Water Supply And Demand Characteristics And Drought Analysis Of Sugarcane In Guangxi

Guangxi is located on the southwest coast of China,located at the junction of tropical and subtropical regions in China.The terrain gradually increases from southeast to northwest,and karst landforms are widely distributed.Guangxi is the main origin of sugarcane in China,and drought is one of the common natural disasters in sugarcane planting in Guangxi,and it is an important factor restricting the production of sugarcane.Based on years of meteorological observation data and various remote sensing data,this paper calculates and analyzes the spatial and temporal patterns of water demand and water deficit of sugarcane in Guangxi,and the distribution of dryness and humidity in Guangxi.The conclusions are as follows:The distribution of precipitation and evapotranspiration in Guangxi is uneven in both time and space.The total annual rainfall in the province is large.Rainfall accounts for 80%of the annual rainfall.Rainfall and evapotranspiration are negatively correlated with annual changes.The water requirement of sugarcane is similar to the normal distribution of the average monthly variation,mainly in the middle period,accounting for about 72%of the total water requirement.The difference in the start time of sugarcane at different growth stages in various regions of Guangxi leads to obvious regional differences in water demand..The average annual ten-year change of water shortage in Guangxi showed a"with-no-yes" distribution pattern,that is,water shortages occurred in spring and autumn.During the growth period,the distribution pattern of "West-No-East-Total" is presented.The maximum water shortage in the initial period is located in Baise and Chongzuo in western Guangxi.During the growing season,the water shortage occurs in the province.The maximum amount of water shortage in the middle period is located in the northeast of Guangxi.The Ministry of Guilin,Liuzhou and Laibin have a relatively light water shortage in most parts of the province.The correlation between AI and water deficit in time distribution is as high as 0.933.The spatial distribution is closely related to the distribution of precipitation,and AI has two oscillation periods of 25 years and 5 years in 63 years.The spatial and temporal distribution of TVDI shows that the temperature vegetation drought index in Guangxi showed a downward trend from 2000 to 2013,and the space is high in the west and low in the east.The spatial and temporal distribution of soil moisture in GLDAS indicates that the wetlands dry in the west.The reciprocal correlation between AI and soil moisture was 0.835,and the correlation between the water demand change curve and the two was as high as 0.896 and 0.766,respectively.The correlation was very obvious,and the correlation between TVDI and the other three was poor.The mean value of soil moisture data is well correlated with the soil moisture data of GLDAS,and there is a certain lag.The verified results of the drought disaster data and water shortages were better.