Ground water tables in Punjab are declining at alarming rates in most districts of Punjab. One of the major causes of declining water tables is the increased cropping intensity. Whereas cropping intensity in Punjab was only 120% until about 50 years ago, it is now 190%. With one crop per year, a balance was maintained between water extraction and aquifer recharge. With two crops per year, this balance has been altered. Homogenization of crops in the state has also exacerbated the problem. Even more serious threat to nation’s agriculture is climate change. Himalayan glaciers, which are water towers for our rivers, are retreating. This will reduce the water flow in our rivers. While the climate-change impact on our water availability is several years away, we must address immediate problem of declining water tables in the state. Suggested interventions include crop diversification, precision agriculture, including water saving technologies, and developing crop varieties with improved water-use efficiency.

The North China Plain (NCP) is a major food producing region in China. Overexploitation of groundwater for irrigation and overapplication of nitrogen (N) fertilizer have contributed to increased food production but have also resulted in water shortages and groundwater contamination. This paper reviews potential conflicts between strategies that ensure water security, food security, and water pollution reduction in the NCP. It outlines some agriculture-related strategies for resolving water shortages. Besides water saving and N saving technologies, policies such as fallow tillage, a water transfer project accounting for the recovery of groundwater level, and N management limiting N input in farmland are discussed. In particular, there are conflicts between the strategies for recovering shallow groundwater and releasing N from the unsaturated zone to the aquifer in the piedmont plain because a large amount of N is stored in the thick unsaturated zone. A transition from food-oriented strategies to sustainable development management of resources and the environment is necessary. To benefit from synergies and avoid tradeoffs between water security, food security, and clean water in the NCP, we must combine water and N management, groundwater level and water quantity control, socioeconomic issues, and climate change.

This paper presents the first groundwater‒energy‒food (GEF) nexus study of Iran’s agronomic crops based on national and provincial datasets and firsthand estimates of agricultural groundwater withdrawal. We use agronomic crop production, water withdrawal, and energy consumption data to estimate groundwater withdrawal from electric-powered irrigation wells and examine agronomic productivity in Iran’s 31 provinces through the lens of GEF nexus. The ex-post GEF analysis sheds light on some of the root causes of the nation’s worsening water shortage problems. Access to highly subsidized water (surface water and groundwater) and energy has been the backbone of agricultural expansion policies in Iran, supporting employment in agrarian communities. Consequently, water use for agronomic crop production has greatly overshot the renewable water supply capacity of the country, making water bankruptcy a serious national security threat. Significant groundwater table decline across the country and increasing energy consumption underscore dysfunctional feedback relations between agricultural water and energy price and groundwater withdrawal in an inefficient agronomic sector. Thus, it is essential to implement holistic policy reforms aimed at reducing agricultural water consumption to alleviate the looming water bankruptcy threats, which can lead to the loss of numerous agricultural jobs in the years to come.

Understanding the complexity and feedbacks among food, energy, and water (FEW) systems is key to making informed decisions about sustainable development. This paper presents qualitative representation and quantitative system dynamics simulation of the water resources system in the Qazvin Plain, Iran, taking into account the energy intensity of water supply and interconnected water use sectors (e.g., urban, industrial, and agricultural). Qazvin Plain faces water resources challenges that are common to arid/semi-arid areas, including frequent droughts, declining surface water and groundwater, and increased urban and agricultural water demand. A system dynamics model is developed using historical data (2006–2016) to investigate the effects of anticipated dynamics of integrated water and energy sectors in the next two decades. The results of policy scenarios (2020–2039) demonstrate that the continuation of the existing management policies will cause severe damage to the water and energy sectors, pushing the system towards water resources limits to growth. An annual groundwater table decline of nearly 1 m is anticipated, indicating significant overshoot of the plain's natural recharge capacity, which may lead to the depletion of recoverable groundwater in the plain within the next three decades. The groundwater table decline will cause energy consumption of water supply to increase by about 32% (i.e., 380 GWh) to maintain irrigated agriculture. It is critical to implement a combination of water demand and supply management policies (e.g., net agricultural water savings and recycling treated wastewater) to delay the problem of water limits to growth in the region.

Land application of food-processing waste water occurs throughout California's Central Valley and may be degrading local ground water quality, primarily by increasing salinity and nitrogen levels. Natural attenuation is considered a treatment strategy for the waste, which often contains elevated levels of easily degradable organic carbon. Several key biogeochemical processes in the vadose zone alter the characteristics of the waste water before it reaches the ground water table, including microbial degradation, crop nutrient uptake, mineral precipitation, and ion exchange. This study used a process-based, multi-component reactive flow and transport model (MIN3P) to numerically simulate waste water migration in the vadose zone and to estimate its attenuation capacity. To address the high variability in site conditions and waste–stream characteristics, four food-processing industries were coupled with three site scenarios to simulate a range of land application outcomes. The simulations estimated that typically between 30 and 150% of the salt loading to the land surface reaches the ground water, resulting in dissolved solids concentrations up to sixteen times larger than the 500 mg L⁻¹ water quality objective. Site conditions, namely the ratio of hydraulic conductivity to the application rate, strongly influenced the amount of nitrate reaching the ground water, which ranged from zero to nine times the total loading applied. Rock–water interaction and nitrification explain salt and nitrate concentrations that exceed the levels present in the waste water. While source control remains the only method to prevent ground water degradation from saline wastes, proper site selection and waste application methods can reduce the risk of ground water degradation from nitrogen compounds.

