Vertisols are one of the most fertile soils in the tropics but crop production is often limited by physical features related to shrink-swell movement under different moisture conditions making management strategies mostly tilted towards soil moisture control. However, most crops planted on vertisols often show signs of nutritional deficiencies whose causes are not yet fully understood. The main aim of the present work was therefore to characterize the vertisols of the Benue floodplain, to highlight some potential causes of nutritional deficiencies and to attempt a fertility suitability classification (FCC) of those soils. The work was done in the field and in the laboratory. The main results revealed that those soils, with a depth of 2-2.5 m above the water table, showed a dark grey color, a heavy clayey texture. Physico-chemically, they were characterized by high cation exchange capacity (CEC), high sum of exchangeable bases (S), high base saturation (S/T ratio), low organic carbon (OC), high total available phosphorus (TAP), low total nitrogen (TN) and high C/N ratio (10-26.5). The nitrogen versus pH equilibrium revealed that despite the suitable pH(H2O), close to neutrality, TN was deficient and limiting to plant growth. The Ca/Mg/K ratio revealed a cationic imbalance for Ca, Mg and K. The other equilibrium factors like potassium versus texture, sum of bases versus texture, CEC versus texture equilibrium and individual exchangeable bases versus CEC equilibrium revealed a very rich chemical fertility for the studied soils. Despite this richness, the heavy clayey texture and cationic imbalance of the different nutrients indicated limited nutritional uptake by plants, suggesting that management strategies for crop production on vertisols should not only be geared towards water management, but also towards nutrient balance.
Terrain analysis is useful in so many areas ranging from military operations to landuse and agricultural planning, urban planning, forestry management, drainage, hydrology and site suitability assessment of agricultural, settlement, industrial and transportation projects. Gombe State is one of the newest states in Nigeria; they need industrial growth, agricultural development, transport planning and development and most especially sustainable use of the general environment, hence, the state is in need of reliable spatial information of the terrain. SRTM DEM data acquired online was used in conjunction with other complimentary maps of Gombe State to analyze the terrain of the State in ArcGIS environment. The raster surface modules of ArcGIS 9.3 was used in this paper to generate, classify and analyze the Digital Elevation Models (DEM) using the SRTM data of the state into four classes: highlands, uplands, plains and river basins. Cultural features such as settlement and transportation were also analyzed, while various topographical features such as DEM, slope, hill-shading and contour lines were derived from the DEM data for the analysis of the terrain of the state. The 2013 NIGER_SAT image of the state was classified into six landuse and landcover classes through the classification modules of ERDAS IMAGINE 9.2 for the analysis of the vegetation and landcover of the state. The study revealed that 33.06% and 34.81% of the land area of Gombe State comprised of the River Basin and plains respectively, while 26.65% and 5.48% are of uplands and highland areas respectively. Yamaltu/Deba, Funakaye and Balanga LGAs have more than half of their land area located within the Basin of River Gongola, while Kaltungo, Balanga and Shongom have more highland areas than the other LGAs. It was recommended that remotely sensed data and GIS techniques be used for terrain analysis because of its accuracy and reliability of data output, and its time saving over conventional methods.
This research considers the support provided by remote sensing and GIS methods for the delineation of potential sites susceptible to natural hazards such as earthquakes, flash floods and karst phenomena in the Black Hills area in South Dakota and Wyoming, USA.
By an integration of satellite data (Landsat, Sentinel), evaluations of digital elevation model data (DEM) and DEM derived morphometric maps, meteorological, geophysical and geological data in a GIS database an overview of potentially affected sites could be achieved. The analysis of digital enhanced satellite imageries, digital topographic data and open source geodata contributed to the acquisition of the specific tectonic, geomorphologic / topographic settings influencing local site conditions in the Black Hills area influencing the disposition to geo-hazards.
Weighed overlay tools in ArcGIS software helped to identify causal morphometric factors (such as flattest and lowest areas) influencing the susceptibility to flooding in case of flash floods. This tool was used as well to delineate areas susceptible to relatively higher earthquake ground motion due to local site conditions. Visual lineament analysis based on Landsat 8 and Sentinel radar images contributed to the detection of the tectonic / structural pattern influencing the development of karst phenomena (dolines/sinkholes). Dolines were mapped based on Landsat 8 and BingMap Aerial images.
Whenever a natural hazard occurs in the Black Hills and surrounding areas it can derived by the analysis of the above mentioned data and derived maps, which areas are likely to be more affected than others during future events.
The Egyptian northern Deltaic lakes including Burullus Lake suffer from pollution of intensive agri culture, domestic and industrial activities. The objective of this research was to evaluate water and sediment quality in Burullus Lake based on certain physical and chemical characteristics. Mapping the spatial distribution of these parameters will be done using ordinary Kriging method to reveal the link with potential pollution sources. Geo-referenced water and sediments samples were collected from 34 and 37 representative sites in the lake, respectively. The obtained results indicated that the quality of both water and sediments in receiving drainage water of the southern parts of the lake were relatively inferior compared to that of the northern parts. So we recommended that wastewater from different drains should be treated before being drained into the Lake.
Climate observations are essential for understanding the complexities of the global climate system; indeed virtually all breakthroughs that have been made in understanding climate have come from observations. Observations provide critical benchmarks for testing and further developing our predictive capability through models.
Nigeria needs to translate the landscape of national policy commitments into an assessment of risk and opportunity across the value chain. At the same time, Nigeria has to pay attention to conserving her natural resources and improving the status of our environment.