Digital Soil Mapping

Generation of Sample Site Locations [sp package for R]

Submitted by dylan on Fri, 2008-08-15 04:56.

 
Premise
Setting up sampling designs is a non-trivial aspect to any field experiment that includes a spatial component. The sp package for R provides a simple framework for generating point sampling schemes based on region-defining features (lines or polygons) and a sampling type (regular spacing, non-aligned, random, random-stratified, hexagonal grid, etc.). The rgdal package provides a set of functions for importing/exporting common vector data formats. This example demonstrates simple import/export, iterating over sp objects, and reconstituting new objects from lists of objects. A more complex sampling scheme is demonstrated here.

Sensor Installation

Submitted by dylan on Thu, 2008-05-29 23:37.

Sensor installation at SJER 5-1 detail

Submitted by dylan on Thu, 2008-05-29 23:37.
Sensor installation at SJER 5-1 detail

EC-5 sensors installed at 10cm, 30cm, and 50cm. ECT sensors installed at 30cm and 50cm.

Sensor installation at SJER 5-1

Submitted by dylan on Thu, 2008-05-29 23:36.
Sensor installation at SJER 5-1

EC-5 sensors installed at 10cm, 30cm, and 50cm. ECT sensors installed at 30cm and 50cm.

SJER RU 5-1 Estimated Soil Series Map

Submitted by dylan on Wed, 2008-05-14 19:20.
SJER RU 5-1 Estimated Soil Series Map

Preliminary estimation of three landscape units and associated soil series.

San Joaquin Experimental Range (SJER)

Submitted by dylan on Mon, 2008-04-07 16:08.

 
Site Description:

Pedon Sampling: Status and Future Planning

Submitted by dylan on Wed, 2007-02-07 20:29.

 
Overview:
Description of the sampling density of completed soil survey efforts. Identification of under-sampled, critical areas (for solar-radiation modeling study), and creation of a sampling plan for spring 2007. A (nearly) design-based 'cluster random sampling' scheme (de Gruijter et al, 2006) will be used to address the main problems with collecting field samples at Pinnacles:

  1. accessibility and navigation are limiting factors
  2. travel time and navigation are equally problematic
  3. significant gradients exist in known areas, and are of particular interest (landscape orientation and slope)

Finding pockets of soil between the Pinnacles

Submitted by dylan on Wed, 2006-04-26 06:38.

Using ColorBrewer to assist with thematic map color selection

Submitted by dylan on Mon, 2006-02-27 19:26.

Computing terrain-specific slope classes by region

Submitted by dylan on Sun, 2006-02-26 21:46.

 

Background

Four regions were selected within the PINN boundary for analysis of intrinsic slope classes, based on terrain type.Figure 1 illustrates the four regions that were choosen. Figure 2 shows histograms of each region along with intrinsic slope class breaks (red) and NRCS slope class breaks (gray). Note that NRCS slope classes were derived from a similar analysis (k-means clustering) of slope values from the entire park: e.g. without regard for specific landform. See attached PDF version of Figure 2 at the bottom of this page.