Small Farm Irrigation Coefficients

[julieshortridge]

Task: Develop county-level coefficients of small farm (estimated to be under reporting threshold) unreported irrigation withdrawals.
@laljeet @jdkleiner @rburghol

• Action items:
  • Table with coefficients of small farm unreported as percentage of reported irrigation withdrawals in counties with usda and vdeq irrigation data for each county c and usda year y:
    C_irr_c,y = W_{unr_sm} / W_{rep_irr}
  • Table with coefficients of small farm unreported as percentage of reported withdrawals (all use types) in all counties with usda data for each county c and usda year y:
    C_tot_c,y = W_{unr_sm} / W_{rep_tot}
  • Map of C_irr
  • Map of C_tot
  • Trend analysis: Mann Kendall won't work with four data points, but we could do a quick test to see if the four values are a monotonic increase or decrease, and identify the locations where this is the case.

[laljeet]

C_irr _c,y and C_tot _c,y coefficients would be same in either case because of how we convert the "under threshold" acres from census data to million gallons. Multiplying C-tot with total withdrawals in a county a would give a large unreported withdrawal amounts.

e.g. GILES has C_irr _c,y or C_tot _c,y of 0.22
Using DEQ irrigation withdrawals, the Unreported withdrawal is 43 mgd
Using total withdrawals, the Unreported withdrawal is 132 mgd

Possible solutions:

For counties with DEQ data continue using C_irr

For counties missing DEQ data

1. Use Survey irrigation depth (limitation that the irrigation depth is for following year)
2. Use effective rainfall method to calculate the expected irrigation for the counties.

Here is the detailed calculation of C_irr and C_total:

[julieshortridge]

I think the issue is in the third line of your equations - in the formulation you have there, "total withdrawals in a county" should refer to irrigation withdrawals but not total withdrawals. When we have DEQ irrigation withdrawals, it's reasonable to assume that the UT (under threshold) percent is the same for both acreage and gallons. IE, if 20% of the irrigated acreage in a county is under the reporting threshold, then we assume 20% of the irrigation volume also is under the reported threshold. However, there's no reason to assume that the UT percent would also refer to non-irrigation withdrawals.

We can talk through the equations tomorrow, but in general I think the best approach in counties with no VDEQ irrigation withdrawals is to calculate the irrigated acreage below threshold, and then apply a depth to those acres using the rainfall deficit approach.

[laljeet]

C_irr c,y = Acres under threshold c,y / Total Irrigated acres c,y

2002

County	County_Code	Total.Irri.Area	Irr.Area.Under.TH	Facility_withdrawal_mg	C_irr
ACCOMACK	1	9716	17	3444.534	0
AMELIA	7	886	109	42.093	0.12
AUGUSTA	15	3416	184	461.554	0.05
CAROLINE	33	2272	25	960.526	0.01
CHARLES CITY	36	1122	21	268.67	0.02
CHESTERFIELD	41	571	35	55	0.06
CLARKE	43	327	94	42.8	0.29
CULPEPER	47	589	111	4.11	0.19
DINWIDDIE	53	1164	115	14.055	0.1
ESSEX	57	246	39	140.34	0.16
FAIRFAX	59	101	101	14.599	1
FRANKLIN	67	1126	242	11.81	0.21
FREDERICK	69	520	159	9	0.31
GREENSVILLE	81	734	0	50.8297	0
HALIFAX	83	2617	82	26.816	0.03
HANOVER	85	2393	278	236.0457	0.12
ISLE OF WIGHT	93	791	5	97.5	0.01
KING AND QUEEN	97	743	64	256.91	0.09
KING WILLIAM	101	2457	15	143.51	0.01
LOUDOUN	107	3666	185	36.6	0.05
LUNENBURG	111	1484	61	10	0.04
MECKLENBURG	117	4158	236	5.59	0.06
MIDDLESEX	119	651	16	13.4	0.02
MONTGOMERY	121	303	41	17	0.14
NELSON	125	795	145	192.13	0.18
NEW KENT	127	458	15	11.89	0.03
NORTHAMPTON	131	9338	44	742.087	0
ORANGE	137	1556	53	0.45	0.03
PAGE	139	238	14	34.476	0.06
PITTSYLVANIA	143	5606	211	86.068	0.04
POWHATAN	145	230	32	0.58	0.14
PRINCE EDWARD	147	526	46	38.6	0.09
PRINCE WILLIAM	153	1173	10	3.4	0.01
ROANOKE	161	92	82	20.7	0.89
ROCKINGHAM	165	4355	174	276.896	0.04
SHENANDOAH	171	1110	36	30.277	0.03
SOUTHAMPTON	175	2385	0	41	0
SPOTSYLVANIA	177	346	40	60.56	0.12
SURRY	181	1472	30	53.203	0.02
SUSSEX	183	1410	16	38.6	0.01
WESTMORELAND	193	1474	122	311.381	0.08
SUFFOLK CITY	800	1167	109	208.64	0.09

2007

County	County_Code	Total.Irri.Area	Irr.Area.Under.TH	Facility_withdrawal_mg	C_irr
ACCOMACK	1	6508	49	1779.744	0.01
AMELIA	7	562	38	15.681	0.07
AUGUSTA	15	3813	195	592.1592	0.05
BEDFORD	19	567	41	11.9226	0.07
CAMPBELL	31	779	107	59.51	0.14
CAROLINE	33	2112	79	541.364	0.04
CHARLES CITY	36	739	12	11.9	0.02
CHARLOTTE	37	731	136	23.2	0.19
CHESTERFIELD	41	185	46	37.9	0.25
CLARKE	43	514	60	44	0.12
CULPEPER	47	1266	67	410.727	0.05
DINWIDDIE	53	1885	25	97.3087	0.01
FAIRFAX	59	40	40	17.4	1
FREDERICK	69	298	101	13.534	0.34
HALIFAX	83	1549	123	9.12	0.08
HANOVER	85	3188	116	274.1886	0.04
ISLE OF WIGHT	93	702	44	123	0.06
KING AND QUEEN	97	16	16	293.42	1
KING GEORGE	99	672	21	175.802	0.03
KING WILLIAM	101	2690	0	702.694	0
LOUDOUN	107	3533	142	32.6308	0.04
LUNENBURG	111	770	35	8.66	0.05
MECKLENBURG	117	3235	60	7.17	0.02
MIDDLESEX	119	480	0	90.576	0
MONTGOMERY	121	384	38	46.54	0.1
NELSON	125	774	97	468.463	0.13
NEW KENT	127	495	7	138.01	0.01
NORTHAMPTON	131	9286	48	907.2193	0.01
ORANGE	137	627	39	70	0.06
PAGE	139	296	47	12.17	0.16
PATRICK	141	432	22	1	0.05
PITTSYLVANIA	143	4187	64	65.3438	0.02
POWHATAN	145	28	2	3.3	0.07
PRINCE WILLIAM	153	685	89	2.632	0.13
ROCKINGHAM	165	4808	241	167.963	0.05
SHENANDOAH	171	755	125	29.928	0.17
SOUTHAMPTON	175	3507	90	259.1787	0.03
SPOTSYLVANIA	177	144	79	25.43	0.55
SURRY	181	1028	22	39.699	0.02
SUSSEX	183	1645	0	41.22	0
WESTMORELAND	193	1673	5	863.926	0
CHESAPEAKE CITY	550	239	56	1.440575	0.23
SUFFOLK CITY	800	616	68	180.6075	0.11

2012

County	County_Code	Total.Irri.Area	Irr.Area.Under.TH	Facility_withdrawal_mg	C_irr
ACCOMACK	1	5371	54	3414.518	0.01
AMELIA	7	374	45	85.5	0.12
AUGUSTA	15	3271	87	424.6243	0.03
BEDFORD	19	93	54	11.55	0.58
CAMPBELL	31	290	98	57.88	0.34
CAROLINE	33	1959	25	792.39	0.01
CHARLES CITY	36	1435	11	405.611	0.01
CHARLOTTE	37	759	85	15.3	0.11
CHESTERFIELD	41	64	12	22.9	0.19
CLARKE	43	249	28	46.58	0.11
CULPEPER	47	641	64	93.1449	0.1
DINWIDDIE	53	1162	53	17.00596	0.05
FLOYD	63	192	133	21.1	0.69
GREENSVILLE	81	246	9	32.252	0.04
HALIFAX	83	2152	223	2.139	0.1
HANOVER	85	3338	247	560.29	0.07
HENRICO	87	7	7	100.69	1
ISLE OF WIGHT	93	702	13	5.75	0.02
KING AND QUEEN	97	18	18	246.17	1
KING GEORGE	99	350	34	216.35	0.1
KING WILLIAM	101	1125	16	352.326	0.01
LOUDOUN	107	580	235	0.4321	0.41
LUNENBURG	111	444	33	6.76	0.07
MIDDLESEX	119	477	18	88.8	0.04
MONTGOMERY	121	349	37	65.645	0.11
NELSON	125	862	57	424.98	0.07
NORTHAMPTON	131	6335	47	881.646	0.01
ORANGE	137	563	51	11	0.09
PAGE	139	1005	19	51.94	0.02
PITTSYLVANIA	143	3717	184	27.14079	0.05
POWHATAN	145	99	20	4	0.2
PRINCE EDWARD	147	96	11	0.05148	0.11
PRINCE WILLIAM	153	1006	69	47.42	0.07
ROCKINGHAM	165	5645	350	578.196	0.06
SHENANDOAH	171	719	111	31.96	0.15
SOUTHAMPTON	175	3246	28	159.7402	0.01
SPOTSYLVANIA	177	58	29	10.2	0.5
SURRY	181	1238	65	22.35	0.05
SUSSEX	183	1371	25	71.71	0.02
WESTMORELAND	193	1642	2	380.14	0
SUFFOLK CITY	800	414	62	133.01	0.15

