HYDROLOGIC MODELLING OF KATSINA-ALA RIVER BASIN: AN EMERGING SCENARIO FROM LAKE NYOS THREAT

Understanding the hydrologic system surrounding crater lakes is of great importance for prevention of flooding damages, conservation of ecological environment, and assessment of socio-economic impact of dam failure on the civilians in the downstream regions. Lake Nyos is a crater lake formed by volcanic activities at the Oku volcanic field on the Cameroon Volcanic Line. It is a freshwater lake with a maximum depth of 200 meter. In 1986, a limnic eruption at the lake emitted 1.6 million tonnes of carbon dioxide from the bottom of saturated water into the air and suffocated up to 1,800 people and 3,500 livestock at nearby villages. The lake waters are held in place by a natural dam composed of loosely consolidated volcanic rock, which is now at the verge of collapse due to accelerated erosion. This study was carried out to determine the flood risks and vulnerability of population and infrastructure along Katsina-Ala drainage basins. The project integrated both satellite images and field datasets into a hydrologic model for Katsina-Ala River Basin and its vicinity including the Lake Nyos. ArcHydro was used to construct a hydrologic database as 'data models' and MIKE SHE was employed to conduct hydrologic simulations. Vulnerable infrastructures, population and socio-economic activities were identified to assist the Federal and State governments in disaster mitigation and management plans. The result of the project provides comprehensive knowledge of hydrologic system of Katsina-Ala drainage basin to mitigate potential future disasters from a potential dam failure and manage water resources against such disasters

Accessibility to Primary Health Center Facilities Using Geospatial Techniques In Southern Plateau, Nigeria

The Primary Health Center (PHC) System comprises of those small health care facilities which are based within communitiesand are more accessible to people in need of healthcare. However, assessment of spatial patterns, distribution and provisionof public health services has been neglected. This research analyzes the availability and accessibility of Primary HealthCenter (PHC) across Southern Plateau, Jos Plateau State. Spatial distribution of PHC was analyzed using ArcGIS to produceaccurate measure of accessibility. The spatial pattern of the PHC distribution was examined using average nearest neighbor5km walking distance to providers (PHC) for each of the six LGAs using near analysis. In addition, the ratios of PHC topopulation were calculated to identify underserved and served areas. The findings clearly indicate that the spatial pattern ofthe distribution of PHC was significantly clustered in Quaan pan (62) [p-value 0.015305, Z-score 0.139526], Wase (38) [pvalue0.046571, Z-score -1.990183] and Langtang South (34) [p-value > 0.096827, Z-score -1.660434], random in Mikang(26) [p-value 0.889035 Z-score 0.139526] and Langtang North (52) [p-value 0.0883033, Z-score 0.147125) and dispersed inShendam (63) [p-value 0.072625, Z-score 1.795182]. PHC are dense within the central parts of each LGAs while low densityaround the marginal parts. Substantially, more than half of the population 742,523 (62.74%) have no access to PHC within 5-km distance and 441,063 (37.26%) of the population have access to PHC. More so, the population ratio to PHCs shows that 1PHC served 3477 in Langtang North (least) and 1 to 5338 in Wase (highest). The output of this analysis which is spatialdistribution map and accessibility to this PHCs will assist policy-makers and authorities in planning public health delivery. Keywords: Geospatial, Techniques, Accessibility, PHC, Southern Plateau, Nigeria