Answer:
Around the world the most significant restriction on access to potable water is money. While access to raw water sources, clean or otherwise, is important, the purification process itself is expensive. Once water has been rendered potable, it is important that it be delivered without reintroducing contamination.
To map the field of a variable quantity, you will want to use a system of temporary reference points within the field. This way, you'll be able to move within the study area without losing your geographical references. You'll be able to map things like trees, allowing you to make repeated measurements and verify your data.
Erosion landforms start with letter e