2017

County	County_Code	Total.Irri.Area	Irr.Area.Under.TH	Facility_withdrawal_mg	C_irr
ACCOMACK	1	5079	58	1673.848	0.01
AMELIA	7	205	19	9.343	0.09
AUGUSTA	15	2550	199	175.66	0.08
BEDFORD	19	51	51	16.15	1
CAMPBELL	31	313	40	121.59	0.13
CAROLINE	33	3411	19	543.92	0.01
CHARLES CITY	36	1376	15	344.0851	0.01
CHARLOTTE	37	534	94	15.35	0.18
CLARKE	43	143	34	16.56	0.24
CULPEPER	47	615	167	81.2651	0.27
DINWIDDIE	53	1578	27	31.129	0.02
ESSEX	57	3	3	340.34	1
FLOYD	63	182	122	31.672	0.67
GREENSVILLE	81	5	5	48.91836	1
HANOVER	85	3569	179	583.8264	0.05
HENRICO	87	28	28	97.14	1
ISLE OF WIGHT	93	934	37	71.1	0.04
KING AND QUEEN	97	1221	37	418.6888	0.03
KING WILLIAM	101	1618	17	285.391	0.01
MIDDLESEX	119	270	26	22.39	0.1
MONTGOMERY	121	323	36	42.2739	0.11
NELSON	125	1016	66	474.32	0.06
NEW KENT	127	271	18	24.19	0.07
NORTHAMPTON	131	5857	8	529.2497	0
PAGE	139	108	20	25.55	0.19
POWHATAN	145	63	16	4.3	0.25
PRINCE WILLIAM	153	943	34	14.541	0.04
ROANOKE	161	71	71	0.75	1
ROCKINGHAM	165	5526	282	254.245	0.05
SHENANDOAH	171	893	99	36.38	0.11
SOUTHAMPTON	175	1624	14	138.2595	0.01
SPOTSYLVANIA	177	96	27	0.146	0.28
SURRY	181	929	10	43.719	0.01
SUSSEX	183	699	15	195.364	0.02
WESTMORELAND	193	882	111	321.7426	0.13
CHESAPEAKE CITY	550	72	57	0.896212	0.79
SUFFOLK CITY	800	585	60	111.95	0.1

[laljeet]

For counties without DEQ withdrawals:

C_tot c,y = Volume of Irrigation c,y / Total DEQ withdrawals c,y
Volume of Irrigation c,y = (Acres unreported * Irrigation)
Irrigation(inches) = (30 – Precipitation)

2002

County	Total.Irri.Area	Irr.Area.Under.TH	Facility_withdrawal_mg	PPT	Irrigation	Vol_Unreported	C_tot
ACCOMACK	9716	17	5389.55086	590.39	172	3.11	0
ALBEMARLE	1387	120	3908.210335	618.8	143	18.27	0
ALLEGHANY	191	11	21938.65572	624.98	137	1.6	0
AMELIA	886	109	42.093	521.54	240	27.86	0.66
AMHERST	144	36	5863	572.1	190	7.28	0
APPOMATTOX	508	19	87.302	559.43	203	4.11	0.05
AUGUSTA	3416	184	4341.0051	550.03	212	41.54	0.01
BATH	109	0	4118.789482	620.65	141	0	0
BEDFORD	676	159	4864.389855	603.95	158	26.75	0.01
BLAND	135	21	72.718	638.86	123	2.75	0.04
BOTETOURT	253	77	2906.553869	592.4	170	13.94	0
BRUNSWICK	1474	126	731.753	626.09	136	18.25	0.02
BUCKINGHAM	469	16	459.12	537.66	224	3.82	0.01
CAMPBELL	1328	130	2215.3349	600.31	162	22.43	0.01
CAROLINE	2272	25	2657.6773	547.01	215	5.72	0
CARROLL	785	60	168.574	617.35	145	9.26	0.05
CHARLES CITY	1122	21	291.196	534.07	228	5.1	0.02
CHARLOTTE	1454	202	116.545	671.38	91	19.57	0.17
CHESTERFIELD	571	35	32908.70612	517.94	244	9.09	0
CLARKE	327	94	259.376083	670.68	91	9.11	0.04
CRAIG	130	30	862.29	642.46	120	3.83	0
CULPEPER	589	111	598.094	559.55	202	23.88	0.04
CUMBERLAND	222	27	2.622	533.07	229	6.58	2.51
DINWIDDIE	1164	115	102.639	620.38	142	17.39	0.17
ESSEX	246	39	295.8453	565.75	196	8.14	0.03
FAIRFAX	101	101	31715.8939	566.39	196	21.08	0
FAUQUIER	862	202	917.868	610.4	152	32.7	0.04
FLOYD	779	196	59.2953	553.55	208	43.41	0.73
FLUVANNA	57	24	264.928204	591.98	170	4.34	0.02
FRANKLIN	1126	242	414.587	634.41	128	32.99	0.08
FREDERICK	520	159	672.497	691.32	71	12.02	0.02
GILES	193	28	24886.2384	640.34	122	3.64	0
GLOUCESTER	98	51	445.9206	614.63	147	7.98	0.02
GOOCHLAND	101	23	695.2937	569.18	193	4.73	0.01
GRAYSON	619	77	67.504	638.42	124	10.17	0.15
GREENE	36	36	201.205732	642.09	120	4.6	0.02
GREENSVILLE	734	0	647.5772	614.14	148	0	0
HALIFAX	2617	82	772.2776	631.56	130	11.35	0.01
HANOVER	2393	278	5914.3517	530.95	231	68.38	0.01
HENRICO	49	49	677.181536	562.04	200	10.44	0.02
HENRY	416	39	1815.299008	631.9	130	5.4	0
ISLE OF WIGHT	791	5	16964.96468	650.36	112	0.6	0
JAMES CITY	102	12	5502.30478	563.49	199	2.54	0
KING AND QUEEN	743	64	261.51	570.35	192	13.09	0.05
KING GEORGE	3	3	761.1532	528.79	233	0.74	0
KING WILLIAM	2457	15	7514.2431	532.84	229	3.66	0
LEE	1374	204	597.42	612.89	149	32.37	0.05
LOUDOUN	3666	185	2154.691	637.32	125	24.62	0.01
LOUISA	365	51	199.934	620.98	141	7.66	0.04
LUNENBURG	1484	61	231.424	672.19	90	5.85	0.03
MADISON	333	72	39.538	621.72	140	10.73	0.27
MATHEWS	117	5	1.113	652.68	109	0.58	0.52
MECKLENBURG	4158	236	1132.005	610.36	152	38.2	0.03
MIDDLESEX	651	16	117.3	621.79	140	2.39	0.02
MONTGOMERY	303	41	8396.0889	561.49	201	8.78	0
NELSON	795	145	593.2255	614.15	148	22.85	0.04
NEW KENT	458	15	14967.40878	544.5	218	3.48	0
NORTHAMPTON	9338	44	997.0889	615.94	146	6.84	0.01
NORTHUMBERLAND	38	10	73.9144	580.23	182	1.94	0.03
NOTTOWAY	457	32	214.159	571.71	190	6.47	0.03
ORANGE	1556	53	569.231	576.79	185	10.44	0.02
PAGE	238	14	876.3444	640.63	121	1.8	0
PATRICK	325	134	241.6111	605.88	156	22.26	0.09
PITTSYLVANIA	5606	211	1800.3949	617.82	144	32.35	0.02
POWHATAN	230	32	32.6476	564.26	198	6.75	0.21
PRINCE EDWARD	526	46	408.714	527.16	235	11.51	0.03
PRINCE WILLIAM	1173	10	21593.872	584.32	178	1.9	0
PULASKI	320	3	1760.111	577.87	184	0.59	0
RAPPAHANNOCK	335	10	14.576	626.16	136	1.45	0.1
ROANOKE	92	82	7430.9603	610.41	152	13.27	0
ROCKBRIDGE	700	55	1333.348511	560.82	201	11.77	0.01
ROCKINGHAM	4355	174	8784.345484	599.61	162	30.02	0
RUSSELL	251	118	1644.2773	681.2	81	10.18	0.01
SCOTT	637	180	380.623	634.17	128	24.53	0.06
SHENANDOAH	1110	36	1967.5901	682.09	80	3.07	0
SMYTH	452	38	2503.458	691.43	71	2.87	0
SOUTHAMPTON	2385	0	6068.35342	688.41	74	0	0
SPOTSYLVANIA	346	40	3729.491	527.05	235	10.01	0
STAFFORD	186	22	3516.87	546.65	215	5.04	0
SURRY	1472	30	136.30141	640.18	122	3.9	0.03
SUSSEX	1410	16	397.3285	704.91	57	0.97	0
TAZEWELL	245	29	1763.684	647.91	114	3.52	0
WARREN	151	70	3691.9461	676.93	85	6.34	0
WASHINGTON	836	155	3081.793	732.74	29	4.79	0
WESTMORELAND	1474	122	663.730732	581.08	181	23.51	0.04
WISE	28	10	2350.4953	679.66	82	0.87	0
WYTHE	1061	22	1596.5893	612.32	150	3.51	0
YORK	41	41	31129.51068	566.96	195	8.51	0
CHESAPEAKE CITY	314	189	1681.9399	723.58	38	7.65	0
SUFFOLK CITY	1167	109	35591.81728	639.65	122	14.16	0
VIRGINIA BEACH CITY	431	35	10522.48339	704.96	57	2.12	0

