Final answer:
Maya should use a water use calculator to measure irrigation water use reduction, and the most appropriate metric unit for her family's annual water use in Australia would likely be kiloliters (kL). The ESRI GEO Inquiry tool can help students understand the broader impacts of water use.
Step-by-step explanation:
To calculate the irrigation water use reduction compared to a baseline for WEp Outdoor Water Use Reduction, Maya would likely use a water use calculator designed for this purpose. In the context of Australia, where water conservation is important, the calculator would take into account the duration of showers, frequency of laundry and dishwasher use, and lawn watering practices, often using questions from a survey that Maya completed about her family's water usage habits.
When deciding on the most appropriate metric unit for estimating her family's yearly water use, Maya would typically use liters (L) for smaller volumes or kiloliters (kL) for larger volumes, as these are the standard metric units for measuring volume in Australia. In the provided case, given that it's a yearly estimate of a household's water consumption, kiloliters would be the most likely choice due to the larger quantities of water being used.
In educational settings, teachers can further illustrate water use through tools like the ESRI GEO Inquiry where students can explore the impacts of human activities on water resources worldwide using online mapping software. Additionally, understanding the global water use through the lens of virtual water flow in international trade can contextualize the broader implications of water conservation measures.