Water Stress Trend (WST) product
About “Water Stress Trend (WST)”"WST (Water Stress Trend)" is index to understand the droughty state of ground.
Using the characteristic of specific heat of water, WST is calculated from the temperaturechange during daytime and nighttime.
On this site, WST product calculated from brightness temperature data of Terra/MODISand Aqua/MODIS is provided.
Ranges of WST value is [0:1].
The degree of dryness is strong when WST value approaches 1.
On the other hand, the degree of dryness is weak when WST value is 0.

(Example)－ Japan －－ Global －Water Stress Trend (WST) in September, 2009

Water Stress Trend (WST) product data
WST product provides the binary data (two kinds) and the text data.
(1) Binary (raw) data of half-monthly
half-monthly: from the 1st to the 15th
from the 16th to the end day of the month(2) Binary (raw) data of monthly(3) Text data
○ Analysis area & Binary data file size
Bit type: 8-bit signed integer(a) Japan
binary (raw) data file size: Header (2701)+2701×2601 pixel(b) Global

binary (raw) data file size: Header (7200)+7200×3601 pixel○ Range of WST value: [0:1](0: The dryness degree is weak, 1: The dryness degree is strong)
However, WST value of the binary (raw) file allocates to 1-255.
○ Product unit (period)
half-monthly (from the 1st to the 15th, from the 16th to the end day of the month)
monthly （It is made from two half-monthly product at the end of the month.）

Detailed information about product file
○ Binary (raw) data file
･ Filename: MDSYYYYMMDD_YYYYMMDD-WST_#.raw(Example: MDS20091101_20091115-WST_#.raw)
MDS: MODIS
20091101: first day of observation
20091115: end day of observation
WST: WST product#: Area (J: Japan, A: Global)･ binary (raw) data file size
Bit type: 8-bit signed integer(a) Japan area: Header (2701)+2701×2601 pixel(b) Global area: Header (7200)+7200×3601 pixel･ WST value: [0:255]
0: sea, cloud, and snow ice area
1-255: Value in which WST value of [0 :1] was allocated(1 - The dryness degree is weak, 255 - The dryness degree is strong)○ Text data file
WST values of each prefecture or country are written in text file.
･ Filename: halfmonthly-WST_#.txt#: Area (J: Japan, A: Global)

･ Contents of txt file(a) JapanYYYY MM D1 D2 Val Val01 Val02 Val03 ……. Val45 Val46 Val47（Ex.）
2009 9 1 30 0.3647 0.3697 0.3508 0.3758 0.3225 0.3699 0.3766 0.3706 0.4033
0.4038 0.4157 0.4259 0.3569 0.3942 0.3923 0.3823 0.3652 0.3638 0.3375 0.3785 0.3999
0.3658 0.3843 0.3845 0.3357 0.3417 0.3147 0.3995 0.3221 0.3041 0.3147 0.3091 0.3409
0.3473 0.3527 0.3569 0.2925 0.3571 0.3478 0.3218 0.3931 0.3641 0.3432 0.3877 0.3666
0.3633 0.3558 0.290

YYYY: year
MM: monthD1: first day of observation
D2: end day of observation
Val: WST value of whole area of Japan
Val01-47: WST value of each prefecture
Prefecture number:
01: Hokkaido
06: Yamagata
11: Saitama
16: Toyama
21: Gifu
26: Kyoto
31: Tottori
36: Tokushima
41: Saga
46: Kagoshima

02: Aomori
07: Fukushima
12: Chiba
17: Ishikawa
22: Shizuoka27: Osaka
32: Shimane
37: Kagawa
42: Nagasaki
47: Okinawa

03: Iwate
08: Ibaraki
13: Tokyo
18: Fukui
23: Aichi
28: Hyogo
33: Okayama
38: Ehime
43: Kumamoto

04: Miyagi
09: Tochigi
14: Kanagawa
19: Yamanashi
24: Mie
29: Nara
34: Hiroshima
39: Kochi
44: Oita

