Alec Hoffman
Lab 4
November 3, 2008
Analysis:
Section 1
The first map was created using the combine function. I did not use the raster calculator, because the results did not add up to 16, while using combine gave me 16 different categories. The map is of limited value, because with 16 categories it is very difficult to make out what changes have occurred over the ten years.
Section 2
The regional comparison of the two time periods showed a trend towards slightly increasing forest, declining urban and water areas and increasing farm areas. The histograms clearly show the changes; 1 is forest, 2 is farm, 3 is urban, and 4 is water.
At the farm level, the change has trended more towards a major growth in farm area at the expense of the other three area types.
Section 3
The first thing I looked at was the difference in development between those farms that were close to roads available throughout the year. From the road shape file I selected bridges and all roads that were classified as 30 or above. I then created a 50 meter buffer around those roads and selected any farm that intersected the buffer. Comparing the changes over time between the farms connected to major roads and those that were not connected to major roads, farms located near major roads had a decrease in forest area and water area, very little increase in farm coverage and a large increase in urban areas. Farms located away from major roads had a decrease in forest, water and urban areas and a very large increase in farm areas.
Farms near roads:
Farms with no Roads
I then looked at rivers, but every farm was connected to the same type of waterway, so I did not see any way that that could make a difference.
Section 4
The first thing I looked at with communities was the comparison of LULC around LagoAgria. I compared farms that were closer than 20 km with those that were more than 20 km from the town. The changes on farms that were closer than 20 km were relatively stable; there was a little less forest area and slight increases in urban and non-forest areas. The farms more than 20 km from the town had much greater changes. Forest land, water, and urban land decreased dramatically, while farm land climbed by over a third. The charts below show the changes.
Looking at the relationship between all the communities and LULC on the farms, I first separated the communities into three categories, 1 for the largest, 2 for mid-size, and 3 for the smallest communities. Since none of the urban areas had complete information, I created a chart looking at any of the columns. If C1A was over 2500 it was 1 or over 1000 it was a 2, C1B were 3 for more than 500 and 2 for more than 200, C3A was 3 for over 500 and 2 for above 150, and if C3B was over 200 it was a 1 and over 50 was a 2. If an urban area did not meet any of these requirements it was classified as a 3. Based on the town classification I created buffers around each city, for the small urban areas the rings were at 1 km, 2 km, and 5 km, the medium cities were ringed with buffers of 2 km, 5 km and 10 km and the largest cities were ringed as 5 km, 10 km and 25 km. Farms within the inner buffer of each one were given 3 points, the second ring was given 2 points, the outer buffer was worth 1 point and the outside was worth 0 points. I compared the two farms with the highest score to the two farms with the lowest score. The highest scoring farms had a doubling of non-forest land, while the other three land types all went down. The lowest scoring farms had some non-forest increase, but it was very minor.
Section 5
The first data set I compared with demographics was forest change. I found the difference between 1990 forest levels and 1999 levels and also added up the tech information into one number. Looking at the chart, there is no clear trend based on loss of forest cover and increasing technology.
When comparing technology levels and diversity, it seems that the less technological farms have a greater diversity of crops, but this is hard to verify because there are many -999 responses.