https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45094 Wed 22 Mar 2023 18:14:26 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:37850 −1 month ⁻¹, about 30 times higher than the pre-fire erosion and 10 times higher than the average erosion rate at the same period because of the intense storm events and rainfall erosivity with a return period over 40 years. The high post-fire erosion risk areas (up to 23.8 Mg ha⁻¹ month⁻¹) were at sub-catchments near Warragamba Dam which forms Lake Burragorang and supplies drinking water to more than four million people in Sydney. These findings assist in the timely assessment of post-fire erosion and water quality risks and help develop cost-effective fire incident management and mitigation actions for such an area with both significant ecological and drinking water assets. The methodology developed from this study is potentially applicable elsewhere for similar studies as the input datasets (satellite and radar data) and computing platforms (GEE, GIS) are available and accessible worldwide.]]> Wed 19 May 2021 11:38:03 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:52611 Wed 18 Oct 2023 13:46:35 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:50901 Wed 15 May 2024 15:33:39 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26654 Den) of a 69-year-old Eucalyptus regnans forest comprising 251 plots with resolution of the order of 0.04 ha. Using the NCut method we predicted basal area (BA_Ha) per hectare and sapwood area (SA_Ha) per hectare, a well-established proxy for transpiration. Sapwood area was also indirectly estimated with allometric relationships dependent on LiDAR derived S_Den and BA_Ha using a computationally efficient procedure. The individual tree detection (ITD) rates for the LMF and NCut methods respectively had 72% and 68% of stems correctly identified, 25% and 20% of stems missed, and 2% and 12% of stems over-segmented. The significantly higher computational requirement of the NCut algorithm makes the LMF method more suitable for predicting S_Den across large forested areas. Using NCut derived ITD segments, observed versus predicted stand BA_Ha had R² ranging from 0.70 to 0.98 across six catchments, whereas a generalised parsimonious model applied to all sites used the portion of hits greater than 37 m in height (PH₃₇) to explain 68% of BA_Ha. For extrapolating one ha resolution SA_Ha estimates across large forested catchments, we found that directly relating SA_Ha to NCut derived LiDAR indices (R² = 0.56) was slightly more accurate but computationally more demanding than indirect estimates of SA_Ha using allometric relationships consisting of BA_Ha (R² = 0.50) or a sapwood perimeter index, defined as (BA_HaS_Den)^½ (R² = 0.48).]]> Wed 11 Apr 2018 16:13:53 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:31428 3. These results suggest that structure from motion is a viable tool for ongoing monitoring of ecologically-significant coral reefs, especially to establish effects of disturbances, provided the measurement error is considered.]]> Wed 11 Apr 2018 10:45:16 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:53294 Wed 07 Feb 2024 15:04:49 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:54451 Tue 27 Feb 2024 13:58:57 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:41113 Tue 26 Jul 2022 08:41:17 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:50427 Tue 25 Jul 2023 18:47:10 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:28833 Tue 24 Aug 2021 14:30:59 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:53041 Tue 14 Nov 2023 11:50:37 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:36567 Tue 09 Jun 2020 11:26:42 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34440 Tue 03 Sep 2019 18:26:42 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34927 Tue 03 Sep 2019 17:58:44 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33490 Tue 03 Sep 2019 17:54:21 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:50665 This study focuses on the development of a time-variable regional geo-potential model for Antarctica using the spherical cap harmonic analysis (SCHA) basis functions. The model is derived from line-of-sight gravity difference (LGD) measurements obtained from the GRACE-Follow-On (GFO) mission. The solution of a Laplace equation for the boundary values over a spherical cap is used to expand the geo-potential coefficients in terms of Legendre functions with a real degree and integer order suitable for regional modelling, which is used to constrain the geo-potential coefficients using LGD measurements. To validate the performance of the SCHA, it is first utilized with LGD data derived from a L2 JPL (Level 2 product of the Jet Propulsion Laboratory). The obtained LGD data are used to compute the local geo-potential model up to Kmax = 20, corresponding to the SH degree and order up to 60. The comparison of the radial gravity on the Earth’s surface map across Antarctica with the corresponding radial gravity components of the L2 JPL is carried out using local geo-potential coefficients. The results of this comparison provide evidence that these basis functions for Kmax = 20 are valid across the entirety of Antarctica. Subsequently, the analysis proceeds using LGD