Variation Of Drought And Comparative Impact On Vegetation Between Qinghai Province And Sudan

(1)Drought is the most serious natural disasters,a big common problem facing the entire world in global threat,which is direct affect to human,grassland,livestock,crop yield and society economic development.Recently the drought index researches are becoming the important issue to investigate global climate change research direction.Drought is the,compared with other natural disasters,a wide range of drought,which lasted long,not only intensified conflicts between water supply and demand but also pose a serious threat to the environment,directly affect the sustainable development of social economy.China drought is particularly prominent,involving a very wide range,mainly in the northwest and northeast regions,Qinghai Province is located in the dry arid areas of northwest China.Sudan drought particularly prominent,involving a very wide range,mainly in the northern part,which is located in the biggest desert of the world.The world's arid areas are mainly distributed in most parts of Asia,most of the Australia,most of the Africa,western North America and western South America.Drought is continuing deficit caused by a decrease in moisture and water that had directly affected in the human being,animal and plant life events,social and economic activities and natural ecosystems.(2)The main objectives of the present study to investigate climate and drought in Qinghai Province and Sudan using characteristics of SPEI,SPI and Pa indices as a meteorological drought index over a 53 years period of 1961-2013,for measuring the degree of climate change,also using NDVI period of 2001-2013.This study to investigate distinguishes the effects of climate change on grassland over the Qinghai Province and Sudan.Fill the gaps of the old researchers in these two regions as possible and comparative between the climate of Qinghai Province and Sudan.Qinghai Province has many researches in drought index,but Sudan has a shortage in researchers about drought index,the importance of this study it is the first study investigated the drought index: SPEI,SPI and Pa in Sudan,this study will be a good reference to the researchers in drought issue in Sudan.(3)This current research to investigate the drought in Qinghai Province(northwest of China)and Sudan(northeast of Africa),periods of 1961-2013,three kinds of index have a good corresponding relation with precipitation,recognition ability of drought event in recent 53 years in both Qinghai Province and Sudan,Pa > SPI > SPEI,three indices is consistent with the actual drought.In Qinghai Province the high frequency of annual-SPEI drought in Banma,Tongde,Xining,Chaka and Ge'ermu,while SPI drought in Lenghu,Qilian,Delingha,Chaka,Doulan,Qiaboqia,Tongde and Qingshuihe.SPEI 12-month shows a high frequency of drought in 1972,1992-1993,1995-1996,and 1998-2004,while SPI 12-month shows a high frequency of drought in 1962,1966-1967,1970,1973,1986,1992-1993,1996 and 2001-2004.1960 s shows SPEI,SPI,Pa is: 40,80 and 70 %,1970 s is: 40,70 and 60 %,1980 s is: 20,40 and 40 %,1990 is: 80,60 and 60 %,2000 s is: 70,30 and 40%,respectively.SPEI is upward trend rate of 98/10 a,SPI and Pa downward rate of-108/10 a and-60/10 a,respectively.(4)In Sudan the high frequency of annual-SPEI drought in Portsudan,Abuhamed,Atbara,Elobeid,Malakal and Wau,while SPI drought in Portsudan,Abuhamed,Shendi,Khartoum,Juba,and Malakal.SPEI 12-month shows a high frequency of drought in 1973-1975,1981,1991-1992,2000-2001,2003-2006 and 2008-2011.while SPI 12-month shows a high frequency of drought in 1966-1968,1974,1984-1985,1991-1992,2000-2003,2005-206 and 2010.1960 s shows SPEI,SPI,Pa is: 0,40 and 40 %,1970 s is: 40,40 and 60,1980 s is: 20,70 and 70 %,1990 s is: 60,20 and 60 %,2000 s is: 70,60 and 40 %,respectively.SPEI,SPI and Pa are an upward trend rate of 1.5848/10 a,0.23/10 a and 0.124/10 a,respectively.