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Northwest A&F University (2017)

Analysis Adaptability of Three Drought Index of Agricultural Region in Eastern Qinghai Provience

多普增;

Titre : Analysis Adaptability of Three Drought Index of Agricultural Region in Eastern Qinghai Provience

Auteur :

Grade : Master’s Theses 2017

Université : Northwest A&F University

Résumé
Drought is a global problem,it is one of the most severe natural disasters in the world that has wide range of effects,long duration,causing harm,high frequency of human society,Drought leads to a lack of water supply,endangering crop growth,reducing crop yields,and affecting residents’ lives,industry and other social activities.Qinghai Province is located in the inland hinterland,the northern part of the Qinghai-Tibet Plateau,it is the largest,the highest and the most complex terrain plateau in the world,warm and humid air group is not easy to invade,most areas are in arid and semi-arid zone,which has a great impact on agriculture and animal husbandry.Drought index studies can quantify the process of drought,but drought index has various kinds and different adaptability in different area.Therefore,this paper selected the percentage of Precipitation Anomalies,Standardized Precipitation Index,Compound drought Index to analysis the adaptability of agricultural region in eastern Qinghai provience.It is important to select the suitable drought index for the northwest arid area to improve the accuracy of forecasting and provide the reference and scientific planning for disaster prevention and mitigation.It is important to improve the sustainable utilization and management of water resources.In this paper,based on the data from 1996 to 2006 in eastern agriculture area of Qinghai Provience,the EOF decomposition and the MK trend test were used to analyze the interannual and annual changes of precipitation in the study area.By calculating three selected drought indexes to compae drought characteristics,and check the actual drought situation to get the optimal drought index,and to analyze the study of drought and spatiotemporal distribution of the study area based on the optimal drought index.Concluded as follow :(1)The precipitation in the study area from 1960 to 2006 has been increasing since 1972,and it has continued until 2002,but this trend is not obvious.Therefore,the overall trend of annual precipitation in 47 years is not obvious The In the spatial distribution,the contribution rate of the first modal variance of EOF is 70.57%,the first mode is the same as the whole trend,the central change is large,and the change between the north and the south is relatively small.During the year,the precipitation is mainly concentrated from May to September,Accounting for 84% of the annual precipitation,and in May and other 11 months of precipitation trends in the opposite direction,precipitation changes in the month of July,August and September.(2)During the spring and summer drought,the trend of the SPI and Pa in the quarter scale is consistent,and the trend of seasonal average CInew in some years is different from the other two indexes,and some small fluctuations will occur.The CInew index can monitor the drought on a daily basis and can detect the occurrence and development of drought.However,due to the effect of precipitation and evapotranspiration in the early 90 days,the performance is not very good at the monthly and daily scales,and there is an error,In the early 90 d of the weight of precipitation and evapotranspiration on the issue of re-consideration.MI index in the heavy drought performance is very good,in other drought performance in general.SPI is in the drought where the light performance is better in the drought performance in general.Pa index can better show the situation and development of drought,and in contrast with the actual drought,Pa index stable to maintain a high accuracy.(3)the greater the trend of drought and drought in spring and summer,the more frequent the drought ;spring drought,light drought as the main drought,Lido,people,Xunhua,Shizha,Huangnan area prone to severe drought ;Summer to light drought as the main drought,Guide,Lok,Xunhua,Huangnan,Chase prone to drought.Spring drought continued to improve,while the summer drought was sustained deterioration of the situation

Mots clés : agricultural region in eastern Qinghai provience; drought index; empirical orthogonal function; spatio-temporal distribution;

Présentation (CNKI)

Page publiée le 20 février 2018