Spatial and Temporal Distribution of Cumulative Disturbance Impacts due to Military Training on Land Condition

The United States Army manages land across the country for use in combat training exercises. Different training activities are causing variable levels of disturbance on the ground and hindering natural growth of vegetation and degrading land condition. This consequently creates unrealistic training environments for soldiers and impedes the readiness of the US Army. Thus, there is a strong need to develop methods that can be used to map and predict the military training-induced impacts on the land condition and monitor their dynamics for planning of military training activities and land reclamation. For this purpose, in this study the methods were developed to map the military training-induced annual and cumulative disturbances and impacts on the land condition and further conduct spatial analysis of the maps for a time period of 13 years from 1989 to 2001 for Fort Riley installation, Kansas. Satellite Landsat Thematic Mapper TM imagery for each of the years was used in tandem with RTLA (Range Training Land Assessment) sample plot data that measured the disturbances to create the annual and cumulative disturbance maps. A plot derived data based method was employed to generate the spatial distribution maps of the annual disturbance and a point recorded data based method was utilized to create the cumulative disturbance maps. The spatial analyses included tests of spatial auto-correlation, high-low clustering and hot spot and outliers. The results showed that in Fort Riley i) The TM images and their various transformations were significantly correlated with the disturbances, which provided the ability to interpolate the disturbance values from the sample plot data to unobserved locations; ii) Low levels of disturbance were prominent in both annual and cumulative disturbance maps, and moderate and high disturbances were mainly located in the central and northwest regions of the study area, which was related to the use of heavy loads of military training activities in these regions; iii) Both methods well revealed the varying levels of the annual and cumulative disturbances; iv) There was a lack of consistent spatio-temporal pattern of the disturbances, implying the use of rotation of the military training activities and land reclamation in this study area reduced the degradation of the land condition. Overall, this study greatly enhanced the understanding of the military training-induced impacts on the land condition for the US Army installations and provided useful guidelines for the land managers in terms of sustaining both land condition and land military carrying capacity