Impact of spatial input data resolution on hydrological and erosion modeling: Recommendations from a global assessment

Publication date: 2014 Source:Physics and Chemistry of the Earth, Parts A/B/C, Volumes 67–69 Author(s): V. Chaplot The need to precisely describe the characteristics of a landscape is well-known in mathematical modeling from different environmental disciplines. Because spatial input data, such as climate, relief and soil maps are costly to obtain, especially when large areas are considered, several research studies have investigated the extent to which the resolution of these can be reduced. Yet, a consensus has not been reached on the question of models’ sensitivity to the whole range of spatial input data and for different environmental conditions. This issue was illustrated with the analysis of existing results from 41 watersheds from 30 research studies using the Soil and Water Assessment Tool (SWAT). Because these studies were not consistent in the type of spatial input data considered and the range of resolutions, an application of SWAT was performed in a flat 2612ha flat watershed of central Iowa (USA) where the sensitivity of runoff (R), NO3–N (N) and sediment (SED) yields was tested for changes in the resolution of all the required spatial input data (digital elevation model: DEM: 20–500m; n =12; number of rain gauge: NRAIN from 1 to 13; n =8; soil map: SOIL: 1/25,000–1/500,000; n =3) and in the number of watershed sub-divisions (NSW from 4 to 115; n =4). At the flat watershed, a Canonical Correlation Analysis with 67.4% of data variance explained by t...

Source: Physics and Chemistry of the Earth, Parts ABC - January 5, 2015 Category: Science Source Type: research