An Ecological Assessment of the Louisiana Tensas River Basin Chapter 3 
Chapter 3: The Tensas River Basin 
Landscape Assessment __ 
This chapter illustrates the landscape indicators used to 
assess watershed conditions in the Tensas River Basin. 
Each indicator is discussed separately; maps illustrate 
he relative rankings of subwatersheds and charts show 
; he distributions of indicator values. 
A/e begin with a brief look at the biophysical setting of 
^he Tensas River Basin including maps of the data used to 
’ ;alculate indicator values. Included are regional pictures 
)f topography, rivers, watershed boundaries, and land 
:over. An important criterion when choosing digital data 
was consistency across the watershed. Consistency is 
essential because the goal is a sub-watershed 
comparative assessment. 
Figure 3.1 
Shaded relief map of the Tensas River Basin. Source: U. S. Geological 
Survey, Digital Elevation Model, 3 arc-second. 
The landscape indicators are grouped according to three 
themes: human use, forests, and water. The following 
discussions introduce each theme and a number of 
analyses pertinent to the Tensas River Basin are applied 
to each theme. The interpretation of indicators are not 
exhaustive. In addition, these groups are subjective since 
any given indicator could be relevant to more than one 
theme and each affect water quality, the subject of Chapter 
4. For example, a discussion of an indicator of forest 
change along streams or riparian corridors appears in both 
the analysis of forest change and the analysis of water. 
The concluding section in this chapter describes a 
current program that focuses on restoring wetlands. 
Based on analyses presented in this chapter, a GIS 
illustration of areas of potential restoration gives land 
managers an example of a powerful decision tool. 
Biophysical Setting 
The Tensas River Basin encompasses approximately 
375,834 hectares (930,000 acres) of Mississippi River 
alluvial flood plain in Northeast Louisiana. The Tensas 
River is now hydrologically connected to the Atchafalaya 
River which is a major distributary of the Mississippi River. 
Historically, most of the Basin was covered with bottom¬ 
land hardwood forested wetlands. The bottomland 
hardwoods of the Tensas River Basin have been de¬ 
scribed as some of the richest ecosystems in the country 
in terms of diversity and productivity of plant and animal 
species. At the same time, these lands are recognized as 
some of the nation's most productive farmland for grain 
and fiber. The result is a conflict of land use between 
traditional row crop agricultural interests and concern for a 
healthy, diverse, and stable ecosystem. 
The alluvial flood plain of the region forms the backdrop 
for all of the physical and biological processes that shape 
the watershed. Generally when you look at a map of a 
watershed, whether it is a physical map, a vegetation 
map, or even a socio-political map, the most striking 
features of the landscape are created by topographic 
features. In the Tensas River Basin (Figure 3.1) a lack of 
topographic variety encourages a variety of different 
landforms including point-bars, abandoned river courses, 
abandoned channels, natural levees, and backswamps. 
The Tensas River Basin is unique in that natural levees 
along the riparian vegetation lie on the highest ground in 
the Basin. This causes drainage water to run parallel to 
streams for many miles before actually entering the 
stream and river water channels. Wetlands and 