data obtained from the Level 1B product of GFO by transforming these LGD data into the SCHA coordinate system and applying them to constrain the SCHA harmonic coefficients up to Kmax = 20. In this case, several independent LGD profiles along the trajectories of the satellites are devised to verify the accuracy of the local model. These LGD profiles are not employed in the inverse problem of determining harmonic coefficients. The results indicate that using regional harmonic basis functions, specifically spherical cap harmonic analysis (SCHA) functions, leads to a close estimation of LGD compared to the L2 JPL. The regional harmonic basis function exhibits a root mean square error (RMSE) of 3.71 × 10−4 mGal. This represents a substantial improvement over the RMSE of the L2 JPL, which is 6.36 × 10−4 mGal. Thus, it can be concluded that the use of local geo-potential coefficients obtained from SCHA is a reliable method for extracting nearly the full gravitational signal within a spherical cap region, after validation of this method. The SCHA model provides significant realistic information as it addresses the mass gain and loss across various regions in Antarctica.]]> Tue 01 Aug 2023 13:56:14 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39935 Thu 30 Jun 2022 13:26:31 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39476 Thu 28 Jul 2022 15:10:21 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:41207 Thu 28 Jul 2022 12:01:25 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39720 Thu 28 Jul 2022 08:45:14 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45388 Thu 27 Oct 2022 15:22:27 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38302 Thu 26 Aug 2021 10:22:38 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26688 Thu 09 Aug 2018 11:37:07 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38569 0.74. The results of this paper suggest that the official ICE retracker for LRM data and APD-PPT retracker for SARIn-mode waveforms are the most appropriate retrackers over Dianchi Lake and TP lakes, respectively. The trend estimates of the time series derived by both retrackers are 61.0 ± 10.8 mm/yr for Gemang Co and Zhangnai Co in TP, and 30.9 ± 64.9 mm/yr for Dianchi Lake, indicating that the lake levels over three lakes were continuously rising over the study period. The results of this study show that CryoSat-2 SARIn-mode data can be used for monitoring many small lakes that have not been measured by other altimetry missions in TP.]]> Thu 04 Nov 2021 16:25:08 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45643 Mon 30 Oct 2023 15:22:21 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:37511 Mon 25 Jan 2021 14:24:20 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:44835 Mon 24 Oct 2022 09:52:47 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32889 Mon 23 Sep 2019 12:24:56 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:48500 Mon 20 Mar 2023 14:12:52 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:35025 Fri 31 May 2019 16:24:59 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:52677 Fri 20 Oct 2023 09:30:13 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:40605 Fri 15 Jul 2022 11:35:14 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:53661 The assessment of ecosystem quality and the maintenance of optimal ecosystem function require understanding vegetation area dynamics and their relationship with climate variables. This study aims to detect vegetation area changes downstream of the Hali dam, which was built in 2009, and to understand the influence of the dam as well as climatic variables on the region’s vegetation areas from 2000 to 2020. The case study is located in an arid area with an average rainfall amount from 50 to 100 mm/year. An analysis of seasonal changes in vegetation areas was conducted using the Normalized Difference Vegetation Index (NDVI), and supervised image classification was used to evaluate changes in vegetation areas using Landsat imagery. Pearson correlation and multivariate linear regression were used to assess the response of local vegetation areas to both hydrologic changes due to dam construction and climate variability. The NDVI analysis revealed a considerable vegetation decline after the dam construction in the dry season. This is primarily associated with the impoundment of seasonal water by the dam and the increase in cropland areas due to dam irrigation. A significantly stronger correlation between vegetation changes and precipitation and temperature variations was observed before the dam construction. Furthermore, multivariant linear regression was used to evaluate the variations in equivalent water thickness (EWT), climate data, and NDVI before and after the dam construction. The results suggested that 85 percent of the variability in the mean NDVI was driven by climate variables and EWT before the dam construction. On the other hand, it was found that only 42 percent of the variations in the NDVI were driven by climate variables and EWT from 2010 to 2020 for both dry and wet seasons.]]> Fri 15 Dec 2023 11:05:47 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47943 Fri 10 Feb 2023 15:17:59 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:51523 Fri 08 Sep 2023 12:05:47 AEST ]]>