5.7°C) and surface water reduction due to dam and sustained groundwater decline may reduce food security (~55%); (iii) tipping risk increases due to severe reduction of food security when increasing temperature (>3.5°C) is combined with upstream water withdrawal (30%–50%), subsidy reduction (50%–100%), population growth and political instability. These indicate the need for an SES system perspective for increasing crop production and food security, simultaneously ensuring sustainable water resources and climate change adaptation. The model and findings are useful to achieve food security, and other related SDGs (1&6) in the context of climate change in Bangladesh and similar areas (e.g., Kenya), informed by the consequences of plausible alternative futures.

Will there be water? Climate change, housing needs, and future water demand in California

Climate change in California is expected to alter future water availability, impacting water supplies needed to support future housing growth and agriculture demand. In groundwater-dependent regions like California's Central Coast, new land-use related water demand and decreasing recharge is already stressing depleted groundwater basins. We developed a spatially explicit state-and-transition simulation model that integrates climate, land-use change, water demand, and groundwater gain-loss to examine the impact of future climate and land use change on groundwater balance and water demand in five counties along the Central Coast from 2010 to 2060. The model incorporated downscaled groundwater recharge projections based on a Warm/Wet and a Hot/Dry climate future from a spatially explicit hydrological process-based model. Two urbanization projections from a parcel-based, regional urban growth model representing 1) recent historical and 2) state-mandated housing growth projections were used as alternative spatial targets for future urban growth. Agricultural projections were based on recent historical trends from remote sensing data. Annual projected changes in groundwater balance were calculated as the difference between land-use related water demand, based on historical estimates, and climate-driven recharge plus agriculture return flows. Results indicate that future changes in climate-driven groundwater recharge, coupled with cumulative increases in agricultural water demand, result in overall declines in future groundwater balance, with a Hot/Dry future resulting in cumulative groundwater decline in all but Santa Cruz County. Cumulative declines by 2060 are especially prominent in San Luis Obispo (−2.9 to −5.1 Bm3) and Monterey counties (−6.5 to −8.7 Bm3), despite limited changes in agricultural water demand over the model period. These two counties show declining groundwater reserves in a Warm/Wet future as well, while San Benito and Santa Barbara County barely reach equilibrium. These results suggest future groundwater supplies may not be able to keep pace with regional demand and declining climate-driven recharge, resulting in a potential reduction in water security in the region. However, our county-scale projections showed new housing and associated water demand does not conflict with California's groundwater sustainability goals. Rather, future climate coupled with increasing agricultural groundwater demand may reduce water security in some counties, potentially limiting available groundwater supplies for new housing.

Satellite gravimetry observations on the state of groundwater level variability in the Arabian Peninsula Region and the associated socio-economic sustainability challenges

Groundwater is an important resource for the Arabian Peninsula Region. The population increase, rise in agricultural activities, and Gulf Cooperation Council (GCC) countries (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates) inclination towards economic diversification and tourism promotion have heightened the freshwater demand. As a result of climate change and varying weather patterns, the situation has become more complicated. Due to arid conditions, recharge is mostly less than withdrawal which consequently results in underground water level decline over time. In the research, we have used Gravity Recovery and Climate Experiment (GRACE/GRACE-FO) MASCON solutions, Global Land Data Assimilation System (GLDAS) soil moisture, and the Integrated Multi-satellite Retrievals for Global Precipitation Mission (IMERG) rainfall data to observe the Equivalent Water Thickness (EWT), and rainfall patterns in this region for the past two decades (2002–2023). The results indicate that in Saudi Arabia the water level is declining nearly at a linear rate and the linear regression model fits well with the data (R2 value, the coefficient of determination, for different cities of Saudi Arabia is ≥ 0.94). In the Al Jouf Area, the water decline is the highest at −1.69 cm/year which is 43% greater than the previous calculations. The lowest decline rate is in Sanaa (Yemen) which is −0.13 cm/year. Furthermore, all the other studied locations show a groundwater declining trend. In Saudi Arabia's Makkah, Madina, Riyadh, and Damam the reduction rate is −0.36, −0.48, −0.72, and −0.48 (cm/year) respectively. Kuwait, UAE's Dubai, and Al Ain show a similar groundwater reduction rate of −0.19 cm/year. In Oman's Masqat, the groundwater decline rate is −0.22 cm/year. Also, in the recent data, one can see the higher seasonal amplitudes that are indicative of greater fluctuations in EWT data in recent times. If water mining continues at the same pace, this important resource can become a rare commodity. Limited water supply can likely become a limiting factor for further social, agricultural, and industrial development. That's why major reviews and shifts are necessary in the current policies related to water resource management and conservation.

