New Mexico Water eNews

NMSU Undergrad Helps Implement Drip Irrigation System at Agricultural University in Colombia
by Catherine Ortega Klett

Department of Plant and Environmental Sciences student Sativa Cruz, whose Faculty Sponsor is Dr. Kenneth Carroll, is participating in an environmental and cultural exchange program between NMSU and Universidad De La Salle (ULSA) Utopia campus in Yopal, Colombia. The main focus of the program is on developing collaborative innovations in sustainable agriculture and water management. The current project within the program deals with the design, implementation, and monitoring of a drip irrigation system for a Theobroma cacao field.

Theobroma (Greek for "food of the gods") cacao trees are prized as the source of all chocolate products. They thrive in humid forest ecosystems, but they also can be easily stressed by drought conditions, the threat of which is increasing with a warming climate. This challenge in water management is being addressed by designing and installing a drip irrigation system, and by monitoring its performance through an extensive program of meteorological data acquisition as well as by field measurements of soil moisture, pH or acidity, dissolved oxygen, organic matter content, plus overall crop performance, evapotranspiration effects, and other environmental factors.

This international collaboration is intended to encourage students to be agents of constructive change in developing programs of sustainable agriculture for the future. Having a local New Mexican artist and muralist, Mr. Sebastian “VELA” Velazquez, as a member of the research and field teams helped to provide additional perspective of what it means to achieve positive results by bringing about a fusion of culture, self knowledge, and science to the task. His vision of that synthesis is shown below in a mural titled, “Consilience” that he created in the span of just four hours of the final afternoon on the Utopia campus.

UNM Grad Student Studying Life Cycle of New Mexico Mountain Snowpacks
by Catherine Ortega Klett

It's well known that water from melting snow is a critical resource in New Mexico. The seasonal snow cover is the natural reservoir that stores water from winter storms for later release during the warm seasons. Accordingly, it is very important to be able to assess and predict the lifecycles of these snowpacks. The climatic warming that has been occurring in recent years will likely increase the stress on available water supply, which further underscores the need for better monitoring and understanding of the behavior of these snowpacks.

An ambitious combined field and modeling study of this problem is currently underway. Chad Mickschl, a master’s student in the Civil Engineering (Hydraulics and Water Resources) Master’s Program at UNM with faculty advisor Dr. Mark Stone, is studying the snowpacks in the Alamo Creek watershed in the Jemez mountains of New Mexico. The heating and cooling of snowpacks is driven primarily by the energy exchange processes that occur at the interfaces of the snowpacks with air and the ground. The main focus of the present study is on the contribution of the ground heat flux on snowmelt, including an assessment of whether near surface ground temperatures can be used as a reliable indicator of the onset of snowmelt.

The pattern of snow deposition and melt in semi-arid mountainous watersheds will, of course, depend strongly on altitude, and the exposure or shelter provided by topography and vegetative cover. In this study, relatively open areas with north and south facing slopes at various altitudes were chosen. To capture the energy fluxes, two portable weather stations have been set up to provide time series data on air temperature, pressure, relative humidity, wind speed and direction, precipitation, snow depth, soil moisture, and net thermal radiation.

Energy fluxes beneath the snowpack are monitored using temperature sensors buried at four different shallow depths below the ground surface. These ground temperatures are being monitored at five distributed "footprints," each of about 10 square meters in extent, in order to capture small scale variability. In addition, two snow profile plots have been established, wherein the structure, temperature, and density of the snowpack is monitored as a function of time. This provides a closer look at snowpack properties, including snow grain size and shape and temperature, which in turn helps determine the direction of the water vapor flux and the likely changes in snow properties, which also affects the transport of heat in the snow. Finally, additional observations are being carried out in the form of five snow course survey sites, at which the snowpack depth and liquid water content is tracked.

