This is the project in SQL nanodegree program from Udacity
- The pdf file Pranay_project_deforestation_exploration_solution.pdf is the project report.
- images folder contains images of the outputs of all the queries which I have ran.
- Understand which countries and regions around the world seem to have forests that have been shrinking in size.
- Which countries and regions have the most significant forest area both in terms of total area and % of total area.
Making informed and well motivated decisions with respect to making the biggest impact given the few resources available.
CREATE OR REPLACE VIEW forestation
AS
SELECT f.country_code AS forest_cc,
f.country_name AS f_name,
f.year AS f_year,
f.forest_area_sqkm AS f_sq_km,
l.total_area_sq_mi AS l_total_area_sq_mi,
r.region AS r_region, r.income_group AS r_income_group,
(f.forest_area_sqkm/(l.total_area_sq_mi*2.59))*100 AS perc_forest_area
FROM forest_area f
Join land_area l
ON f.country_code = l.country_code
JOIN regions r
ON l.country_code = r.country_code
WHERE f.year = l.year ORDER BY 1;- What was the total forest area (in sq km) of the world in 1990? Please keep in mind that you can use the country record denoted as "World" in the region table.?
SELECT f.forest_area_sqkm
FROM forest_area f
WHERE f.country_name = 'World'
AND f.year = 1990;
- What was the total forest area (in sq km) of the world in 2016? Please keep in mind that you can use the country record in the table is denoted as "World"?
SELECT f.forest_area_sqkm
FROM forest_area f
WHERE f.country_name = 'World'
AND f.year = 2016;
- What was the change (in sq km) in the forest area of the world from 1990 to 2016?
SELECT sub1.forest_area_sqkm - sub2.forest_area_sqkm AS diff_forest_area_sq_km
FROM (SELECT f.country_code AS cc, f.forest_area_sqkm
FROM forest_area f
WHERE f.country_name = 'World'
AND f.year = 1990) AS sub1
JOIN (SELECT f.country_code AS cc,f.forest_area_sqkm
FROM forest_area f
WHERE f.country_name = 'World'
AND f.year = 2016) AS sub2
ON sub1.cc = sub2.cc;
- What was the percent change in forest area of the world between 1990 and 2016?
SELECT ((sub1.forest_area_sqkm-sub2.forest_area_sqkm)/sub1.forest_area_sqkm)*100 AS perc_change_fa
FROM (SELECT f.country_code AS cc, f.forest_area_sqkm
FROM forest_area f
WHERE f.country_name = 'World'
AND f.year = 1990) AS sub1
JOIN (SELECT f.country_code AS cc,f.forest_area_sqkm
FROM forest_area f
WHERE f.country_name = 'World'
AND f.year = 2016) AS sub2
ON sub1.cc = sub2.cc;
- If you compare the amount of forest area lost between 1990 and 2016, to which country's total area in 2016 is it closest to?
SELECT l.country_name,
l.total_area_sq_mi*2.59 AS total_area_sqkm,
ABS((l.total_area_sq_mi*2.59)- (SELECT sub1.forest_area_sqkm - sub2.forest_area_sqkm AS diff_forest_area_sq_km
FROM (SELECT f.country_code AS cc, f.forest_area_sqkm
FROM forest_area f
WHERE f.country_name = 'World'
AND f.year = 1990) AS sub1
JOIN (SELECT f.country_code AS cc,f.forest_area_sqkm
FROM forest_area f
WHERE f.country_name = 'World'
AND f.year = 2016) AS sub2
ON sub1.cc = sub2.cc)) AS diff_fa_la_sqkm
FROM land_area l
WHERE l.year = 2016
ORDER BY 3 LIMIT 1;
- Create a table that shows the Regions and their percent forest area (sum of forest area divided by sum of land area) in 1990 and 2016. (Note that 1 sq mi = 2.59 sq km).
CREATE OR REPLACE VIEW regional_distr
AS
SELECT r.region,
l.year,
SUM(f.forest_area_sqkm) total_forest_area_sqkm,
SUM(l.total_area_sq_mi*2.59) AS total_area_sqkm,
(SUM(f.forest_area_sqkm)/SUM(l.total_area_sq_mi*2.59))*100 AS percent_fa_region
FROM forest_area f
JOIN land_area l
ON f.country_code = l.country_code AND f.year = l.year
JOIN regions r
ON l.country_code = r.country_code
GROUP BY 1,2
ORDER BY 1,2;- What was the percent forest of the entire world in 2016?
SELECT ROUND(CAST(percent_fa_region AS numeric),2) AS percent_fa_region
FROM regional_distr
WHERE year = 2016 AND region = 'World';
- Which region had the HIGHEST percent forest in 2016, and which had the LOWEST, to 2 decimal places?