2007

<style> </style>

County	Total.Irri.Area	Irr.Area.Under.TH	Facility_withdrawal_mg	PPT	Irrigation	Vol_Unreported	C_tot
ACCOMACK	6508	49	3324.218	500.84	261	13.62	0
ALBEMARLE	1026	70	3966.777	557.78	204	15.21	0
AMELIA	562	38	15.681	513.37	249	10.08	0.64
AMHERST	147	27	5940.585	488.48	274	7.88	0
APPOMATTOX	43	43	97.49015	518.25	244	11.17	0.11
AUGUSTA	3813	195	4114.818	539.74	222	46.1	0.01
BATH	7	7	4446.422	520.42	242	1.8	0
BEDFORD	567	41	6611.068	477.33	285	12.44	0
BLAND	10	10	57.531	479.97	282	3	0.05
BOTETOURT	63	25	659.3764	467.02	295	7.85	0.01
BRUNSWICK	1316	26	931.0598	447.85	314	8.69	0.01
BUCKINGHAM	39	26	161.2807	523.56	238	6.59	0.04
CAMPBELL	779	107	2235.982	506.56	255	29.05	0.01
CAROLINE	2112	79	2399.617	435.93	326	27.42	0.01
CARROLL	600	31	163.0234	495.17	267	8.81	0.05
CHARLES CITY	739	12	45.21013	592.14	170	2.17	0.05
CHARLOTTE	731	136	119.473	500.17	262	37.94	0.32
CHESTERFIELD	185	46	33392.74	525.1	237	11.61	0
CLARKE	514	60	258.6409	460.73	301	19.23	0.07
CRAIG	6	6	32.0455	495.58	266	1.7	0.05
CULPEPER	1266	67	1255.776	451.15	311	22.19	0.02
DINWIDDIE	1885	25	156.3327	539.53	222	5.91	0.04
FAIRFAX	40	40	34091.97	400.92	361	15.38	0
FAUQUIER	920	160	1254.396	446.42	316	53.84	0.04
FLOYD	108	108	22.396	451.88	310	35.65	1.59
FLUVANNA	264	30	346.6548	530.21	232	7.41	0.02
FRANKLIN	872	140	492.8103	474.21	288	42.94	0.09
FREDERICK	298	101	2243.942	475.26	287	30.87	0.01
GILES	30	13	22192.28	480.59	281	3.89	0
GLOUCESTER	58	58	507.5373	538.68	223	13.77	0.03
GOOCHLAND	20	20	949.7262	512.68	249	5.3	0.01
GRAYSON	97	37	50.13227	499.8	262	10.32	0.21
GREENE	154	47	248.5711	556.51	205	10.26	0.04
HALIFAX	1549	123	698.4145	467.77	294	38.51	0.06
HANOVER	3188	116	1033.165	502.63	259	31.99	0.03
HENRICO	25	25	11258.71	554.78	207	5.51	0
HENRY	525	6	1111.624	497.37	265	1.69	0
ISLE OF WIGHT	702	44	15366.27	514.08	248	11.62	0
JAMES CITY	29	16	5613.277	568.54	193	3.29	0
KING AND QUEEN	16	16	298.32	494.21	268	4.57	0.02
KING GEORGE	672	21	1242.08	413.82	348	7.78	0.01
KING WILLIAM	2690	0	7165.262	487.08	275	0	0
LEE	297	43	766.738	488.68	273	12.5	0.02
LOUDOUN	3533	142	2538.797	416.87	345	52.17	0.02
LOUISA	279	54	196.0423	503.44	259	14.89	0.08
LUNENBURG	770	35	216.203	469.82	292	10.88	0.05
MADISON	69	39	105.548	534.38	228	9.47	0.09
MATHEWS	53	19	5.9702	524.13	238	4.82	0.81
MECKLENBURG	3235	60	713.222	422.02	340	21.72	0.03
MIDDLESEX	480	0	160.2157	515.77	246	0	0
MONTGOMERY	384	38	8688.828	421.31	341	13.8	0
NELSON	774	97	1060.21	536.6	225	23.24	0.02
NEW KENT	495	7	10425.08	554.77	207	1.54	0
NORTHAMPTON	9286	48	1183.686	506.03	256	13.09	0.01
NORTHUMBERLAND	62	1	987.2377	463.76	298	0.32	0
NOTTOWAY	386	32	464.5778	521.51	240	8.18	0.02
ORANGE	627	39	719.1761	485.71	276	11.46	0.02
PAGE	296	47	605.7942	561.4	201	10.06	0.02
PATRICK	432	22	285.8151	566.11	196	4.59	0.02
PITTSYLVANIA	4187	64	1073.054	457.89	304	20.72	0.02
POWHATAN	28	2	50.1273	477.33	285	0.61	0.01
PRINCE EDWARD	123	60	30.88316	485.45	277	17.7	0.57
PRINCE GEORGE	6	6	255.9439	561.35	201	1.28	0.01
PRINCE WILLIAM	685	89	28178.82	409.63	352	33.36	0
PULASKI	241	23	1780.94	438.12	324	7.94	0
RAPPAHANNOCK	132	56	14.271	505.34	257	15.33	1.07
RICHMOND	243	2	113.7787	444.8	317	0.68	0.01
ROANOKE	94	53	4487.925	480.21	282	15.92	0
ROCKBRIDGE	109	46	1052.877	547.77	214	10.48	0.01
ROCKINGHAM	4808	241	9031.399	598.69	163	41.83	0
RUSSELL	134	28	644.7502	571.25	191	5.69	0.01
SCOTT	243	84	397.3463	494.93	267	23.88	0.06
SHENANDOAH	755	125	2007.441	535.87	226	30.08	0.01
SMYTH	188	66	1719.006	485.98	276	19.4	0.01
SOUTHAMPTON	3507	90	5903.591	512	250	23.96	0
SPOTSYLVANIA	144	79	4155.782	451.3	311	26.16	0.01
STAFFORD	221	11	4652.618	456.94	305	3.57	0
SURRY	1028	22	103.262	579.76	182	4.26	0.04
SUSSEX	1645	0	588.938	541.49	221	0	0
TAZEWELL	330	29	1247.325	534.23	228	7.04	0.01
WARREN	58	58	4304.443	481.47	281	17.36	0
WASHINGTON	410	123	3408.196	531.8	230	30.12	0.01
WESTMORELAND	1673	5	1235.924	394.71	367	1.95	0
WISE	115	5	1773.069	569.56	192	1.02	0
WYTHE	164	55	3002.442	419.3	343	20.09	0.01
YORK	17	17	32214.19	561.86	200	3.62	0
CHESAPEAKE CITY	239	56	4509.785	489.99	272	16.22	0
SUFFOLK CITY	616	68	38298.19	541.07	221	16	0
VIRGINIA BEACH CITY	193	51	13960.18	442.99	319	17.32	0