Assessment of heavy metals and its treatment through phytoremediation in groundwater along River Kabul in district Charsadda

Life cannot exist without water. Water scarcity is caused by massive groundwater decline. Water contamination is the most common problem spreading worldwide quicker than ever, along with anthropogenic water scarcity. Since tainted water can harm health, water contamination is also contributing to water scarcity. Heavy metals in drinking water have plagued most Asian, African, and European nations for decades. Studies reveal that heavy metals have caused damage in Pakistan, India, and China. This study detects heavy metals in groundwater and treats them with phytoremediation along the river Kabul in district Charsadda. It also measures pH, EC, TDS, turbidity, fluoride, phosphates, nitrites, and nitrates. All indicators meet the WHO and national environmental quality criteria for drinking water, except for turbidity, which exceeds the limit of ≤5 NTU in four examined regions, reaching a maximum of 9.99 NTU. Chemical parameters were within the standard limits, except for high concentrations of arsenic (As) and cadmium (Cd) in samples from S2 (15.20 μg/L) and S1 (20.50 μg/L) compared to WHO’s 10 and 5 μg/L standards. However, the limit is within EPA Pakistan’s 50 and 100 μg/L standards for drinking water, which Pakistan still follows. Heavy metals can harm health, even at low levels. Since the majority of the study area’s population relies on groundwater for drinking and other needs, heavy metal pollution of the groundwater can cause many ailments. Thus, phytoremediation is increasingly vital to reduce these heavy metals to WHO limits to protect human health and the environment.

An Analysis of Research Trends on Groundwater Utilization in Indonesia: A Bibliometric Study

This study uses the Biblioshiny-R tool to assess the impact of elements in articles related to groundwater use in Indonesia. Groundwater is a renewable energy source that needs to be considered in terms of quantity and availability. Groundwater that is not managed correctly will pose a threat to scarcity and sustainability in its availability. This research utilizes the Scopus database, which was published in 1980. The first article was "Water Resources for Bandung City," written by Riemer Wynfrith and published by Technical Review - Mitsubishi Heavy Industries. The analysis shows top authors such as Putra DPE, Wilopo W, and Abidin HS had the highest h-index. Gadjah Mada University and the IOP Conference Series appeared as affiliates of most publications, and "Chaussard E, 2013, Remote Sens Environ" was the most cited theme in the publication, followed by the theme "Indonesia" and "land subsidence." Many discussions on the theme "Groundwater” are not followed by discussions on the theme of groundwater pollution, so the theme of groundwater pollution is interesting to discuss in further scientific research most collaborations, especially with Japan. This research also found that the age of a document does not significantly affect the number of citations a document receives. This research provides a comprehensive picture of groundwater utilization in Indonesia. In addition, this research examines the impact of groundwater decline and the need for integrated water management on the sustainability of groundwater availability in Indonesia.

A comparative analysis of simulation approaches for predicting permeability and compressive strength in pervious concrete

