Which tool should be used to determine the most viable tract of land based on cost and environmental impact?

The most suitable tool for determining the most viable tract of land based on cost and environmental impact is the Weighted Overlay. This method allows for the consideration of multiple factors (like cost and environmental impacts) by assigning different weights to each factor based on their importance.

In a Weighted Overlay, you can combine various raster datasets, each representing a different criterion that influences the decision-making process. By applying the weights, the analysis reflects the significance of each criterion to the overall assessment. This results in a more nuanced understanding of how different areas perform concerning the evaluated factors, thus helping to identify the best tract of land for a particular purpose.

On the other hand, while Fuzzy Overlay deals with degrees of membership and allows for a more flexible treatment of data, it may not effectively handle the weighted approach required for this analysis. Fuzzy Membership and Weighted Membership focus on individual datasets and their belongingness to a category rather than properly integrating multiple criteria with varying influences, which is essential for this specific scenario.