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| dc.contributor.author | Fekadie, Bazie Enyew | |
| dc.date.accessioned | 2024-03-15T05:39:30Z | |
| dc.date.available | 2024-03-15T05:39:30Z | |
| dc.date.issued | 2024-01 | |
| dc.identifier.uri | http://ir.bdu.edu.et/handle/123456789/15697 | |
| dc.description.abstract | Drought monitoring is a key to planning, vulnerability and impact assessment, forwarding adaptation and mitigation options, and predicting its occurrences, frequency, and severity levels. This study aimed to monitor agro-meteorological drought conditions using geospatial technology in Menna Watershed, Northwestern Ethiopia. The study used Climate Hazard Group InfraRed Precipitation with Stations (CHIRPS) rainfall data, two Moderate Resolution Imaging Spectro-radiometer (MODIS) datasets (MOD13Q1 and MOD11A2), meteorological station data and Crop yield data. Meteorological station rainfall data was used to evaluate the performance of the CHIRPS rainfall data. The CHIRPS dataset was used to characterize meteorological drought, determine the onset, cessation, and length of the rainy season and to analyze climate extreme indices. Mann–Kendall (MK) test and Sen’s slope estimator were employed to detect the rainfall trends and magnitude of change, respectively. Coefficient of variation (CV) was used to analyze variability of rainfall. In addition, the percent of normal (PN), standardized anomaly index (SAI), and standardized precipitation index (SPI) were computed from the CHIRPS rainfall. Normalized Difference Vegetation Index (NDVI), Vegetation Condition Index (VCI), Temperature Condition Index (TCI), and Vegetation Health Index (VHI) were employed during the crop growing seasons from 2000 to 2022 to characterize agricultural drought. The performance evaluation result of the study revealed that there was a good agreement between the station and CHIRPS rainfall data (R2=0.88). The result of MK and Sen’s slope trend test shows that the Kiremt season has an insignificant decreasing trend while annual and Belg registered a significant increasing trend. The study also reveals that the highland and upper highland part of the study area was characterized as having a longer length of rainy season, whereas, lowland and midland zones have shorter lengths of rainy season. In addition, the computed extreme temperature indices revealed that significant decrease in the number of cold days and nights, and an increase in the number of warm days and nights. Conversely, extreme rainfall indices showed a decreasing trend throughout the study area. The spatiotemporal distribution of meteorological and agricultural drought reveals that during 2009 and 2015 the area was extensively hit by drought while 2001 and 2007 were wet years with good crop yields. The frequency of agro meteorological drought occurrence ranges from 0-22 times in the last 23 years. The lowland and midland parts of the study area were frequently affected by droughts. The combined drought-prone area map also showed that 15.1% and 82.8% of the study area were vulnerable to moderate and slight droughts, respectively. Thus, the Menna watershed, as a drought-prone area, has frequently been affected by recurrent droughts, which needs regular drought monitoring. Therefore, the community in the study area should be assisted by an improved early warning system and introduce quick-mature and drought-resistant crops. | en_US |
| dc.language.iso | en_US | en_US |
| dc.subject | Geography and Environmental Studies | en_US |
| dc.title | Agro-meteorological Drought Monitoring Using Geospatial Technology: The Case of Menna Watershed, Northwestern Ethiopi | en_US |
| dc.type | Thesis | en_US |
