I have a set of xyz (z points are negative) points obtained from a bathymetric survey of a lake. We are trying to determine the thickness of sediments accumulated over a year. I will be comparing data from last year to those we just obtained. I just have some questions and was also wondering if the workflow below is the right approach to arrive at the goal:
1. convert points to TIN
- will the negative depth values interfere with the conversion of the data to TIN?
2. convert TIN to raster
- is this step necessary or can I directly compute the surface volume just with the TIN?
3. Use Surface Volume tool
- what should be the plane height? While onboard the boat, GPS gave an elevation of 7 meters at one point
4. Do steps 1-3 for newer dataset and compare the two volumes calculated to arrive at the volume of sediments accumulated, I'm assuming the boundary/mask feature should be the same for both of the TIN?
P.S. - the lake is actually connected to a major river and essentially drains to the sea
