Study On Dynamic Change Of Drought And Causes In Xingtai District

Drought is the major factor which effecting our country agricultural production, particularly in irrigative plain of North of China. The drought situation of Xingtai district which situate at North of China is serious, therefore, drought of this district needs to be prevented and relieved. We need to study the changes of drought situation and the driving firstly, afterward can make the reasonable countermeasure to prevent and reduce disaster according to the driving mechanism.This research based on the MODIS product of Xingtai in March to September 2003-2008, has established the different phase image database, and carried on related processing through GIS and the RS technology, then obtained different phase drought situation spatio-temporal of Xingtai. Has analyzed data of natural background, social economy, drought disaster situation, climate statistical and so on, According to the rules of drought situation dynamic change in Xingtai, has contrasted the drought situation under the natural precipitation condition and the manual intervene, Analyzed driving influence which causes drought situation dynamic changing from two aspects(the natural environment and the human factor), proposed the reasonable countermeasure to prevent and reduce disaster in Xingtai. Has drawn the following conclusions:(1) Drought situation pattern in Xingtai can be divided into two stages, the first stage is from early March to late May, the second stage is from early June to late September. In the first stage, the fundamental space pattern of drought is: the east of low plain maintains drought situation, the west of low plain is normal, middle the piedmont region is normal in early April,late April and early May,but it present heavy drought,mid-drought and light drought in other time,the east of hilly area maintains drought situation,the west of hilly area is normal in early May and late May,but it presents heavy drought,mid-drought or light drought in other time. In the second stage, the fundamental space pattern of drought is: the east of low plain is normal, the west of low plain present drought situation in early June and late June, but it is normal after late June, middle the piedmont region displays mid-drought or light drought in early June and late June, it is normal after late June, the east of hilly area maintains drought situation,the west of hilly area is normal. (2) Under the natural precipitation condition, take the precipitation anomalous percentage as a target, classed drought in Xingtai, and then know the rules of drought situation in Xingtai. The drought situation under the natural precipitation condition and the manual intervention is contrary. For example, under the natural precipitation condition, Nagong county displays waterlogged in May, 2004, May, 2006, March, 2007, but under the manual intervene, it displayed Mid-drought.(3) The factors which affect agricultural drought situation dynamic changing are divided into the natural environment and the human factor. Soil erosion is serious in hilly area, then it is not fit of the crops growing, drought situation is serious. irrigation level, the farmer average per person net income, the even chemical fertilizer employment quantity and the place even agricultural chemicals employment quantity in the west of low region is the maximum level, present drought situation probability to be smallest.(4) Carry on the reasonable countermeasure to prevent and reduce disaster in different areas according to the character of different areas in Xingtai. In hilly area, we should carry on the vegetation construction; developing the rain water collection project, highly effective agriculture and rain raises agriculture; adjusting planter structure.In middle the piedmont region and west of the low region, we should construct the saving water facility strongly; Uses micro spurts or the spray irrigation carries on the irrigation; adjusting the planter structure, construct protective forest.In partial villages and towns of Julu county, Guangzong county, Ningjin county, we should store water reasonably, use the spray irrigation to irrigate; adjust agriculture, forest, herd land proportion. West of Wei county, southeast of Julu county, middle of Xinhe county west of Nagong county should build the farmland shelter belt, construct the orchard and pasturage; Adjust agriculture planter structure. Qinghe county, Nangong county, most districts of Wei county, should adjust the agricultural structure and the crop production structure positively.