SELECT region,
ROUND(CAST(total_area_sqkm AS NUMERIC),2) AS total_area_sqkm,
ROUND(CAST(percent_fa_region AS NUMERIC),2) AS percent_fa_region
FROM regional_distr
WHERE ROUND(CAST(percent_fa_region AS NUMERIC),2) = (SELECT MAX(
ROUND(
CAST(percent_fa_region AS numeric),2
)
) AS max_percent
FROM regional_distr
WHERE year = 2016
)
AND year=2016;
SELECT region,
ROUND(CAST(total_area_sqkm AS NUMERIC),2) AS total_area_sqkm,
ROUND(CAST(percent_fa_region AS NUMERIC),2) AS percent_fa_region
FROM regional_distr
WHERE ROUND(CAST(percent_fa_region AS NUMERIC),2) = (SELECT MIN(
ROUND(
CAST(percent_fa_region AS numeric),2
)
) AS max_percent
FROM regional_distr
WHERE year = 2016
)
AND year = 2016;
- What was the percent forest of the entire world in 1990?
SELECT ROUND(CAST(percent_fa_region AS numeric),2) AS percent_fa_region
FROM regional_distr
WHERE year = 1990 AND region = 'World';
- Which region had the HIGHEST percent forest in 1990, and which had the LOWEST, to 2 decimal places?
SELECT region,
ROUND(CAST(total_area_sqkm AS NUMERIC),2) AS total_area_sqkm,
ROUND(CAST(percent_fa_region AS NUMERIC),2) AS percent_fa_region
FROM regional_distr
WHERE ROUND(CAST(percent_fa_region AS NUMERIC),2) = (SELECT MAX(
ROUND(
CAST(percent_fa_region AS numeric),2
)
) AS max_percent
FROM regional_distr
WHERE year = 1990
)
AND year=1990;
SELECT region,
ROUND(CAST(total_area_sqkm AS NUMERIC),2) AS total_area_sqkm,
ROUND(CAST(percent_fa_region AS NUMERIC),2) AS percent_fa_region
FROM regional_distr
WHERE ROUND(CAST(percent_fa_region AS NUMERIC),2) = (SELECT MIN(
ROUND(
CAST(percent_fa_region AS numeric),2
)
) AS max_percent
FROM regional_distr
WHERE year = 1990
)
AND year = 1990;
- Based on the table you created, which regions of the world DECREASED in forest area from 1990 to 2016?
WITH table1990 AS (SELECT * FROM regional_distr WHERE year =1990),
table2016 AS (SELECT * FROM regional_distr WHERE year = 2016)
SELECT table1990.region,
ROUND(CAST(table1990.percent_fa_region AS NUMERIC),2) AS fa_1990,
ROUND(CAST(table2016.percent_fa_region AS NUMERIC),2) AS fa_2016
FROM table1990 JOIN table2016 ON table1990.region = table2016.region
WHERE table1990.percent_fa_region > table2016.percent_fa_region;
- Which 5 countries saw the largest amount decrease in forest area from 1990 to 2016? What was the difference in forest area for each?
WITH table1990 AS (SELECT f.country_code,
f.country_name,
f.year,
f.forest_area_sqkm
FROM forest_area f
WHERE f.year = 1990 AND f.forest_area_sqkm IS NOT NULL AND f.country_name != 'World'
),
table2016 AS (SELECT f.country_code,
f.country_name,
f.year,
f.forest_area_sqkm
FROM forest_area f
WHERE f.year = 2016 AND f.forest_area_sqkm IS NOT NULL AND f.country_name != 'World'
)
SELECT table1990.country_code,
table1990.country_name,
r.region,
table1990.forest_area_sqkm AS fa_1990_sqkm,
table2016.forest_area_sqkm AS fa_2016_sqkm,
table1990.forest_area_sqkm-table2016.forest_area_sqkm AS diff_fa_sqkm
FROM table1990
JOIN table2016
ON table1990.country_code = table2016.country_code
AND (table1990.forest_area_sqkm IS NOT NULL AND table2016.forest_area_sqkm IS NOT NULL)
JOIN regions r ON table2016.country_code = r.country_code
ORDER BY 6 DESC
LIMIT 5;
- Which 5 countries saw the largest percent decrease in forest area from 1990 to 2016? What was the percent change to 2 decimal places for each
WITH table1990 AS (SELECT f.country_code,
f.country_name,
f.year,
f.forest_area_sqkm
FROM forest_area f
WHERE f.year = 1990 AND f.forest_area_sqkm IS NOT NULL AND f.country_name != 'World'
),
table2016 AS (SELECT f.country_code,
f.country_name,
f.year,
f.forest_area_sqkm
FROM forest_area f
WHERE f.year = 2016 AND f.forest_area_sqkm IS NOT NULL AND f.country_name != 'World'
)
SELECT table1990.country_code,
table1990.country_name,
r.region,
table1990.forest_area_sqkm AS fa_1990_sqkm,
table2016.forest_area_sqkm AS fa_2016_sqkm,
table1990.forest_area_sqkm-table2016.forest_area_sqkm AS diff_fa_sqkm,
ABS(ROUND(CAST(((table2016.forest_area_sqkm-table1990.forest_area_sqkm)/table1990.forest_area_sqkm*100) AS NUMERIC),2)) AS perc_change
FROM table1990
JOIN table2016
ON table1990.country_code = table2016.country_code
AND (table1990.forest_area_sqkm IS NOT NULL AND table2016.forest_area_sqkm IS NOT NULL) JOIN regions r ON table2016.country_code = r.country_code
ORDER BY ROUND(CAST(((table2016.forest_area_sqkm-table1990.forest_area_sqkm)/table1990.forest_area_sqkm*100) AS NUMERIC),2)
LIMIT 5;
- If countries were grouped by percent forestation in quartiles, which group had the most countries in it in 2016?