Porous concrete plays a crucial role in addressing various environmental challenges and mitigating the impacts of climate change. It proves effective in reducing issues such as flooding, heat phenomena in the earth, and groundwater decline. Typically devoid of sand content, porous concrete’s key attributes lie in its permeability and compressive strength. Accurate prediction of these properties is essential for cost and time savings, ensuring precise proportions of materials in the concrete mixture. This article explores different models, including the linear model (LR), nonlinear model (NLR), and Artificial Neural Network (ANN), to predict and estimate permeability and compressive strength in porous concrete. The analysis incorporates 139 samples from various papers and experimental studies, utilizing significant parameters and variables like water-to-cement ratio, coarse aggregate content, cement content, porosity, and curing time as input variables. Statistical assessments, such as Root Mean Square Error (RMSE), Mean Absolute Error (MAE), Scatter Index (SI), OBJ value, and coefficient of determination (R2), are employed to assess model performance. The results reveal that the ANN model outperforms other models in forecasting permeability and compressive strength of porous concrete. The SI and OBJ value of the ANN model are lower than those of all other models, indicating superior performance. The robust performance of the ANN model has significant implications for construction applications, ensuring precise material proportions and contributing to the durability of porous concrete structures. The success of the ANN model suggests avenues for refinement, including architecture adjustments and dataset expansion. These findings offer valuable insights into the ongoing efforts to optimize simulation techniques for predicting key properties of construction materials. On the other hand, the use of these models to optimize concrete mix design not only enhances efficiency but also significantly conserves raw materials and reduces energy consumption. These advancements contribute to lowering carbon emissions and promoting sustainable practices in the construction industry.

Decoding uranium variation over the Indian peninsula through leveraging standardized precipitation evapotranspiration indices and groundwater level fluctuations

The present study aims to predict the concentration of uranium (U) in groundwater in India by utilizing water quantity indicators, such as Standardised Precipitation Index (SPI), Standardised Precipitation Evapotranspiration Index (SPEI), and Gravity Recovery and Climate Experiment (GRACE) based groundwater levels. The study adopts a multi-scale approach, ranging from state-level to agroclimatic zones. The findings indicate that the highest levels of U (101–500 μg.L−1), which surpass the World Health Organization (WHO) prescribed limit of 30 μg.L−1 for drinking water, are primarily concentrated in India's plateau and hills regions. The GRACE data map portrays a downward trend in groundwater levels throughout India, with the mid-Gangetic plains experiencing the most significant decline. The meteorological aspect of the study, as indicated by SPI and SPEI, reveals that the plateau and hills region is experiencing a decline in rainfall. The SPEI further underscores the grim picture of decreasing precipitation in northern India. Additionally, the study employs cluster analysis to cluster states according to the division of agro-climatic zones. Lastly, the study employs a random forest algorithm to assess the relative importance of each predictor and predict U concentration under the trinity of precipitation, extraction, and evaporation. The most significant contribution of this work is to identify the hotspots in India that require the most attention in terms of U toxicity owing to groundwater decline. Overall, this study highlights the need for immediate attention to mitigate the adverse impacts of U contamination and aims at sensitizing the stakeholders towards the compelling need to fulfil SDG-3 (health aspects due to U hazard) and SDG-6 (groundwater over-exploitation and deteriorating water quality).

Groundwater decline has negatively affected the well-preserved amphibian community of Doñana National Park (SW Spain)

Abstract The success of amphibian conservation efforts is highly dependent on the preservation of amphibian breeding habitats. Doñana National Park contains an abundance of ponds with heterogeneous characteristics, which has historically favoured its amphibian community. However, most of the park’s ponds are groundwater dependent, and aquifer overexploitation outside the park is leading to shorter hydroperiods and even desiccation in the pond network. This problem has been exacerbated by the scarcity of rain over the last decade. In 2021-2022, we surveyed the occurrence of the park’s 11 amphibian species, with a view to comparing our findings with those from the last previous survey in 2003-2004. We mapped the species occurrence within the park for the two survey periods. While all 11 amphibian species could still be found in Doñana, their occurrence had decreased across the board. In 2003-2004, 6 species were present across more than 50% of the sampling area. In contrast, 18 years later, such was the case for only two species (Pelophylax perezi and Hyla meridionalis). Declines were greatest for Epidalea calamita, followed by Pelobates cultripes, Triturus pygmaeus, and Lissotriton boscai. The mean number of species per sampling unit (i.e., grid cell) dropped from 4.3 to 3.1. To preserve Doñana’s amphibian community, it is important to restore the park’s pond network, which implies reducing regional groundwater overexploitation.

