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Journal of Water Resource and Protection 2016年第12期8卷 1044-1052页

作者： martín mundo-molina Investigation Centre Faculty of Engineer Autonomous University of Chiapas Tuxtla Gutiérrez Mexico Investigation Centre CIDESTA Tuxtla Gutiérrez México

In Chiapas highlands to southeast of Mexico, the scarcity of water is worrying, according to technical reports of the IPCC the runoff will less between 150 to 250 mm per year in the southeast of Mexico, this situation will increase the problems of water availability in Chiapas highlands in the future. For actually more of 18,160 small rural indigenous communities (SRIC) in Chiapas there is not drinking water. In order to contribute a given solution to scarcity of drinking water in the SRIC, The Autonomous University of Chiapas (UnACH in its Spanish acronym) and Mexican Institute of Water Technology (IMTA in its Spanish acronym) designed and constructed in 1999 the Rain Water Harvesting (RWH) in Yalentay municipality of Zinacantan in Chiapas, Mexico. The scientific and technical contributions of RWH are: The design guarantee the water quality for a prolonged time of storage avoiding the photosynthesis inside the system;not emitted greenhouse gasses because it doesn’t need any kind of fossil fuels;not produces anything kind of damage to the environment;It has to be inexpensive, using in its construction manpower and materials from de region;Store the maximum quantity of water in the minimum space. The RWH has increased the standard of living of the habitants from Yalentay and improving their health conditions.

关键词： Climatic Change Rain Water Harsvesting Technology Appropiatte Greenhouse Gasses

Climate Change Effects on Evapotranspiration in Mexico

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American Journal of Climate Change 2015年第2期4卷 163-172页

作者： martín mundo-molina Investigation Centre Faculty of Engineer Autonomous University of Chiapas Tuxtla Gutiérrez Mexico

In Mexico’s case, the scarcity of water in the north of the country is worrying, even more from the agricultural point of view because according to the results of general circulation models, a major impact due to global warming is expected in this region, and it will have important repercussions on the rural sector in the north of Mexico. According to [1] the results of the sensitivity analysis made in this study indicate that the most vulnerable zone is the north of Mexico, wherein the increase of evapotraspiration (ET) is greater in comparison to the rest of the country;up to 8% annual average for a +3°;C growth in mean annual temperature. Due to some limitations in this preliminary investigation (e.g., global temperature data was used without regionalizing it), it was decided to make more detailed studies to estimate the climate change effects on ET on a regional scale, using the downscaling method to adjust temperature data. In this study a new methodology to estimate the ET before climate change scenarios is introduced, which includes the selection of the Hargreaves-Samani method (HS), calibrated and compared against the Penman-Monteith ASCE method in various irrigation districts in the northern part of the country, obtaining ET estimations with a 93% precision. This procedure was applied to nine states in north Mexico: Baja California, Baja California Sur, Chihuahua, Sinaloa, Sonora, Tamaulipas, nuevo León, Coahuila y Durango. The principal results are enunciated as follows: the ET variations between the contemporary scenario and the 2030 scenario are quite significant, according to the data of 160 meteorological stations;for temperature variations between 0.1°;C to 0.45°;C the corresponding ET fluctuation goes from 2% in the current scenario to 7% in the 2030 scenario. These obtained percentages are greater than the ones expected to happen for the precision of the method. It is important to note that a 7% rise of ET (related to a regional temperature increase

关键词： Climatic Change Reference Evapotranspiration Irrigation Agriculture

Kp Pan Evaporation and ETo Monthly Maps Using Information of 60 Weather Observatories Included in the Climate normals (1941-1970) from Mexico

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Journal of Water Resource and Protection 2014年第15期6卷 1475-1500页

作者： martín mundo-molina Investigation Centre Faculty of Engineer Autonomous University of Chiapas Tuxtla Gutiérrez Mexico

