Geographic Information Systems (Gis) and Remote Sensing in the Management of Shallow Tropical Lakes

Abstract

A Ab bs st tr ra ac ct t. . This paper reviews applications of remote sensing and geographic information systems (GIS) techniques to the assessment of tropical waters. These applications are discussed in the context of specific management objectives and sensors used. The need to monitor the spreading patterns of weeds in the tropical waters, land-use changes in the areas surrounding them, change detection, disappearance of wetlands, productivity and nutrient status, in order to establish trends and subsequently develop predictive models to facilitate effective management, is highlighted. GIS capability can be used to link ecological information with the management decisions of these waters. Remote sensing provides useful information in the form of satellite images and aerial photographs that can be integrated and analyzed in a GIS to provide useful spatial information and temporal changes over large geographic areas affecting the structure and function of tropical waters. K Ke ey yw wo or rd ds s: : GIS, remote sensing, sustainable management I In nt tr ro od du uc ct ti io on n Shallow tropical waters play a vital role in many people's lives and contain remarkable communities of plants and animals. Shallow tropical waters are profoundly affected by their locality and by changes taking place on land, even at great distances from them. They are often faced with a number of threats as a result of socio-economic activities, taking place within them and their catchments. Rapid population growth in catchment zones has resulted in intensive use of land for farming, deforestation and growth of urban centers. Consequently, there is accelerated runoff leading to increased silt and nutrients discharge into the shallow tropical waters.Currently most tropical lakes are being choked by water hyacinth (Eichhornia crassipes), which continues to cause severe hardship and immense economic difficulties to most countries. The pressure on tropical waters from the weed requires intensive research in order to come up with useful suggestions towards their management. It is at this level that availability of automated, real time data becomes imperative. Remote sensing has developed rapidly to address these needs. The advantage of remote sensing as documented by Richards [64] and Sabins [69] is its ability to capture and record land details instantaneously. Its spatial resolution and aerial coverage provide the researcher with a synoptic view of a land surface. Such data derived from remotely sensed images may be stored efficiently and analysed effectively in a GIS (Risser and Treworgy,[67]).

Spectral discrimination of papyrus vegetation (Cyperus papyrus L.) in swamp wetlands using field spectrometry

“…Remote sensing, on the other hand, is a technique that gathers data regularly about the earth's features without actually being in direct contact with those features. The main advantages that make remote sensing preferable to field-based methods in landcover classification, are that it has repeat coverage which allows continuous monitoring, and its digital data can be easily integrated into a geographic information system (GIS) for more analysis which is less costly and less time-consuming (Shaikh et al, 2001;Ozesmi and Bauer, 2002;Mironga, 2004;Schmidt and Skidmore, 2003).…”

A Review of the Invasive, Biological and Beneficial Characteristics of Aquatic Species Eichhornia Crassipes and Salvinia Molesta

“…This has caused a reduction of fish biomass, obstruction of shipping routes, losses of water in irrigation systems due to higher evaporation and increased sedimentation by trapping silt particles. Invasion of water hyacinth has had great environmental and socio-economic impacts in Lake Victoria (Williams et al, 2005;Twongo et al, 2005;Katerrega and Sterner, 2007) and many other tropical lakes (Mironga, 2004). Keterrega and Sterner (2007) reliably estimated the extent of water hyacinth coverage for the period 1990-2001 and showed the greatest coverage of Lake Victoria by E. crassipes occurred after 1995 and its reduction after 1997.…”

Determining the Seasonal Ornithological Potential of the Dönemeç (Engil) Delta and Generate the Digital Maps Using Geographical Information Systems (GIS)

“…Currently, Geographic Information Systems (GIS) is commonly used to monitor and conserve the avian species and their habitats in order to reduce the threats and to enhance their population such as in coastal regions (Mironga, 2004), in Matsula wetland west of Estonia (Magi et al 2004), wetlands of Pakistan (WWF, 2007), and coastal and water birds in coastal regions of California (Stralberg, 2010). Habitat preferences by feeding areas of water birds which feed by diving and from surface in their study conducted in Delta Marsh in Canada, in this study in which GIS analysis technique was used, it was conducted that habitats where species are fed seasonally change in relation with vegetation density and water depth.…”