Land use and water management effects on soil N2O emissions in the Hai He river basin, China

该项目旨在量化正在进行和预计的土地利用、管理和环境条件变化对陆地生态系统、大气和水圈之间碳氮组分动态交换的影响。模型的开发将基于涡旋相关（EC）量子级联激光（QCL）和静态室测量获得的N2O（以及CH4和CO2）通量在场尺度上的空间变异性的量化。通过对过去、现在和未来条件的长期回顾和预测模型运行进行分析，可以评估自由交易和管理对交换过程的影响。为了在景观尺度上量化温室气体（GHG）排放和氮淋失，必须考虑区域水文过程（例如，地下水位动态和灌溉带来的养分分散）对碳和氮的生物地球化学循环的影响。为了解决这种复杂性，我们将Mobile2D （MOBILE-DNDC的区域版本）与区域水文模型相结合。Mobile2D以及耦合系统将用于评估预测的LU/管理变化和气候条件对碳和氮储量、温室气体净交换（NGE）、水的可用性和质量（N浸出）的影响。在一个包含LU、土壤和植被特性以及气候信息的GIS数据库的驱动下，模拟将为不同发展路径、管理实践和气候变化情景下的一系列实际和潜在种植系统创建田间和区域（哈尔河流域）尺度的温室气体清单和来源优势评估。

The project aims at the quantification of impacts of on-going and projected changes in land use (LU), management and environmental conditions on the dynamic exchange of carbon and nitrogen (C & N) components between the terrestrial ecosystem, atmosphere and hydrosphere. Model development will be based on the quantification of spatial variability of N2O (as well as CH4 and CO2) fluxes at field scale obtained from eddy covariance (EC) quantum cascade laser (QCL) and static chamber measurements. Assessment of impacts of LU and management on exchange processes will be obtained by analyzing long-term retrospective as well as prognostic model runs for past, present and future conditions. For quantification of greenhouse gas (GHG) emissions and N-leaching on landscape scale, impacts of regional hydrology processes (e.g. water table dynamics and nutrient dispersion by/ with irrigation) on the biogeochemical cycling of C & N have to be accounted for. To address this complexity, we will couple Mobile2D (the regional version of MOBILE-DNDC) with a regional hydrological model. Mobile2D as well as the coupled system will be used to assess the impact of changes in predicted LU/ management and climate conditions on C & N stocks, the net GHG exchange (NGE), water availability and quality (N-leaching). Simulations driven by a GIS database holding information on LU, soil & vegetation properties and climate will create GHG inventories and sources strengths assessments on field and regional (Hal He basin) scales for a series of actual and potential cropping systems under different development pathways, management practices and climate change scenarios.