Dynamic Monitoring And Quantitative Evaluation Of Drought In Guangdong, China

In light of global warming,regional water balance and extreme climate events has become a hot issue.Favored by the monsoon humid climate of southern subtropical zone,Guangdong province have abundant resource of precipitation,however,parcel and seasonal drought occurs frequently due to distinct spatial-temporal variation of precipitation,plentiful radiation,high temperature,great evaporation and long growth stage.Dynamic monitoring and quantitative evaluation of drought provided reference for measures making for artificial rainfall,disaster prevention and reduction,dealing with climate change,exploitation and utilizing of climate resource and planting zoning adjustment.The study helps to safeguard social economic sustainable development, eco-security and food security;therefore,the study has significant meanings both scientifically and applicably.Based on the latest climate data,using moisture index(MI),climate dryness/wetness status of Guangdong and its spatial-temporal distribution was analyzed systematically.It was humid.Seasonal and spatial variation and distribution was consistent with precipitation.Both in spring and autumn,MI spatially varied with latitude,but changing direction was opposite.Hotter and drier trend of climate was discovered in Guangdong province in recent 50 years.Consulting concept of moisture balance in Palmer Drought Model,daily Soil-Moisture-Balance model was built up,and a set of drought index meeting dynamic monitoring of drought needs was put forward.Sensitivity analysis of model parameters was conducted which provided references when the model was popularized in different regions.It was able to describe formation,development as well as spatial-temporal variation of drought in detail;therefore,it was properly applied in regional dynamic monitoring and evaluation of drought.According to national criterion of Meteorological Drought and actual status in Guangdong,comparison analysis of 9 drought index was carried out to validate applicability feature in Guangdong,considering 3 aspects—drought frequency, drought process description and spatial distribution.Results showed that the Soil-Moisture-Balance Model index system Which was presented in the study performs better,therefore,it was more valuable to popularize in operation.Spatial-temporal distribution characteristics of drought in Guangdong in recent 45 years were analyzed based on Soil-Moisture-Balance Model index system,which provided reliable and integrated information for drought monitoring and evaluation. Relationship between Drought Course Index and drought area proportion was quantitatively analyzed and a set of drought impact statistical model was built up.Causes of drought in Guangdong were analyzed and countermeasures of disaster precaution and reduction were brought out finally.