2012

<style> </style>

County	Total.Irri.Area	Irr.Area.Under.TH	Facility_withdrawal_mg	PPT	Irrigation	Vol_Unreported	C_tot
ACCOMACK	5371	54	4613.682	632.31	130	7.48	0
ALBEMARLE	1456	168	3716.215	644.28	118	21.11	0.01
ALLEGHANY	8	8	14351.13	609.36	153	1.3	0
AMELIA	374	45	117.781	514.16	248	11.88	0.1
APPOMATTOX	105	81	42.3	543.42	219	18.89	0.45
AUGUSTA	3271	87	4038.266	645.82	116	10.75	0
BATH	19	19	3818.33	607.05	155	3.14	0
BEDFORD	93	54	6562.061	541.56	220	12.65	0
BOTETOURT	52	25	621.3561	620.79	141	3.75	0.01
BRUNSWICK	1280	40	361.7987	707.79	54	2.3	0.01
BUCKINGHAM	16	16	125.099	563.72	198	3.37	0.03
CAMPBELL	290	98	1786.791	533.15	229	23.9	0.01
CAROLINE	1959	25	2654.551	538.57	223	5.94	0
CARROLL	1086	19	190.4055	645.46	117	2.37	0.01
CHARLES CITY	1435	11	428.0656	661.99	100	1.17	0
CHARLOTTE	759	85	82.747	566.97	195	17.65	0.21
CHESTERFIELD	64	12	32729.12	590.77	171	2.19	0
CLARKE	249	28	252.6576	595.18	167	4.98	0.02
CRAIG	10	10	895.4523	567.43	195	2.08	0
CULPEPER	641	64	998.4472	670.89	91	6.2	0.01
CUMBERLAND	18	18	2.3137	558.09	204	3.91	1.69
DICKENSON	12	12	2145.649	678.39	84	1.07	0
DINWIDDIE	1162	53	52.41692	587.33	175	9.88	0.19
FAIRFAX	50	50	32000.1	510.42	252	13.42	0
FAUQUIER	394	207	1089.439	687.56	74	16.31	0.01
FLOYD	192	133	34.472	581.25	181	25.63	0.74
FLUVANNA	144	61	326.771	617.1	145	9.42	0.03
FREDERICK	151	79	1624.9	599.77	162	13.63	0.01
GILES	32	32	24019.44	558.04	204	6.95	0
GLOUCESTER	46	46	475.7657	575.49	187	9.16	0.02
GOOCHLAND	32	32	801.5221	609.96	152	5.18	0.01
GRAYSON	45	45	36.6599	633.3	129	6.18	0.17
GREENE	49	38	228.9864	687.62	74	2.99	0.01
GREENSVILLE	246	9	743.8175	748.38	14	0.13	0
HALIFAX	2152	223	675.589	591.38	171	40.61	0.06
HANOVER	3338	247	1177.759	569.68	192	50.5	0.04
HENRICO	7	7	9648.405	611.66	150	1.12	0
HENRY	137	40	1209.686	639.79	122	5.2	0
HIGHLAND	20	9	2577.252	625.07	137	1.31	0
ISLE OF WIGHT	702	13	4499.247	781.34	-19	-0.26	0
JAMES CITY	37	15	2230.916	675.2	87	1.39	0
KING AND QUEEN	18	18	250.445	548.93	213	4.08	0.02
KING GEORGE	350	34	636.7857	490.13	272	9.85	0.02
KING WILLIAM	1125	16	7903.223	557.05	205	3.49	0
LEE	61	61	800.624	659.72	102	6.63	0.01
LOUDOUN	580	235	2337.318	619.47	143	35.78	0.02
LOUISA	278	88	217.1385	651.05	111	10.4	0.05
LUNENBURG	444	33	170.069	650.8	111	3.9	0.02
MADISON	70	30	49.5564	729.54	32	1.02	0.02
MATHEWS	17	17	7.8853	584.54	177	3.2	0.41
MECKLENBURG	2760	66	585.5844	754.24	8	0.56	0
MIDDLESEX	477	18	144.406	551.98	210	4.03	0.03
MONTGOMERY	349	37	10645.25	514.26	248	9.77	0
NELSON	862	57	1032.9	608.89	153	9.29	0.01
NORTHAMPTON	6335	47	1177.015	597.22	165	8.26	0.01
NORTHUMBERLAND	38	2	135.1638	578.11	184	0.39	0
NOTTOWAY	75	55	392.96	583.26	179	10.48	0.03
ORANGE	563	51	641.9746	692.79	69	3.75	0.01
PAGE	1005	19	646.848	584.92	177	3.58	0.01
PATRICK	108	38	251.0541	709.38	53	2.14	0.01
PITTSYLVANIA	3717	184	703.5115	600.95	161	31.55	0.04
POWHATAN	99	20	40.7775	572.11	190	4.05	0.1
PRINCE EDWARD	96	11	380.8697	548.7	213	2.49	0.01
PRINCE GEORGE	8	8	107.5899	634.53	127	1.08	0.01
PRINCE WILLIAM	1006	69	24517.31	610.34	152	11.17	0
PULASKI	14	14	1651.929	568.02	194	2.89	0
RAPPAHANNOCK	121	95	13.24	652.05	110	11.13	0.84
RICHMOND	126	21	100.346	538.06	224	5.01	0.05
ROANOKE	96	53	4364.626	591.58	170	9.59	0
ROCKBRIDGE	137	59	818.7137	673.92	88	5.53	0.01
ROCKINGHAM	5645	350	9269.704	623.14	139	51.81	0.01
RUSSELL	12	12	233.732	721.29	41	0.52	0
SCOTT	56	23	377.6281	676	86	2.11	0.01
SHENANDOAH	719	111	1984.426	636.18	126	14.89	0.01
SMYTH	18	18	2090.007	649.18	113	2.17	0
SOUTHAMPTON	3246	28	1398.276	791.2	-29	-0.86	0
SPOTSYLVANIA	58	29	3808.417	549.21	213	6.58	0
STAFFORD	25	25	3946.842	591.17	171	4.55	0
SURRY	1238	65	78.11996	671.16	91	6.3	0.08
SUSSEX	1371	25	456.542	652	110	2.93	0.01
TAZEWELL	18	18	613.3172	705.16	57	1.09	0
WARREN	12	12	3510.696	590.47	172	2.2	0
WASHINGTON	224	89	3633.409	690.08	72	6.82	0
WESTMORELAND	1642	2	757.3936	524.4	238	0.51	0
WISE	12	12	2587.331	753.31	9	0.12	0
WYTHE	72	52	2699.777	614.98	147	8.14	0
YORK	21	8	8251.782	667.58	94	0.8	0
CHESAPEAKE CITY	282	68	2422.933	727.02	35	2.53	0
SUFFOLK CITY	414	62	33496.68	809.76	-48	-3.17	0
VIRGINIA BEACH CITY	180	44	7247.616	693.88	68	3.19	0

