| Bayannaoer is located in western of Inner Mongolia Autonomous Region, its climate belongs to temperate continental monsoon climate, and it has the characteristics of perennial drought, long time of sunshine and strong evaporation. It is located in arid and semi-arid region, desert and steppe transition zone, the ecological environment is fragile. The grassland livestock is in recession year after year because of the drought. It is the main source and performance of Fragile Eco-regions in Wulate that shortage of water and drought. So using satellite remote sensing monitor the grassland evaportranspiration to achieve real water saving and efficient use of water resources for the effective management of water resources in pastoral areas. The Hetao Irrigation area of Bayannaoer City as one of the most important food production areas, seriously hampered the sustainable development of irrigated agriculture , because of poor drainage,irrigation and drainage and long-term imbalance. Therefore, the precise irrigation water planning and management plays a significant role in sustainable development of the Hetao Irrigation area. Using remote sensing to estimate evapotranspiration irrigation, can rationalize the distribution of water resources in the region and protect the ecological health of the region to provide technical support and business services.The SEBS model algorithm has been realized through programming interactive data language (IDL)of ENVI platform by using MODIS images, combined with the data of meteorological observation site, and the April-October 2006-2008 evapotranspiration data sets have been established in the paper. Finally, spatial change of evapotranspiration of different types of land in Bayannaoer is analysised. Most traditional calculations of regional evapotranspiration based on the date of a single site, which is difficult to obtain accurate results on the popularization and application in large areas though it has a high precision. Whereas using remote sensing technology can be more intuitive,real-time,accurate , avoiding the shortcomings of traditional methods, to reflect their spatial and temporal distribution. The conclusion is:The distribution of evapotranspiration: the evapotranspiration of water is the largest, followed by is farmland in Hetao Irrigation area, the evapotranspiration of grass is less than farmland, and the evapotranspiration of other land is minimum. In April, the evapotranspiration of the entire study area is the smallest one, and the difference of different types lands is minimum, except the waters, the evapotranspiration of other types of land is smaller than 4mm; In May, the evapotranspiration of all types lands began to increase, the water is most obvious, reaching 6.5mm; In June, with the rise of temperatures and the sunshine, the evapotranspiration continues to rise; In July and August, the evapotranspiration has reached 6.5mm, much higher than other types of lands. Followed by grassland, other types of lands is still the smallest, the evapotranspiration of all types of the lands reached the maximum in the study area at this time within a year. In September, the evapotranspiration began to decrease, to October , the average of evapotranspiration in the study area has been less than 4mm, just behind April.The distribution of total showed a single peak in each year in the study area, in July and August the evapotranspiration is maximum, in June and September the evapotranspiration is high, in April,May and October the evapotranspiration is minimum. The cumulative total evapotranspiration from April to October in 2006 is maximum, followed is 2008, the cumulative total evapotranspiration from April to October in 2007 is minimum;In the study area, the monthly average evapotranspiration from April to October in 2006,2007 and 2008 is water>cultivated field> farmland>other land. |
