Landuse and climate change: Impacts on Ontario's water resources

在世界上许多发达地区，土地利用和土地覆盖（LULC）是动态的，在安大略省南部尤其如此，那里居住着近四分之一的加拿大人口，那里的气候和土壤条件最有利于农业。事实上，农业无处不在地围绕着安大略省的城市地区，这种主要农业用地和庞大且不断增长的人口之间的交叉点对水资源构成了特别的挑战。气候变率也是常态，在发达地区，气候变化和极端天气对水资源的影响往往被放大。然而，在有季节性积雪覆盖的发达景观中，对水文气候扰动的研究很少，通常更关注温暖季节的极端降水（即风暴、干旱）。此外，在流域尺度上，关于所谓可持续的LULC与气候变率的相互影响的研究很少。LULC可以放大水资源对气候变化的敏感性，这一观察启发了提出的研究计划，该计划有两个主要问题：(1)过去和现在的LULC和气候变化如何影响安大略省南部的水量和水质？(2)可持续实践是否达到预期效果？这些问题将通过各种方法来解决，利用现有的长期监测数据以及新的、空间和时间密集的基于流域的测量。研究将集中在安大略湖盆地，从多伦多延伸到贝尔维尔，从安大略湖海岸线向北延伸到橡树岭冰碛。这一领域特别适合于理清气候和土地利用成本变化对水量和水质的累积影响，因为它正在经历城市扩张和农业集约化以及土地利用做法的转变。它也是西顿开发区的所在地，该开发区被指定为“可持续城市社区”，在加拿大是独一无二的。重要的是，安大略的这一部分不像伊利湖流域那样有着悠久的集约化农业历史，因此许多区域性的长期水量和水质监测站都是在变化开始之前建立的。虽然将测量各种水质参数，但这项研究的主要重点将放在主要营养物质上：碳、氮和磷。

Land use and land cover (LULC) are dynamic in many developed parts of the world, and this is particularly true in southern Ontario, where nearly ¼ of the Canadian population resides and where climatic and soil conditions are most favourable for agriculture. Indeed, agriculture ubiquitously surrounds urban areas in S. Ontario, and this intersection between prime agricultural land and a large and growing population poses particular challenges for water resources. Climate variability is also the norm and the impacts of climate shifts and extreme weather on water resources are often amplified in developed landscapes. However, there are few studies of hydroclimatic perturbations in developed landscapes that have seasonal snow cover, and generally there has been a greater focus on precipitation extremes during the warm season (i.e. storms, droughts). In addition, there have been few, if any studies of the interactive impacts of so-called sustainable' LULC and climate variability at the watershed scale. The observation that LULC can amplify the sensitivity of water resources to climate change inspired the proposed research program, which has two primary questions: (1) how have past and current LULC and climate shifts affected water quantity and quality in southern Ontario? And, (2) are sustainable' practices having the desired effect? These questions will be addressed through a variety of approaches, utilizing existing long-term monitoring data as well as new, spatially and temporally intensive watershed-based measurements. Research will be focused in the Lake Ontario basin, extending between Toronto and Belleville and from the Lake Ontario shoreline northwards to the Oak Ridges Moraine. This area is particularly appropriate for disentangling the cumulative influence of climate and LULC change on water quantity and quality because it is undergoing both urban expansion and agricultural intensification as well as shifts in land use practices. It is also home to the Seaton Development area, which has been designated a sustainable urban community' and is unique in Canada. Importantly, this part of Ontario does not have the same long history of intensive agriculture as the Lake Erie basin and therefore many of the regional long-term water quantity and quality monitoring stations were established before change began. While a variety of water quality parameters will be measured, the primary focus of this research will be on the major nutrients: carbon, nitrogen and phosphorus.