Monitoring urban land use in developing countries—an aerial photographic approach

In most developing countries, the ground survey method of data collection is usually the traditional method of monitoring urban land use. Since this procedure is costly in terms of time and energy, which developing countries can hardly afford, it is suggested that aerial photography be employed in monitoring urban land use. The usefulness of sequential aerial photography in estimating the relative growth of thirteen land-use categories in Ilorin (Nigeria) has been evaluated. It was discovered that the spatial distribution pattern of the land-use types in 1950, 1963, and 1973 could be estimated and changes detected. The methodology employed emphasises simplicity and speed of data collection, and so could be incorporated into an overall urban information system on which land-use planning could be based.     

Land use and solid waste generation in Ilorin, Kwara State, Nigeria

Solid waste collection services in Ilorin, Nigeria are shown to be unsatisfactory. The poor service is related to rapid population growth, insufficient data and inconsistent government policies. Surveys have been conducted to assess the quantities and types of solid waste and to show how these, in part, vary according to the nature of the land use and the properties being served. Suggestions for an improved service are offered.     

Global tectonics and agriculture: A geochemical perspective

The global distribution of regions of sustained productive agriculture shows that an ample supply of fresh rock residues is vital to soil fertility. Once such rock debris is removed soil degradation will be evident in falling yields and trends within the clay fraction from chemically diverse smectite clays towards impoverished kaolinite-gibbsite soils. Increased erosion will follow the clay degradation. Reliance on N, P and K and organic residues alone will not be sufficient to counteract this trend unless Nature, through geological forces, or Man, through the application of appropriate rock dusts, intervenes to restore nutrient balance and a better clay spectrum. The geological evidence of natural weathering rates, and soil evidence of leaching rates, points to applications only of the order of 1 ton ha^?1 year^?1 being the amount of fresh rock replenishment required to hold the soil in balance for agriculture. Failure to achieve this makes way for a progressive trend towards soil degradation accelerating, as changes induced in the nature of the clay fraction enhance the leaching effect of the aerial environment.On a world scale these effects can best be seen by comparing the enhanced fertility of soils that have benefited from volcanic renewal near active plate boundaries or the fresh rock enrichment arising from the rock grinding involved in glaciation, with the almost ‘impossible’ soils typical of geologically quiescent areas, such as the Amazon and Congo basins where, merely to fertilise with N, P and K alone so impoverishes the soils of their critically limited supplies of other essential nutrients, that disaster is inevitable.     

Waste scavenging in Third World cities: A case study in Ilorin, Nigeria

Solid waste poses a serious problem to government agencies and people in third world cities. Recycling as a way of managing waste has received relatively little attention. This paper examines the role of waste scavengers in the waste recycling process. The preliminary findings reported here indicate that the waste scavenger could be incorporated formally into the recycling process. Using plastic waste as an example, it is demonstrated that such recycling is economically viable.     

The growth of ilorin: a documentation in aerial photography

The ground survey method of monitoring urban growth in Nigeria has been criticized for being slow in generating current data on city areal extent. The use of aerial photography has been suggested as an alternative. The growth and spatial expansion of Ilorin is examined using the 1963, 1973, and 1982 aerial photographs of Ilorin. Data on a land absorption coefficient and land consumption rate were generated for Ilorin. These indices are in themselves raw materials for planning purposes. A cartographic comparison of the areal extent of the city in a time series manner is presented. The use of aerial photography as an operational monitoring technique is suggested in this study.     

Dynamics of land use land cover and its impact on carbon stocks in Sub-Saharan Africa: an overview

Environment, Development and Sustainability - Land use land cover change (LULCC) is a global environmental trend that plays a key role in worldwide environmental change and sustainable development....     

Cross-sectional biomonitoring study of pesticide exposures in Queensland,Australia, using pooled urine samples

A range of pesticides are available in Australia for use in agricultural and domestic settings to control pests, including organophosphate and pyrethroid insecticides, herbicides, and insect repellents, such as N,N-diethyl-meta-toluamide (DEET). The aim of this study was to provide a cost-effective preliminary assessment of background exposure to a range of pesticides among a convenience sample of Australian residents. De-identified urine specimens stratified by age and sex were obtained from a community-based pathology laboratory and pooled (n = 24 pools of 100 specimens). Concentrations of urinary pesticide biomarkers were quantified using solid-phase extraction coupled with isotope dilution high-performance liquid chromatography–tandem mass spectrometry. Geometric mean biomarker concentrations ranged from <0.1 to 36.8 ng/mL for organophosphate insecticides, <0.1 to 5.5 ng/mL for pyrethroid insecticides, and <0.1 to 8.51 ng/mL for all other biomarkers with the exception of the DEET metabolite 3-diethylcarbamoyl benzoic acid (4.23 to 850 ng/mL). We observed no association between age and concentration for most biomarkers measured but noted a “U-shaped” trend for five organophosphate metabolites, with the highest concentrations observed in the youngest and oldest age strata, perhaps related to age-specific differences in behavior or physiology. The fact that concentrations of specific and non-specific metabolites of the organophosphate insecticide chlorpyrifos were higher than reported in USA and Canada may relate to differences in registered applications among countries. Additional biomonitoring programs of the general population and focusing on vulnerable populations would improve the exposure assessment and the monitoring of temporal exposure trends as usage patterns of pesticide products in Australia change over time.