Establishment Of Dry Indexes In Guanzhong Irrigation Areas And Research On Drought-resistant Measures

On the premise of the study about reasons coming into being drought in the Guanzhong irrigation areas, aiming for several important factors which have an effect on drought, this paper established dry indexes system in drought and half drought regions, applied the Geographical Information System into the theory and look up information about Guanzhong irrigated areas and evaluate the drought, in order to utilize water resources reasonably, takes corresponding measures and improve irrigated areas' management level and decision-making means. The paper mainly analyzed rainfall, ground rainoff. groundwater and the reservoir deposited water, applied the fuzzy synthetic evaluating model into drought evaluation and exploit the GIS systems. Main results are as follows:(1) To set up evaluation indexes model of single factor. Rainfall is evaluated by Z model; ground rainoff is analyzed by comparing runoff amount in every year and many years; reservoir deposited water index is storage water rate and groundwater is calculated by comparing exploited groundwater with confined groundwater.(2) To establish the fuzzy synthetic evaluating model. Using of the fuzzyrelation principle, the model made rainfall, ground rainoff, groundwater and reservoir water measurable and synthesize to evaluate intangibly.(3) To use the model. The paper used the model which had established above to evaluate 1993 and 1997 year, evaluating result accorded with the reality completely which showed that the model suited Guanzhong irrigated areas.(4) To adjust measures to local conditions to fight a drought. Combining with natural and geological conditions, agricultural planting structure, crop output level, water resource' exploitation and utilization degree and management ability about preventing drought and decreasing disaster, worked out counLerrneasure for drought and disaster ar.rordingly.(5) To develop GIS system. To introduce GIS into dry index evaluation systems can combine figures with datum expediently and adequately in order to express datum with geological figurer,' information adequately. The system can query and evaluate Guanzhong irrigated areas' information.