PROJECT 6 : Agriculture Expansion Analysis

Agriculture is the heartbeat of human civilization, but as populations grow, so does our footprint on the environment. In my latest GIS project, I delve into a pivotal period—the 1990s—to explore how agricultural expansion transformed landscapes. This analysis spans from 1990 to 2000, leveraging Geographic Information Systems (GIS) to reveal patterns, trends, and impacts of increased agricultural land use. Join me as we journey through data to understand how this decade reshaped our fields, forests, and future.

To analyse agricultural expansion over time, we used historical maps of the study area from 1990 and 2000. The maps below illustrate land use dedicated to agriculture during each of these years. By comparing the distribution and extent of agricultural land use in 1990 with that of 2000, we can assess the patterns and extent of agricultural growth over the decade. This comparison will provide valuable insights into the spatial changes and trends associated with agricultural expansion within the specified time frame.

Land Use Year 1990

Land Use Year 2000

The maps above depict land utilized for various agricultural activities, including rubber plantations, mixed horticulture, orchards, and farms. A notable difference between the two maps is the increase in agricultural land use from 1990 to 2000, highlighting a clear trend of expansion. To analyse and categorize these changes, we reclassified the maps, adding a new attribute field to distinguish agricultural and non-agricultural land. This classification allowed for clearer identification of land-use changes across different regions. All steps in this analysis were conducted using ArcGIS software, facilitating detailed and accurate spatial analysis of agricultural land expansion. The analysis of land use change between 1990 and 2000 was conducted by combining spatial data from both time periods using the Union tool in ArcGIS. This method allowed for the seamless integration of two distinct maps, alongside their respective attribute data, to generate a comprehensive new map. The Union tool automatically merges both the spatial and attribute information, facilitating a detailed understanding of land transformations over time. In this case, the union process revealed regions that transitioned from their previous land use to agricultural land between 1990 and 2000. The resulting map, shown below, visually illustrates this land use changes, offering valuable insights into how agricultural expansion occurred within the studied area over the decade.

The comparison of agricultural and non-agricultural land areas was calculated and organized into a table. This data was derived using the Union function in ArcGIS, which combines spatial data from the 1990 and 2000 maps. By overlaying these maps, the Union function allowed us to identify changes in land use over the decade, providing a clear view of the expansion or reduction in agricultural land areas relative to non-agricultural areas. The resulting table highlights these differences, making it easier to analyze trends and patterns in land use between 1990 and 2000.

Agriculture Land Area Calculation 

To calculate the area for each land use category in ArcGIS, begin by opening the attribute table of the land use layers for both 1990 and 2000. Add a new field by clicking on the Add Field option, name the field Area, and set its field type to Double to ensure it can store precise numeric values. After the field is created, right-click on it and select Calculate Geometry. In the geometry calculation window, choose the Area property, set the units to square meters, and confirm the calculation. This will populate the new field with the area values for each feature in the dataset.

Once the area is calculated for both datasets, you can analyze the changes by comparing the total area of agricultural land in 1990 and 2000. This allows you to quantify how much land has been converted into agricultural use and identify which land use types (e.g., forest, wetlands, or built-up areas) were transformed into agriculture. Understanding these changes provides valuable insights into the extent and impact of agricultural expansion, contributing to environmental assessments and land management planning.

The table illustrates the land use changes between 1990 and 2000, highlighting the transitions in land categories and their respective areas in hectares (ha). It compares the original land use in 1990 with the updated classifications in 2000, detailing whether the land remained the same for example agriculture-to-agriculture or underwent a transformation such as non-agriculture-to-agriculture. The blue-highlighted rows specifically represent areas converted into agriculture land, reflecting significant shifts from non-agricultural uses such as forest or scrub to agricultural use. The area column quantifies the extent of each change, showing the size of land parcels involved in these transitions. This data is essential for analyzing agricultural expansion and its implications on land resources, particularly the conversion of natural landscapes into farming areas. Such insights are critical for assessing environmental impacts, biodiversity loss, and informing sustainable land management practices.

Agriculture Expansion Rate

To calculate the total agricultural expansion rate from 1990 to 2000, the agricultural area for both years was analyzed and compared. The formula used for this calculation was:

    

   

To analyze the agricultural expansion between 1990 and 2000, a systematic approach was employed using GIS techniques to measure and quantify changes in land use. The process began with gathering data on agricultural areas for the years 1990 and 2000. Using appropriate GIS datasets and methods, the total land area utilized for agricultural purposes in both years was identified and measured. This step provided a baseline of agricultural land coverage at the beginning and end of the decade, establishing a foundation for the analysis. The next step involved calculating the difference between the agricultural areas in 2000 and 1990. By subtracting the total agricultural area in 1990 from that in 2000, the net change in agricultural land use over the decade was determined. This difference revealed whether there had been an expansion or reduction in agricultural land use during this period. Such calculations are essential for understanding the dynamics of land use change.