Gisser-Sánchez revisited: A model of optimal groundwater withdrawal under irrigation including surface–groundwater interaction

We revisit the classic problem of determining economically optimal groundwater withdrawal rates for irrigation. The novelty compared to previous mathematical analyses is the inclusion of non-linear groundwater-surface water interaction that allows for incorporating the impact of capture, i.e. the fact that all or part of the pumped groundwater comes out of reduced surface water flow or increased recharge. We additionally included the option to internalize environmental externalities (e.g. streamflow depletion) and maximize social welfare rather than farmer’s profit. This analysis results in a fixed optimal groundwater withdrawal rate qopt when withdrawal q remains smaller than some critical withdrawal rate (maximum capture) qcrit and provides depletion trajectories, either under competition or optimal control, if q is larger than qcrit. Based on the relative value of q, qcrit and qopt it also yields four quadrants of distinct withdrawal strategies. Using global hydrogeological and hydroeconomic datasets we map the global occurrence of these four quadrants and provide global estimates of optimal groundwater withdrawal rates and depletion trajectories. For the quadrants with groundwater depletion (q > qcrit) we derive and compare depletion trajectories under competition, optimal control and optimal control including environmental externalities, and assessed globally where the differences between these depletion modes are small, which is known as the Gisser-Sánchez effect. We find that the Gisser-Sánchez effect is globally ubiquitous, but only if environmental externalities are ignored. The inclusion of environmental externalities in optimal control withdrawal result in notably reduced groundwater decline and larger values of social welfare in many of the major depletion areas.

Seasonal and Species‐Level Water‐Use Strategies and Groundwater Dependence in Dryland Riparian Woodlands During Extreme Drought

AbstractDrought‐induced groundwater decline and warming associated with climate change are primary threats to dryland riparian woodlands. We used the extreme 2012–2019 drought in southern California as a natural experiment to assess how differences in water‐use strategies and groundwater dependence may influence the drought susceptibility of dryland riparian tree species with overlapping distributions. We analyzed tree‐ring stable carbon and oxygen isotopes collected from two cottonwood species (Populus trichocarpa and P. fremontii) along the semi‐arid Santa Clara River. We also modeled tree source water δ18O composition to compare with observed source water δ18O within the floodplain to infer patterns of groundwater reliance. Our results suggest that both species functioned as facultative phreatophytes that used shallow soil moisture when available but ultimately relied on groundwater to maintain physiological function during drought. We also observed apparent species differences in water‐use strategies and groundwater dependence related to their regional distributions. P. fremontii was constrained to more arid river segments and ostensibly used a greater proportion of groundwater to satisfy higher evaporative demand. P. fremontii maintained ∆13C at pre‐drought levels up until the peak of the drought, when trees experienced a precipitous decline in ∆13C. This response pattern suggests that trees prioritized maintaining photosynthetic processes over hydraulic safety, until a critical point. In contrast, P. trichocarpa showed a more gradual and sustained reduction in ∆13C, indicating that drought conditions induced stomatal closure and higher water use efficiency. This strategy may confer drought avoidance for P. trichocarpa while increasing its susceptibility to anticipated climate warming.

Groundwater abstraction and woodland mortality: Lessons from Namibia

In response to escalating worldwide groundwater dependence amid climate change, accurate estimation of sustainable groundwater yield becomes crucial. This study investigated the impact of groundwater abstraction on tree mortality in Namibia. We compared tree mortality around production boreholes with monitoring boreholes and we correlated groundwater decline rates with tree mortality, establishing a model from which we derived a groundwater decline rate range limit. Ana tree mortality was significantly higher (P = 0.01) around production boreholes (13.3%) than around monitoring boreholes (0%). In the dammed Swakop River, Ana tree mortality correlated with decline rates (rS = 0.64, P < 0.01). The study suggests that decline rates of above 0.2–0.23 cm day−1 may cause elevated mortality (3–7%) and should not be sustained for extended periods. Rates exceeding 0.5 cm day−1 should be avoided, while monitoring is recommended for rates between 0.23 and 0.5 cm day−1. Woodlands in rivers with altered flood frequencies may be more sensitive to groundwater abstraction than previously thought. The study's methods offer a universal framework for refining sustainable yield calculations worldwide.

