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Managing Scarce Water Resources in Irrigated Agri-Food Systems of Central Asia Two Case Studies Full text
2017
Irrigated agriculture is the backbone of Central Asian economies. Therefore, efficient irrigation water management is of crucial importance to the sustainable crop production in the region. Presented here are two studies aiming to improve agricultural water productivity â?? ET-based irrigation scheduling in Uzbekistan; and valuation of ecosystem services in Kazakhstan. The ET-based irrigation scheduling method has potential to replace subjective daily water management decisions at Water Users Association level with crop water demand-based decisions to improve water-use efficiency. Results from a two year study show that there can be a 32-35% saving of water when irrigation is applied using the ET-based scheduling method. The pilot plots are representative of 38% of irrigated area in Fergana Valley (241,407ha) and 50% in Khorezm (137,500ha) area. If this methodology is widely adopted, large amounts of water can be saved which can be diverted for other purposes. Flood irrigation of cotton is practiced on 128,000ha in the Bugunski Reservoir watershed of Kazakhstan. This practice is unsustainable due to seasonal unavailability in water supply and depletion of river discharges that were historically important at maintaining water levels downstream in nearby wetlands and the Aral Sea. Farmer surveys were used along with RIOS and SWAT modeling to evaluate alternative irrigation practices and cropping systems that can conserve water from the Bugunski Reservoir while maintaining farmer incomes. Simulations show significant reductions in irrigation water demand in the alternative scenario relative to the baseline scenario. Under baseline flood irrigation of cotton, annual irrigation demand was 928 MCM/yr averaged over the 32 year climatic record simulated. Irrigation demand decreased by 38% to 573 MCM/yr when 40,439ha of flood irrigated cotton was converted to drip irrigated cotton, sprinkler irrigated alfalfa and drip irrigated grapes. This represents a savings of 355 MCM/yr in water extracted from irrigation canals and groundwater wells | Vinay Nangia. (7/11/2016). Managing Scarce Water Resources in Irrigated Agri-Food Systems of Central Asia Two Case Studies. Phoenix, United States: American Society of Agronomy.
Show more [+] Less [-]Assessing the impacts of nature-based solutions on ecosystem services: A Water-Energy-Food-Ecosystems nexus approach in the Nima River Sub-Basin (Colombia) Full text
2024
Restrepo, Juan Diego | Bottaro, Giorgia | Barci, Linda | Beltran, Lucila Marcela | Londoño-Behaine, Martin | Masiero, Mauro
Forest ecosystem services are critical for maintaining ecological balance and supporting human well-being from different perspectives. However, rapid land use changes driven by agricultural expansion, urbanization, and industrial activities have significantly altered forest ecosystems, degrading the services they provide. We here conduct an ecosystem service assessment through biophysical and economic estimates for a multipurpose Andean water sub-basin in western Colombia. We compare a business as usual (BAU) with a forest nature-based solution (NbS) scenario focused on forest landscape restoration. The research employed participatory methods for the NbS selection and economic valuation techniques to evaluate water flow regulation, water provisioning, water purification, and food provisioning services. Results show that the NbS scenario yielded a net positive economic impact across most evaluated ecosystem services, with notable trade-offs. Specifically, the NbS scenario increased water retention by 2.9% compared to BAU. Water flow regulation demonstrated the most substantial economic benefit, increasing by EUR 11.39 million/year in the NbS scenario. On the other hand, the food provisioning service presented a reduction of EUR 3.2 million/year in the NbS scenario. These findings highlight the potential of forest-based NbS to address the Water–Energy–Food–Ecosystem (WEFE) nexus challenges. The study’s outcomes provide valuable insights for policymakers and practitioners, supporting the development of Payment for Ecosystem Services schemes and integrating ecosystem service valuation into land use planning and decision-making processes.
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