Agricultural Drought Indices - US Department of Agriculture

More documents

Recommendations

Info

Crop Moisture Index (CMI): CMI is a non-cumulative index based on the difference between the current ETa and the expected ETa (climatological value) for the same period, as proposed by Palmer (1968): CMI = ETa observed – ETa expected (4) Negative values indicate that deficient evapotranspiration occurred, indicating a drought condition, whereas positive values show that ETa was more than expected for the period. Crop Water Development Index (CWDI): CWDI is an agricultural index used to follow the development conditions of crops in general. This index is based on the relationship between soil water storage (SWS) and SWHC, called the crop water development fraction (CWDF). SWS is obtained from the climatological water balance of Thornthwaite and Mather (1955), but can also be estimated with different WB models. CWDF and CWDI are calculated by the following procedures: CWDF = SWS / SWHC (5) CWDI = (CWDF * 0.4) – 1 (6) Accumulated CWDI (ACWDI) is then obtained for normalized conditions, by ACWDI = ∑ CWDI / (1.5 n) (7) where n is the number of periods considered. The classification of the crop development conditions is presented in Table 5. Table 5. Classification of ACWDI for crop development conditions. Source: www.infoseca.sp.gov.br. ACWDI lasses Crop development conditions 0.8 ≤ ACWDI ≤ 1 Very good 0.6 ≤ ACWDI < 0.8 Good 0.4 ≤ ACWDI < 0.6 Reasonable 0.3 ≤ ACWDI < 0.4 Unfavorable 0.2 ≤ ACWDI < 0.3 Critical 0.1 ≤ ACWDI < 0.2 Severe ACWDI < 0.1 Extremely severe Soil Water Storage (SWS) (or relative soil moisture): Another way to identify agricultural droughts is by soil water storage monitoring. SWS is an output of the water balance (WB). This variable can be obtained by different WB methods, such as those proposed by Thornthwaite and Mather (1955), Molinas and Andrade (1993), Allen et al. (1998), and Ritchie (1998). Each kind of WB method will require specific inputs, but basically they require climate (rainfall and potential evapotranspiration), soil (physical properties), and plant (crop type, leaf area, crop sensitivity to water stress, crop water requirement for each phenological phase, and management practices) information, depending on their complexity. In Brazil, Thornthwaite and Mather’s WB is used by INMET, AGRITEMPO, and several regional M&HSs. CPTEC/INPE employs Richards’s equation (Hillel 1998, Gevaerd and Freitas 2006), also known as the hydrological model, using rainfall and temperature data derived from satellite images as inputs, whereas FUNCEME uses MUSAG WB model (Molinas and Andrade 1993), which has rainfall, ETP, soil water storage in the previous period, and pedo-transfer functions for hydraulic soil characterization as inputs. Figures 7, 8, and 9 present examples of the products provided by INMET, CPTEC, and FUNCEME, where SWS data are spacialized in maps. 67
Soil Water Storage (SWS) September 2010 Figure 7. SWS in Brazil at the end of September 2010, determined by Thornthwaite and Mather’s WB, considering a SWHC = 125 mm. Source: www.inmet.gov.br. Soil Water Storage (SWS) Depth: 37.5 cm – 28 OCT 2010 Soil Water Storage (SWS) Depth: 137.5 cm – 28 OCT 2010 Figure 8. SWS in South America, October 28, 2010, determined by a hydrological WB model, for two soil profiles (37.5 and 137.5 cm). Source: www.cptec.inpe.br. 68
Page 1 and 2:
Agricultural Drought Indices Procee
Page 3 and 4:
© World Meteorological Organizatio
Page 5 and 6:
Page 7 and 8:
Preface With the world population p
Page 9 and 10:
Segura River Basin: Spanish Pilot R
Page 11 and 12:
Table 3. Segura River Basin resourc
Page 13 and 14:
Figure 5. Segura River Basin water
Page 15 and 16:
Drought Indicator Expression After
Page 17 and 18:
Table 5. Analysis of drought impact
Page 19 and 20:
Even with this drought action plan
Page 21 and 22:
that complicates water management b
Page 23 and 24: Understanding the nature of the haz
Page 25 and 26: Figure 2. U.S. Drought Monitor for
Page 27 and 28: Summary Drought is a creeping pheno
Page 29 and 30: Agricultural Drought—WMO Perspect
Page 31 and 32: c) CAgM-VI (Washington, USA, 1974)
Page 33 and 34: an unusually large moisture demand.
Page 35 and 36: the-clock nature of WIGOS, the anal
Page 37 and 38: and temporal variations in drought
Page 39 and 40: Support to Regional Institutions WM