05: Akita
10: Gunma
15: Niigata
20: Nagano
25: Shiga
30: Wakayama
35: Yamaguchi
40: Fukuoka
45: Miyazaki(b) Global
YYYY MM D1 D2 Val Val1 Val2 Val001 Val002 Val003 …. Val135 Val136 Val137(Ex.）
2009 9 1 30 0.4743 0.4614 0.5210 0.3709 0.4765 0.4243 0.3816 0.6017 0.2493
0.3822 0.4443 0.4253 0.3666 0.4905 0.3660 0.4214 0.3850 0.3595 0.3967 0.3786 0.3394
0.5500 0.3598 0.3802 0.5161 0.6949 0.6302 0.6377 0.0000 0.0000 0.5714 0.7404 0.0000
0.0000 0.7424 0.5010 0.3590 0.4938 0.3401 0.5669 0.4151 0.6389 0.5514 0.0000 0.0000
0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000
0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000
0.0000 0.0000 0.3646 0.4411 0.3706 0.5543 0.4352 0.5421 0.3909 0.4749 0.4628 0.5078
0.4349 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000
0.0000 0.0000 0.3476 0.5290 0.4107 0.3092 0.4508 0.0000 0.0000 0.0000 0.0000 0.0000
0.0000 0.0000 0.0000 0.0000 0.0000 0.4248 0.3938 0.3657 0.3778 0.4308 0.5094 0.3714
0.3679 0.4782 0.3756 0.5788 0.3831 0.4196 0.4204 0.3843 0.4078 0.0000 0.0000 0.0000
0.0000 0.0000 0.0000 0.0000 0.0000 0.6418 0.4129 0.3887 0.0000 0.0000 0.0000

YYYY: year
MM: monthD1: first day of observation
D2: end day of observation
Val: WST value of global
Val1: WST value of whole area of northern hemisphereVal2: WST value of whole area of southern hemisphere
Val001-137: WST value of each country

country number:
East Asia
000: Korea
003: Japan

001: China
004: Mongolia

002: North Korea
005: Taiwan

Southeastern Asia
010: Indonesia
015: Vietnam

011: Cambodia 012: Thailand
016: Malaysia, Singapore

013: Philippine
017: Myanmar

014: Brunei
018: LaosSouthern Asia
020: India
024: Bangladesh

021: Sri Lanka
025: Bhutan

022: Nepal
023: Pakistan
026: other South Asia

Central Asia
030: Uzbekistan
031: Kazakhstan
033: Tajikistan
034: Turkmenistan
West Asia (including Middle East and Turkey)
040: Afghanistan
041: Iran
043: other West Asia (Arabian Peninsula)032: Kirgizia

042: Turkey

North Africa
050: Algeria
051: Egypt
053: Morocco (Including Western Sahara)
055: Sudan
056: Chad057: Niger

052: Tunisia
054: Libya
058: Mali
059: Mauritania

Western Africa
060: Ghana
061: Cote d'Ivoire
062: Senegal 063: Nigeria
064: Burkina Faso
065: other Gulf of Guinea (nine countries such as Guinea, Burkina Faso, and Liberia)
074: Gabon
075: Cameroon
076: Republic of Congo
077: Democratic Republic of the Congo
078: Equatorial Guinea
079: Central Africa

Southern Africa
080: Angola
081: Zambia
082: Zimbabwe
083: Namibia
084: Botswana
085: South Africa
086: Mozambique
087: other Southern Africa(three countries: Malawi, Kingdom of Lesotho, and Kingdom of Swaziland)
099: Madagascar
100: other Indian Ocean (four islands: Comoros, Seychelles, Mauritius, and Réunion)

Eastern Africa
090: Ethiopia, Eritrea
091: Kenya
092: Somalia
093: Tanzania
094: other East Africa (four countries: Uganda, Djibouti, Rwanda, and Burundi)

Europe110: Ireland
111: Britain
112: Italy
113: Estonia
114: Austria
115: Greece
116: Sweden
117: Spain
118: Slovakia
119: Slovene
120: Czech
121: Denmark
122: Germany
123: Hungary124: Finland
125: France
126: Bulgaria
127: Poland
128: Portugal
129: Latvia
130: Lithuania
131: Romania
132: Netherlands, Belgium, Luxembourg
133: other EU
140: Iceland
141: Azerbaijan
142: Albania
143: Armenia
144: Ukraine
145: Georgia
146: Croatia
147: Switzerland
148: Serbia, Montenegro
149: Norway
150: Belarus 151: Bosnia-Herzegovina
152: Macedonia
153: Moldova
154: other Non-EU

Western Russia
160: West Russia(west of E60)

161: West Siberia(60-90E)

Eastern Russia
162: Central Siberia (90-120E)
164: Far Eastern Russian (east of 150E)

Canada172: Canada

Alaska171: Alaska

North America

163: East Siberia (120-150E)

170: continental U.S., Hawaii (Excluding Alaska)
173: Mexico
174: other North America, Central America･Caribbean islands

South America
200: Argentina
204: Colombia
208: Brazil
212: Guiana (French)

201: Uruguay
202: Ecuador
203: Guyana
205: Suriname
206: Chile207: Paraguay
209: Venezuela
210: Peru
211: Bolivia
213: other South America, Falkland islands

Oceania
220: Australia

221: New Zealand

222: other Oceania islands

Greenland
240: Greenland

South Pole
241: South Pole

Svalbard, Jan Mayen Island
242: Svalbard, Jan Mayen Island･ WST value: [0:1] (0: The dryness degree is weak, 1: The dryness degree is strong)

2010/1/26