The most precise equation in order to estimate the evapotranspiration (ET) of crops is the Penman-Monteith (PM). However, the PM equation needs specific data that, in the majority of Mexico’s irrigation districts, it is not available because there are few automated weather stations. For this reason, it is convenient to develop simple methods that allow to precise estimation of ET. A reliable way to estimate ET is by using the pan evaporation that, according to the revised literature, continues to be used nowadays. Investigators like to include its use in irrigation water management projects in various parts of the world. However, this method uses Kp from the FAO that is not calibrated in Mexico. The use of FAO Kp affects the precision of the results, since some variables like radiation, wind, temperature and relative humidity vary from place to place;therefore ET is under estimated or overestimated. This paper presents an original contribution across method to estimate “Kp pan evaporation and ETo monthly maps”, using information from 60 weather observatories included in The Climate normals (1941-1970) from Mexico, based on the PM method and the class A pan evaporation. Once the Kp values were obtained from each weather observatory, the Kringing method was used. This way, by interpolating data of the triad “latitude, longitude and Kp” and “latitude, longitude and ET”, monthly normalized maps of Kp and ET were established for Mexico, except the upland areas (Sierra Madre Occidental and Sierra Madre Oriental), as well as other highland zones above 2700 meters over sea level, for the highest observatory is located in Toluca, State of Mexico (key 14-0039), at 2680 m over sea level.

关键词： Reference Evapotranspiration Pan Evaporation Kp Pan Evaporation

Origin of Erosion and Hydraulic Problems of the San Roque Underground Arched Culvert Channel and Its Relationship with the Maximum Flow Rate and the Maximum Permissible Velocity

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Journal of Water Resource and Protection 2020年第12期12卷 1123-1139页

作者： martín mundo-molina Daniel Hernández-Cruz Academic Group Science and Engineering Engineering Faculty Chiapas State University Chiapas Mexico

This work presents the hydrologic estimations of the hydraulic underground arched culvert channel (UACC) in Sabinal Basin, Chiapas, México and the hydrological problems associated with it, such as the erosion phenomenon and abrasion cavity formation in it. On the other hand, the maximum flows that the UACC could transport were analyzed, concluding that it no longer has the hydraulic capacity to transport the flow rate associated to return periods equal to or greater than five years and that maximum permissible velocity UACC’s bottom is 3 m/s.

关键词： Collapse Underground Arched Culvert Channel Maximum Flow Rate Maximum Permissible Water Velocity Open Channel Bottom Erosion

Physical-Mathematical Foundations of the Penman Equation from the Perspective of the First Law of Thermodynamics and Energy Balance Theory

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Journal of Water Resource and Protection 2017年第12期9卷 1377-1390页

作者： martín mundo-molina Enrique De Coss-Gomez Investigation Centre Faculty of Engineer Autonomous University of Chiapas Tuxtla Gutierrez Mexico Investigation Centre CIDESTA Tuxtla Gutierrez Mexico

The evapotranspiration is indispensable for the planning and management of water resources in watersheds and for the design of important engineering projects. The accuracy of its estimation depends, among other things, on the proper determination of the date and frequency of irrigation. One of the most accurate equations for estimating the reference crop evapotranspiration (ETo) is the Penman-Monteith equation, which was derived from the Penman equation published in 1948, which in turn is based on the energy balance equation. In this paper we present the theoretical foundations of Penman’s equation from the perspective of the first law of thermodynamics and the theory of energy balance as a contribution for the students and engineers who use Penman’s or Penman-Monteith equations in a utilitarian way within the historical and theoretical framework of the origin of this equation.

