Showing papers on "Digital soil mapping published in 1998"

A Conterminous United States Multilayer Soil Characteristics Dataset for Regional Climate and Hydrology Modeling

Abstract: Soil information is now widely required by many climate and hydrology models and soil-vegetation-atmosphere transfer schemes. This pa- per describes the development of a multilayer soil characteristics dataset for the conterminous United States (CONUS-SOIL) that specifically addresses the need for soil physical and hydraulic property information over large areas. The State Soil Geographic Database (STATSGO) developed by the U.S. De- partment of Agriculture-Natural Resources Conservation Service served as the starting point for CONUS-SOIL. Geographic information system and Perl computer programming language tools were used to create map coverages of soil properties including soil texture and rock fragment classes, depth-to-bed- rock, bulk density, porosity, rock fragment volume, particle-size (sand, silt, and clay) fractions, available water capacity, and hydrologic soil group. In- terpolation procedures for the continuous and categorical variables describing these soil properties were developed and applied to the original STATSGO data. In addition to any interpolation errors, the CONUS-SOIL dataset reflects the limitations of the procedures used to generate detailed county-level soil

The development of a hydrological classification of UK soils and the inherent scale changes

Abstract: Although soil is of major importance in influencing river hydrology, there is often a lack of soil hydrological data available to quantify the ameliorating effects of soil on steam flow. The HOST classification (Hydrology of Soil Types) was developed using pedotransfer rules and functions to derive a set of semi-quantified soil attributes from existing soil morphological information as surrogates for the missing hydraulic data. The rules were applied to the soil horizon information and were scaled to the catchment level through the known relationships between soil horizons and soil taxonomic units and between soil taxonomic units and 1:250 000 scale soil map units. The resulting classification, however, is not scale-specific and is capable of predicting river flow indices at the catchment scale (r2 = 0.79) and of predicting the dominant pathways of water movement through individual soil profiles.

Application of Landsat TM data to evaluate soil hydrological status in the Arno basin, Italy: preliminary results

Abstract: Remote sensing can be a very interesting source of distributed data for large or medium scale hydrological modeling, where soil status and land conditions can be extremely different from one zone to another and a large amount of in-situ measurement would be necessary. In this study two Landsat TM images of the lower part of the Arno basin (Tuscany, Italy) taken in 1991 have been processed using several techniques. Cluster analysis gave interesting results in monitoring the state of soil and vegetation in the two different periods of the year. Clusters obtained have been compared with the distribution of different pedological classes and soil use and with geomorphological information derived from the DTM. Landsat data have been used also to obtain several soil water content indexes, and produce maps of soil moisture. A principal component analysis has been used to obtain data that are directly dependent on soil and as less influenced as possible by other factors like vegetation. Finally, an algorithm to retrieve soil hydraulic properties (permeability, gravitational storage, capillary storage) from geomorphologic data (slope, aspect) and pedological class has been studied, using Monte Carlo simulation and optimization techniques. The spatially distributed hydraulic properties of soil have been applied in a physically based hydrological model. The results have been compared with soil water content indexes obtained from Landsat data analysis on two sub-basins of the Arno river.

A regional model of soil-landscape relationships by the example of the Klin-Dmitrov Ridge

Abstract: The regional model of soil-landscape relationships is a systematized representation of all information available on relationships characterizing the soil cover of the studied area. These relationships include both those between individual soil properties and those between soils and other landscape components. Using a particular example, the necessity of this model, possibilities for its use in soil mapping, the study of the dynamics of the soil cover, and soil diagnostics are considered.

A system of soil maps : Experience in application of a polycomponent basic classification of soils for mapping purposes

Abstract: The potentialities of the application of a basic polycomponent classification of soils for mapping purposes are discussed. The approach suggested is based on a concept of soil cover as a complex system that can be characterized by the sets of stable features developed in the course of pedogenesis and inherited from soil-forming rocks, and by modern processes and regimes of soil functioning. Pedogenic and lithogenically inherited soil features, as well as soil regimes, have their own specific regularities and are classified in different components of the basic classification of soils. They can be mapped separately on corresponding maps. A system of such maps has an increased information capacity and can be successfully used for solving various practical and theoretical tasks.