Annual, monthly and daily pan evaporation maps for the state of South Dakota

The design of waste stabilization and retention ponds is affected by evaporation, which is a toy parameter that determines the volume and footprint of these systems. It impacts the design life and operation of such systems. Underdesigning of such ponds can potentially lead to adverse impacts upon the environment and over designing leads to financial loss.; Determination of the pan evaporation throughout the state of South Dakota was the main objective of this study. The available pan evaporation stations are widely scattered and have incomplete records of data, necessitating a means of interpreting, adjusting and extending pan evaporation was a part of be objective. Missing data were interpolated using statistical analysis. Based on a literature search and statistical analysis, the best evaporation model was applied and calibrated with existing pan evaporation and meteorological data. The model was verified by comparing field pan evaporation with predicted pan evaporation values. The model was then used to compute spatial estimates of pan evaporation anywhere in the state of South Dakota. The pan evaporation stations from neighboring states were included in the research to give a realistic view to pan evaporation contours, and also to serve as boundary conditions.; The pan evaporation maps were presented in both paper and digital format. ArcViewRTM 3.2 was used to illustrate the maps. The exceedence levels were calculated at the 10th, 25th, 50 th, 75th and 90th percentiles to assign some level of risk to pan evaporation values.