Table 2. Cross-tabulation of current land-use maps and groundwater travel-time maps categorized by land-change submodel. Values are expressed as (A) percent of total groundwatershed and (B) percentage of land-use/cover class in a groundwater travel-time class in which each class represents a backcast land-change submodel.

A. Cross-tabulation of GWTT maps with submodel classes and current land use/cover maps
GWTT class  
Urban
 
Agriculture
 
Shrub
 
Forest
 
Wetlands
 
Totals
2006 (0-age)  
2.82
 
5.32
 
3.44
 
11.59
 
3.05
 
26.23
1998–2005  
1.45
 
0.06
 
1.07
 
3.57
 
0.03
 
6.19
1978–1998  
1.30
 
1.48
 
2.01
 
9.37
 
0.32
 
14.49
1978–1939  
0.76
 
3.12
 
2.26
 
9.90
 
0.57
 
16.61
1900–1939  
0.42
 
2.68
 
1.58
 
4.56
 
0.36
 
9.60
Pre-1900  
1.15
 
11.72
 
4.24
 
8.74
 
1.04
 
26.89
Column totals  
7.92
 
24.38
 
14.59
 
47.74
 
5.37
 
100.0
% of 0-age in cover
class [(1)*100/(RT)]
 
10.76
 
20.28
 
13.12
 
44.21
 
11.63
 
 
B. Percentage of column totals
GWTT Class  
Urban
 
Agriculture
 
Shrub
 
Forest
 
Wetlands
2006 (0-age)  
35.63
 
21.82
 
23.58
 
24.29
 
56.80
1998–2005  
18.37
 
0.25
 
7.33
 
7.48
 
0.57
1978–1998  
16.44
 
6.07
 
13.79
 
19.63
 
5.98
1978–1939  
9.65
 
12.78
 
15.46
 
20.74
 
10.63
1900–1939  
5.35
 
11.00
 
10.80
 
9.55
 
6.69
Pre-1900  
14.56
 
48.08
 
29.05
 
18.30
 
19.32
Column totals  
100.0
 
100.0
 
100.0
 
100.0
 
100.0