Modelled Hillslope Erosion over New South Wales

This landing page is a collection of data packages and reports which supports the Modelled Hillslope Erosion over New South Wales.\r\n\r\n### Hillslope Erosion\r\nSoil erosion by water includes sheet and rill erosion (also referred to as hillslope erosion)\r\nis a major form of land degradation in NSW landscapes. Hillslope erosion was\r\ncalculated using the revised universal soil loss equation (RUSLE) which estimates soil\r\nloss (t ha-1 yr-1) by runoff. Rainfall-runoff erosivity (R) factor (MJ mm ha-1 hr-1 yr-1) in\r\nRUSLE was estimated using a daily rainfall erosivity modelling for NSW and long-term\r\nrainfall records (Yang and Yu 2015). The soil erodibility (K) factor (t ha h ha-1 MJ-1 mm-1)\r\nwas estimated from digital soil mapping products and soil profile data (Yang et al 2017).\r\nSlope length and steepness (LS, unitless) factor was calculated, on catchment basis, from\r\nhydrologically corrected digital elevation model (SRTM DEM-H) based on comprehensive\r\nalgorithms considering cumulative overland flow length (Yang 2015). The time series\r\ngroundcover products (the latest version, V310) from Moderate Resolution Imaging\r\nSpectroradiometer (MODIS) were used to estimate groundcover and RUSLE cover and\r\nmanagement (C, unitless) factor (Yang 2014). Time-series hillslope erosion datasets and maps were produced on monthly and annual bases from 2000 to present. The state and trends of hillslope erosion\r\nacross New South Wales are summarised in Yang (2020). The relevant references are \r\nbelow: \r\n\r\n### Cover Erosion\r\nThis occurs when there is vegetation or ground cover, like grasses, shrubs or leaf litter, on the slope. The cover helps protect the soil from direct raindrop impact, reduces the velocity of surface runoff, and increase infiltration. As a result, erosion rates tend to be lower because the cover acts as a natural barrier that holds soil in place.\r\n\r\n### Bare Soil Erosion\r\nThis takes place on slopes with exposed soil, lacking any form of vegetation or cover. Bare soil is more vulnerable to erosion because there's nothing to cushion the impact of rainfall or slow down water flow. The lack of cover results in higher runoff velocity, which intensifies erosion processes, leading to greater soil displacement, sediment transport and potentially faster degradation of the slope.\r\n\r\n1. Yang, X., Gray, J., Chapman, C., Zhu, Q., Tulau M., McInnes-Clarke, S. (2017). Digital mapping of soil erodibility for water erosion in New South Wales, Australia. Soil Research. 56(2), 158-170. https://doi.org/10.1071/SR17058.\r\n\r\n2. Yang X (2015) Digital mapping of RUSLE slope length and steepness factor across New South Wales. Soil Research 53, 216-225. https://doi.org/10.1071/SR14208.\r\n\r\n3. Yang X, Yu B (2015) Modelling and mapping rainfall erosivity in New South Wales, Australia. Soil Research. 53, 178-189. https://doi.org/10.1071/SR14188.\r\n\r\n4. Yang X (2014) Deriving RUSLE cover factor from time-series fractional vegetation cover for soil erosion risk monitoring in New South Wales. Soil Research 52, 253-261. https://doi.org/10.1071/SR13297. \r\n\r\n5. Yang X (2020) State and trends of hillslope erosion across New South Wales, Australia. Catena 186, 104361. https://doi.org/10.1016/j.catena.2019.104361.\r\n\r\n### Interactive Map\r\nTo view the Hillslope bare soil and cover erosion annual layers via SEED map ['Click Here'](https://geo.seed.nsw.gov.au/vertigisstudio/web/?app=cabd04d595ec43c1aaf4298e80e83ec2&workflow=36ea26c1-e8e2-4355-8600-5d1558259ad3&workflowParams=%7B%22portalItems%22:%20%5b%7B%22itemId%22:%20%2208dc3d21e8fa47f69a732b38b87f3687%22,%20%22layerIds%22:%20%220,9,19,48,39,29%22%7D%5d%7D "Interactive Map")\r\n\r\nThe ‘Show on SEED map link will load some of the data due to its complexity. To load more layers please go to the Layer Catalogue and add them. Get help on using the Layer Catalogue ['Click Here'](https://www.seed.nsw.gov.au/need-help/finding-and-using-data-on-seed-map/how-to-use-layer-catalogue\r\n "How To")\r\n

