R/intensityAnalysis.R
intensityAnalysis.RdThis function implements an Intensity Analysis (IA) according to Aldwaik & Pontius (2012), a quantitative method to analyze time series of land use and cover (LUC) maps. For IA, a cross-tabulation matrix is composed for each LUC transition step in time.
intensityAnalysis(dataset, category_n, category_m, area_km2 = TRUE)
| dataset | list. The result object from |
|---|---|
| category_n | character. The gaining category in the transition of interest (n). |
| category_m | character. The losing category in the transition of interest (m). |
| area_km2 | logical. If TRUE the change is computed in km2, if FALSE in pixel counts. |
Intensity object
IA includes three levels of analysis of LUC changes. Consecutive analysis levels detail hereby information given by the previous analysis level (Aldwaik and Pontius, 2012, 2013).
The interval level examines how the size and speed of change vary across time intervals.
The category level examines how the size and intensity of gross losses and gross gains in each category vary across categories for each time interval.
The transition level examines how the size and intensity of a category’s transitions vary across the other categories that are available for that transition.
At each analysis level, the method tests for stationarity of patterns across time intervals.
The function returns a list with 6 objects:
lulc_table: tibble. Contingency table of LUC transitions at all
analysed time steps, containing 6 columns:
Period: <fct>. Evaluated period of transition in the format
year t - year t+1.
From: <fct>. The category in year t.
To: <fct>. The category in year t+1.
km2: <dbl>. Area in square kilometers that transited from the
category From.
to the category To in the period.
QtPixel: <int>. Number of pixels that transited from.
the category From to the category To in the period.
Interval: <int>. Interval in years of the evaluated period.
lv1_tbl: An Interval object containing the
St and U values.
category_lvlGain: A Category object
containing the gain of the LUC category in a period (Gtj).
category_lvlLoss: A Category object
containing the loss of the LUC category in a period (Lti).
transition_lvlGain_n: A Transition object
containing the annualized rate of gain in category n (Rtin) and
the respective Uniform Intensity (Wtn).
transition_lvlLoss_m: A Transition object
containing the annualized rate of loss in category m (Qtmj) and
the respective Uniform Intensity (Vtm).
Aldwaik, S. Z. and Pontius, R. G. (2012) ‘Intensity analysis to unify measurements of size and stationarity of land changes by interval, category, and transition, Landscape and Urban Planning. Elsevier B.V., 106(1), pp. 103–114. doi: 10.1016/j.landurbplan.2012.02.010 .
Aldwaik, S. Z. and Pontius, R. G. (2013) ‘Map errors that could account for deviations from a uniform intensity of land change, International Journal of Geographical Information Science. Taylor & Francis, 27(9), pp. 1717–1739. doi: 10.1080/13658816.2013.787618 .
