In this study,cloud base height（CBH） and cloud top height（CTH） observed by the Ka-band（33.44 GHz） cloud radar at the Boseong National Center for Intensive Observation of Severe Weather during fall 2013（Septembe...In this study,cloud base height（CBH） and cloud top height（CTH） observed by the Ka-band（33.44 GHz） cloud radar at the Boseong National Center for Intensive Observation of Severe Weather during fall 2013（September-November） were verified and corrected.For comparative verification,CBH and CTH were obtained using a ceilometer（CL51） and the Communication,Ocean and Meteorological Satellite（COMS）.During rainfall,the CBH and CTH observed by the cloud radar were lower than observed by the ceilometer and COMS because of signal attenuation due to raindrops,and this difference increased with rainfall intensity.During dry periods,however,the CBH and CTH observed by the cloud radar,ceilometer,and COMS were similar.Thin and low-density clouds were observed more effectively by the cloud radar compared with the ceilometer and COMS.In cases of rainfall or missing cloud radar data,the ceilometer and COMS data were proven effective in correcting or compensating the cloud radar data.These corrected cloud data were used to classify cloud types,which revealed that low clouds occurred most frequently.展开更多
Dhidhessa River Basin is physio-graphically and hydrologically important in the Blue Nile basin, however, its morphometry and hydrology are not well known. This study aimed to characterize hydro-geomor-phology of the ...Dhidhessa River Basin is physio-graphically and hydrologically important in the Blue Nile basin, however, its morphometry and hydrology are not well known. This study aimed to characterize hydro-geomor-phology of the basin via basin morphometry analysis. SRTM DEM, geological and hydrological maps of the area were used in ArcGIS 10.3 environment for this analysis. Results showed that a 33,468 km total stream length of all orders was found distributed within 28,637 km2 drainage area in a dendritic pattern. According to morphometric parameter classification, total stream length and stream order of the basin were high whereas stream length ratio, bifurcation ratio and hydrologic storage coefficient were low. Furthermore, drainage area was large, drainage frequency was coarse, basin shape was more elongated, drainage density was medium, infiltration number was low, overland flow was long and constant of channel maintenance was high. Moreover, the basin's relief, relief ratio, ruggedness number, gradient ratio and the slope was high. In general, the study asserted that the basin was underlain by uniform resistant rocks, less prone to flooding, with high water resources potential and susceptible to soil erosion. The morphometric analysis approach pursued in this study was cost- and time-effective for basin characterization.展开更多
基金supported by the principal project, “Development and application of technology for weather forecasting (NIMR-2012-B-1)” of the National Institute of Meteorological Sciences of the Korea Meteorological Administration
文摘In this study,cloud base height（CBH） and cloud top height（CTH） observed by the Ka-band（33.44 GHz） cloud radar at the Boseong National Center for Intensive Observation of Severe Weather during fall 2013（September-November） were verified and corrected.For comparative verification,CBH and CTH were obtained using a ceilometer（CL51） and the Communication,Ocean and Meteorological Satellite（COMS）.During rainfall,the CBH and CTH observed by the cloud radar were lower than observed by the ceilometer and COMS because of signal attenuation due to raindrops,and this difference increased with rainfall intensity.During dry periods,however,the CBH and CTH observed by the cloud radar,ceilometer,and COMS were similar.Thin and low-density clouds were observed more effectively by the cloud radar compared with the ceilometer and COMS.In cases of rainfall or missing cloud radar data,the ceilometer and COMS data were proven effective in correcting or compensating the cloud radar data.These corrected cloud data were used to classify cloud types,which revealed that low clouds occurred most frequently.
文摘Dhidhessa River Basin is physio-graphically and hydrologically important in the Blue Nile basin, however, its morphometry and hydrology are not well known. This study aimed to characterize hydro-geomor-phology of the basin via basin morphometry analysis. SRTM DEM, geological and hydrological maps of the area were used in ArcGIS 10.3 environment for this analysis. Results showed that a 33,468 km total stream length of all orders was found distributed within 28,637 km2 drainage area in a dendritic pattern. According to morphometric parameter classification, total stream length and stream order of the basin were high whereas stream length ratio, bifurcation ratio and hydrologic storage coefficient were low. Furthermore, drainage area was large, drainage frequency was coarse, basin shape was more elongated, drainage density was medium, infiltration number was low, overland flow was long and constant of channel maintenance was high. Moreover, the basin's relief, relief ratio, ruggedness number, gradient ratio and the slope was high. In general, the study asserted that the basin was underlain by uniform resistant rocks, less prone to flooding, with high water resources potential and susceptible to soil erosion. The morphometric analysis approach pursued in this study was cost- and time-effective for basin characterization.