本登录页面汇集了一系列数据集与研究报告，用于支撑新南威尔士州坡面侵蚀模拟相关研究。

### 坡面侵蚀
水力土壤侵蚀涵盖面蚀与细沟侵蚀（亦称为坡面侵蚀），是新南威尔士州景观中主要的土地退化类型之一。本研究采用修正通用土壤流失方程（Revised Universal Soil Loss Equation, RUSLE）计算坡面侵蚀量，该方程可通过径流过程估算土壤流失量（单位：吨·公顷⁻¹·年⁻¹，t ha⁻¹ yr⁻¹）。RUSLE中的降雨径流侵蚀力（R）因子（单位：兆焦·毫米·公顷⁻¹·小时⁻¹·年⁻¹，MJ mm ha⁻¹ hr⁻¹ yr⁻¹）基于新南威尔士州逐日降雨侵蚀力模型与长期降雨观测记录进行估算（Yang与Yu，2015）。土壤可蚀性（K）因子（单位：吨·公顷·小时·公顷⁻¹·兆焦⁻¹·毫米⁻¹，t ha h ha⁻¹ MJ⁻¹ mm⁻¹）由数字土壤制图产品与土壤剖面数据估算得到（Yang等，2017）。坡长与坡度（LS，无量纲）因子以流域为单元，基于经水文校正的数字高程模型（SRTM DEM-H），结合考虑地表汇流路径长度的综合算法计算得到（Yang，2015）。研究采用中分辨率成像光谱仪（Moderate Resolution Imaging Spectroradiometer, MODIS）的时序地表覆盖产品（最新版本V310），估算地表覆盖状况并计算RUSLE中的覆盖与管理（C，无量纲）因子（Yang，2014）。本研究生成了2000年至今的月度与年度时序坡面侵蚀数据集及配套地图。新南威尔士州全域坡面侵蚀的现状与趋势总结于Yang（2020）的研究中。相关参考文献如下：

### 覆盖保护下的侵蚀
此类侵蚀发生于斜坡上存在植被或地表覆盖（如草本植物、灌木或枯枝落叶）的区域。覆盖层可保护土壤免受雨滴直接冲击，降低地表径流流速，并提升土壤入渗能力。因此，侵蚀速率通常较低，因为覆盖层作为天然屏障可固定土壤颗粒。

### 裸土侵蚀
此类侵蚀发生于裸露无任何植被或覆盖物的斜坡区域。裸土更易遭受侵蚀，因为缺乏缓冲降雨冲击、减缓水流的介质。覆盖层的缺失会导致径流流速加快，加剧侵蚀过程，造成更严重的土壤位移、泥沙搬运，甚至加速斜坡整体退化。

1. Yang, X., Gray, J., Chapman, C., Zhu, Q., Tulau, M., McInnes-Clarke, S. (2017). 澳大利亚新南威尔士州水蚀土壤可蚀性数字制图. 《土壤研究》, 56(2), 158-170. https://doi.org/10.1071/SR17058.

2. Yang, X. (2015). 新南威尔士州RUSLE坡长与坡度因子数字制图. 《土壤研究》, 53, 216-225. https://doi.org/10.1071/SR14208.

3. Yang, X., Yu, B. (2015). 澳大利亚新南威尔士州降雨侵蚀力建模与制图. 《土壤研究》, 53, 178-189. https://doi.org/10.1071/SR14188.

4. Yang, X. (2014). 基于时序植被覆盖度提取RUSLE覆盖因子以监测新南威尔士州土壤侵蚀风险. 《土壤研究》, 52, 253-261. https://doi.org/10.1071/SR13297.

5. Yang, X. (2020). 澳大利亚新南威尔士州坡面侵蚀现状与趋势. 《喀泰纳》, 186, 104361. https://doi.org/10.1016/j.catena.2019.104361.

### 交互式地图
可通过SEED地图查看坡面裸土与覆盖保护下侵蚀的年度图层，请"点击此处"(https://geo.seed.nsw.gov.au/vertigisstudio/web/?app=cabd04d595ec43c1aaf4298e80e83ec2&workflow=36ea26c1-e8e2-4355-8600-5d1558259ad3&workflowParams=%7B%22portalItems%22:%20%5b%7B%22itemId%22:%20%2208dc3d21e8fa47f69a732b38b87f3687%22,%20%22layerIds%22:%20%220,9,19,48,39,29%22%7D%5d%7D)。由于数据复杂度较高，点击"在SEED地图中显示"链接仅会加载部分数据。如需加载更多图层，请前往图层目录并手动添加。如需获取图层目录的使用帮助，请"点击此处"(https://www.seed.nsw.gov.au/need-help/finding-and-using-data-on-seed-map/how-to-use-layer-catalogue)。