关键词： Evapotranspiration Penman Penman-Monteith Irrigation Requirement

Hydrology and Estimation of Real Erosion in the Patria nueva Micro-Basin for Five Return Periods

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Journal of Water Resource and Protection 2022年第12期14卷 783-789页

作者： martín mundo-molina José Luis Pérez-Díaz Investigation Centre Faculty of Engineer Autonomous University of Chiapas Chiapas Mexico

This paper will discuss the actual erosion estimation of the Patria nueva micro basin in tons/ha/year (E), located in Tuxtla Gutiérrez Chiapas, Mexico. We used the universal soil loss equation (USLE), considered one of the best theoretical tools for planning and soil preservation in the USA and other countries. The actual erosion rates were estimated for 5, 20, 50, 100, and 500 years return periods (Rp), with elevated results due to high degrees of anthropogenic alteration of the micro-basin, especially in the last 50 years. High erosion rates generate the following problems: loss of soil, which is unfavorable for plant life, due to the soil being a non-renewable resource, the undermine can never renovate, the hydraulic area in the main channel reduces during the rainy season (when the river overflows). The sediment accumulates at the lower part of the micro-basin along with waste, garbage, and mud.

关键词： Erosion Return Periods Basins USLE Sediment

Proposed Equation to Estimate the Length of a Hydraulic Jump in a Rectangular Open Channel Hydraulic with Variable Slope, and Its Comparison with Seven Theoretical Equations of Specialized Literature

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Journal of Water Resource and Protection 2019年第12期11卷 1481-1488页

作者： martín mundo-molina José Luis Díaz Pérez Engineering Faculty Chiapas State University Chiapas Mexico

A hydraulic jump is a localized phenomenon that generates on an open hydraulic channel;however, its mathematical demonstration is not possible in the turbulent area of the phenomenon, especially in the area where the jump occurs and where its length is measured, so the data must be obtained with direct measurements in a laboratory and through empiric equations. This work presents the results of the generated hydraulic jumps and the measure of its length in a series of tests, where we input different flow rates in a transportable open channel hydraulic with a constant gate opening “a” and a slope of S = 0.0035, in the Engineering Faculty Research Centre of the Autonomous University of Chiapas. We also present the experimental method to generate a hydraulic jump, the measure of its length and a comparison with seven empirical equations, including the Sieñchi equation used in H-Canales, the most used software for hydraulic channels design in Latin America. The results show that the calculus of L with the proposed equation has a mean squared error (MSE) of 0.1337, a Bias of -0.0049, a model efficiency (ME) of 0.9991 and a determination coefficient (R2) of 0.9993 when compared with the experimental model. Meanwhile, the comparison of L calculated with the Sieñchi equation versus the experimental model resulted in a MSE of 0.1741, a bias of -0.0437, a ME of 0.9984 and a R2 of 0.9997. Both equations are highly recommended to estimate L in rectangular channels under the conditions presented in this paper, thus, the proposed equation can be applied if??y . Finally, it must be stated that we also proved that the Pavlosky equation is comparable in precision and accuracy concerning to proposed equation and Sieñchi equation.

关键词： Hydraulic Jump Open Channel Hydraulic Hydraulics Experiments Length of the Stilling Basin

Methodology for Volumetric Measuring Transport of River Sand, in a Laboratory Channel with Mobile Bottom

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Engineering（科研） 2018年第11期10卷 759-768页

作者： martín mundo-molina Jose Luis Pérez-Díaz Daniel Hernández-Cruz Engineering Faculty Chiapas State University Tuxtla Gutiérrez Chiapas Mexico

Most public universities in Latin America and Mexico lack laboratories for measuring sediment transport or to do academic activities. The Research Center of the engineering faculty of Chiapas state university (UnACH by its acronym in Spanish) designed a portable prismatic channel for teaching and researching the sediment transportation in rivers. This paper presents the method to measure river sand transportation in a laboratory channel with a mobile bottom and presents the results of twenty-seven experiments done in the portable channel, using nine different slope inclinations and 27 flow and water speed values. The three main results are the following: 1) The construction of the channel with variable slopes, to experiment and measure sediment transportation. 2) A method developed for measuring the volume of sediment in a laboratory. 3) In a channel with a bottom slope of 0.071, a water flow of 2 l/s and a water speed of 1.77 m/s, the volume of transported sediment was 0.015 m3;in a channel with a bottom slope of 0.44, a water flow of 2 l/s and a water speed of 0.788 m/s, the volume of transported sediment was 0.006 m3;in a channel with the bottom slope of 0.024, a water flow of 2 l/s and a water speed of 0.62 m/s, the transported sediment was 0 m3.

