Study Of Drought Occurrence And Mitigation Measures In Dry-Land Farming Area In Shaanxi

Shaanxi located in the fragile ecological environment belt in china. It was secluded inland, faraway form the sea and low air fall. Drought is the most important meteorological disasters in Shaanxi province. The most part of Shaanxi was located in the arid and semi arid areas. With the economic development, the water consume increased dramatically and the water availability was reduce. The environment of water was deterioration. So Shaanxi agricultural drought was exacerbated. With the economic's development and population's growth, the losses, caused by drought, was also in increasing trend. Drought disaster council was directly related to region or even the national sustainable development. So,it was extremely important to research and assessment of drought.The dry-land farming area in Shaanxi were divided into five survey region(following shortened for subdistricts ) ,they were North Shanbei,South Shanbei,North Wei,West Guanzhong and East Guanzhong. According to the historical drought materials of dry-land farming area in Shaanxi province during A.D1950-2008, this paper analysis the regular pattern of the drought. The results showed that: in the 59 years, the total times of the drought in the five subdistricts were 594; The drought frequency was in a rising trend. The most serious drought was 20th century 90's; In this region,the mainly drought were in spring and summer ;The most highly frequency of drought was North Shanbei and the least was West Guanzhong; In the 59 years, the whole region's serious drought was 12 times; This paper pointed out the causes of drought.Based on the principle of Markov theory, considering the change of all kinds of disaster-causing factors as a Markov process to analyze the structural change of dry-land farming area in Shaanxi from 1990 to 2008. Counting of transfer matrix and trend factor came to the results that: the structural of drought changes significant in 1994,1995,1999 and 2000.Using the load coefficient of 2008 as the initial vector to predicte the change of drought about the next 10 years. Forecasting arrive at a conclusion that there will be to occur a serious drought around 2011～2014 and put forward several suggestions of how to defense the drought disaster.This article analysis the cause of drought in dryland farming in Shaanxi. The results show that: The underlying causes of droughts were uneven rainfall and the large precipitation. Drought has a great relationship with human activities. The ecological balance was destroyed by human activities and the frequency of drought was increased. Water facilities'behind also have aggravated the drought. For the actual situation of Shaanxi dryland agricultural areas proposed following measures to mitigation drought.(1) Starting from the macro-strategic level, to establish the crop species that can compatible with precipitation and improve the use efficiency of water.(2) Promote fertilization, soil tillage and other technical measures.(3) Research and development new agricultural technology system and technical system which can suitable for different precipitation years and the dependable crop was high stable.