The worsening water scarcity has imposed a significant stress on food production in many parts of the world. This stress becomes more critical when countries seek self-sufficiency. A literature ...review shows that food self-sufficiency has not been assessed as the main factor in determining the optimal cultivation patterns. However, food self-sufficiency is one of the main policies of these countries and requires the most attention and concentration. Previous works have focused on the virtual water trade to meet regional food demand and to calculate trade flows. The potential of the trade network can be exploited to improve the cropping pattern to ensure food and water security. To this end, and based on the research gaps mentioned, this study develops a method to link intra-country trade networks, food security, and total water footprints (WFs) to improve food security. The method is applied in Iran, a water-scarce country. The study shows that 781 × 10
m
of water could be saved by creating a trade network. Results of the balanced trade network are input to a multi-objective optimization model to improve cropping patterns based on the objectives of achieving food security and preventing water crises. The method provides 400 management scenarios to improve cropping patterns considering 51 main crops in Iran. Results show a range of improvements in food security (19-45%) and a decrease in WFs (2-3%). The selected scenario for Iran would reduce the blue water footprint by 1207 × 10
m
, and reduce the cropland area by 19 × 10
ha. This methodology allows decision makers to develop policies that achieve food security under limited water resources in arid and semi-arid regions.
Asia has a large water scarcity problem, especially in countries depending on irrigation, limiting agricultural production, and increasing food insecurity. When water becomes scarce, it needs ...conveyance over longer distances or pumping from deeper groundwater stocks, requiring pumping energy, often fossil energy, emitting greenhouse gasses. This causes a trade-off between irrigation water supply and fossil energy use contributing to global warming. This research focuses on the water–energy–food nexus in irrigated agriculture to improve resource management. It uses Pakistan as its case study area and assesses water consumption, energy (EFs), and carbon footprints (CFs) associated with irrigation water supply for the major crops (wheat, rice, sugarcane, and cotton) per district. The method first assesses irrigation water volumes (surface and groundwater) per crop per district and next the energy and CO
2
emissions to provide this water. Data on allocated water volumes, crop areas and pumping types were taken from governmental reports. Groundwater tables and energy data were taken from scientific publication based also on actual measurements. The research identifies unfavorable hotspots and favorable areas from a water and energy perspective. Drivers determining water consumption, EFs, and CFs related to irrigation water supply show spatial and temporal differences and include crop types, temporal crop water requirements, fractions of gravity-fed and pumped water, groundwater tables, and energy sources (diesel, electric, and solar). In Pakistan, annual irrigation supply requires 103 PJ of energy generating a CF of 11 10
9
kg CO
2
(6% of the national CF). Diesel pumps, pumping shallow groundwater, contribute most (73%), followed by electric pumps pumping deep groundwater. Energy for surface water pumping is negligible. Wheat contributes 31% to the EF, cotton 27%, and sugarcane and rice 21% each. CFs, caused by fossil energy use to pump irrigation water, are also dominated by wheat (32%) and cotton (31%), followed by rice and sugarcane (19% each). Ten hotspot districts contribute 42% to the EF of the major crops and increased by 21% in fourteen years. Wheat and cotton in Punjab and rice and cotton in Sindh are the most energy-intensive. EFs range between 3,500 and 5,000 TJ per district, with some districts in Punjab, the most important agricultural province, using even more. Large differences occur among EFs per unit of irrigation water, ranging between 7 and 2,260 KJ/m
3
, CFs between 1 and 444 g CO
2
/m
3
. The identification of hotspots may contribute to measures to minimize water consumption, EFs and CFs for agriculture in Pakistan. Other countries that also rely on irrigation could apply methods applied here to identify hotspots.
•Water, land & carbon footprints (WF, LF, CF) of meat vary across farming systems.•WF, LF & CF of chicken meat in Tunisia are 6030litre, 9m2 and 3 CO2-eq per kg.•Average WF, LF & CF of sheep meat are ...18900litre, 57m2 & 28 CO2-eq per kg.•The WF, LF & CF of chicken meat are dominated by feed production.•WF & LF of sheep meat are dominated by feed production, CF by manure & digestion.
Meat production puts larger demands on water and land and results in larger greenhouse gas emissions than alternative forms of food. This study uses footprint indicators, the water, land and carbon footprint, to assess natural resources use and greenhouse gas emissions for sheep and chicken meat produced in Tunisia in different farming systems in the period 1996–2005. Tunisia is a water-scarce country with large areas of pasture for sheep production. Poultry production is relatively large and based on imported feed. The farming systems considered are: the industrial system for chicken, and the agro-pastoral system using cereal crop-residues, the agro-pastoral system using barley and the pastoral system using barley for sheep. Chicken meat has a smaller water footprint (6030litre/kg), land footprint (9m2/kg) and carbon footprint (3 CO2-eq/kg) than sheep meat (with an average water footprint of 18900litre/kg, land footprint of 57m2/kg, and carbon footprint of 28 CO2-eq/kg). For sheep meat, the agro-pastoral system using cereal crop-residues is the production system with smallest water and land footprints, but the highest carbon footprint. The pastoral system using barley has larger water and land footprints than the agro-pastoral system using barley, but comparable carbon footprint.
This chapter gives relationships between dietary transition and income, showing trends between per capita gross domestic product (GDP) and animal versus plant energy in human food consumption. For ...small incomes, GDP increase is accompanied by changes toward more foods. Small incomes derive a large part of dietary energy from carbohydrates; meat and dairy consumption is negligible. Large incomes derive dietary energy mainly from carbohydrates and fat, with substantial contribution of meat and dairy. In Europe, the dietary transition was a gradual process, with agriculture able to keep pace with demand. Continuation of present economic trends causes pressure on natural resources, such as land and freshwater. For meat, production systems are relevant, with feed conversion efficiencies, feed composition, and feed origin as the main factors. In general, diets with meat have larger use of natural resources than diets based on plant energy. To decrease the environmental impacts of animal energy intake, important interventions need to be made through policy.
Water for bioenergy: A Global Analysis Gerbens-Leenes, P. Winnie; Hoekstra, Arjen Y.; Van der meer, Theo H.
Socioeconomic and Environmental Impacts of Biofuels,
08/2012
Book Chapter
PDF
