NCGIA education activities: the core curriculum and beyond

Abstract

Education has been part of the NCGIA's mission from the earliest discussions of the concept of the Center at the National Science Foundation. To respond to the need for short-term solutions to the shortage of adequately trained personnel in GIS, the Center developed a set of teaching materials or core curriculum. The steps in its development are described and an analysis of initial distribution statistics is presented. Current efforts to develop a framework for laboratory materials are outlined. The paper ends with an assessment of the project and comparison with other disciplines.     

HyperArc: a task-oriented hypertext GIS interface

Abstract

The rationale, development and -implementation of a task-oriented hypertext GIS interface (HyperArc) are described. HyperArc is a fully functional interface on an Apple Macintosh computer acting as a client to a host computer running the ARC/INFO GIS. The package has been developed using the HyperCard package, and makes full use of the Apple Macintosh WIMP interface, enabling the user to perform a range of standard ARC/INFO tasks, including a variety of map displays and data queries. The key advantage of this kind of interface is that it permits the creation of tasks or sets of spatial procedures which can be easily customised and executed by the end user without any knowledge of the system command language.     

Vegetation structure in the south of the Lena-Katanga plateau

Presented are the results from investigating the cenotic structure, structural-dynamical characteristics and spatial differentiation in vegetation of taiga geosystems in the south of the Lena-Katanga plateau of the interfluves between the Lower Tunguska and Nepa rivers. The 1:75 000 map for the present status of vegetation in the key area has been compiled.     

Cyclic and Seasonal Beach Response: A Comparison of Oceanside and Bayside Beaches

This study compares the cyclic and seasonal geomorphic responses of oceanside and bayside beaches on Sandy Hook Spit, New Jersey. It was hypothesized that the different nature of onshore wind regimes at bayside and oceanside beaches would cause different types of beach change. On the east-facing ocean shoreline, rates of beach change are related to weather patterns associated with the passage of mid-latitude cyclonic storms. Bayside beach change is related to the influence of the prevailing westerlies. Storm erosion and post-storm deposition is more rapid on oceanside beaches. Swell waves occurring between storms rapidly reinstate pre-storm equilibrium conditions. Lower bay-side wave energies occurring between storms have little effect on profile development, and foreshore slopes inherited from previous storms undergo little change. Bayside beaches therefore appear to be more in equilibrium with storm conditions than oceanside beaches.

Changes in foreshore slope, beach volume, and beach position associated with individual storm events are compared to seasonal trends to test the applicability of the Hayes cyclic model of beach development to both oceanside and bayside beaches. There is evidence of a cyclic trend of develop-ment on the more exposed ocean sites and seasonal development on the more sheltered bayside sites, which suggests that cyclic development may be causally related to the difference among the energy levels of the storm and nonstorm wave regimes.     

Structure and evolution of mass transport deposits in the South Caspian Basin,Azerbaijan

The Quaternary to late Pliocene sedimentary succession along the margin of the South Caspian Basin contains numerous kilometre‐scale submarine slope failures, which were sourced along the basin slope and from the inclined flanks of contemporaneous anticlines. This study uses three‐dimensional (3D) seismic reflection data to visualise the internal structure of 27 mass transport deposits and catalogues the syndepositional structures contained within them. These are used to interpret emplacement processes occurring during submarine slope failure. The deposits consist of three linked structural domains: extensional, translational and compressive, each containing characteristic structures. Novel features are present within the mass transport deposits: (1) a diverging retrogression of the headwall scarp; (2) the absence of a conventional headwall scarp around growth stratal pinch outs; (3) restraining bends in the lateral margin; (4) a downslope increase in the throw of thrust faults. The results of this study shed light on the deformation that occurred during submarine slope failure, and highlight an important geological process in the evolution of the South Caspian Basin margin.     

Do free-ranging domestic goats show ‘landscapes of fear’? Patch use in response to habitat features and predator cues

One factor that influences foraging is predation risk. As a result, herbivores may not use landscapes uniformly due to spatial differences in perceived predation risk. Wild herbivores forage across these ‘landscapes of fear’; however, the extent to which domestic herbivores consider them is generally unknown. Using a grid of artificial food patches and measuring giving up densities (GUDs), we mapped landscapes of fear of free-ranging domestic goats on three substrates. In the first experiment, we related GUDs to landscape variables. Goats preferred feeding in open ground with firm substrate compared to a sandy riverbed or a rocky hillside. We suggest that differences relate to escape potential and the occurrence of ambush sites. Landscape variables that influenced feeding effort were patch visibility and plants next to a patch. In a second experiment, we increased predation risk by adding predator dung and urine into the habitats. In response, feeding effort declined across all three habitats. Furthermore, goats only responded to patch visibility and not plants next to the patches. Better sightlines increase predator detection and allow individuals to see group members. Our results indicate that predation risk influences the extent to which free-ranging domestic herbivores utilise landscapes.     

Mapping landslide susceptibility from small datasets: A case study in the Pays de Herve (E Belgium)

A landslide susceptibility map is proposed for the Pays de Herve (E Belgium), where large landslides affect Cretaceous clay outcrop areas. Based on a Bayesian approach, this GIS-supported probabilistic map identifies the areas most susceptible to deep landslides. The database is comprised of the source areas of ten pre-existing landslides (i.e. a sample of 154 grid cells) and of six environmental data layers, namely lithology, proximity to active faults, slope angle and aspect, elevation and distance to the nearest valley-floor. A 30-m-resolution DEM from the Belgian National Geographical Institute is used for the analysis. Owing to the small size of the sample, a special cross-validation procedure of the susceptibility map is performed, which uses in an iterative way each of the landslides to test the predictive power of the map derived from the other landslides. Four different sets of variables are used to produce four susceptibility maps, whose prediction curves are compared. While the prediction rates associated with the models not involving the “proximity to active fault” criterion are comparable to those of the models considering this variable, strong weaknesses inherent in the fault data on which the latter rely suggest that the final susceptibility map should be based on a model that excludes any reference to fault. This highlights the difference between a triggering factor and determining factors, and in the same time broadens the scope of the produced map. A single reactivated slide is also used to test the possibility of predicting future reactivation of existing landslides in the area. Finally, the need for geomorphological control over the mathematical treatment is underlined in order to obtain realistic prediction maps.     

Evaluation of ostracod-based palaeoenvironmental reconstruction with instrumental data from the arid Faiyum Depression,Egypt

The utility of ostracod-based palaeoenvironmental reconstruction was evaluated using instrumental data for Lake Qarun, Egypt. The euryhaline ostracod Cyprideis torosa was the only species found in the lake’s recent sediment record. This species is known to tolerate salinity levels and water solute compositions that may prevent colonisation by other species. Oxygen and carbon isotope ratios of ostracod carbonate from lake sediments covary with changes in instrumental values for lake level and salinity for the period 1890–1974. δ¹³C-values correlate negatively with lake water salinity (r ² = 0.87) and δ¹⁸O-values correlate negatively with measured lake level changes (r ² = 0.41). Other ostracod proxy data provide qualitative information on lake level trends. Fossil assemblage data (juvenile/adult and valve/carapace ratios and valve preservation) provide information on wave energy. Ecophenotypic variation of C. torosa valves provided some useful palaeolimnological information. Sr/Ca and Mg/Ca ratios in ostracods were not found to reflect water composition, due to the uncoupling of these ratios with salinity in Lake Qarun. Overall, our results highlight the need to calibrate ostracod proxy data in modern systems prior to their use for palaeoenvironmental reconstruction.