AUTHORS: Connor Crank, Jiquan Chen, Ranjeet John - Michigan State University, Department of Geography
ABSTRACT: Land use and cover change (LUCC) are caused by joint forces of physical changes and human activities, and have consequent roles in ecosystem and societal functions. Using a typical landscape of the Midwest region, the Kalamazoo Watershed in southern Michigan (2,200 km2), we quantified LUCC from 1976 to 2015 and examined the causes and consequences from socio-ecological perspectives, including variables of population, climate, and ecosystem function. We quantified the spatiotemporal changes in seven major cover types (i.e., barren, built-up, cropland, forest, grassland, water, and wetland) at five-year intervals based on classified images of Landsat MMS and Landsat TM using an object-oriented classification system (86.4% accuracy). Using historical records of temperature, precipitation, and net primary production, we aim to further explore the connections between LUCC and long-term changes in social and physical properties.
Urban/built-up area increased from 3.5% in 1976 to 14% in 2015. While cropland dominated the landscape during the 40-year study period, it showed the greatest degree of overall change, declining from 60% to 48%. Amount of forest cover decreased by 5%, while the water and wetland increased by 1% and 5%, respectively. During this period, population increased by ~73%. The built-up and wetland cover types showed strong positive correlations with population growth (R=0.95 and 0.86, respectively), while cropland and forest land were negatively correlated with population growth (R=-0.94, -0.87, respectively). Temperature and precipitation showed no significant relationships with the growth or decline of land use/cover types. Using a novel MODIS-to-LANDSAT downscaling method, we will quantify net primary production of each cover type for every 5-year period to examine how long-term changes in LUCC affected ecosystem function within the watershed.
