Objectives Southern polar region of the Mars planet become an interesting area for researchers after the recent discovery of large water body in the Planum Australe region [1]. The objective of this study is to investigate the surface hydrology based on the drainage basins and streamline features or rivers. MOLA DEMs were used to delineate watershed using ArcGIS. Different tools from ArcGIS were applied to understand the surface hydrology of this red planet. Methodology References Abstract Fig. 1. Study area on southern polar region of Mars (Australe Planum) Fig. 3. Delineated watershed and stream lines Fig. 2. Watershed delineation model in ArcGIS using model builder Fig. 6. Radar evidence of 20 km wide liquid water body in the 200- km study area [1] Results [1] Orosei, R., Lauro, S. E., Pettinelli, E., Cicchetti, A., Coradini, M., Cosciotti, B., … Pajola, M. (2018). Radar evidence of subglacial liquid water on Mars. Science, 361(6401), 490-493. [2] Von Paris, P., Petau, A., Grenfell, J. L., Hauber, E., Breuer, D., Jaumann, R., … Tirsch, D. (2015). Estimating precipitation on early Mars using a radiative-convective model of the atmosphere and comparison with inferred runoff from geomorphology. Planetary and Space Science, 105, 133–147. SURFACE HYDROLOGICAL MODELLING USING ARCGIS & HEC-RAS ON THE PLANUM AUSTRALE REGION OF MARS Authors: Dr. Khaula Alkaabi 1 ([email protected]) ; Eng. Qasim Khan 2 1 Geography & Urban Sustainability Department, United Arab Emirates University 2 Civil & Environmental Engineering Department, United Arab Emirates University Step B: Applying HEC-RAS model to the delineated watershed A B Fit of HEC-RAS Model with ArcGIS Streamlines Runoff Model using HEC-RAS Drainage Network Streamlines using ArcGIS Basins A and B in the Planum Australe Region Fig. 4. Applying precipitation to model flow using HEC-RAS 10; 11; 12 Basins Divide Drainage Network of Planum Australe Region, Mars Stream Order Step A: Delineation of watershed and streamlines from DEM OBJECT ID DEM Elevation Fill Elevation Elev. Difference in Min due to sink Max DEM Elevation MinDEM Elevation Max Fill Elevation Min Fill Elevation 1 3841 -828.75 3841 313.25 1142 2 4798 -1170 4798 819.25 1989.25 3 4768.75 -112.25 4768.75 950.25 1062.5 4 3308.75 -363.25 3308.75 1265 1628.25 5 3305.25 -1840.25 3305.25 534.25 2374.5 6 3113.75 -350.5 3113.75 825 1175.5 7 3708 -633.5 3708 929 1562.5 Table 1. Z-elevation of DEM before and after applying fill/sink function The high-resolution digital elevation model (DEM), derived from Mars Orbiter Laser Altimeter (MOLA), NASA’s Mars Global Surveyor spacecraft (MGS) and the High-Resolution Stereo Camera (HRSC), were used to characterise high land fluvial system quantitatively and qualitatively. ArcGIS was used to delineate surface drainage basins, extract valley networks and derive basin morphometric parameters such as drainage density and stream order. Hydrologic mapping was extracted using algorithmic extraction, in the Arc Geographical Information System, of valley networks from the DEMs to assess the hydrologic setting of the Planum Australe. The applied algorithms ranged from the hydrological tools, fill function, flow direction, watershed function, and the flow accumulation. Conclusion Step C: Fig. 7. Cross-section C- C’ upstream (see Fig. 5 for C- C’) Step D: This study presents the run-off modelling and the cross-sectional profile originating from 1.5 km below surface and 20 km extending sideways liquid water body [1] in the Planum Australe region. Future research can examine and apply different methodologies and approaches to further investigate the surface hydrological setting of the newly discovered liquid body of water at the Planum Australe region and its related ecosystem. The topographic profile was generated across the upstream (C-C’) and downstream (D-D’) of the study area basins A and B (see Fig. 4). The two depressions at upstream (Fig. 5) when combined with the HEC-RAS flow model (Fig. 3) showed that the there were depression-like continuous structure in both Basins A and B. The 20 km wide liquid water body, underneath 1.5 km solid ice, was also discovered in the same area [1]. Fig. 8. Cross-section D-D’ downstream (see Fig. 5 for D-D’) Fig. 5. Geological map of Basins A and B of Planum Australe, Mars Source: Map was retrieved from Tanaka et al., (2004). The runoff model (Fig. 3) has a good fit with the streamlines generated in ArcGIS (Fig. 4). This approach of using HEC-RAS provided the basis of surface flow. The runoff model showed that the flow velocity was high at the basin A, possibly due to high flow rate and steep slope at the upstream. The velocity downstream of basin B around the craters showed higher value which indicated the topping of water over crater boundary. The flooding can be seen downstream at both the basins which was largely due to the flat topography. The red planet Mars, has been a focus for scientists for decades. This study presents the surface hydrology based on the drainage basins and streamline features. The functions and logarithm of ArcGIS were used to map the hydrological component of this mysterious planet. Ninth International Conference on Mars July 22-25, 2019