Add UK tier 1 drainage PEC calculations

1 files changed, 33 insertions, 0 deletions

diff --git a/pkg/tests/testthat/test_UK_drainage.R b/pkg/tests/testthat/test_UK_drainage.R
new file mode 100644
index 0000000..3a57db8
--- /dev/null
+++ b/pkg/tests/testthat/test_UK_drainage.R
@@ -0,0 +1,33 @@
+library(pfm)
+context("UK drainage PEC calculations")
+
+test_that("The mobility classification and the drained percentage are correct", {
+  # Expected results are from the CRD drainage calculator, retrieved 2015-06-11
+  
+  expect_equivalent(SSLRC_mobility_classification(1), list("Very mobile", 1.9))
+  expect_equivalent(SSLRC_mobility_classification(15), list("Mobile", 1.9))
+  expect_equivalent(SSLRC_mobility_classification(30), list("Mobile", 1.9))
+  expect_equivalent(SSLRC_mobility_classification(74.9), list("Mobile", 1.9))
+  expect_equivalent(SSLRC_mobility_classification(75), list("Moderately mobile", 0.7))
+  expect_equivalent(SSLRC_mobility_classification(100), list("Moderately mobile", 0.7))
+  expect_equivalent(SSLRC_mobility_classification(800), list("Slightly mobile", 0.5))
+  expect_equivalent(SSLRC_mobility_classification(2000), list("Slightly mobile", 0.02))
+  expect_equivalent(SSLRC_mobility_classification(5000), list("Non mobile", 0.01))
+})
+
+test_that("UK drainflow PECs are correct", {
+  # Expected results are from the CRD drainage calculator, retrieved 2015-06-11, except
+  # for the third example from the data requirements handbook
+
+  # This is the first example calculation from the data requirements handbook, where they give
+  # 8.07 µg/L as the result (obviously a rounding error).
+  expect_equal(round(PEC_sw_drainage_UK_ini(150, interception = 0, Koc = 100), 4), 8.0769)
+
+  # This is the second example calculation from the data requirements handbook
+  expect_equal(round(PEC_sw_drainage_UK_ini(90, interception = 0, Koc = 10), 4), 13.1538)
+
+  # This is the third example calculation from the data requirements handbook, 
+  expect_equal(round(PEC_sw_drainage_UK_ini(60, interception = 0.5, Koc = 550,
+                                            latest_application = "01 July",
+                                            soil_DT50 = 200), 2), 0.84)
+})