Land Use Change Impacts on Soil Hydraulic Function

该博士学位的总体目标是评估同一土壤类型上不同的土地覆盖，例如树木、草地和耕地系统，如何改变水力功能和生态系统服务的提供。这将使我们能够创建经验派生的查找表来参数化模型，以预测同一土壤类型上的土地利用转变将如何影响土壤水力功能。这将：(I)提高我们对土地利用变化中土壤水力功能的理解，并使我们能够考虑到水文和生态系统服务模式的这种变化。(Ii)提供实用的解决方案，以优化景观，以最大限度地提高水的渗透率和保持率，减轻洪水和极端天气的影响，以及(Iii)告知受水分保持影响的生物地球化学循环模型，例如微生物活动介导的碳和养分循环模型，该课程将利用可公开获得的NERC数据集，其中包括土壤母质、G-BASE、土地覆盖、乡村调查和Glastir监测。利用数据挖掘、统计建模和地理信息系统的结合，学生将利用这些独特的资源来确定主要的土地利用-土壤类型组合，并进行高质量的测量活动，以确定土壤的水力和生化性质，如质地、孔隙度、碳、排斥性等。这些信息将被用于提供信息和参数化模型(例如，Hydrus 3D或MM5-LSM6)，以展示土地利用类型和空间位置的变化对生态系统服务提供的可能影响。这满足了NERC最需要的技能审查确定的培训需求，并提供了高质量的科学和高影响力的期刊文章。第1年：对全球范围内最近的研究(过去10年中的40篇论文)进行回顾，以确定土地利用变化对同一土壤类型上土壤水力性质的影响(1-6个月)。利用土地复盖和土壤数据确定与经验数据收集有重大相关性的现场组合，并开展测量技术培训(6-12个月)。第2年：对土壤水力性质(例如饱和和非饱和导水率)和土壤物理性质(如排水性、土壤有机质、容重、质地)进行经验测量，并使用UMS Hyprop蒸发法和十角形WP4进行土壤水分释放的实验室测量(12-24个月)。学生可以利用班戈尔树木密度实验的优势，详细探索差异，并在转移到其他野外地点之前练习测量技术。对水力功能和土壤特性之间的关系进行数据分析，根据土地覆盖类型(如树木、草地、耕地)和土壤类型(12-24个月)编制水力特性的土地管理查询表。第3年：确定并使用一个简单的地表水文模型(如MM5-LSM6)，以综合数据并测试土地覆盖类型变化对水文反应和生态系统服务提供的影响的模型预测(24-36个月)。完成分析和论文写作(36-42个月)。

The overarching aim of this PhD is to assess how different land covers, e.g. trees, grass and arable systems, on the same soil type, change hydraulic function and ecosystem service delivery. This will allow us to create empirically derived lookup tables to parameterize models to predict how land use transitions, on the same soil type, will affect soil hydraulic function. This will: (i) improve our understanding of soil hydraulic function in response to land use change, and enable us to account for this change in hydrological and ecosystem service models. (ii) Provide practical solutions to optimising landscapes to maximise water infiltration, retention, and to mitigate flooding and the impacts of extreme weather, and (iii) inform biogeochemical cycling models impacted by moisture retention such as carbon and nutrient cycling models mediated by microbial activity, This studentship will draw on publically available NERC datasets that include soil parent material, G-BASE, land cover, Countryside Survey and Glastir monitoring. Using a combination of data mining, statistical modelling and GIS the studentship will exploit these unique resources to identify major land use - soil type combinations and conduct a high quality measurement campaign to determine soil hydraulic and biochemical properties, e.g. texture, porosity, carbon, repellency etc. This information will be used to inform and parametrize models (e.g. Hydrus 3D or MM5-LSM6) to demonstrate the likely impact of changes in both land use type, and spatial location on the delivery of ecosystem services. This meets the training needs identified by NERC's Most Wanted Skills Review as well as delivering high quality science with high impact journal articles.Year 1: Conduct a review of recent research (40+ papers last 10 yrs) from across the globe to determine the impact of land use change on soil hydraulic properties on the same soil type (months 1-6). Use land cover and soil data to identify field site combinations of major relevance for empirical data collection and conduct training in measurement techniques (months 6-12). Year 2: Empirical measurements of soil hydraulic properties e.g. saturated and unsaturated hydraulic conductivity and soil physical properties such as water repellency, SOM, bulk density, texture and conduct laboratory measurements of soil water release using a UMS HYPROP evaporation method and Decagon WP4 (months 12-24). The student can take advantage of the Bangor tree density experiment to explore differences in detail and practice measurement techniques before moving to other field sites. Data analysis of the relationships between hydraulic function and soil properties to produce land management lookup tables for hydraulic properties based on land cover type (e.g. tree, grass, arable) and soil type (months 12-24). Year 3: Identify and use a simple land surface-hydrology model (e.g. MM5-LSM6, ) to synthesise data and test model prediction of the impact of changes in land cover type on hydrological response and ecosystem service provision (months 24-36). Finalise analysis and thesis writing (months 36-42).