Agricultural Drought Conditions in North Wollo Zone, Amhara Regional State, Ethiopia

Gebre, Eshetu (2017) Agricultural Drought Conditions in North Wollo Zone, Amhara Regional State, Ethiopia. Masters thesis, Addis Ababa University.

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Abstract

Drought is the most complex but least understood of all natural hazards. Major food production in Ethiopia, especially in the Amhara Region, North Wollo Zone, is almost fully dependent on rain-fed agriculture and the area is often hit by periodic droughts. This drought causes serious economic, social, food security and environmental problems. Arid climatic conditions in North Wollo Zone are characterized by erratic rainfall and successive drought years together with high rate of moisture deficiency has adversely affected the agricultural production levels. Thereby increases drought risk. In this study, the Standardized Precipitation Evaporation Index (SPEI), Normalized Difference Vegetation Index (NDVI) and Vegetation Condition Index (VCI), were applied to characterize the agricultural drought conditions in North Wollo Zone from 2000 to 2015. Correlation analysis was performed between NDVI and SPEI, rainfall and NDVI, VCI and rainfall and NDVI and Crop Yield Anomaly and SPEI and Crop Yield Anomaly. SPEI values were interpolated to get the spatial pattern of meteorological based drought. Ground based crop yield data was used to evaluate the drought monitoring index. Finally, the combined drought severity map was generated by overlaying the agricultural and meteorological drought severity maps. The results showed that there was good correlation between rainfall and NDVI (r=0.71), VCI and Rainfall (r = 0.77), NDVI and SPEI (r=0.82) and NDVI and Crop Yield anomaly, (r=0.78) and SPEI and Crop Yield Anomaly (r=8.3). Analysis result of Spatial pattern of long term seasonal average rainfall and NDVI from 2000 to 2015 years, showed that there was a large variation during the main cropping season and the corresponding NDV1 values was also almost similar. The minimum and maximum rainfall observed during this period was found to be 250 to 599 mm where it indicates a large variation in distribution of rainfall in all the weather stations. This might be the effect of altitude among other factors. The drought severity was analyzed from 2000 to 2015 based on satellite and climate data. The two years 2005 and 2015 were considered as drought years and 2009 and 2013 were taken as slight-drought years. The extent of drought severity was increased by increasing time scale. The combined risk map showed that approximately 5% of the area has slight risk, 42.5 % of the area faced by very severe risk, 19.5 % of the area considered as moderate risk and 33 % area face severe risk within the study area. It can be seen severe drought year from 2000 to 2015 because it has received low rainfall at 2005 and 2015. Hence, it is concluded that, the study area was affected by severe drought in year 2005 and 2015 and slight drought in 2009 and 2013 and the drought monitoring indices results almost similar with ground truth data result of crop yield. Drought from socioeconomic aspect has not been studied. Besides, delineating areas under drought risk relevancy of risk assessment can be made more meaningful when the human population as well as livestock population under risk will be assessed. Therefore, it is recommended to include the socio-economic data to better understand the vulnerability factors.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	Agricultural drought, Meteorological drought, SPOT, NDVI and SPEI.
Subjects:	G Geography. Anthropology. Recreation > GE Environmental Sciences Q Science > QE Geology S Agriculture > S Agriculture (General) S Agriculture > SB Plant culture
Divisions:	Africana
Depositing User:	Selom Ghislain
Date Deposited:	29 Jun 2018 11:27
Last Modified:	29 Jun 2018 11:27
URI:	http://thesisbank.jhia.ac.ke/id/eprint/6292

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