Surface Armour and Erosion – Impacts on Long‐term Landscape Evolution

The parameterisation of landscape evolution models is key to their reliable use. To determine reliable parameter sets, data collected from many events over a number of years are required. However, for many recently disturbed, degraded and/or rehabilitated sites, this data may not represent the long‐term behaviour of the surface as armouring, weathering, together with vegetation establishment change the erodibility of the surface. Here, we evaluate a new armouring sub‐model within the SIBERIA landscape evolution model. The calibration of the armour model is conducted using 6 years of field data from four plots, each composed of different surface materials and vegetation characteristics. The calibrated model is then tested on an area of the proposed rehabilitated landform of the Ranger Uranium Mine in the Northern Territory, Australia. The SIBERIA model was then run for a simulated period of 100,000 years using parameters representing (i) a surface constructed of fresh waste rock; (ii) a vegetated surface; and (iii) the calibrated armour sub‐model. The results demonstrate that the different parameter sets produce catchments that are unique despite the same starting surface. Surface material properties exert a first‐order control on landscape evolution. Therefore making predictions for the evolution of a landscape requires a reliable understanding of the material properties. This requires a knowledge of what material will be placed where in the catchment. Copyright © 2017 John Wiley & Sons, Ltd.     

土壤侵蚀信息熵:单元地表可蚀性的综合度量指标

提出了土壤侵蚀信息熵 (侵蚀熵 )的概念 ,并以公式 H=- cΣni=1 ωiaijlog(ωiaij)来表达。当把侵蚀过程的影响因子分为外部的降雨因子和内部的下垫面因子时 ,侵蚀熵在本质上反映的是土壤侵蚀下垫面可侵蚀性的综合信息。侵蚀熵模型可用于土壤侵蚀过程的空间数字模拟 ,预测水土保持措施的客观效果。侵蚀熵模型与降雨侵蚀力 R(R=EI30 )的乘积γHR(γ为因次换算系数 ) ,可真实描述地表土壤侵蚀量及其空间分布     

LISEM:一个基于GIS的流域土壤流失预报模型

９０年代初,荷兰学者以荷兰南部黄土区土壤侵蚀水土保持规划研究为基础,开发了基于土壤侵蚀物理过程和ＧＩＳ的土壤侵蚀的预报模型－ＬＩＳＥＭ（ＬＩｍｂｕｒｇＳｏｌｉＥｒｏｓｉｏｎＭｏｄｅｌ）为水土保持规划提供了一个支持工具,该模型考虑了土壤侵蚀发生的主要过程,可以与栅格ＧＩＳ集成,并可直接利用遥感动态数据,由于对土壤侵蚀和水文学过程的认识以及土壤水分时空变异性的描述方法还不尽成熟,所以ＬＩＳＥＭ模型仍需     

重点生态功能区水土流失敏感性评价与分布研究—以贵州省雷山县为例

为了定量分析重点生态功能区雷山县水土流失敏感性现状,揭示其空间分布特征,识别出水土流失敏感性关键地域,也为县域水土流失综合防治和生态环境治理提供理论依据,研究选取2010年10月覆盖雷山县全域的ALOS遥感影像和1∶50 000地形图等为数据源,通过地理空间信息技术(RS和GIS技术)结合使用,运用3D Analyst栅格计算功能,提取雷山县DEM、坡度、坡向和土地利用等主要因子,运用ENVI软件,结合归一化植被指数模型,获取植被覆盖度,运用ArcMap空间叠加分析方法,划分出水土流失敏感性等级,得到研究区水土流失敏感性空间分布情况。结果表明,雷山县轻度及以上水土流失敏感性区域面积812.29km2,占总面积的67.45%,水土流失敏感性以轻度为主;强烈以上等级占总面积5.96%,所占面积小;同时研究区不同高程、坡向、坡度和植被覆盖度等级与水土流失敏感性之间存在显著关系,即轻度以上的水土流失敏感性区域面积出现先增大后减小的单峰分布;水土流失敏感性区域主要出现在高程为800~1 400m范围内,坡向为东南和西北,坡度为15°~35°,植被覆盖度在30%~45%的区域。     

Assessment of soil erosion hazard and prioritization for treatment at the watershed level: Case study in the Chemoga watershed,Blue Nile basin,Ethiopia

Soil erosion by water is the most pressing environmental problem in Ethiopia, particularly in the Highlands where the topography is highly rugged, population pressure is high, steeplands are cultivated and rainfall is erosive. Soil conservation is critically required in these areas. The objective of this study was to assess soil erosion hazard in a typical highland watershed (the Chemoga watershed) and demonstrate that a simple erosion assessment model, the universal soil loss equation (USLE), integrated with satellite remote sensing and geographical information systems can provide useful tools for conservation decision‐making. Monthly precipitation, soil map, a 30‐m digital elevation model derived from topographic map, land‐cover map produced from supervised classification of a Land Sat image, and land use types and slope steepness were used to determine the USLE factor values. The results show that a larger part of the watershed (>58 per cent of total) suffers from a severe or very severe erosion risk (>80 t ha⁻¹ y⁻¹), mainly in the midstream and upstream parts where steeplands are cultivated or overgrazed. In about 25 per cent of the watershed, soil erosion was estimated to exceed 125 t ha⁻¹ y⁻¹. Based on the predicted soil erosion rates, the watershed was divided into six priority categories for conservation intervention and 18 micro‐watersheds were identified that may be used as planning units. Finally, the method used has yielded a fairly reliable estimation of soil loss rates and delineation of erosion‐prone areas. Hence, a similar method can be used in other watersheds to prepare conservation master plans and enable efficient use of limited resources. Copyright © 2009 John Wiley & Sons, Ltd.     

以集水区为单元进行露天矿水土流失量的预测与治理-以福建省安溪县铁峰山花岗岩矿区水土保持方案设计为例

介绍了福建省安溪县铁峰山花岗岩矿区水土流失基本情况,以集水区为单元探讨了水土流失量的预测,取得了理想结果,并在实际中得到成功应用.在此基础上,提出了露天矿水土流失量的预测不能只针对矿区,而应以集水区为单元进行综合评估,才能合理布置综合治理措施,进行彻底治理的技术性途径.     

土壤侵蚀经济损失及治理投入产出优化模型——以四川省名山县蒙山为例

 基于环境经济学的原理和方法,对研究区土壤侵蚀经济损失进行估算和分析。结果表明:研究区水土流失的直接经济总损失为1亿6901万元,占同期当地第一产业总产值的50.01%,水土流失直接经济损失最严重的是林地和坡耕地;其次,根据环境经济济产出表的基本结构,得出治理土壤侵蚀投入产出表,从理论上初步探索并建立治理土壤侵蚀过程中所得收益与不利产物的宏观总量的离散差分方程,进而导出优化模型。对土壤侵蚀经济损失估算及土壤侵蚀治理投入产出优化模型的初步探讨,可评估研究区土壤侵蚀的危害程度,并对引进基于市场机制的经济管理手段,建立直接管制和经济激励相结合的政策体系,促进当地水土保持工作开展及环境与经济协调发展等提供科学指导。