Operations in Range Unit 5-1

Image: Deconstructing NAIP Imagery

Problem Statement:
Foothill regions represent an important link in the storage and movement of surface waters in California. Low characteristic slopes and weakly permeable bedrock contribute to relatively long periods in which water is in contact with plant and soil material. Understanding the behavior of water and its constituents in foothill conditions is critical to predicting how this system will react to perturbations induced by climate change. Since movement and chemistry of surface water are strongly controlled by soil characteristics, detailed inventories of soil resources in foothill regions will be of increasing value to planners and scientists.

Soil Survey has traditionally mapped foothill regions at a very coarse scale, under the original pretext that the land would only ever be used as range. Rapid development in the foothills suggests that the soil resources of the foothills need a fresh look; both in terms of data quality and scale.

Working Hypotheses:

  1. soil parameters can be predicted via terrain/vegetation induced variation in microclimate and landscale position
  2. an updated soil inventory for foothill regions can be generated via several benchmark landscapes on representative geologies


  1. generate raster-based, high resolutions of soil resources along with an assessment of uncertainty
  2. quantify soil microclimate
  3. quantify an "effective precipitation" as a function of location
  4. quantify variation in mineral weathering rates as a function of soil microclimate
  5. establish new methods and tools for use in the development and reporting of soil survey information


  1. topographic survey by RTK GPS
  2. installation of 15 pits instrumented with moisture and temperature sensors
  3. installation of 9 pits instrumented with zero-tension lithium lysimeters
  4. field description of an additional 10 pits
  5. supplimental auger observations and sampling
  6. lab characterization of all samples


Trees in SJER RU 5-1: Oak tree distribution as estimated from NAIP imagery and SMAP supervised classification.