panicum area, respectively (Table 2). 



a. Foredune Accumulation . Despite the fact that the two 

 northern locations are apparently receiving little new sand now, they 

 apparently have previously because in the area of the plantings they 

 continue to accumulate sand at a significant rate (Table 6) . As 

 indicated previously, the unplanted foredune area from August 1975 



to August 1976 accumulated 4.0 cubic yards per linear foot of beach 

 versus 2.3 and 3.3 cubic yards (3.1 cubic meters per linear meter 

 of beach versus 1.8 and 2.5 cubic meters) for the 1,200-foot sea 

 oats and 1,100-foot bitter panicum dunes, respectively (Table 6). 

 However, if yearly trapping rates from the time of planting through 

 the August 1976 measurements are considered, the planted segments 

 are still well ahead with 6.25 versus 4.0 cubic yards per linear 

 foot (4.8 versus 3.1 cubic meters per linear meter) of beach per 

 290-foot cross section. 



Enough vegetation, primarily sea oats, has become established in 

 front of the plantings that significant volumes of sand are trapped 

 in front of the planted dunes (Fig. 24). This is believed to be 

 responsible for the low amount of sand accumulating in the middle 

 and south segments of the 1,200-foot sea oats dune (Table 5). 



If periodic studies are made on these plantings, a special 

 effort should be made to find the rate of natural dune replacement 

 and how rapidly the vegetation in the foredune area reaches the same 

 status as that behind planted dunes. Presently, the unplanted dune 

 area appears more arid than that behind the planted dunes (Fig. 25). 



b. Beach Erosion or Accretion . Apparently, a major source 

 of concern relative to beach processes is, what will a particular 

 action do to erosional and depositional patterns? Table 10 gives 

 the distances from the east base line (App. A) to MSL. Although 

 variations of 30 feet were common from date to date, surprisingly 

 little change was recorded overall for the four measurements. 

 There was probably no actual change during this period other than 

 normal short-term fluctuations. 



c. Net Losses or Gains . Brown, et al . (1976) reported that 

 northern Padre Island is in a period of relative stability. 

 However, they believe that during the past 125 years the island has 

 entered an erosional phase, and that the volume of sediment being 

 supplied to the Corpus Christi area has reached a critical deficiency, 

 Therefore, the long-term trend is erosional rather than accreting. 



The data in this study tend to indicate slight erosion on the 

 north end (Table 7) and a stable beach from the dune-width extension 

 south. This trend also agrees with the relative sand volume data 

 reported by Brown, et al. (1976). 



51 