Environmental analyst Lester R. Brown documents the ways In which human demands are outstripping the earth's natural capacities--and how the resulting environmental damage is undermining food production.--From publisher description.

The winter wheat–summer maize double cropping system caused overexploitation of groundwater in the North China Plain; it is unsustainable and threatens food security and the overall wellbeing of humankind in the region. Finding water-saving cropping systems without compromising food security is a more likely solution. In this study, six alternative cropping systems’ water conservation and food supply capacity were compared simultaneously. A combined water footprint method was applied to analyze the cropping systems’ water consumption. The winter wheat–summer maize system had the largest water consumption (16,585 m³/ha on average), followed by the potato/spring maize, spinach–spring maize, rye–spring maize, vetch–spring maize, pea/spring maize, soybean||spring maize and mono-spring maize cropping systems. For the groundwater, the spinach–spring maize, pea/spring maize, soybean||spring maize systems showed a higher degree of synchronization between crop growth period and rainfall, which could reduce use of groundwater by 36.8%, 54.4% and 57.6%, respectively. For food supply capacity, the values for spinach–spring maize, pea/spring maize, soybean||spring maize systems were 73.0%, 60.8% and 48.4% of winter wheat–summer maize, respectively, but they showed a better feeding efficiency than the winter wheat–summer maize system. On the whole, spinach–spring maize may be a good option to prevent further decline in groundwater level and to ensure food security in a sustainable way.

Riparian areas of riverine plains develop extensive floodable areas named riverine wetlands, which are essential to the water cycle balance and ecosystem dynamics. In this study, we contrasted the hydrological and physicochemical variables of riverine wetlands of both peri-urban areas impacted by intensive farming and those of rural areas with the indicators of the biotic structure (taxonomic richness, Shannon diversity and total density) of benthic diatoms, phytoplankton, zooplankton, macroinvertebrates, chironomids, fishes, turtles, and birds. The study was performed on riverine waters of the Pampean plain, Argentina, with four seasonal samplings conducted in 2017–2018. Our results showed that the significant deepening of the groundwater level caused by aquifer overexploitation in peri-urban areas, as well as the declining surface water quality with higher phosphorus and total nitrogen concentrations, affected the taxonomic richness, diversity, and total density of the biotic assemblages of riverine wetlands. The taxonomic richness of birds, turtles, phytoplankton, chironomids, and fishes was the most sensitive to land use. Phytoplankton, chironomid, and fish diversity showed the greatest differences between rural and peri-urban riverine waters, while the total density of chironomids and birds showed the greatest differences according to land use. The results suggest that the socioeconomic development in those riverine wetlands that still maintain conditions close to the natural ones needs to be subject to guidelines derived from integrated basin management and sustainable urban planning.

The North China Plain (NCP) is one of the major grain production areas in China where the groundwater level has declined rapidly in recent years because of irrigation. To alleviate the pressure on water resources, in 2016, the government developed and implemented a reasonable subsidy policy, known as the Winter Fallow Policy (WFP), to fallow cultivated land in a selected pilot area in the funnel region (Heilonggang region, HR). In the present study, a large-scale household survey was conducted across the NCP groundwater overexploitation region (OR) to evaluate the possible impact of the WFP on groundwater and food security. Our survey results indicated that the education level of decision makers, the dependency ratio of farmers, laborers per cultivated area, and the magnitude of the importance of water-saving in agriculture of decision makers have significant impacts on farmers' willingness to fallow. The average ecological compensation (EC) was 8781 CNY/ha (1358 USD/ha) and varied from 6932 to 10816 CNY/ha (1072–1673 USD/ha) in different counties. Winter wheat fallow in semiarid, dry subhumid and humid areas can save approximately 4642, 3325 and 1906 m³/ha, respectively, of groundwater in the OR. In the HR, a fallow area of 0.31×10⁶ ha is recommended for maintaining the current groundwater table, and an area of 0.42×10⁶ ha is recommended for restoring or recovering groundwater resources; these areas are greater than the existing fallow area and will reduce wheat yields, accounting for 1.55% and 2.08%, respectively, of national wheat production. Thus, EC standards should be determined based on local commodity price standards and modified based on annual changes in local conditions. Furthermore, the winter fallow acreage should be expanded in the HR to maintain the groundwater table.

The feasibility of a hydrogeological modeling approach to simulate several thousand shallow groundwater-fed lakes and wetlands without explicitly considering their connection with groundwater is investigated at the regional scale (~40,000 km²) through an application in the semi-arid Nebraska Sand Hills (NSH), USA. Hydraulic heads are compared to local land-surface elevations from a digital elevation model (DEM) within a geographic information system to assess locations of lakes and wetlands. The water bodies are inferred where hydraulic heads exceed, or are above a certain depth below, the land surface. Numbers of lakes and/or wetlands are determined via image cluster analysis applied to the same 30-m grid as the DEM after interpolating both simulated and estimated heads. The regional water-table map was used for groundwater model calibration, considering MODIS-based net groundwater recharge data. Resulting values of simulated total baseflow to interior streams are within 1% of observed values. Locations, areas, and numbers of simulated lakes and wetlands are compared with Landsat 2005 survey data and with areas of lakes from a 1979–1980 Landsat survey and the National Hydrography Dataset. This simplified process-based modeling approach avoids the need for field-based morphology or water-budget data from individual lakes or wetlands, or determination of lake-groundwater exchanges, yet it reproduces observed lake-wetland characteristics at regional groundwater management scales. A better understanding of the NSH hydrogeology is attained, and the approach shows promise for use in simulations of groundwater-fed lake and wetland characteristics in other large groundwater systems.