# editing the category name SL_2002_2014$tb_legend$categoryName <- factor(c("Ap", "FF", "SA", "SG", "aa", "SF", "Agua", "Iu", "Ac", "R", "Im"), levels = c("FF", "SF", "SA", "SG", "aa", "Ap", "Ac", "Im", "Iu", "Agua", "R")) SL_2002_2014$tb_legend$color <- c("#FFE4B5", "#228B22", "#00FF00", "#CAFF70", "#EE6363", "#00CD00", "#436EEE", "#FFAEB9", "#FFA54F", "#68228B", "#636363") intensityAnalysis(dataset = SL_2002_2014, category_n = "Ap", category_m = "SG", area_km2 = TRUE) #> $lulc_table #> # A tibble: 130 × 6 #> Period From To km2 QtPixel Interval #> <fct> <fct> <fct> <dbl> <int> <int> #> 1 2002-2008 Ap Ap 6543. 7269961 6 #> 2 2002-2008 Ap Iu 1.56 1736 6 #> 3 2002-2008 Ap Ac 55.2 61320 6 #> 4 2002-2008 Ap R 23.9 26609 6 #> 5 2002-2008 FF Ap 37.5 41649 6 #> 6 2002-2008 FF FF 2133. 2370190 6 #> 7 2002-2008 FF aa 155. 172718 6 #> 8 2002-2008 FF Ac 7.48 8307 6 #> 9 2002-2008 FF R 0.356 395 6 #> 10 2002-2008 FF Im 0.081 90 6 #> # … with 120 more rows #> #> $interval_lvl #> An object of class "Interval" #> Slot "intervalData": #> # A tibble: 4 × 4 #> # Groups: Period [4] #> Period PercentChange St U #> <fct> <dbl> <dbl> <dbl> #> 1 2012-2014 3.32 1.66 1.13 #> 2 2010-2012 4.23 2.12 1.13 #> 3 2008-2010 0.880 0.440 1.13 #> 4 2002-2008 5.18 0.864 1.13 #> #> #> $category_lvlGain #> An object of class "Category" #> Slot "lookupcolor": #> Ap FF SA SG aa SF Agua Iu #> "#FFE4B5" "#228B22" "#00FF00" "#CAFF70" "#EE6363" "#00CD00" "#436EEE" "#FFAEB9" #> Ac R Im #> "#FFA54F" "#68228B" "#636363" #> #> Slot "categoryData": #> # A tibble: 23 × 6 #> # Groups: Period, To [23] #> Period To Interval GG_km2 Gtj St #> <fct> <fct> <int> <dbl> <dbl> <dbl> #> 1 2012-2014 aa 2 14.9 0.510 1.66 #> 2 2012-2014 Ap 2 612. 3.92 1.66 #> 3 2012-2014 Ac 2 110. 1.14 1.66 #> 4 2012-2014 Im 2 0.195 0.337 1.66 #> 5 2012-2014 Iu 2 6.79 2.67 1.66 #> 6 2010-2012 aa 2 47.0 1.18 2.12 #> 7 2010-2012 Ap 2 707. 4.84 2.12 #> 8 2010-2012 Ac 2 189. 2.00 2.12 #> 9 2010-2012 Iu 2 1.90 0.792 2.12 #> 10 2010-2012 R 2 2.76 0.951 2.12 #> # … with 13 more rows #> #> Slot "categoryStationarity": #> # A tibble: 12 × 5 #> To Gain N Stationarity Test #> <fct> <int> <int> <chr> <chr> #> 1 aa 2 4 Active Gain N #> 2 Ap 2 4 Active Gain N #> 3 Ac 1 4 Active Gain N #> 4 Iu 2 4 Active Gain N #> 5 Agua 1 4 Active Gain N #> 6 R 2 4 Active Gain N #> 7 aa 2 4 Dormant Gain N #> 8 Ap 2 4 Dormant Gain N #> 9 Ac 3 4 Dormant Gain N #> 10 Im 3 4 Dormant Gain N #> 11 Iu 2 4 Dormant Gain N #> 12 R 1 4 Dormant Gain N #> #> #> $category_lvlLoss #> An object of class "Category" #> Slot "lookupcolor": #> Ap FF SA SG aa SF Agua Iu #> "#FFE4B5" "#228B22" "#00FF00" "#CAFF70" "#EE6363" "#00CD00" "#436EEE" "#FFAEB9" #> Ac R Im #> "#FFA54F" "#68228B" "#636363" #> #> Slot "categoryData": #> # A tibble: 29 × 6 #> # Groups: Period, From [29] #> Period From Interval GL_km2 Lti St #> <fct> <fct> <int> <dbl> <dbl> <dbl> #> 1 2012-2014 FF 2 15.4 0.365 1.66 #> 2 2012-2014 SF 2 3.49 0.224 1.66 #> 3 2012-2014 SA 2 25.3 0.845 1.66 #> 4 2012-2014 SG 2 46.9 0.634 1.66 #> 5 2012-2014 aa 2 541. 13.6 1.66 #> 6 2012-2014 Ap 2 111. 