I have some depth measurements and corresponding area at each depth of a water column:

```
depth = [0,2,4,6,7,9,10];
Area = [2000,1890,1873,1654,1523,1433,1200];

figure(1);
plot(Area,depth);set(gca,'ydir','reverse');

```

I want to calculate the volume of water between each depth indicated and then calculating the entire volume of water from this. Firstly I have interpolated the depth and area values to improve the accuracy of the calculation:

```
dz = 0.1;
newD = min(depth):dz:max(depth);
newA = interp1(depth,Area,newD);

figure(2);
plot(newA,newD);set(gca,'ydir','reverse');

```

Where would I go from here for calculating the volume of water between each of the depths?