The Importance of High Resolution Digital Elevation Models for Improved Hydrological Simulations of a Mediterranean Forested Catchment

Abstract

Eco-hydrological models can be used to support effective land management and planning of forest resources. These models require a Digital Elevation Model (DEM), in order to accurately represent the morphological surface and to simulate catchment responses. This is particularly relevant on low altimetry catchments, where a high resolution DEM can result in a more accurate representation of terrain morphology (e.g., slope, flow direction), and therefore a better prediction of hydrological responses. This work intended to use Soil and Water Assessment Tool (SWAT) to assess the influence of DEM resolutions (1 m, 10 m and 30 m) on the accuracy of catchment representations and hydrological responses on a low relief forest catchment with a dry and hot summer Mediterranean climate. The catchment responses were simulated using independent SWAT models built up using three DEMs. These resolutions resulted in marked differences regarding the total number of channels, their length as well as the hierarchy. Model performance was increasingly improved using fine resolutions DEM, revealing a bR2 (0.87, 0.85 and 0.85), NSE (0.84, 0.67 and 0.60) and Pbias (−14.1, −27.0 and −38.7), respectively, for 1 m, 10 m and 30 m resolutions. This translates into a better timing of the flow, improved volume simulation and significantly less underestimation of the flow.

High Mountain Asian glacier response to climate revealed by multi-temporal satellite observations since the 1960s

“…3) as well as with those of different methodologies or data sources (for detailed comparisons see Supplementary Note 3, Supplementary Figs. [25][26][27][28][29][30][31][32] and Supplementary Tables 20-27) and offer a temporally resolved view of the evolution of glaciers towards their current state across HMA.…”

“…Declassified stereo imagery acquired by the Corona KH-4 satellite in the 1960s and early 1970s 28,29 is of high (~2 m) spatial resolution, which increases the probability of image matching during DEM generation. Moreover, this data provides the opportunity to capture glacier elevation change during a period when no other high resolution stereo data were available 30,31 . Although Corona KH-4 data were first employed to study glacier elevation changes over a decade ago in the Mt.…”

Urban flood risk analysis of buildings using HEC-RAS 2D in climate change framework

“…Model is discretized into an equal number of grid cells of 30 m  30 m, i.e., equal geometry to maintain spatial uniformity. In addition, DEM of the same resolution is adopted, as it is appropriate for hydrological modeling studies (Buakhao & Kangrang 2016;Rocha et al 2020;Abili 2021). Simultaneously, other topographical features and infrastructural layers are also made similar to maintain uniformity.…”

Modeling Streamflow and Sediment Loads with a Photogrammetrically Derived UAS Digital Terrain Model: Empirical Evaluation from a Fluvial Aggregate Excavation Operation

“…While LiDAR derived terrain models in hydrologic applications have their place as an essential data source [18], traditional photogrammetrically derived products like digital elevation models (DEMs) are still an important source of topographic information that informs hydrologic applications [22,23]. Historically, such DEM products have been retrieved from medium resolution optical and microwave images [7,24,25].…”