Direct/Delayed Response Project: Definition of Soil Sampling Classes and Selection of Sampling Sites for the Northeast

EPA/600/3-89/041The Direct/Delayed Response Project (DDRP) has been designed and implemented to estimate the number of lakes and streams that might become acidic in three regions due to current or altered levels of acidic deposition. As part of DDRP, 145 watersheds in the northeast US were mapped at 1:24,000 for soils, vegetation, depth to bedrock, and bedrock geology. About 600 soils were identified during mapping. These were grouped into 38 soil sampling classes. Each of these was sampled about 8 times across the region, so that regional means and standard deviations of soil properties could be computed for each class. The regional soil data will be used with the soil maps to estimate soil properties for each watershed. The watershed estimates will be used in the array of DDRP models to estimate future effects of acidic deposition on lakes in the northeast. The sampling classes were developed at a workshop held in Corvallis, Oregon July 16-18, 1985. The report documents the process and decisions of the workshop