Land-use and land-cover change (LULCC), especially those caused by human activities, is one of the most important components of global environmental change (Jessen 3rd edition: 1-526 2005). In this study the effects of geographic and demographic factors on LULCC are analyzed in northeastern Latvia using official estimates from census and vital statistics data, and using remotely sensed satellite imagery (Landsat Thematic Mapper) acquired from 1992 and 2007. The remote sensing images, elevation data, in-situ ground truth and ground control data (using GPS), census and vital statistics data were processed, integrated, and analyzed in a geographic information system (GIS). Changes in six categories of land-use and land-cover (wetland, water, agriculture, forest, bare field and urban/suburban) were studied to determine their relationship to demographic and geographic factors between 1992 and 2007. Supervised classifications were performed on the Landsat images. Analysis of land cover change based on “change-to” categories between the 1992 and 2007 images revealed that changes to forest were the most common type of change (17.1% of pixels), followed by changes to agriculture (8.6%) and the fewest were changes to urban/suburban (0.8%). Integration of population data and land-cover change data revealed key findings: areas near to roads underwent more LULCC and areas far away from Riga underwent less LULCC. Range in elevation was positively correlated with all LULCC categories. Population density was found to be associated with most LULCC categories but the direction of effect was scale dependent. This paper shows how socio-demographic data can be integrated with satellite image data and cartographic data to analyze drivers of LULCC at multiple spatial scales.

Giant Hogweed is a poisonous invasive weed in Latvia that poses significant threat to biodiversity and human health. Local residents are afraid and have very special concerns about the safety of their children because the plant causes phytophotodermatitis (severe burns), painful blistering, permanent scarring and blindness when the sap of the plant comes in contact with the human body and is exposed to sunlight. This study utilizes public participation GIS (PPGIS) involving Latvian high school students as data collectors to monitor the geographic distribution of Giant Hogweed in Northeast Latvia. This paper also explores challenges with implementing such a public program, how to maximize participation, and how participation impacts environmental awareness of participants. In this study we also assessed the accuracy of PPGIS-collected data and how the utilization of such data impacts mapping and monitoring of Giant Hogweed in the study area. Results indicate that this PPGIS program is effective in facilitating data collection for monitoring Giant Hogweed in Latvia. Tested methods of increasing participation have proven largely unsuccessful to date. Statistical analyses of survey responses indicate participation had a marked effect on sensitivity towards environmental issues. Accuracy assessments indicate that quality of point data collected by participants is sufficient for mapping and for use as ground verification.