2017

<style> </style>

County	Total.Irri.Area	Irr.Area.Under.TH	Facility_withdrawal_mg	PPT	Irrigation	Vol_Unreported	C_tot
ACCOMACK	5079	58	3309.035	762.03	0	0	0
ALBEMARLE	783	113	4644.929	693.66	68	8.18	0
AMELIA	205	19	59.99334	722.81	39	0.79	0.01
AMHERST	176	23	6120.39	723.11	39	0.96	0
APPOMATTOX	24	24	6.5	729.19	33	0.84	0.13
AUGUSTA	2550	199	3502.974	667.19	95	20.13	0.01
BEDFORD	51	51	6874.716	704.21	58	3.15	0
BLAND	801	4	68.0126	716.89	45	0.19	0
BOTETOURT	10	10	532.3323	720.18	42	0.45	0
BRUNSWICK	2115	6	588.3132	698.93	63	0.4	0
BUCKINGHAM	65	19	121.18	697.69	64	1.29	0.01
CAMPBELL	313	40	2235.733	656.74	105	4.47	0
CAROLINE	3411	19	1675.266	746.74	15	0.3	0
CHARLES CITY	1376	15	389.4208	731.57	30	0.48	0
CHARLOTTE	534	94	97.947	719.35	43	4.3	0.04
CHESTERFIELD	75	28	36089.35	697.96	64	1.91	0
CLARKE	143	34	237.3854	692.66	69	2.5	0.01
CRAIG	115	19	1247.686	733.08	29	0.59	0
CULPEPER	615	167	1074.751	699.43	63	11.2	0.01
CUMBERLAND	167	23	5.11825	673.55	88	2.16	0.42
DINWIDDIE	1578	27	156.4844	677.3	85	2.44	0.02
ESSEX	3	3	440.2143	700.16	62	0.2	0
FAIRFAX	60	60	32642.41	685.04	77	4.92	0
FAUQUIER	452	217	1176.654	745.83	16	3.7	0
FLOYD	182	122	79.81044	757.98	4	0.52	0.01
FLUVANNA	79	18	311.7914	665.36	97	1.86	0.01
FREDERICK	38	15	1937.021	694.38	68	1.09	0
GILES	27	27	25126.1	739.64	22	0.63	0
GLOUCESTER	13	13	486.6015	698.29	64	0.89	0
GOOCHLAND	112	20	732.6279	692.97	69	1.47	0
GREENE	24	24	229.4875	776.84	-15	-0.38	0
GREENSVILLE	5	5	729.4155	722.7	39	0.21	0
HALIFAX	1061	52	730.0528	741.91	20	1.11	0
HANOVER	3569	179	1365.922	721.9	40	7.62	0.01
HENRICO	28	28	9402.481	722.35	40	1.19	0
HENRY	43	14	1227.356	731.91	30	0.45	0
ISLE OF WIGHT	934	37	7678.511	784.73	-23	-0.91	0
JAMES CITY	40	27	3185.089	689.62	72	2.07	0
KING AND QUEEN	1221	37	423.2449	707.53	54	2.13	0.01
KING WILLIAM	1618	17	7126.215	697.2	65	1.18	0
LANCASTER	12	12	177.5552	767.45	-5	-0.06	0
LEE	32	32	870.482	788.78	-27	-0.92	0
LOUDOUN	392	242	4344.776	726.59	35	9.02	0
LOUISA	215	90	264.1097	680.16	82	7.86	0.03
LUNENBURG	1408	15	189.453	712.28	50	0.8	0
MADISON	80	67	65.751	728.85	33	2.35	0.04
MATHEWS	10	10	4.953694	697.56	64	0.68	0.14
MECKLENBURG	4163	101	717.9267	708.26	54	5.81	0.01
MIDDLESEX	270	26	92.47545	742.2	20	0.55	0.01
MONTGOMERY	323	36	9659.75	706.04	56	2.15	0
NELSON	1016	66	1035.723	707.15	55	3.87	0
NEW KENT	271	18	6832.186	719.9	42	0.81	0
NORTHAMPTON	5857	8	883.1606	718.58	43	0.37	0
NOTTOWAY	44	44	392.2	685.01	77	3.61	0.01
ORANGE	214	39	638.6902	697.28	65	2.7	0
PAGE	108	20	658.1734	633.55	128	2.73	0
PITTSYLVANIA	1492	78	929.0033	760.41	2	0.17	0
POWHATAN	63	16	69.95639	727.74	34	0.58	0.01
PRINCE EDWARD	14	14	428.1339	684.28	78	1.16	0
PRINCE WILLIAM	943	34	25403.48	728.82	33	1.19	0
PULASKI	28	28	1598.12	677.24	85	2.53	0
RAPPAHANNOCK	61	61	12.237	733.68	28	1.82	0.15
RICHMOND	29	16	102.711	682.79	79	1.35	0.01
ROANOKE	71	71	4181.906	783.81	-22	-1.66	0
ROCKBRIDGE	83	40	670.4299	711.06	51	2.17	0
ROCKINGHAM	5526	282	8875.608	642.22	120	36.03	0
SCOTT	13	13	415.799	773.02	-11	-0.15	0
SHENANDOAH	893	99	2336.518	644.14	118	12.44	0.01
SMYTH	28	28	2062.959	801.01	-39	-1.16	0
SOUTHAMPTON	1624	14	2809.936	781.38	-19	-0.28	0
SPOTSYLVANIA	96	27	4081.042	722.63	39	1.12	0
STAFFORD	10	10	4400.723	685.75	76	0.81	0
SURRY	929	10	119.0785	717.98	44	0.47	0
SUSSEX	699	15	541.7868	762.22	0	0	0
WARREN	10	10	3619.162	629.1	133	1.42	0
WASHINGTON	122	51	3971.443	813.66	-52	-2.82	0
WESTMORELAND	882	111	436.6395	715.9	46	5.44	0.01
WISE	27	15	2262.56	812.04	-50	-0.8	0
WYTHE	18	18	2789.952	735.75	26	0.5	0
YORK	11	11	6494.848	723.11	39	0.46	0
CHESAPEAKE CITY	72	57	1982.655	847.3	-85	-5.16	0
SUFFOLK CITY	585	60	35939.42	827.5	-66	-4.22	0
VIRGINIA BEACH CITY	315	65	10503.86	851.03	-89	-6.16	0

[laljeet]

C_irr c,y

[laljeet]

[laljeet]

MK for Area under Th

<style> </style>

County	c2002	c2007	c2012	c2017	p_MK	Tau_MK
ACCOMACK	17	49	54	58	0.089	1
LOUISA	51	54	88	90	0.089	1
FAUQUIER	202	160	207	217	0.308	0.667
JAMES CITY	12	16	15	27	0.308	0.667
KING WILLIAM	15	0	16	17	0.308	0.667
LOUDOUN	185	142	235	242	0.308	0.667
MIDDLESEX	16	0	18	26	0.308	0.667
PULASKI	3	23	14	28	0.308	0.667
RAPPAHANNOCK	10	56	95	61	0.308	0.667
ROCKINGHAM	174	241	350	282	0.308	0.667
VIRGINIA BEACH CITY	35	51	44	65	0.308	0.667
WISE	10	5	12	15	0.308	0.667
NOTTOWAY	32	32	55	44	0.47	0.548
APPOMATTOX	19	43	81	24	0.734	0.333
AUGUSTA	184	195	87	199	0.734	0.333
ISLE OF WIGHT	5	44	13	37	0.734	0.333
PAGE	14	47	19	20	0.734	0.333
BUCKINGHAM	16	26	16	19	1	0.183
ALBEMARLE	120	70	168	113	1	0
CRAIG	30	6	10	19	1	0
CULPEPER	111	67	64	167	1	0
FAIRFAX	101	40	50	60	1	0
FLUVANNA	24	30	61	18	1	0
GILES	28	13	32	27	1	0
HALIFAX	82	123	223	52	1	0
HENRY	39	6	40	14	1	0
KING AND QUEEN	64	16	18	37	1	0
MATHEWS	5	19	17	10	1	0
MECKLENBURG	236	60	66	101	1	0
PRINCE WILLIAM	10	89	69	34	1	0
SHENANDOAH	36	125	111	99	1	0
SOUTHAMPTON	0	90	28	14	1	0
SUSSEX	16	0	25	15	1	0
GOOCHLAND	23	20	32	20	1	-0.183
ROANOKE	82	53	53	71	1	-0.183
BEDFORD	159	41	54	51	0.734	-0.333
CHARLES CITY	21	12	11	15	0.734	-0.333
CHESAPEAKE CITY	189	56	68	57	0.734	-0.333
CHESTERFIELD	35	46	12	28	0.734	-0.333
DINWIDDIE	115	25	53	27	0.734	-0.333
FLOYD	196	108	133	122	0.734	-0.333
GREENE	36	47	38	24	0.734	-0.333
HANOVER	278	116	247	179	0.734	-0.333
HENRICO	49	25	7	28	0.734	-0.333
MADISON	72	39	30	67	0.734	-0.333
NORTHAMPTON	44	48	47	8	0.734	-0.333
PITTSYLVANIA	211	64	184	78	0.734	-0.333
POWHATAN	32	2	20	16	0.734	-0.333
PRINCE EDWARD	46	60	11	14	0.734	-0.333
ROCKBRIDGE	55	46	59	40	0.734	-0.333
SMYTH	38	66	18	28	0.734	-0.333
STAFFORD	22	11	25	10	0.734	-0.333
SURRY	30	22	65	10	0.734	-0.333
WESTMORELAND	122	5	2	111	0.734	-0.333
WYTHE	22	55	52	18	0.734	-0.333
CAROLINE	25	79	25	19	0.47	-0.548
ORANGE	53	39	51	39	0.47	-0.548
AMELIA	109	38	45	19	0.308	-0.667
BRUNSWICK	126	26	40	6	0.308	-0.667
CHARLOTTE	202	136	85	94	0.308	-0.667
CLARKE	94	60	28	34	0.308	-0.667
GLOUCESTER	51	58	46	13	0.308	-0.667
LEE	204	43	61	32	0.308	-0.667
NELSON	145	97	57	66	0.308	-0.667
SPOTSYLVANIA	40	79	29	27	0.308	-0.667
YORK	41	17	8	11	0.308	-0.667
BOTETOURT	77	25	25	10	0.149	-0.913
CAMPBELL	130	107	98	40	0.089	-1
FREDERICK	159	101	79	15	0.089	-1
LUNENBURG	61	35	33	15	0.089	-1
MONTGOMERY	41	38	37	36	0.089	-1
SCOTT	180	84	23	13	0.089	-1
SUFFOLK CITY	109	68	62	60	0.089	-1
WARREN	70	58	12	10	0.089	-1
WASHINGTON	155	123	89	51	0.089	-1

[julieshortridge]

Thanks Lal. A few questions/suggestions:

1. Are the rainfall deficit values using total or effective rainfall?
2. For the trend analysis, do the test on the coefficient values for each year, not the irrigated area. Note that with four values we'll never get a statistically significant trend (max p possible is 0.089) but we can look at the tau to see if it's monotonic.
3. For the counties with VDEQ irrigation withdrawals, it would interesting to see a comparison of the unreported small farm VOLUME calculated in each of the two ways (as a percentage of irrigation withdrawals, or using rainfall deficit). For instance, in 2002 Augusta county would end up with 461.554 * 0.05 = 23MG based on VDEQ irrigation withdrawals, and 41.54 MG based on rainfall deficit. A scatterplot of these values (x axis is volume based on VDEQ irrigation withdrawals, y axis is volume based on rainfall deficit) would allow us to see if the rainfall deficit approach is consistently resulting in higher or lower values than the method based on VDEQ withdrawals, and fine tune the rainfall deficit approach as necessary.