关键词： Volumetric Measurement of Sediment Sediment Transport Transportable Prismatic Channel Measurement of Sediment in Laboratory

Cost Comparison and Hydraulic Design of Four Types of Residential Rainwater Harvesting Systems for Small Rural Communities, Considering natural or Anthropogenic Climate Change Factors

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Journal of Water Resource and Protection 2018年第11期10卷 1115-1128页

作者： martín mundo-molina Eber Godinez José Luis Pérez-Díaz Daniel Hernández Engineering Faculty Chiapas State University Tuxtla Gutiérrez México

This document presents the technical description and cost comparison of four rainwater harvesting systems for homes, the method for its hydraulic design and an equation to estimate the minimum catchment area, with the goal to supply drinking water to segregated small communities in Mexico considering climate change effects, both natural and anthropogenic. The four Rainwater Harvesting Systems (RHS) introduced in this work are the following: two rigid, one system built with ferrocement and the other built with clay bricks, and two flexible: one is a commercial collector while the other is a system built with a 3/8-inch reinforcing bar mesh and covered with a linear low-density polyethylene geomembrane. The RHS consist in cylindrical containers built with diverse materials, and in the case of rigid RHSs, they can store up to 50,000 liters of water. Also, rigid RHSs have a longer useful life and are more resistant than flexible RHSs, but their cost is notably higher. Rigid RHSs compete in price with commercial rainwater harvesting system brands like Rotoplas, but commercial RHSs disadvantages are their lower durability, storage capacity, and resistance. On the other hand, flexible RHSs are less durable than rigid ones, although, in the case of the rainwater harvesting system made with a 3/8-inch reinforcing bar mesh, the system can be rebuilt and reused and the cost is much lower. The design of the collectors takes into consideration the climate variability of the study area, natural or anthropogenic.

关键词： Rainwater Harvesting Systems Rural Communities Hydraulic Design

Detecting Climate Change in Using Extreme Data from Two Surface Weather Stations: Case Study Valle of Comitan and La Esperanza, Chiapas, Mexico

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Journal of Water Resource and Protection 2021年第12期13卷 1061-1075页

作者： martín mundo-molina Eber A. Godinez-Gutiérrez José Luis Pérez-Díaz Daniel Hernández-Cruz Investigation Centre Faculty of Engineer Autonomous University of Chiapas Chiapas Mexico

The study area is located between the cities of Comitan (16°10'43"n and 92°04'20''W) a city with 150,000 inhabitants and La Esperanza (16°9'15''n and 91°52'5''W) a town with 3000 inhabitants. Both weather stations are 30 km from each other in the Chiapas State, México. 54 years of daily records of the series of maximum (tmax) and minimum temperatures (tmin) of the weather station 07205 Comitan that is on top of a house and 30 years of daily records of the weather station 07374 La Esperanza were analyzed. The objective is to analyze the evidence of climate change in the Comitan valley. 2.07% and 19.04% of missing data were filled, respectively, with the WS method. In order to verify homogeneity three methods were used: Standard normal Homogeneity Test (SnHT), the Von neumann method and the Buishand method. The heterogeneous series were homogenized using climatol. The trends of tmax and tmin for both weather stations were analyzed by simple linear regression, Sperman’s rho and Mann-Kendall tests. The Mann-Kendal test method confirmed the warming trend at the Comitan station for both variables with ZMK statistic values equal to 1.57 (statistically not significant) and 4.64 (statistically significant). However, for the Esperanza station, it determined a cooling trend for tmin and a slight non-significant warming for tmax with a ZMK statistic of -2.27 (statistically significant) and 1.16 (statistically not significant), for a significance level α = 0.05.

关键词： Detecting Climate Change in Using Extreme Data from Two Surface Weather Stations: Case Study Valle of Comitan and La Esperanza Chiapas Mexico