Integration of bio-physical and economic models to analyze management intensity and landscape structure effects at farm and landscape level

We present an integrated spatially explicit land use modeling framework, which integrates two key components of agricultural systems, the bio-physical production system and the management system, by coupling the bio-economic farm optimization model FAMOS[space], the crop rotation model CropRota, and the bio-physical process model EPIC (Environmental Policy Integrated Climate). The integrated modeling framework has been developed to analyze the cost-effectiveness of selected agri-environmental program (AEP) measures. We also focus on the landscape development and therefore include a detailed representation of landscape elements such as fields or orchard meadows in our analysis. An indicator set represents all main environmental AEP objectives, i.e. preservation of water and soil resources, mitigation of climate change, protection of biodiversity, maintenance of cultural landscapes as well as farm income support. The integrated modeling framework is applied to 20 farms in the Austrian ‘Mostviertel’ region, which are selected from the Integrated Administration and Control System (IACS) of the European Union. The cost-effectiveness of AEP measures is assessed under different premium levels. The implementation of the AEP clearly affects environmental quality in a positive way. Nitrogen rates are reduced, landscape elements can be sustained, and the landscape becomes more diverse. The program also increases farm gross margins on average. However, the cost-effectiveness ratios (CER) are declining with increasing premium levels. The results indicate that the cost-effectiveness of AEP measures can be improved by spatial targeting.     

基于LU-SWAT模型的土地利用/覆被变化对水文过程的影响研究——以黑河上游为例

【目的】揭示内陆河流域集水区土地利用/覆被变化对水文过程的影响及其成因。【方法】基于能够逐年调用土地利用/覆被数据的LU-SWAT模型,并结合控制变量法研究了黑河流域集水区黑河上游1990—2009年土地利用/覆被变化对地表径流、侧向流、蒸散发量、地下径流以及总产水量的影响。【结果】LU-SWAT模型对于黑河上游月、年出山径流模拟结果较好,其月径流模拟的纳什系数为0.93,相关性系数为0.94;其年径流模拟的纳什系数为0.83,相关性系数为0.86。此外,其对各个水文要素的模拟结果符合西北干旱区内陆河流域集水区的水文特征;1990—2001年黑河上游土地利用变化主要表现在林地的减少,而2002—2009年土地利用的变化除了林地和草地的增加之外,还表现在裸地的大面积减少;1990—2001年黑河上游地表径流、侧向流、蒸散发量以及总产水量都呈现增加趋势,而地下径流呈减少趋势,2002—2009年流域地表径流、侧向流、蒸散发量以及总产水量减少,而地下径流量增加。在黑河上游,干旱条件下各水文要素对于土地利用覆被变化的响应更明显。【结论】1990—2001年林地的减少可能是流域地表径流、侧向流、蒸散发量以及总产水量都呈现增加趋势而地下径流呈减少趋势的主要原因。2002—2009年裸地的大面积减少可能是流域地表径流、侧向流、蒸散发量以及总产水量减少而地下径流量增加的主要原因。