[laljeet]

1. Yes these are rainfall deficit values

2. MK on Coefficient

County_Name	c2002	c2007	c2012	c2017	Tau_MK	p_MK
ACCOMACK	0	0.01	0.01	0.01	0.707	0.371
ALBEMARLE	0	0	0.01	0	0.236	1
AMELIA	0.12	0.07	0.12	0.09	-0.183	1
APPOMATTOX	0.05	0.11	0.45	0.13	0.667	0.308
AUGUSTA	0.05	0.05	0.03	0.08	0.183	1
BEDFORD	0.01	0.07	0.58	1	1	0.089
BOTETOURT	0	0.01	0.01	0	0	1
BRUNSWICK	0.02	0.01	0.01	0	-0.913	0.149
BUCKINGHAM	0.01	0.04	0.03	0.01	-0.183	1
CAMPBELL	0.01	0.14	0.34	0.13	0.333	0.734
CAROLINE	0.01	0.04	0.01	0.01	-0.236	1
CHARLES CITY	0.02	0.02	0.01	0.01	-0.816	0.245
CHARLOTTE	0.17	0.19	0.11	0.18	0	1
CHESAPEAKE CITY	0	0.23	0	0.79	0.548	0.47
CHESTERFIELD	0.06	0.25	0.19	0	-0.333	0.734
CLARKE	0.29	0.12	0.11	0.24	-0.333	0.734
CRAIG	0	0.05	0	0	-0.236	1
CULPEPER	0.19	0.05	0.1	0.27	0.333	0.734
DINWIDDIE	0.1	0.01	0.05	0.02	-0.333	0.734
FAIRFAX	1	1	0	0	-0.816	0.245
FAUQUIER	0.04	0.04	0.01	0	-0.913	0.149
FLOYD	0.73	1.59	0.69	0.67	-0.667	0.308
FLUVANNA	0.02	0.02	0.03	0.01	-0.183	1
FREDERICK	0.31	0.34	0.01	0	-0.667	0.308
GILES	0	0	0	0	1	1
GLOUCESTER	0.02	0.03	0.02	0	-0.548	0.47
GOOCHLAND	0.01	0.01	0.01	0	-0.707	0.371
GREENE	0.02	0.04	0.01	0	-0.667	0.308
HALIFAX	0.03	0.08	0.1	0	0	1
HANOVER	0.12	0.04	0.07	0.05	-0.333	0.734
HENRICO	0.02	0	1	1	0.548	0.47
HENRY	0	0	0	0	1	1
ISLE OF WIGHT	0.01	0.06	0.02	0.04	0.333	0.734
JAMES CITY	0	0	0	0	1	1
KING AND QUEEN	0.09	1	1	0.03	-0.183	1
KING WILLIAM	0.01	0	0.01	0.01	0.236	1
LEE	0.05	0.02	0.01	0	-1	0.089
LOUDOUN	0.05	0.04	0.41	0	-0.333	0.734
LOUISA	0.04	0.08	0.05	0.03	-0.333	0.734
LUNENBURG	0.04	0.05	0.07	0	0	1
MADISON	0.27	0.09	0.02	0.04	-0.667	0.308
MATHEWS	0.52	0.81	0.41	0.14	-0.667	0.308
MECKLENBURG	0.06	0.02	0	0.01	-0.667	0.308
MIDDLESEX	0.02	0	0.04	0.1	0.667	0.308
MONTGOMERY	0.14	0.1	0.11	0.11	-0.183	1
NELSON	0.18	0.13	0.07	0.06	-1	0.089
NORTHAMPTON	0	0.01	0.01	0	0	1
NOTTOWAY	0.03	0.02	0.03	0.01	-0.548	0.47
ORANGE	0.03	0.06	0.09	0	0	1
PAGE	0.06	0.16	0.02	0.19	0.333	0.734
PITTSYLVANIA	0.04	0.02	0.05	0	-0.333	0.734
POWHATAN	0.14	0.07	0.2	0.25	0.667	0.308
PRINCE EDWARD	0.09	0.57	0.11	0	-0.333	0.734
PRINCE WILLIAM	0.01	0.13	0.07	0.04	0	1
PULASKI	0	0	0	0	1	1
RAPPAHANNOCK	0.1	1.07	0.84	0.15	0	1
ROANOKE	0.89	0	0	1	0.183	1
ROCKBRIDGE	0.01	0.01	0.01	0	-0.707	0.371
ROCKINGHAM	0.04	0.05	0.06	0.05	0.548	0.47
SCOTT	0.06	0.06	0.01	0	-0.913	0.149
SHENANDOAH	0.03	0.17	0.15	0.11	0	1
SMYTH	0	0.01	0	0	-0.236	1
SOUTHAMPTON	0	0.03	0.01	0.01	0.183	1
SPOTSYLVANIA	0.12	0.55	0.5	0.28	0	1
STAFFORD	0	0	0	0	1	1
SUFFOLK CITY	0.09	0.11	0.15	0.1	0.333	0.734
SURRY	0.02	0.02	0.05	0.01	-0.183	1
SUSSEX	0.01	0	0.02	0.02	0.548	0.47
VIRGINIA BEACH CITY	0	0	0	0	1	1
WARREN	0	0	0	0	1	1
WASHINGTON	0	0.01	0	0	-0.236	1
WESTMORELAND	0.08	0	0	0.13	0.183	1
WISE	0	0	0	0	1	1
WYTHE	0	0.01	0	0	-0.236	1
YORK	0	0	0	0	1	1

3. I have removed one value from DEQ irrigation method for plotting each year from 2007 to 2017
2007: 293 mgd (king and queen county)
2012: 246 mgd (king and queen county)
2012: 340 mgd (essex)

[rburghol]

I really like the points @julieshortridge made above, and I also really like @laljeet responses here. These charts seem to suggest that there is not a clear bias in one direction or the other, but I would be interested in seeing all years on a single chart, rather than each year in a separate chart. Also, rainfall deficit by month or season could be beneficial to see if it improves error.

[rburghol]

Actually, in and of itself, I speculate that comparing the model error between annual rainfall deficit and seasonal/monthly deficit approaches could provide a nice validation of the method if it in fact moves in the direction that I think it will.

[laljeet]

Changes after the meeting:

1. Effective precipitation months used: June- August
2. Use the deficit irrigation for counties with DEQ irrigation withdrawals

Updated Scatter plots: Looks a lot better
Some counties with unreported deficit irrigation methods are zero due to C_tot = 0 i.e. Irrigation volume (calculated by deficit method) is very small as compared to Total DEQ withdrawals

