Mark Horner

CE 547

Spring 2006

Assignment 6

1) Download & extract STATSGO data for New Mexico from the NRCS website:

2) Add data to ArcMap and change Symbology:

3) Use “pecoshuc” (from Assignment 5) to clip NM STATSGO data:

STATSGO soils

data clipped with pecoshuc

4) Add Info tables: mapunit, layer, and comp to .mxd project. Join mapunit table to

pecoshuc_statsgo; a many (other attributes)-to-one (unique record in the attribute table)

relationship:

5) To be Turned in – Describe NM963 in terms of the properties in Mapunit and Component tables:

b) Q: What are their names? A: Regnier (three components), Latom (two components),

Rock Outcrop, Los Tanos, and Gallen.

c) Q: What percentage of the map unit does each component comprise? A: In mapunit order

(superscript) – Regnier¹ = 27%, Regnier⁵ = 7%, Regnier⁷ = 3%; Latom² = 27%, Latom⁶ = 5%;

Rock Outcrop³ = 18%; Los Tanos⁴ = 12%; Gallen⁸ = 2%.

d) Q: What is the predominant surface slope where this soil unit is found? A: The soil unit

contains various slopes from 0-99% slope; however the predominant (most frequently occurring

bounded range) appears to be 0-40% slope - six of the eight components (75% of the total soil

unit has lower and upper limits in this range).

e) Q: What is the dominant soil texture? A: The dominant surface soil texture appears to be

Loamy soils (L) of various combinations (i.e. CL and SL).

f) Q: What percentage of the soil is in hydrologic soil groups A, B, C, and D? A: A = 0%; B = 2%;

C = 12%; and D = 86%

g) Q: Do these soil properties make sense considering where this soil is located? A: Yes, given that

this assemblage (soil unit) is located along the Pecos River and the depositional nature of upstream

sediment transport and river avulsion and channel incision (for slope) – see below.

NM963

6) Relate pecos_statsgo (having Joined mapunit table with the attributes) with comp table

using the field mapunit:MUID as the unique identifier. Thus a typically one-to-many or

many-to-many record relationship:

7) Set visible fields of layer table to select few:

8) Relate layer and comp tables:

9) Selection of NM120 and the related table attributes:

10) To be turned in – mapunit NM963

a) Q: How many layers does each component have? A: See table below.

b) Q: What is the total soil depth for each layer? A: See table below.

c) Q: What is the average depth for the mapunit? A: 29.68 in.

d) Q: What is the total water holding capacity over the full soil depth for

each component? A: See table below.

e) Q: What is the average water holding capacity for soils in this mapunit?

A: 1.88 in.

11) Download (http//:rgis.unm.edu), classify, and append land use/land cover:

12) Intersect land use and soils and create layout: