Using nontraditional water sources and implementing water conservation practices under changing climate

Abstract

Abstract. Agriculture is the largest water-consuming sector on global level, and this consumption is about two-thirds of the entire freshwater consumption. With the change in climate, the requirement for irrigation water is increasing, though the availability of freshwater is decreasing accordingly. Shortage of freshwater sources leads to a decrease in the number of productive farms, irrigated areas, and crop yield. In the US, the primary sources of irrigation are 1) groundwater from on-farm wells (often freshwater from the confined aquifers), 2) on-farm surface water, and 3) off-farm water from a variety of sources. To reduce the pressure on the freshwater sources and keep up the productivity of the farms, it is necessary to consider alternative sources of water. For this reason, the idea of using recycled water came forward. Many countries around the world and Some of the western states in the US have already started using recycled water as a source of irrigation water. There are other solutions including demand management strategies, such as using modern irrigation technologies with high application efficiencies, water-conserving Best Management Practices (BMPs), and the development of drought-resistant crops. Though limited, recycled water is being used for irrigation in Maryland, a temperate zone, as well. Despite a lot of benefits, wastewater use has some challenges e.g., recycled water quality, social acceptance, and conflicts between different stakeholders. This presentation will cover the results of a hydrologic model (e.g., Soil Water Assessment Tool - SWAT) and the agent-based model to identify the need and challenges of using recycled water in Maryland, analyze the demand for recycled water use in irrigation, and develop a Diagnostic Decision Support System (DDSS) that helps provide alternative water management recommendations to the stakeholders. In this framework, the SWAT model is used to determine and forecast crop water requirements based on long-term climate variability, and the agent-based modeling system is used to investigate how the adoption of water management strategies emerges because of socio-economic factors and human-environment interactions, and how management policies influence this process. For the initial analysis, two different watersheds have been chosen in Maryland. These two watersheds are the Zekiah Watershed and the Greensboro Watershed. Although both watersheds are within the Coastal Plain Physiographic region and drain to Chesapeake Bay, they are different in demography, land use, and water demand. Results indicate that differences in these watersheds dictate specific water management strategies based on the soils, land use, and demographics present in each watershed.