Effects of groundwater level decline on soil‐vegetation system in semiarid grassland influenced by coal mining

AbstractAlthough it is well known that groundwater significantly influences the plant communities, there have been few studies on how the soil and plant communities respond to a rapid decline of groundwater in a short time affected by coal mining. This paper focuses on the examination of changes in groundwater depth before and after coal mining and the soil‐vegetation response in a typical semi‐arid grassland coal mine area of Hulunbuir Steppe, Northeastern China. The IsoSource model, based on the dual stable isotopes of δ D and δ18O, was employed to estimate groundwater contributions to shallow soil (0–100 cm) water under different groundwater depths. The results revealed that groundwater was the dominant water source (75.7% ± 17.1%) for shallow soil water when the groundwater depth is less than 4 m, indicating that 4 m is a threshold in groundwater depth, separating groundwater‐dependent, and precipitation‐driven vegetation system in the study area. Secondly, a strong nonlinear response was observed between vegetation species, height, coverage, and the decline in groundwater. The vegetation properties were found to be the lowest in the areas where groundwater depth increased from 1.5–4 m to 4–28 m before and after coal mining. Finally, the groundwater level decline in the mining area significantly influenced the groundwater‐dependent vegetation ecosystem, the soil cation exchange capacity and organic matter reduced lead to the degradation of plant communities and the transition of mesophytes to xerophytes. Besides, the soil‐vegetation system in the non‐groundwater‐dependent area has no obvious response to the groundwater decline. These results suggest that caution should be exercised when mining in groundwater‐dependent ecosystem regions.

Incorporating Spatio-Temporal Changes of Well Irrigation into a Distributed Hydrologic Model to Improve Groundwater Anomaly Estimations for Basins with Expanding Agricultural Lands

This paper seeks to address the deficiency of utilizing satellite-based GRACE observations and model-based GLDAS water budget components in estimating the changes in the groundwater storage in Konya Endorheic Basin (KEB), a basin experiencing considerable land use land cover (LULC) change, primarily agricultural expansion. Cereal cultivation in the basin has a slight decreasing trend, however, the cultivation of crops with high water consumption, such as maize and sunflower, is increasing substantially. And total agricultural areas are increasing. GRACE-GLDAS approach does not accurately give the long-term groundwater decline in the basin, mainly because the land surface models employed in GLDAS cannot realistically simulate variations in water budget components as they do not consider the changes in LULC and do not possess an elaborated irrigation scheme. Here, we used a fully-distributed mesoscale hydrologic model, mHM, that can handle multiple LULC maps from different years. The model was modified to incorporate the spatio-temporal changes of agricultural fields in KEB and an explicit irrigation scheme since we hypothesized that the groundwater depletion is mainly caused by well irrigation. mHM was calibrated against streamflow observations for the period 2004–2019. The simulations show that the use of mHM with the incorporated features gives groundwater storage changes that are more consistent with the well-based observations than those obtained from the GRACE-GLDAS approach. On the other hand, the mHM simulation with a static LULC map, as in GLDAS models but with a better representation of irrigated fields, provides groundwater anomaly changes that are more consistent with the GRACE-GLDAS results, a further justification of insufficiency of the GLDAS-based approach in estimating groundwater variations for basins with considerable landscape change.

Cover crops and irrigation impacts on corn production and economic returns

Increases in irrigated crop acreage and frequent droughts during the growing season have caused continual groundwater decline of the Mississippi River Valley Alluvial Aquifer in the Mississippi Delta region. A field experiment was conducted from 2019 to 2021 to determine if combinations of irrigation scheduling thresholds and cover crops (CCs) could improve corn (Zea mays L.) production, water productivity (WP), irrigation water use efficiency (IWUE), and net returns. The irrigation thresholds used for irrigation scheduling were a wet threshold (−40 kPa), a dry threshold (−90 kPa), and no irrigation. The CC treatments were cereal rye (Secale cereale L.), hairy vetch (Vicia villosa R.), wheat (Triticum aestivum L.)-radish (Raphanus sativus L.)-turnip (Brassica rapa L.) mix, and no cover crop. In 2020, CCs reduced corn yield by 9–26% compared to no cover crop. In 2021, wet irrigation threshold treatments had 8% and 9% higher corn yield than no irrigation and dry irrigation threshold treatments, respectively. No irrigation treatments showed higher WP than dry and wet irrigation thresholds, while hairy vetch had higher in WP among CC treatments in year two of this study. Hairy vetch under the dry irrigation threshold had higher IWUE than all other treatments. The no-CC treatments generated $167, $340, and $58 ha−1 more under the wet, dry, and no irrigation treatments, respectively, when averaged over both years. Water conservation was affected by CC selection and irrigation management.

