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title: "Ghana land use dynamics - Exploration" author: "Cecile Renier" date: "1/3/2022" output: html_document: keep_md: yes word_document: default editor_options: chunk_output_type: inline

1. Load & Clean data

2. Checks

Comparing district shapefiles

Comparing Food crop area vs. Left-over area

3. Cocoa production data

We have various cocoa datasets:

COCOBOD production data at the (old) regional level 1947 to 2019, obtained from the COCOBOD website
COCOBOD production data at the CHED district level 2014 to 2019, obtained from ETH
CIAT production data at the district AND the regional level 1980-2015, obtained on S3 (source?)
FAOSTAT production data, yields and area at the national level 2000-2019, obtained from FAOSTAT website

CIAT merged at regional level gives the same production as the published regional dataset of COCOBOD. Which means that somehow it should be possible to get the COCOBOD breakdown at district level also for the 2015-2019 period. We have the ETH data but it is CHED districts = difficult to make it correspond to the 2005 data.

Methods to get the 2005 area

average production over 4 years (for instance) around the year considered: 2004-2007 and 2018-2021 and use the 2019 yield (using the 2019 cocoa map) to estimate the area in 2005.
use the method of Valentin (with a production trend model)
use yield data from surveys around 2005, ideally per district or region

Problem of smuggled cocoa from CIV that disturbs the production data - and thus the area.

COCOBOD 2014-2019 per CHED district

COCOBOD 2014-2019 grouped per region

CIAT 1980-2015 per district --> WHERE DOES IT COME FROM? POSSIBLE TO GET UP TO 2019?

CIAT 1980-2015 grouped per region

COCOBOD 1947-2019 per region

Calculate cocoa area in 2005 and expansion area 2005-2019

## [1] 2531516

## [1] 2662292

Comparing cocoa area 2005 with cocoa-UTMF 2019

As we can see, blablabla

4. Food crop area

##  [1] "MAIZE"     "RICE"      "CASSAVA"   "YAM"       "COCOYAM"   "PLANTAIN" 
##  [7] "GROUNDNUT" "SORGHUM"   "MILLET"    "COWPEA"    "SOYABEAN"  "MAIZE "   
## [13] "RICE "

5. Land cover dynamics: Sankeys

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6. Deforestation and degradation

Direct deforestation and degradation due to Land uses

Direct deforestation and degradation due to Land uses IN PROTECTED AREAS

7. Land use expansion areas

Total expansion area of LU in all the country

Total expansion area of LU in all the cocoa-growing regions

Total expansion area of LU per cocoa-growing region

Expansion area outside forest 2005

To attribute foodcrop deforestation to LULC_i expansion, we need to remove all the expansion area that occurred on land that was forest in 2005.

Problem: cocoa direct deforestation from GEE is much higher than cocoa expansion from statistical data.

Expansion area outside forests 2005 in all the cocoa-growing regions

Now, without cocoa degradation

Expansion area outside forests 2005 per cocoa-growing region

Includes cocoa degradation

8. Estimate of food crop deforestation

The Expansion Area of food crops (i.e., food crops on land that has been mapped as losing forest cover) between year 1 to year 2 (EAfoodcrop outside forest y1→y2) is used as an estimate of the upper bar of deforestation and degradation due to food crops === > PROBLEM : this means that in the land balance equation, all the deltaF_fc (=EA_fc) is due to the expansion of food crops.

The problem is that in some regions, the remaining "other" land - not occupied by any of the considered land uses, neither by undisturbed or degraded forest, is quite large. This means that food crops could have been expanding on the "Other" land.

We include here in the calculation a factor "alpha" which = 1 when all the considered land use expands only on forest and = 0 when it expands only on 'other land' (not forest).

Results here with alpha = 1

## # A tibble: 6 x 9
##   REGION      YEAR2_HA YEAR1_HA   EA_HA LANDUSE deltaF_FC_HA deltaO_FC_HA LEFT_HA
##   <chr>          <dbl>    <dbl>   <dbl> <chr>          <dbl>        <dbl>   <dbl>
## 1 ASHANTI      484982   488568   -3586  CROP          -3586             0  1.39e6
## 2 BRONG AHAFO  702553   557497  145056  CROP         145056             0  3.34e6
## 3 CENTRAL      247770   234800   12970  CROP          12970             0  3.12e5
## 4 EASTERN      545977   471174   74803  CROP          74803             0  1.02e6
## 5 VOLTA        260385.  165919   94466. CROP          94466.            0  8.17e5
## 6 WESTERN      280529   228857.  51672. CROP          51672.            0  2.60e5
## # ... with 1 more variable: CHECK <chr>

9. Distributing remaining deforestation and degradation to LU EA

Now, trying the same but only with EA of LULC_i outside land that was forest in 2005

Share of foodcrop deforestation WITHIN protected areas attributed to land use expansion

First problem = amount of deltaF_fc in protected areas??