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Retail Trade Finance, Insurance, and Real Estate Service Industries Public Administration 980 288 1,788 373 19.7 5.8 35.9 7.5 , One of the most dynamic industries is the tourist industry. Improved facilities and transportation have helped the tourist industry to have steady growth and contribute substantially to retail sales as people have corne to take advantage of a variety of natural and cultural attractions throughout the area. IV. PROBLEMS AND OPPORTUNITIES A. Existin~ Flood Problems: The hydrolic analysis of the study area carried out by the Corps of Engineers determined the effect of rainfall and snowmelt of various magnitudes on property along the Rio Grande within the study area. The statistical propability of each rainfall is known based on meteorologic records so that the flood threat can be determined. The liklihood of flood occurrence is generally expressed as the probability of exceedance during a given year. A particular event may be said to have a percent probability of being met or exceeded in a given year. Over a very long period, say several thousand years, this meteorological event would be expected to be met or exceeded once for every 100 years elapsed. Therefore, it is often referred to as the 100-year flood. Very large events can occur in successive years and the 100-year event is not by any means limited to one occurrence in a given 100-year period. It merely affords one method of expressing likelihood. The likelihood of less severe events is expressed by using lower exceedance frequencies (e.g. 50-year or 25-year) which reflect the higher probability of their occurence in a given year. Probability of exceedance in a particular year is the reciprocal of the exceedance frequency. The flow frequency at Alamosa on the Rio Grande are presented in Table 1 as a basis for understanding the problem and approaching solutions. Discharge is expresed in cubic feet of water per second (cfs) flowing through the channel at a given location. TABLE 2 DISCHARGE-FREQUENCY RELATIONSHIP RIO GRANDE AT ALAMOSA FREQUENCY OF EVENT Discharge 10-vear 4,600 25-vear 7,100 50-vear 9,000 100-year 10,900 SPF 18,000 The Corps of Engineers evaluates flood hazard and possible levels of protection in terms of frequency (e.g. 100-year flood) and in terms of a potential event known as the Standard Project Flood (SPF). The SPF is the flood produced from the most severe flood producing rainfall considered reasonably characteristic of the region. The rainfall is furnished to the 6