To further contextualize this change, normalization to 1990 was performed. The difference in agricultural area was divided by the agricultural area in 1990, which served as the base value. This normalization ensured that the change in land use was expressed relative to the initial conditions in 1990. By using the 1990 value as the reference point, the rate of change became more meaningful, allowing for easier interpretation and comparison across different regions or time periods. Finally, the result was converted to a percentage by multiplying it by 100. This step translated the rate of change into a standardized metric, expressed as a percentage, representing the agricultural expansion relative to the initial land use in 1990. This percentage serves as a clear indicator of the extent of land use change for agricultural purposes, enabling researchers, policymakers, and planners to understand the scale of agricultural development over the decade.

If the agricultural expansion rate is positive, it indicates that agriculture has grown. Conversely, a negative rate suggests a reduction in agricultural activity. In this case, an expansion rate of 17% between 1990 and 2000 signifies a notable increase in agricultural land use or activity during that period. This positive growth highlights a significant expansion in agriculture over the decade. By following this methodology, the agricultural expansion rate effectively quantifies land use changes over time. It highlights the implications of agricultural development on land use, environmental systems, and regional planning. The derived percentage is crucial for assessing the balance between agricultural growth and its potential impact on ecosystems and sustainable land management strategies.

Discussion

The detailed analysis of agricultural land use between 1990 and 2000 highlights a substantial expansion, with a growth rate of 17%. This increase signifies a notable shift in land-use patterns, where non-agricultural areas were converted into agricultural land. Through the comparison of historical maps from the two time periods, the study identified changes in the spatial extent of agricultural activities, such as rubber plantations, mixed horticulture, orchards, and general farming. The expansion was quantified using GIS tools, particularly the Union function in ArcGIS, which combined the spatial data from 1990 and 2000 maps to create a comprehensive dataset. This integration allowed for precise identification of areas that transitioned from non-agriculture to agriculture, providing insights into the patterns and scale of the changes.

The observed 17% growth in agricultural land is likely driven by multiple factors. Population growth during this period may have increased the demand for food, leading to the conversion of forests, wetlands, or other natural landscapes into agricultural fields. Economic development and agricultural policies could also have played a role, incentivizing farming activities to boost local economies. Technological advancements in farming methods and the development of infrastructure to support agriculture might have further contributed to this growth. Such expansions, while beneficial for food production and economic stability, often result in trade-offs with environmental health.

The conversion of non-agricultural land into farmland poses significant environmental implications. The loss of natural habitats and biodiversity is one of the most critical concerns, as agricultural expansion often comes at the expense of forests, wetlands, and other ecosystems. Additionally, soil degradation, water resource depletion, and greenhouse gas emissions from land-use changes can further exacerbate environmental challenges. This underscores the need for sustainable land management practices to mitigate the adverse effects of agricultural expansion. The 17% expansion rate provides a clear measure of how land use evolved during the decade, reflecting the growing reliance on agriculture to meet societal demands. However, it also emphasizes the importance of balancing agricultural growth with environmental conservation. By understanding these changes, policymakers, researchers, and planners can develop strategies to promote sustainable agricultural practices that support economic development while preserving natural resources and ecosystems.

Conclusion

This study provides a comprehensive analysis of agricultural expansion in the study area between 1990 and 2000, highlighting the significant land-use changes and their broader implications. By utilizing GIS-based methods, including historical map analysis, reclassification, and spatial data integration through tools like the Union function in ArcGIS, we were able to accurately quantify and visualize the transformation of land from non-agricultural uses to agricultural purposes. The findings revealed a 17% increase in agricultural land during the decade, underscoring a clear trend of agricultural growth in the region.

The expansion was driven by various socio-economic and environmental factors, such as population growth, rising demand for food and resources, and policies promoting agricultural development. However, this growth came at the expense of natural ecosystems, with forests, scrublands, and other non-agricultural areas being converted into agricultural fields. Such changes have significant environmental consequences, including biodiversity loss, habitat destruction, soil degradation, and increased pressure on water resources.

These results demonstrate the importance of balancing agricultural expansion with sustainable land management practices. While agricultural growth supports economic development and food security, it is crucial to address its environmental impacts through informed policies and innovative practices. This study emphasizes the need for integrated planning approaches that prioritize both agricultural productivity and ecological preservation, ensuring long-term sustainability for future generations.

In conclusion, the methodology and findings of this project provide valuable insights into land-use changes over time and serve as a foundation for future research and decision-making. By understanding the dynamics of agricultural expansion, stakeholders can better address challenges related to land management, environmental conservation, and sustainable development in the region.