(5)Seven stations are selecting from all direction of Qinghai Province,which are: Mangya for Northwest,Tuolei for north,Nuomuhong for middle,Minhe for east,Tuotuohe for the west,Jiuzhi for southeast and Nangqian for the south.Mangya,Nuomuhong,Tuotuohe and Jiuzhi show significant positive relationship between SPEI,SPI and Pa with precipitation at the 0.01 while there is a significant negative relationship between SPEI and temperature at the 0.01.Minhe shows significant positive relationship between Pa with precipitation at the 0.05 and a significant negative relationship between SPEI and temperature at the 0.01.Nangqian and Tuolei show there is no a significant relationship between three indices with precipitation and temperature.Five stations are selecting from all direction of Sudan,which is: Elobeid for the middle,Geneina for the west,Halfawadi for the north,Kassala for the east and Juba for the south.Elobeid and Juba show a significant negative relationship between SPEI and temperature at the 0.01.Kassala shows a significant positive relationship between SPEI,SPI and Pa with precipitation at the 0.01 while there is a significant negative relationship between SPEI and temperature at the 0.01.Halfawadi shows a significant positive relationship between SPEI with precipitation at the 0.05 while there is a significant negative relationship between SPEI and temperature at the 0.01.Geneina shows a significant negative relationship between SPEI and temperature at the 0.01.(6)Annual-SPEI UF curve shows lines intersect in 1993 which that is the beginning of mutation detection of the droughts in Qinghai Province,the location of the areas which is changing from humid to drought is: Mangya,Lenghu,Xiaozaohuo,Dachaidan,Ge'ermu,Nuomuhong,Chaka,Yushu,Jiuzhi and Qiaboqia.UF curve beyond the 0.05 level significant lines.While,annual-Pa UF curve showed 2003 that is the beginning of mutation detection of the humid.The northwest part of Qinghai Province is changing to drought,while most the east part is changing to humid.Sudan shows the location of the areas which is changing from humid to drought in the northeast and middle part: Halfawadi,Dongola,Abuhamed,Atbara,Shendi,Portsudan,Tokar,Kassala,Gadarif,Wadmedani and Elobeid.Annual-SPEI UF and UB lines intersect in 1995 which that is the beginning of mutation detection of the droughts.(7)Qinghai Province in space mean presenting features of NDVI is: summer > autumn > spring > winter.By calculating the average annual and seasonal-NDVI value shows that is the main vegetation cover type is an upward trend rate of 0.013/10 a,0.016/10 a,0.035/10 a and 0.058/10 a for annual,winter,spring and autumn,respectively.While winter-NDVI,is downward trend rates of 0.056/10 a.Sudan in space mean presenting features of NDVI is: autumn > summer > winter.Annual and seasonal-NDVI value shows that is the main vegetation cover type is an upward trend rate of 0.014/10 a and 0.008/10 a,for winter and summer,respectively.While winter-NDVI,is downward trend rates of 0.001/10 a and 0.026/10 a for annual and autumn.(8)NDVI in Qinghai Province shows there is a significant positive relationship between mean winter-NDVI with mean winter precipitation temperature at the 0.01.There is a significant positive relationship between mean spring-NDVI with mean spring precipitation at the 0.01.Mean summer-NDVI with mean summer precipitation shows a significant difference at 0.01 while there is a significant negative relationship between mean summer-NDVI with mean summer temperature at 0.01.There is a significant positive relationship between mean autumn-NDVI with mean autumn precipitation at the 0.01.NDVI there is a significant positive relationship between mean winter-NDVI with mean winter precipitation winter temperature at the 0.01.Mean summer-NDVI with mean summer precipitation shows a high significant positive,difference at 0.01 while there is a significant negative relationship between mean summer-NDVI with mean summer temperature at 0.01.There is a high significant positive relationship between mean autumn-NDVI with mean autumn precipitation at the 0.01 while there is a high significant negative difference between autumn-NDVI with mean autumn temperature.