Limits...
Winter wheat water productivity evaluated by the developed remote sensing evapotranspiration model in Hebei Plain, China.

Zhang S, Zhao H, Lei H, Shao H, Liu T - ScientificWorldJournal (2015)

Bottom Line: The spatial variations indicated that the major distribution of ETa ranged from 350 to 450 mm, which trended downward within the study area from west to east.In the study period, the winter wheat CWP was mainly distributed between 0.29 and 1.67 kg/m(3).In space, the CWP was higher in the west than in the east.

View Article: PubMed Central - PubMed

Affiliation: Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Hohhot 010018, China.

ABSTRACT
Agricultural water is the main reason for the rapid decline of the NCP groundwater levels. It is of vital importance for the NCP sustainable agricultural development to master the ETa and its CWP. In this paper, the EBEM model was developed according to the theory of energy balance. From 2001 to 2006, the winter wheat ETa and CWP were estimated, and the spatial and temporal variations and their influencing factors were studied in the Hebei Plain. The results indicate that the EBEM model performed well by applying MODIS data to estimate the daily net radiation and ETa. For the daytime net radiation, the relative error between the estimation and the measurement amounted to 8.2% and the SEE was 0.82 MJ m(-2)/day. The average ETa deviation between the estimates and the measures amounted to 0.86 mm daily, and the SE was 1.2 mm. The spatial variations indicated that the major distribution of ETa ranged from 350 to 450 mm, which trended downward within the study area from west to east. In the study period, the winter wheat CWP was mainly distributed between 0.29 and 1.67 kg/m(3). In space, the CWP was higher in the west than in the east.

No MeSH data available.


The rainfall (column), the model estimates Eta (line), and the Lysimeters observed Eta (point) from 2005 to 2006.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4302380&req=5

fig4: The rainfall (column), the model estimates Eta (line), and the Lysimeters observed Eta (point) from 2005 to 2006.

Mentions: Figure 4 shows the comparison between the estimated ETa and the measured value from 2005 to 2006. It can be seen that the estimated ETa using the model is in a good agreement with the measured values. Fluctuations in the state of the two are almost the same. The data show two distinct peak times, one in 4-5 months and one in 7–9 months, because of the winter wheat-summer corn rotation. Based on the statistical analysis, the daily average deviation is 0.86 mm and the SEE is 1.2 mm between the estimation and the observed values.


Winter wheat water productivity evaluated by the developed remote sensing evapotranspiration model in Hebei Plain, China.

Zhang S, Zhao H, Lei H, Shao H, Liu T - ScientificWorldJournal (2015)

The rainfall (column), the model estimates Eta (line), and the Lysimeters observed Eta (point) from 2005 to 2006.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4302380&req=5

fig4: The rainfall (column), the model estimates Eta (line), and the Lysimeters observed Eta (point) from 2005 to 2006.
Mentions: Figure 4 shows the comparison between the estimated ETa and the measured value from 2005 to 2006. It can be seen that the estimated ETa using the model is in a good agreement with the measured values. Fluctuations in the state of the two are almost the same. The data show two distinct peak times, one in 4-5 months and one in 7–9 months, because of the winter wheat-summer corn rotation. Based on the statistical analysis, the daily average deviation is 0.86 mm and the SEE is 1.2 mm between the estimation and the observed values.

Bottom Line: The spatial variations indicated that the major distribution of ETa ranged from 350 to 450 mm, which trended downward within the study area from west to east.In the study period, the winter wheat CWP was mainly distributed between 0.29 and 1.67 kg/m(3).In space, the CWP was higher in the west than in the east.

View Article: PubMed Central - PubMed

Affiliation: Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Hohhot 010018, China.

ABSTRACT
Agricultural water is the main reason for the rapid decline of the NCP groundwater levels. It is of vital importance for the NCP sustainable agricultural development to master the ETa and its CWP. In this paper, the EBEM model was developed according to the theory of energy balance. From 2001 to 2006, the winter wheat ETa and CWP were estimated, and the spatial and temporal variations and their influencing factors were studied in the Hebei Plain. The results indicate that the EBEM model performed well by applying MODIS data to estimate the daily net radiation and ETa. For the daytime net radiation, the relative error between the estimation and the measurement amounted to 8.2% and the SEE was 0.82 MJ m(-2)/day. The average ETa deviation between the estimates and the measures amounted to 0.86 mm daily, and the SE was 1.2 mm. The spatial variations indicated that the major distribution of ETa ranged from 350 to 450 mm, which trended downward within the study area from west to east. In the study period, the winter wheat CWP was mainly distributed between 0.29 and 1.67 kg/m(3). In space, the CWP was higher in the west than in the east.

No MeSH data available.