Rainfall Variability and Rice Production: An Assessment Based on the Variability in Indian Monsoon and Ground Water Level of Punjab, India

In Punjab, 99 per cent of total cultivated area is under irrigation but it is at the cost of declining ground water table. Due to rainfall variability and very high requirement of water in rice crop, which occupy large area in the state during kharif season, has further deteriorated the situation of water resources. Therefore, this study was conducted to identify the relationship between declining groundwater level, variable monsoonal rainfall and rice yield of different agroclimatic zones of Punjab. The historical data of rainfall for different locations of Punjab viz. Amritsar (1998-2017), Ballowal Saunkhri (1998-2017), Bathinda (1998-2017), Ludhiana (1998-2017) and Patiala (1998-2017) was collected from the Department of Climate Change and Agricultural Meteorology, PAU, Ludhiana and Met Centre, IMD Chandigarh. The productivity data of rice was collected from indiastat.com and Statistical Abstract of Punjab whereas the data related to groundwater table (1998-2017) were collected from the Central Ground Water Board, Punjab. It was observed that the ground water table level showed significant decrease after 2005 at all locations and there was a positive correlation between rice yield and ground water table at all the locations except at Amritsar where it was negatively correlated. The deficit rainfall years showed very less impact on rice yield which has increased continuously. However, the relationship between groundwater table and rainfall indicated that deficit monsoonal rainfall led to further decline in groundwater table as it was not recharged.

Determination of groundwater conservation zones study by considering groundwater recharge changes

This paper aims to find a new groundwater conservation zone concept in Indonesia by improving groundwater zoning by considering groundwater recharge changes. The previous zoning criteria only used groundwater level decrease and selected groundwater quality parameters. The ideas of this new concept are related to actual conditions, in terms of groundwater recharge changes due to global climate changes that control the precipitation frequency and in terms of land use changes that control groundwater recharge quantity. The changes are dynamically altered due to anthropogenic interactions. Based on Decree No. 31 2018, the groundwater conservation zone is based on three criteria: the decline of the groundwater table, the groundwater’s physical quality, and the apparent effect on the environment. This research will improve the criteria by suggesting some improvements to that approach: firstly, the application of modeling in calculating the groundwater decline rate, secondly the investigation of the effect of recharge decline due to land use change, and lastly to include recommendations on each zone in the groundwater conservation zone. This new concept is expected will revise the previous Decree that according to the consensus approach is not a scientific approach

Extending irrigation reservoir histories for improved groundwater modeling and conjunctive water management in two Arkansas critical groundwater areas

Agricultural land managers in the Mississippi Alluvial Plain rely on the Mississippi River Valley Alluvial Aquifer for the majority of the water used for irrigation in the region. Pumping that outpaces recharge has resulted in significant cones of depression in the region, increasing pumping costs and forcing producers to use more surface water, often in the form of constructing on-farm storage reservoirs. At the same time, efforts are underway to improve groundwater models to run scenarios of conjunctive water management in the region. The improved models require accurate depiction of how the system is being managed including the use of on-farm storage reservoirs. This study extends our knowledge of on-farm storage reservoir construction from those established by a previous study that tracked reservoir construction between 1996 and 2015 backward an additional 20 years to 1976. This was accomplished by using older multi-band satellite and aerial imagery. The study area covers portions of two Critical Groundwater Regions in eastern Arkansas. Reservoir construction was classified into five-year bins starting in 1976 and ending in 2015. Details of how older imagery was processed and analyzed are provided. Previously, nearly 50% of the on-farm storage reservoirs had unknown construction dates, but this research study resolved construction dates for 85% and 72% of the reservoirs in the two study areas. Relationships between time and depth to groundwater, reservoir size, previous land use, and saturated aquifer thickness are described and contrasted in the two study areas across the 40-year study period. Use of the information provided will help guide policy and resource allocation for future reservoir construction activities and help improve conjunctive water management of the region. Specifically, the addition of this historic information will allow modelers to further refine groundwater-surface water models and should improve water resources scenarios that include reservoirs as a tool to reduce groundwater decline.