MONITORING THE COASTAL ENVIRONMENT .1. WAVES AND CURRENTS

Measurement waves and currents in the high-energy, hazardous nearshore zone is one of the more challenging endeavors of coastal engineering and research. A measurement program must be thoroughly planned before any gauges are deployed to insure that useful data are collected: (1) Determine what data units and analyzed products are needed to answer t he critical engineering or scientific questions at the site. (2) Deter mine how long the gauges must be at the site (i.e., several years or j ust during the winter season?). (3) Consider placing gauges in locatio ns that are compatible with previous measurement programs. (4) Evaluat e environmental constraints such as ice or trawler activity. (5) Be su re that enough funding is allocated for the analysis of the data. Two general types of wave gauges are commonly used: non-directional and di rectional. Despite the greater cost and complexity, the latter is pref erred for most projects because of the need to evaluate wave refractio n at the coast. Meticulous quality control is critical for all wave me asurement programs! Three general classes of current measuring technol ogy are used in coastal projects: (1) Radar and Lagrangian methods (dy e and drogues); (2) Point source (Eulerian) technology such as ducted impeller instruments; (3) Acoustic Doppler Current Profilers. As gauge s are improved, massive amounts of data are being collected at field p rojects. Clear, simple, and concise display of wave and current data a re important aspects of the analysis procedure.