<style> </style>

County_Name	c2002	c2007	c2012	c2017	Tau_MK	p_MK
APPOMATTOX	0.13	0.24	1.01	1.97	1	0.089
GILES	0	0	0	0	1	1
JAMES CITY	0	0	0	0	1	1
STAFFORD	0	0	0	0	1	1
VIRGINIA BEACH CITY	0	0	0	0	1	1
WISE	0	0	0	0	1	1
YORK	0	0	0	0	1	1
ACCOMACK	0	0.01	0.01	0.02	0.913	0.149
BUCKINGHAM	0.02	0.08	0.07	0.09	0.667	0.308
ISLE OF WIGHT	0.03	0.19	0.87	0.2	0.667	0.308
LOUISA	0.13	0.14	0.2	0.19	0.667	0.308
RAPPAHANNOCK	0.39	2.15	3.63	2.52	0.667	0.308
SPOTSYLVANIA	0.4	1.73	1.65	86.44	0.667	0.308
PULASKI	0	0.01	0	0.01	0.408	0.699
BEDFORD	0.02	1.96	2.68	1.61	0.333	0.734
CHARLOTTE	0.91	3.31	2.9	3.22	0.333	0.734
CHESAPEAKE CITY	0.06	19.21	0.01	23.37	0.333	0.734
FLOYD	1.96	2.85	3.66	2.14	0.333	0.734
HENRICO	0.05	0	0.03	0.14	0.333	0.734
GOOCHLAND	0.02	0.01	0.02	0.02	0.236	1
ROCKBRIDGE	0.03	0.02	0.03	0.03	0.236	1
HENRY	0.01	0	0.02	0.01	0.183	1
ROANOKE	2.13	0.01	0.01	47.88	0.183	1
AUGUSTA	0.25	0.17	0.09	0.6	0	1
CAMPBELL	0.03	1	0.91	0.19	0	1
CULPEPER	15.73	0.1	0.35	1.11	0	1
HALIFAX	1.65	7.86	55.18	0.03	0	1
MADISON	0.97	0.19	0.28	0.51	0	1
MIDDLESEX	0.69	0	0.1	0.55	0	1
PAGE	0.23	1.93	0.19	0.43	0	1
PRINCE EDWARD	0.72	1.12	120.63	0.02	0	1
ROCKINGHAM	0.37	0.66	0.28	0.58	0	1
SHENANDOAH	0.66	2.15	1.65	1.45	0	1
SOUTHAMPTON	0	0.19	0.07	0.04	0	1
KING AND QUEEN	0.15	0.03	0.04	0.04	-0.183	1
KING WILLIAM	0.07	0	0.03	0.03	-0.183	1
SMYTH	0.01	0.02	0	0.01	-0.183	1
WESTMORELAND	0.22	0	0	0.16	-0.183	1
CAROLINE	0.02	0.08	0.02	0.02	-0.236	1
CHARLES CITY	0.05	0.49	0.01	0.02	-0.333	0.734
CLARKE	1.18	0.83	0.33	1.07	-0.333	0.734
DINWIDDIE	4.39	0.14	1.7	0.41	-0.333	0.734
FAUQUIER	0.13	0.08	0.1	0.09	-0.333	0.734
FLUVANNA	0.05	0.04	0.09	0.03	-0.333	0.734
GRAYSON	0.58	0.39	0.67	0.14	-0.333	0.734
LOUDOUN	2.98	2.71	311.57	0.03	-0.333	0.734
NOTTOWAY	0.09	0.04	0.08	0.06	-0.333	0.734
PATRICK	0.31	11.39	0.07	0.16	-0.333	0.734
PITTSYLVANIA	1.37	0.57	3.65	0.04	-0.333	0.734
POWHATAN	34.31	0.34	2.66	1.92	-0.333	0.734
PRINCE WILLIAM	1.79	20.02	0.84	1.15	-0.333	0.734
SUFFOLK CITY	0.28	0.18	0.17	0.21	-0.333	0.734
SURRY	0.31	0.29	1.27	0.1	-0.333	0.734
SUSSEX	0.21	0	0.17	0.03	-0.333	0.734
ALBEMARLE	0.02	0.01	0.02	0.01	-0.408	0.699
CRAIG	0.02	0.1	0.01	0.01	-0.548	0.47
AMELIA	1.59	1.33	0.32	1.01	-0.667	0.308
BRUNSWICK	0.09	0.02	0.05	0	-0.667	0.308
CHESTERFIELD	0.4	0.66	0.29	0	-0.667	0.308
FRANKLIN	10.67	0.15	0.08	0.09	-0.667	0.308
HANOVER	0.74	0.22	0.24	0.15	-0.667	0.308
LEE	0.19	0.03	0.04	0.02	-0.667	0.308
MATHEWS	2.64	1.73	1.03	1.05	-0.667	0.308
MECKLENBURG	23.24	5.08	0.04	0.07	-0.667	0.308
MONTGOMERY	1.47	0.49	0.33	0.45	-0.667	0.308
NELSON	0.45	0.11	0.07	0.08	-0.667	0.308
ORANGE	65.71	0.3	2.22	0.03	-0.667	0.308
BOTETOURT	0.02	0.02	0.02	0.01	-0.707	0.371
WYTHE	0.01	0.01	0.01	0	-0.707	0.371
WARREN	0.01	0.01	0	0	-0.816	0.245
WASHINGTON	0.02	0.02	0.01	0.01	-0.816	0.245
CARROLL	0.18	0.1	0.05	0.05	-0.913	0.149
FAIRFAX	4.25	1.37	0	0	-0.913	0.149
GREENE	0.09	0.09	0.08	0.05	-0.913	0.149
NORTHAMPTON	0.04	0.03	0.03	0.01	-0.913	0.149
FREDERICK	9.43	4.45	0.03	0	-1	0.089
GLOUCESTER	0.07	0.06	0.05	0.01	-1	0.089
LUNENBURG	3.14	2.39	2.3	0.04	-1	0.089
SCOTT	0.24	0.11	0.03	0.01	-1	0.089

[jdkleiner]

Some notes I jotted down during our last call:

• Julie’s proposed plan forward
  1. figure out these coefficient numbers, determine if any show a moving trend that justify having a moving value
  2. apply those, take the observed DEQ withdrawal, multiply by a timseries of unreported small farm and large farm irrigation in each country
  3. take that timeseries, merge these PRISM values on it
  4. do a regression on it, look at what those beta values look like
  5. maybe use it to run a few scenarios

[laljeet]

[laljeet]

