Modeling annual discharge of six Mexico’s northern rivers (doi:10.4136/ambi-agua.705)

Abstract

The overall goal of this report was to understand river discharge variability to improve conventional water management practices of Mexico's northern subtropical rivers. This report addresses whether: a) river discharge tendencies, patterns and cycles can be detected with proxy and instrumental records; and b) annual discharge can be forecasted by stochastic models. Eleven gauging stations of six major rivers; three lowland rivers discharging into the Pacific Ocean (Rios Santa Cruz, Acaponeta, and San Pedro); five upland rivers draining into the Pacific Ocean (Rio San Pedro: Peña del Aguila, Refugio Salcido, San Felipe, Vicente Guerrero and Saltito), one river flowing across the interior Basin (Rio Nazas: Salomé Acosta) and two more rivers discharging into the Northern Gulf of Mexico (Rio San Juan: El Cuchillo and Rio Ramos: Pablillos) were statistically analyzed. Instrumental recorded daily discharge data (1940-1999) and reconstructed time series data (1860-1940) using dendrochronological analysis delivered annual discharge data to be modeled using autoregressive integrated moving average, ARIMA models. Spectral density analysis, autocorrelation functions and the standardized annual discharge data evaluated annual discharge frequency cycles. Results showed ARIMA models with two autoregressive and one moving average coefficient adequately project river discharge for all gauging stations with four of them showing significant declining patterns since 1860. ARIMA models in combination with autocorrelation and spectral density techniques as well as standardized departures, in agreement with present (2002-2010) observations, forecast a wet episode that may last between 9 and 12 years thereafter entering again into a dry episode. Three dry-wet spell cycles with different time scales (1-2 years; 4-7 years; 9-12 years) could be discerned from these analyses that are consistent for all three northern Mexico's river clusters that emerged from a multivariate analysis test.

Basal area increment series of dominant trees of Pseudotsuga menziesii (Mirb.) Franco show periodicity according to global climate patterns

“…The decreasing trends in tree growth sometimes is due to the inclusion of long-lived trees with slow growth rates (Black et al, 2008). However, the oldest age class of trees in this study (181-204 years) sequía de los años 1950 y 1990 también se ha reportado en el análisis de flujo de río en México (Návar, 2012) y las evaluaciones de contenido de humedad del suelo utilizando modelos hidrológicos (Návar, 2015).…”

“…In a percent basis and absolute values, the impact of favorable periods is lower than that of dry periods because the benefit of wet periods on BAI is limited to the water storing capacity of the soils (Castruita, 2014). The decadal drought spell of the 1950's and 1990's has also been reported in river flow analysis in Mexico (Návar, 2012) and soil moisture content evaluations using hydrological models (Návar, 2015).…”

Hydro-climatic variability and forest fires in Mexico’s northern temperate forests

“…Quasi-decadal sequences repeated in the time series and ARIMA models during the 1950's and 1990's. The cooling of the northeastern Pacific Ocean surface waters brings above average rainfall and discharge to northern Mexico (Návar-Cháidez, 2012). The PDO effect has also been noted in Utah although its control is not consistent over time and appears insignificant during periods of instrumental recorded data (Tingstad and MacDonald, 2010).…”

“…That is, in the near future the hypothesis of no shifts in the mean values would probably be rejected as more hydro-climatic data is recorded. A second approach to increase the number of observations is to reconstruct paleoclimate by using several techniques, amongst which dendrochronology is an important methodology for this case studies (Cleaveland et al, 2003;Stahle et al, 1999;González-Elizondo et al, 2005;Návar-Cháidez, 2012).…”