|
Water Resources
|
Monitoring Soil Water Contents in Tarim River Area Using NOAA/AVHRR Data
3. The distribution Map of Soil Water Contents.
Based model (4), operation computer, exporting the map of soil water contents in the form of monitoring screen or photo or printing map. In order to avoid the broken bits of map, and consider the suitable and harmful the limits of soil water contents for staple vegetation (diversiform-leaved poplar, tamarisk, meadow, crop), the soil water contents are divided 6 grades, i.e. <5%, 5-11%, 11-16%, 20-25%, >25% (Fig.1 and Fig.2). The data shows the average soil water contents in 10mm inner surface layer soil.
Fig 2. Distribution of Soil Water Contents in Tarim River Area on May 21, 1993.
Fig 2. Distribution of Soil Water Contents in Tarim River Area on August 23, 1993.
4. Discussion
4.1 The maps of soil water contents distribution confirmed to reality regularity:
-
along with distant place of river bed, the soil water contents reduced gradually, due to the underground water reduced gradually;
- in the same year, the soil water is more in August than May, due to August is in flood, floodwater irrigation and soil water supplied increased;
- the soil water is more in May, 1994 than in May, 1993(Fig.1 and Fig.2), because 1994 is good flood year, 1993 is lean floodwater year, their spring floodwater is different.
4.2 This method was able to remove the interference of vegetation cover. On the basis of test of real observation place, the degree of accuracy is over 80%. NOAA data can be got every day, and therefore it is suited for monitoring fast soil water contents of large area.
References
-
Liu Peijun et al., A method for Monitoring Soil Water Contents Using satellite Remote Sensing, Vol.1, No.2, Beijing, China, 1997.
- Wang Ranghui et al., Selection of Sensitive band for Remote Sensing Soil Water in Arid Area, Xinjiang Meteorology, Vol.18, No.5, Urumqi China, 1995.
- Liu Peijun et al., An Estimate Method of Optical Vegetation Coverage Using TM Data, Remote Sensing Technology and Application, Vol. 10, No.4 Lanzhou China, 1995.
|
|
|
|
|
