Global Waterbody Calculator: A high-resolution global database of lakes and reservoirs depth-area-volume (D-A-V) relationships

Abstract

The new GLRDAV database assembles key morphometric characteristics for over 1.4 million lakes and reservoirs. By integrating data from HydroLAKES and GLOBathy, more than 17 million polynomial (orders 1-5) and power functions describing depth-area-volume (D-A-V) relationships at a 0.1 m depth resolution are presented. The D-A-V relationships are validated against existing databases (ReGeom and GRDL) that provide comparable or simplified global bathymetric relationships, as well as in situ measurements for four waterbodies in the Texas Water Development Board (TWDB). The results show that higher-order polynomial equations (particularly orders 4 and 5) generally yield the lowest RMSE and highest goodness-of-fit (i.e., R^2). Although power functions and lower-order polynomials can offer reasonable representations for simpler and shallower systems, they typically underperform when applied to large or morphologically complex lakes and reservoirs. Our findings underscore the flexibility and robustness of GLRDAV, offering a globally consistent, high-resolution, and computationally scalable resource for hydrological, ecological, and water resource management applications.