An Ecological Assessment of the Louisiana Tensas River Basin Chapter 3 
Water and the Landscape 
Forest 
Forest Loss 
Forest Gain 
Human Use 
Water 
Everyone knows the importance of water. But many 
people do not realize how much its quality depends on 
the surrounding landscape. Water quality, like landscape 
condition, is the cumulative impact of environmental 
stress and land management practices at broad scales. 
Changes in the distribution and pattern of ecological 
resources and human activities can alter fundamental 
water processes including flow and balance, nutrient and 
sediment loading, and chemistry. These changes can, in 
turn, influence the water quality and quantity that are 
valued by society. Figures 3.16 and 3.18 illustrate the 
stream network within the Tensas River Basin. 
This section presents landscape indicators that are 
related to water quality in the streams of the Tensas 
River Basin. “Riparian” indicators describe landscape 
conditions near streams and “watershed” indicators 
describe conditions over entire watersheds. The riparian 
indicators include measures of human activities (agricul¬ 
ture and roads) near streams and the amount of wetland 
area. The size and amount of riparian buffers along 
streambanks is an important determinant of soil loss and 
sediment movement, which in turn affect water quality. 
The group of watershed indicators presented here 
primarily measure the potential for soil and nutrient 
losses from surrounding landscapes which would ulti¬ 
mately be deposited in streams. Put simply, watersheds 
covered by natural forests are more likely to be in good 
condition than watersheds with high percentages of 
intensive human land uses. Because intact riparian 
areas buffer streams from the potentially adverse effects 
of watershed-scale events like erosion, both types of 
indicators need to be evaluated when considering overall 
landscape influences on stream condition and water 
quality. 
Figure 3.17 
Enlargement of Riparian Zone with 1992 NALC Image. 