Total Withdrawals

County_Name	c2002	c2007	c2012	c2017	Tau_MK	p_MK	Monotonic
APPOMATTOX	0.13001	0.24187	1.0052	1.96615	1	0.089	Y
JAMES CITY	0.00137	0.00141	0.00301	0.0044	1	0.089	Y
AMELIA	1.59385	1.33155	0.23068	0.15652	-1	0.089	Y
CARROLL	0.18194	0.10226	0.05336	0.0451	-1	0.089	Y
CHARLOTTE	0.90626	0.64366	0.53597	0.50486	-1	0.089	Y
FREDERICK	0.12614	0.02684	0.02511	0.00406	-1	0.089	Y
GLOUCESTER	0.06869	0.06049	0.04902	0.01365	-1	0.089	Y
LUNENBURG	0.13555	0.09584	0.09155	0.03843	-1	0.089	Y
MONTGOMERY	0.00297	0.0026	0.00201	0.00199	-1	0.089	Y
NORTHAMPTON	0.02622	0.02262	0.01879	0.00459	-1	0.089	Y
SCOTT	0.24223	0.11076	0.02627	0.01479	-1	0.089	Y
SUFFOLK CITY	0.00163	0.00085	0.00068	0.00066	-1	0.089	Y
WARREN	0.01056	0.00789	0.00182	0.00153	-1	0.089	Y
WASHINGTON	0.02084	0.01814	0.0119	0.00606	-1	0.089	Y
ACCOMACK	0.00183	0.00797	0.00557	0.00814	0.667	0.308	N
BUCKINGHAM	0.02148	0.08395	0.06699	0.08731	0.667	0.308	N
HANOVER	0.02958	0.05846	0.11367	0.06419	0.667	0.308	N
ISLE OF WIGHT	0.00016	0.00155	0.00112	0.00188	0.667	0.308	N
LOUISA	0.13474	0.14165	0.19766	0.18723	0.667	0.308	N
PULASKI	0.00099	0.00733	0.00483	0.00989	0.667	0.308	N
RAPPAHANNOCK	0.3938	2.15192	3.62915	2.52104	0.667	0.308	N
ROANOKE	0.00595	0.00662	0.00606	0.00859	0.667	0.308	N
ROCKINGHAM	0.01162	0.01219	0.01733	0.01648	0.667	0.308	N
VIRGINIA BEACH CITY	0.00189	0.00199	0.0029	0.00219	0.667	0.308	N
MIDDLESEX	0.07903	0	0.06316	0.13268	0.333	0.734	N
PAGE	0.00901	0.03883	0.01486	0.0165	0.333	0.734	N
ROCKBRIDGE	0.02548	0.02317	0.03354	0.03164	0.333	0.734	N
WISE	0.00205	0.00144	0.00175	0.00292	0.333	0.734	N
YORK	0.00082	0.00027	0.00043	0.00083	0.333	0.734	N
ALBEMARLE	0.01674	0.00848	0.02258	0.01326	0	1	N
AUGUSTA	0.02613	0.02513	0.00984	0.02994	0	1	N
CULPEPER	0.10811	0.03119	0.03297	0.08389	0	1	N
GILES	0.00061	0.00032	0.00077	0.00053	0	1	N
HALIFAX	0.05744	0.10259	0.17469	0.03459	0	1	N
HENRY	0.01217	0.003	0.01814	0.006	0	1	N
KING AND QUEEN	0.15063	0.0292	0.04017	0.04328	0	1	N
KING WILLIAM	0.00125	0	0.00113	0.00118	0	1	N
MADISON	0.9697	0.18608	0.27645	0.5057	0	1	N
PATRICK	0.31418	0.03985	0.07365	0.15737	0	1	N
PITTSYLVANIA	0.06552	0.03455	0.14065	0.03997	0	1	N
PRINCE WILLIAM	0.00028	0.00187	0.00162	0.00066	0	1	N
SHENANDOAH	0.01021	0.03203	0.02657	0.02265	0	1	N
SOUTHAMPTON	0	0.00831	0.00755	0.00194	0	1	N
SUSSEX	0.01993	0	0.02624	0.01161	0	1	N
WESTMORELAND	0.10412	0.00252	0.00148	0.11749	0	1	N
BEDFORD	0.01813	0.00353	0.00472	0.00378	-0.333	0.734	N
BOTETOURT	0.01532	0.02111	0.02091	0.01041	-0.333	0.734	N
CHARLES CITY	0.04598	0.12785	0.01264	0.01736	-0.333	0.734	N
CHESAPEAKE CITY	0.05923	0.00614	0.01261	0.01056	-0.333	0.734	N
CHESTERFIELD	0.00068	0.00074	0.0002	0.00037	-0.333	0.734	N
CRAIG	0.01889	0.10423	0.00631	0.00842	-0.333	0.734	N
FAIRFAX	0.00196	0.0007	0.00096	0.00091	-0.333	0.734	N
FAUQUIER	0.13006	0.07552	0.10177	0.0927	-0.333	0.734	N
FLOYD	1.96053	2.85497	2.23921	0.84964	-0.333	0.734	N
FLUVANNA	0.05179	0.04388	0.09481	0.03345	-0.333	0.734	N
GOOCHLAND	0.02025	0.01062	0.01977	0.01503	-0.333	0.734	N
GRAYSON	0.577	0.39376	0.66803	0.14141	-0.333	0.734	N
HENRICO	0.04516	0.00111	0.00036	0.00144	-0.333	0.734	N
LOUDOUN	0.05056	0.03478	0.0576	0.02776	-0.333	0.734	N
MECKLENBURG	0.11478	0.05106	0.04416	0.06576	-0.333	0.734	N
NOTTOWAY	0.08704	0.03808	0.07706	0.05854	-0.333	0.734	N
ORANGE	0.05195	0.02905	0.03798	0.03141	-0.333	0.734	N
POWHATAN	0.60954	0.02214	0.26068	0.11793	-0.333	0.734	N
PRINCE EDWARD	0.06819	1.11711	0.0163	0.01754	-0.333	0.734	N
SMYTH	0.00721	0.02159	0.0045	0.00643	-0.333	0.734	N
SURRY	0.12238	0.11001	0.36418	0.03804	-0.333	0.734	N
WYTHE	0.00744	0.01079	0.01042	0.00356	-0.333	0.734	N
BRUNSWICK	0.0882	0.01668	0.04663	0.00464	-0.667	0.308	N
CAMPBELL	0.03312	0.0265	0.02949	0.01025	-0.667	0.308	N
CAROLINE	0.00559	0.01893	0.00538	0.00512	-0.667	0.308	N
CLARKE	0.19451	0.14081	0.06123	0.0749	-0.667	0.308	N
DINWIDDIE	0.60133	0.08431	0.5502	0.08065	-0.667	0.308	N
FRANKLIN	0.30394	0.15489	0.0793	0.08834	-0.667	0.308	N
GREENE	0.09185	0.09482	0.07634	0.04989	-0.667	0.308	N
LEE	0.19271	0.03171	0.03521	0.01609	-0.667	0.308	N
MATHEWS	2.64151	1.72859	1.0285	1.0477	-0.667	0.308	N
NELSON	0.14602	0.04774	0.02809	0.03474	-0.667	0.308	N
SPOTSYLVANIA	0.00655	0.01057	0.00443	0.00309	-0.667	0.308	N
STAFFORD	0.00375	0.00133	0.00366	0.00116	-0.667	0.308	N

[laljeet]

Using Irrigation Withdrawals

County_Name	c2002	c2007	c2012	c2017	Tau_MK	p_MK	Monotonic
NORTHAMPTON	0.03522	0.02952	0.02509	0.00765	-1	0.089	Y
ACCOMACK	0.00287	0.0149	0.00753	0.01609	0.667	0.308	N
AMELIA	1.59385	1.33155	0.31778	1.00503	-0.667	0.308	N
AUGUSTA	0.2458	0.17463	0.09359	0.59712	0	1	N
CAROLINE	0.01546	0.08392	0.01801	0.01577	0	1	N
CHARLES CITY	0.04984	0.48571	0.01334	0.01965	-0.333	0.734	N
CLARKE	1.17874	0.82773	0.33212	1.07367	-0.333	0.734	N
CULPEPER	15.7324	0.09537	0.35343	1.10946	0	1	N
DINWIDDIE	4.39132	0.13545	1.69588	0.40541	-0.333	0.734	N
HANOVER	0.74117	0.22029	0.23895	0.15018	-0.667	0.308	N
ISLE OF WIGHT	0.02821	0.19309	0.87478	0.20338	0.667	0.308	N
KING AND QUEEN	0.15332	0.02968	0.04087	0.04376	0	1	N
KING WILLIAM	0.06536	0	0.02537	0.02957	0	1	N
MIDDLESEX	0.69179	0	0.1027	0.54801	0	1	N
MONTGOMERY	1.46882	0.48603	0.32645	0.45442	-0.667	0.308	N
NELSON	0.45084	0.10803	0.06826	0.07586	-0.667	0.308	N
PAGE	0.22914	1.93262	0.18502	0.42505	0	1	N
POWHATAN	34.3103	0.33636	2.6575	1.9186	-0.333	0.734	N
PRINCE WILLIAM	1.78824	20.019	0.83973	1.1526	-0.333	0.734	N
ROCKINGHAM	0.36869	0.6555	0.27781	0.57519	0	1	N
SHENANDOAH	0.66354	2.14816	1.64956	1.45465	0	1	N
SOUTHAMPTON	0	0.18933	0.06604	0.03935	0	1	N
SPOTSYLVANIA	0.40307	1.7267	1.65294	86.4384	0.667	0.308	N
SUFFOLK CITY	0.27761	0.17923	0.17029	0.2117	-0.333	0.734	N
SURRY	0.31352	0.28615	1.27293	0.10362	-0.333	0.734	N
SUSSEX	0.20518	0	0.16706	0.0322	-0.333	0.734	N
WESTMORELAND	0.22195	0.00361	0.00295	0.15944	-0.333	0.734	N

[laljeet]

Time series

[laljeet]

[julieshortridge]

Thanks Lal, this is helpful to see. From this, it appears that the rainfall deficit approach does tend to result in higher volume estimates than the area proportional approach. That's ok, just useful to know. It also appears that the range of rainfall deficit estimates is somewhat smaller than the range of area proportional estimates. The range of area proportional MG is about 0.01 (eyeballing this, having those lower values marked on the x-axis would be helpful) to 100 MG, while the range of rainfall deficit estimates is about 1 to 100.

It might also be helpful to see a summary of the ratio of volume estimates derived from the two methods:
ratio_c,y = V_rainfalldef_c,y / V_areaprop_c,y
This would allow us to say something like "on average, estimates using the rainfall deficit approach are X% higher than estimates using the area proportional approach"

[laljeet]

The ratio of volume estimates: V_rainfalldefc,y / V_areapropc,y
Mean= 21.7
Median= 2.5

[julieshortridge]

Thanks Lal, this is interesting to see. We didn't get time to talk about it today, but one thing I've been wondering is if we could consider that area proportional approach as a likely lower bound (or at least an estimate that we know is likely to be lower than the true value). I think we can, because one assumption that we're making when we use that approach is that all of the farms above the threshold are accounted for in the VDEQ reported withdrawal, even though we know that's not the case.

If we relax that assumption and assume that some of those large farm acres are not reporting to VDEQ, then our coefficients for small farm irrigation as a percentage of VDEQ withdrawals will necessarily go up. If we assume that VDEQ reports account for about half of actual water used by large farms (as our large farm estimates seem to suggest), then the small farm estimates would double. This seems pretty aligned with that median increase of 2.5 above.

I'm attaching an image of the equations I did just to get my head around this, in case it's useful. I don't think we necessarily need to use this moving forward, but I think it is one more piece of evidence towards the robustness of our rainfall deficit approach.