0.759 1.66 #> 7 2012-2014 Ac 2 1.26 0.0133 1.66 #> 8 2010-2012 FF 2 11.1 0.263 2.12 #> 9 2010-2012 SF 2 4.44 0.283 2.12 #> 10 2010-2012 SA 2 29.7 0.974 2.12 #> # … with 19 more rows #> #> Slot "categoryStationarity": #> # A tibble: 14 × 5 #> From Loss N Stationarity Test #> <fct> <int> <int> <chr> <chr> #> 1 FF 1 4 Active Loss N #> 2 SF 2 4 Active Loss N #> 3 SA 2 4 Active Loss N #> 4 SG 2 4 Active Loss N #> 5 aa 3 4 Active Loss N #> 6 Ap 1 4 Active Loss N #> 7 R 1 4 Active Loss N #> 8 FF 3 4 Dormant Loss N #> 9 SF 2 4 Dormant Loss N #> 10 SA 2 4 Dormant Loss N #> 11 SG 2 4 Dormant Loss N #> 12 aa 1 4 Dormant Loss N #> 13 Ap 3 4 Dormant Loss N #> 14 Ac 4 4 Dormant Loss Y #> #> #> $transition_lvlGain_n #> An object of class "Transition" #> Slot "lookupcolor": #> Ap FF SA SG aa SF Agua Iu #> "#FFE4B5" "#228B22" "#00FF00" "#CAFF70" "#EE6363" "#00CD00" "#436EEE" "#FFAEB9" #> Ac R Im #> "#FFA54F" "#68228B" "#636363" #> #> Slot "transitionData": #> # A tibble: 20 × 7 #> # Groups: Period, From [20] #> Period From To Interval T_i2n_km2 Rtin Wtn #> <fct> <fct> <fct> <int> <dbl> <dbl> <dbl> #> 1 2012-2014 FF Ap 2 12.9 0.307 2.03 #> 2 2012-2014 SF Ap 2 2.38 0.152 2.03 #> 3 2012-2014 SA Ap 2 18.1 0.605 2.03 #> 4 2012-2014 SG Ap 2 42.1 0.569 2.03 #> 5 2012-2014 aa Ap 2 537. 13.5 2.03 #> 6 2010-2012 FF Ap 2 3.63 0.0856 2.26 #> 7 2010-2012 SF Ap 2 1.08 0.0685 2.26 #> 8 2010-2012 SA Ap 2 12.3 0.403 2.26 #> 9 2010-2012 SG Ap 2 8.53 0.114 2.26 #> 10 2010-2012 aa Ap 2 682. 13.0 2.26 #> 11 2008-2010 FF Ap 2 0.968 0.0227 0.0610 #> 12 2008-2010 SF Ap 2 1.10 0.0694 0.0610 #> 13 2008-2010 SA Ap 2 0.971 0.0314 0.0610 #> 14 2008-2010 SG Ap 2 3.94 0.0524 0.0610 #> 15 2008-2010 aa Ap 2 12.0 0.233 0.0610 #> 16 2002-2008 FF Ap 6 37.5 0.268 0.323 #> 17 2002-2008 SF Ap 6 24.8 0.453 0.323 #> 18 2002-2008 SA Ap 6 65.8 0.608 0.323 #> 19 2002-2008 SG Ap 6 48.3 0.198 0.323 #> 20 2002-2008 aa Ap 6 130. 1.02 0.323 #> #> Slot "transitionStationarity": #> # A tibble: 7 × 5 #> From Loss N Stationarity Test #> <fct> <int> <int> <chr> <chr> #> 1 SF 2 4 targeted by Ap N #> 2 SA 1 4 targeted by Ap N #> 3 aa 4 4 targeted by Ap Y #> 4 FF 4 4 avoided by Ap Y #> 5 SF 2 4 avoided by Ap N #> 6 SA 3 4 avoided by Ap N #> 7 SG 4 4 avoided by Ap Y #> #> #> $transition_lvlLoss_m #> An object of class "Transition" #> Slot "lookupcolor": #> Ap FF SA SG aa SF Agua Iu #> "#FFE4B5" "#228B22" "#00FF00" "#CAFF70" "#EE6363" "#00CD00" "#436EEE" "#FFAEB9" #> Ac R Im #> "#FFA54F" "#68228B" "#636363" #> #> Slot "transitionData": #> # A tibble: 14 × 7 #> # Groups: Period, To [14] #> Period To From Interval T_m2j_km2 Qtmj Vtm #> <fct> <fct> <fct> <int> <dbl> <dbl> <dbl> #> 1 2012-2014 aa SG 2 4.76 0.163 0.125 #> 2 2012-2014 Ap SG 2 42.1 0.270 0.125 #> 3 2012-2014 Ac SG 2 0.0621 0.000642 0.125 #> 4 2010-2012 aa SG 2 18.9 0.475 0.0749 #> 5 2010-2012 Ap SG 2 8.53 0.0584 0.0749 #> 6 2010-2012 Ac SG 2 0.632 0.00669 0.0749 #> 7 2008-2010 aa SG 2 30.6 0.584 0.0929 #> 8 2008-2010 Ap SG 2 3.94 0.0290 0.0929 #> 9 2008-2010 Ac SG 2 0.0873 0.000962 0.0929 #> 10 2008-2010 Iu SG 2 0.0504 0.0213 0.0929 #> 11 2002-2008 aa SG 6 244. 1.58 0.273 #> 12 2002-2008 Ap SG 6 48.3 0.118 0.273 #> 13 2002-2008 Ac SG 6 13.1 0.0489 0.273 #> 14 2002-2008 R SG 6 0.0999 0.0129 0.273 #> #> Slot "transitionStationarity": #> # A tibble: 6 × 5 #> To Gain N Stationarity Test #> <fct> <int> <int> <chr> <chr> #> 1 aa 4 4 targeted SG Y #> 2 Ap 1 4 targeted SG N #> 3 Ap 3 4 avoided SG N #> 4 Ac 4 4 avoided SG Y #> 5 Iu 1 4 avoided SG N #> 6 R 1 4 avoided SG N #> #>