PMP Estimation for Mine Tailings Dams in Data Limited Regions

Applied Weather Associates (AWA) recently completed Probable Maximum Precipitation (PMP) and detailed meteorological analyses for several mining locations effected by limited data, extreme meteorological patterns, and highly variable topographic settings. These included a large mine in Papua, Indonesia; a high elevation mine in north central Peru; and a large mine in northern Chile.

AWA utilizes a storm-based approach to derive PMP, following the methods descried in Mukhopadhyay and Kappel (2016), the World Meteorological Organization (2009), and Schreiner and Riedel (1978). Additional meteorological parameters, such as Annual Exceedance Probabilities (AEP) of PMP, regional precipitation frequency (PF) climatologies, and Depth-Duration-Frequency (DDF) curves were also derived. Previous PMP projects completed by AWA provide examples which explicitly considered the topography and meteorological characteristics of each study location. Several of these provided valuable insight about the interaction of extreme precipitation over climatologically similar regions to the mining locations discussed in this paper (Fig. 1). These PMP studies have received extensive review, and the results have been used in computing the Probable Maximum Flood (PMF) for the watersheds and regions covered. The mine locations discussed in this paper were able to leverage those previous studies and follow the same accepted procedures to determine PMP values, to develop the PF database, and calculate other meteorological data for each location.