With table1 AS (SELECT f.country_code,
f.country_name,
f.year,
f.forest_area_sqkm,
l.total_area_sq_mi*2.59 AS total_area_sqkm,
(f.forest_area_sqkm/(l.total_area_sq_mi*2.59))*100 AS perc_fa
FROM forest_area f
JOIN land_area l
ON f.country_code = l.country_code
AND (f.country_name != 'World' AND f.forest_area_sqkm IS NOT NULL AND l.total_area_sq_mi IS NOT NULL)
AND (f.year=2016 AND l.year = 2016)
ORDER BY 6 DESC
),
table2 AS (SELECT table1.country_code,
table1.country_name,
table1.year,
table1.perc_fa,
CASE WHEN table1.perc_fa >= 75 THEN 4
WHEN table1.perc_fa < 75 AND table1.perc_fa >= 50 THEN 3
WHEN table1.perc_fa < 50 AND table1.perc_fa >=25 THEN 2
ELSE 1
END AS percentile
FROM table1 ORDER BY 5 DESC
)
SELECT table2.percentile,
COUNT(table2.percentile)
FROM table2
GROUP BY 1
ORDER BY 2 DESC;
- List all of the countries that were in the 4th quartile (percent forest > 75%) in 2016.
With table1 AS (SELECT f.country_code,
f.country_name,
f.year,
f.forest_area_sqkm,
l.total_area_sq_mi*2.59 AS total_area_sqkm,
(f.forest_area_sqkm/(l.total_area_sq_mi*2.59))*100 AS perc_fa
FROM forest_area f
JOIN land_area l
ON f.country_code = l.country_code
AND (f.country_name != 'World' AND f.forest_area_sqkm IS NOT NULL AND l.total_area_sq_mi IS NOT NULL)
AND (f.year=2016 AND l.year = 2016)
ORDER BY 6 DESC
),
table2 AS (SELECT table1.country_code,
table1.country_name,
table1.year,
table1.perc_fa,
CASE WHEN table1.perc_fa >= 75 THEN 4
WHEN table1.perc_fa < 75 AND table1.perc_fa >= 50 THEN 3
WHEN table1.perc_fa < 50 AND table1.perc_fa >=25 THEN 2
ELSE 1
END AS percentile
FROM table1 ORDER BY 5 DESC
)
SELECT table2.country_name,
r.region,
ROUND(CAST(table2.perc_fa AS NUMERIC),2) AS perc_fa,
table2.percentile
FROM table2
JOIN regions r
ON table2.country_code = r.country_code
WHERE table2.percentile = 4
ORDER BY 1;
- How many countries had a percent forestation higher than the United States in 2016?
With table1 AS (SELECT f.country_code,
f.country_name,
f.year,
f.forest_area_sqkm,
l.total_area_sq_mi*2.59 AS total_area_sqkm,
(f.forest_area_sqkm/(l.total_area_sq_mi*2.59))*100 AS perc_fa
FROM forest_area f
JOIN land_area l
ON f.country_code = l.country_code
AND (f.country_name != 'World' AND f.forest_area_sqkm IS NOT NULL AND l.total_area_sq_mi IS NOT NULL)
AND (f.year=2016 AND l.year = 2016)
ORDER BY 6 DESC
)
SELECT COUNT(table1.country_name)
FROM table1
WHERE table1.perc_fa > (SELECT table1.perc_fa
FROM table1
WHERE table1.country_name = 'United States'
)