Introduction

Mississippi has a dispersed population of nearly three million residents in an area of approximately 48,400 square miles and has a favorable climate for agriculture, with abundant precipitation and minimal extreme temperatures. The topography consists mostly of low hills and lowland plains, with the highest elevation about 800 feet above sea level. An exception is the nearly flat Mississippi Alluvial Plain, or “Delta,” in the northwestern part of the State. Agriculture and forestry are Mississippi’s major industries. With 65 percent of its area forested, the State is one of the country’s top producers of lumber and wood-related products. In addition to agriculture and forest resources management, other important economic activities are infrastructure and construction management, flood risk management, and water supply and quality assessment. High-quality elevation data can help to support these activities. Critical applications that meet the State’s management needs depend on light detection and ranging (lidar) data that provide a highly detailed three-dimensional (3D) model of the Earth’s surface and aboveground features.

The 3D Elevation Program (3DEP; refer to sidebar) is managed by the U.S. Geological Survey (USGS) in partnership with Federal, State, Tribal, U.S. territorial, and local agencies to acquire consistent lidar coverage at quality level 2 or better (table 1) to meet the many needs of the Nation and Mississippi. The status of available and in-progress 3DEP baseline lidar data in Mississippi is shown in figure 1. 3DEP baseline lidar data include quality level 2 or better, 1-meter or better digital elevation models, and lidar point clouds, and must meet the Lidar Base Specification version 1.2 (https://www.usgs.gov/3dep/lidarspec) or newer requirements. The National Enhanced Elevation Assessment (Dewberry, 2012) identified user requirements and conservatively estimated that availability of lidar data would result in at least $10.4 million in new benefits annually to the State. The top 10 Mississippi business uses for 3D elevation data, which are based on the estimated annual conservative benefits of 3DEP, are shown in table 2.

Water Supply and Quality

The Mississippi Alluvial Plain is subject to significant flooding, which can cause substantial change to surface flow patterns, and activities in it rely heavily on a groundwater system that is poorly understood. According to the U.S. Geological Survey (2024), heavy utilization of the available groundwater resources in the Mississippi Alluvial Plain (fig. 2) “has resulted in significant groundwater-level declines and reductions in base flow in streams within this area. These impacts are limiting well production and threatening future water availability for the region.” As a member of the Governor’s Delta Sustainable Water Resources Task Force, the USGS is studying the Mississippi Alluvial Plain (U.S. Geological Survey, 2024) with a goal to increase understanding of past and present water use and to improve estimates of future water availability in the region. The information gained can help support water resource management decisions related to sustaining key agricultural and industrial practices. Quality levels 0 and 1 lidar can be of use in providing additional data on elevation, land use, and soil.

Flood Risk Management

The availability of high-resolution elevation data statewide helps reduce onsite data-collection costs and the amount of time required to complete some phases of a flood-risk assessment project. The quality of analyses and study results is improved as a result of the more accurate elevation data. Comprehensive lidar coverage enables detailed modeling of the overflow from streams and other water bodies resulting from large storm events, catastrophic dam failures, and overland storm surges from the Gulf of Mexico. Quality level 1 lidar data can provide an enhanced ability to predict surface-water movement and inundation in high-risk coastal areas. Communities and agencies can use this information to design evacuation route plans for public safety should a disaster strike.

Forest Resources Management

The Mississippi Forestry Commission (MFC) provides active leadership in forest protection, management, inventory assessment, and information distribution necessary for Mississippi’s sustainable forest-based economy. The MFC is concerned with protecting the State’s forestlands from wildfire and with detecting, evaluating, and controlling pests, diseases, and invasive species. The MFC also provides an assessment of statewide forest resources to estimate tree removals, regeneration, and development of forest cover. The National Park Service’s Gulf Coast Inventory and Monitoring Network conducts terrestrial vegetation monitoring along the Natchez Trace Parkway. Lidar-derived canopy density assessments supplement traditional plot-based sampling methods to inform park staff about forest health (fig. 3). Quality level 1 lidar data could assist in forest analyses and management activities.