APPLICATION OF A GROUND-WATER FLOW MODEL TO THE MESILLA BASIN, NEW MEXICO AND TEXAS
Affiliation
Department of Hydrology & Water Resources, The University of ArizonaIssue Date
1993Keywords
Groundwater flow -- Models -- New Mexico -- Mesilla Velley.Canals -- New Mexico.
Water-supply -- Rio Grande (Colo.-Mexico and Tex.)
Mesilla Basin (N.M.)
Water resources development -- Texas -- El Paso County
Water resources development -- New Mexico -- Dona Ana County
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Copyright © Arizona Board of RegentsCollection Information
This title from the Hydrology & Water Resources Technical Reports collection is made available by the Department of Hydrology & Atmospheric Sciences and the University Libraries, University of Arizona. If you have questions about titles in this collection, please contact repository@u.library.arizona.edu.Abstract
It has been said that watersheds and aquifers ignore political boundaries. This phenomenon is often the reason for extensive regulation of surface -water and ground -water resources which are shared by two or more political entities. Regulation is often the result of years of litigation over who really owns the water, how much is owned, and how much is available for future use. Groundwater models are sometimes used as quantitative tools which aid in the decision making process regarding appropriation and regulation of these scarce, shared, water resources. The following few paragraphs detail the occurrences in the Lower Rio Grande Basin which led to the current ground -water modeling effort. New Mexico, Texas and Mexico have wrestled forever over the rights to the Lower Rio Grande and the aquifers of the Rio Grande Basin (Figure 1). As early as 1867, due to a flood event on the Rio Grande, Texas and Mexico were disputing the new border created by the migrating Rio Grande. During the 1890's, the users upstream from the Mesilla and El Paso Valleys were diverting and applying so much of the Rio Grande that the Mesilla and El Paso valley farmers litigated in order to apportion and guarantee the supply. In the recent past, disputes over who may use the ground -water resources of the region and the effect of surface- water uses on aquifer water levels resulted in litigation between El Paso, Texas, and New Mexico.Series/Report no.
Technical Reports on Hydrology and Water Resources, No. 93-020Collections
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This in turn raises the question of whether initial human entry into the Americas took place by boat along a Pacifi c coastal route, and whether subsequent dispersal involved the Gulf. In most coastal entry and dispersal scenarios, it is assumed that coastally-adapted boat people arriving at the southern tip of Baja California crossed the mouth of the Gulf to the Mexican mainland, making landfall in Sinaloa or even farther south. However, as R. James Hills has pointed out, this is highly unlikely. People arriving at the southern tip of the peninsula would have seen seemingly endless ocean in all directions except along the peninsular coast leading into the Gulf. There would have been no reason for people adapted to coastal resources to set out into an apparently empty sea. Instead, they would have followed the coastline into the Gulf, presumably exploring the islands along the way. 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Radial Growth Losses in Douglas-Fir and White Fir Caused by Western Spruce Budworm in Northern New Mexico: 1700-1983Regional outbreaks of western spruce budworms (Choristoneura occidentalis Freeman) have recurred at least three times in northern New Mexico since the early 1920's when the U. S. Forest Service first began systematic forest-pest surveys and documentation (Lessard 1975, U. S. Forest Service documents). The current outbreak was first noticed in a small area on the Taos Indian Reservation in 1974, and since then the defoliated areas have increased in New Mexico and Arizona to more than 370,000 acres of Federal, Indian, State and private lands (Linnane 1984). Losses in timber values can generally be ascribed to radial growth loss, height growth loss, topkilling, reduced regeneration, and mortality (Carlson et al. 1983, Fellin et al. 1983). A damage assessment project was initiated in 1978 and was aimed at obtaining measurements of some of these losses in budworm infested stands on the Carson National Forest, New Mexico (Holland and Lessard 1979). A large data base has subsequently been developed, including yearly measurements on topkilling, mortality, defoliation, and insect population changes (Stein 1980, 1981, Stein and McDonnell 1982, Rogers 1984). A growth assessment study was undertaken in 1982 to determine the feasibility of using dendrochronological methods to identify the timing of past outbreaks and to quantify radial growth losses associated with budworm defoliation (Swetnam 1984). Results of this work showed that three major outbreaks during the twentieth century were clearly visible in the tree-ring samples obtained from currently infested trees. The radial growth of host trees was corrected for age, climate and other non-budworm environmental effects, and then growth losses were computed as a percentage of expected growth (Swetnam 1984). Additional collections were obtained in 1984 in order to expand the scope of the radial growth study. The objectives included 1) assessment of a larger number of tree -ring samples, 2) comparison of radial growth losses between the two primary host species - Douglas-fir (Pseudotsuga menziesii) and white fir (Abies concolor), 3) comparison of radial growth losses between age classes, and 4) analysis of the relationship between yearly measurements of defoliation, insect populations and radial growth. This report summarizes the findings of the above analyses. Increment core samples from the 1982 collections are included here, therefore this report supersedes the earlier report (Swetnam 1984). Information is also presented on observations derived from the dated tree-ring series on the timing of occurrence of known and inferred spruce budworm outbreaks for the past 284 years (1700- 1983). This is the longest record of spruce budworm occurrence yet developed for western North America.