Page 41 and 42: Williams, M.A.J. and R.C. Balling,
Page 43 and 44: The day after Black Sunday, an Asso
Page 45 and 46: Meteorological research at these in
Page 47 and 48: United States is sent to the Secret
Page 49 and 50: Palmer Drought Severity Index (PDSI
Page 51 and 52: PDSI as an operational index since
Page 53 and 54: WAOB, GIS has become an important t
Page 55 and 56: USDM as the official criteria for F
Page 57 and 58: Monitoring Drought Risks in India w
Page 59 and 60: areas recording large incidences of
Page 61 and 62: The analysis revealed that out of 1
Page 63 and 64: Figure 3. Aridity anomaly chart of
Page 65 and 66: Figure 5. Progression of surface we
Page 67 and 68: Agricultural Drought Indices in Cur
Page 69 and 70: Meteorological and Agricultural Dro
Page 71 and 72: Palmer Drought Severity Index Adapt
Page 73: Accumulated WD and WS April 2010 Ac
Page 77 and 78: hydrological characteristics, and c
Page 79 and 80: Agricultural Drought Indices in Cur
Page 81 and 82: application of drought indices has
Page 83 and 84: The Value of Crop and Pasture Simul
Page 85 and 86: To assist, many agriculturally-spec
Page 87 and 88: change in Australia. The PDSI provi
Page 89 and 90: Mpelasoka, F.S., M.A. Collier, R. S
Page 91 and 92: supply and demand are fully taken i
Page 93 and 94: In Germany, the Deutsche Wetterdien
Page 95 and 96: creation of a system of European su
Page 97 and 98: The second index is extracted from
Page 99 and 100: Figure 7. Standardized Soil Water I
Page 101 and 102: References Durand, Y., E. Brun, L.
Page 103 and 104: Europe around the Iberian Peninsula
Page 105 and 106: The incoming rainwater and the atmo
Page 107 and 108: Figure 6. Example of SPI map for a
Page 109 and 110: The 1991-95 Drought Episode A long-
Page 111 and 112: adverse climatic impacts on agricul
Page 113 and 114: Agricultural Drought Indices in the
Page 115 and 116: efers to deficiencies in surface an
Page 117 and 118: Figure 5. Time series of standardiz
Page 119 and 120: Limitations of Agricultural Drought
Page 121 and 122: Incorporating a Composite Approach
Page 123 and 124: Figure 3. Daily gridded SPI by regi
Page 125 and 126:
The North American Drought Monitor:
Page 127 and 128:
process (a) emulates natural cycles
Page 129 and 130:
Summary Given the complexity that d
Page 131 and 132:
alance models cannot be applied for
Page 133 and 134:
60 50 40 Error 30 20 Systematic Err
Page 135 and 136:
In Figure 4, examples of the normal
Page 137 and 138:
Figure 7. Water balance for Brazil,
Page 139 and 140:
The soil water balance module in th
Page 141 and 142:
Water Balance as a Tool for Agricul
Page 143 and 144:
Conclusions The topics discussed pr
Page 145 and 146:
Use of Crop Models for Drought Anal
Page 147 and 148:
The parameters used in crop simulat
Page 149 and 150:
a model for cassava and potato (Tsu
Page 151 and 152:
ackground. The system’s most impo
Page 153 and 154:
management. In research, however, p
Page 155 and 156:
Smajstrla, A.G. 1990. Technical Man
Page 157 and 158:
Monitoring Regional Drought Conditi
Page 159 and 160:
Figure 2 represents the regression
Page 161 and 162:
Conclusions and Discussion Several
Page 163 and 164:
Experiences During the Drought Peri
Page 165 and 166:
During the years 2007 and 2008, for
Page 167 and 168:
Figure 6. Management simulation mod
Page 169 and 170:
Figure 9. Irrigation diversions in
Page 171 and 172:
References Andreu, J., Ferrer Polo,
Page 173 and 174:
Table 2. MERIS spectral bands MDS N
Page 175 and 176:
Figure 6. Spanish NSDIE during 2008
Page 177 and 178:
References Gu, Y., J. F. Brown, J.
Page 179 and 180:
Agricultural Drought Indices: Summa
Page 181 and 182:
Table 1. Agricultural drought indic
Page 183 and 184:
Accumulated Rainfall Deficits In an
Page 185 and 186:
Heim (2002) notes that as recently
Page 187 and 188:
each calendar day in the base perio
Page 189 and 190:
The purpose of the climatic charact
Page 191 and 192:
to compare moisture conditions at d
Page 193 and 194:
Table 6. Overview of different drou
Page 195 and 196:
have been adopted because of the av
Page 197 and 198:
TCI = 100 (T max - T) / (T max - T
Page 199 and 200:
Figure 1. The February 8, 2011, US
Page 201 and 202:
8) There is a universal interest in
Page 203 and 204:
Mavromatis, T. 2007. Drought index
Page 205:
show all

Agricultural Drought Indices - US Department of Agriculture

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?