In addition to the above comprehensive measurement program, there is an accompanying modeling study underway, the goal of which is ultimately to provide better estimates of the timing and quantity of snowmelt. To this end, a state-of-the-art energy and mass balance simulation model known as SNOBAL is being used to predict snowpack properties from the meteorological and other snowpack data gathered by the field study. The SNOBAL model is initiated by using measurements of snow depth, density, temperature and net water content. Following these initial inputs, their change with time is determined by various forcing variables involving information provided by net solar radiation, precipitation mass, temperature, and estimated density. The model output from this includes the energy, mass balance, and runoff from the snow cover. It is hoped these simulations will support the initial conjecture that near surface ground temperature measurements may provide a reliable indicator of the onset and rate of snowmelt and the amount of energy supplied to the snowpack during melt in this semi-arid mountain climate.

Chad Mickschl received an NM WRRI Student Water Research Grant for this study and his final report will be posted on the institute’s website in July 2016.

Improving Water Law and Policy Focus of NM WRRI Report
by Catherine Ortega Klett

Utton Transboundary Resources Center Director Adrian Oglesby received a grant from the NM WRRI to provide water law and policy options for New Mexico lawmakers that could be implemented in New Mexico to promote water conservation and efficiency. The effort began with the Utton Center convening over forty experienced water managers, lawyers, scientists, engineers, academics, and students to explore water law and policy options for New Mexico. The conference took place in October 2014.

To encourage imaginative and courageous thinking, conference participants abided by the Chatham House Rule, which allows participants to use any information provided at the conference, but prohibits participants from revealing the identity or affiliation of the person who provides that information, nor that of any other participant. Liberated from fear of possible repercussions, the group freely proposed changes to New Mexico water law and policy to help New Mexico incorporate the concept of resilience into its water management objectives and avoid future conflicts over water.

In preparation for the conference, the Utton Center reviewed numerous reports from recent years that proposed ideas that might make New Mexico more water resilient. The final report, Water Resilience in a Time of Uncertainty - How Can Our Water Laws and Policies Better Support Water Resilience? documents the discussions and recommendations developed during that two-day conference and a subsequent presentation on water banking.

Included in the report are chapters on water management; water planning; water rights administration; water banking; water storage; water preservation of agricultural uses; and water for the environment, recreation and tourism. To view the report click here.

NMSU Student Developing Design and Accompanying Manual for Flow Measurement Devices in Open Channels
by Catherine Ortega Klett

Flow measurement is a necessary component of proper water management and water conservation. Water users and managers use flow measurement for accounting and equitable distribution of water. Farmers need flow measurement to schedule their irrigation and make sure their water rights are delivered. Nevertheless, despite the importance of such measurements, the current literature on them is often too complex for practical application, and does not fit well with the conditions of low gradient open channels normally used in New Mexico.

This problem is currently being addressed by Seth Davis, recipient of an NM WRRI student research grant and a master’s student in civil engineering at NMSU, in collaboration with his faculty advisor, Dr. Zohrab Samani. The focus is on the design of flumes for open channels. It turns out that a properly shaped flume, or chute for water, can force the flow into a critical condition characterized by a minimum energy per unit water mass for a given discharge rate. Qualitatively, this corresponds to flow that is at the balance point between being too sluggish versus being too turbulent or chaotic. Such constrained flow has the desirable property that its flow rate can be determined by a simple measurement of depth in the flume channel, thereby obviating the need for relatively cumbersome water velocity measurements.

Three types of such optimal flumes have been developed at the NMSU Civil Engineering Hydraulic Laboratory based on cross-sectional contractions, which are suitable for flow measurement in low gradient open channels. These proposed flumes create critical flow using vertical columns to reduce the flow cross-section and can be constructed at a fraction of the cost of other commercial flumes. Several of these flumes are currently being used by the Elephant Butte Irrigation District in southern New Mexico.

This project will result in a design, construction, and calibration guideline/manual that can be used by students, farmers, extension agents, and water managers for low-cost flow measurement in open channels. The manual will provide the equation and coefficients needed for each flume type, the hydraulics and conditions of the channel in which the flume will be built, design guidelines for the various flume types, and an example of how each flume can be built from conception to implementation. In addition to developing the manual, Seth and Dr. Samani propose to build laboratory scale models of the low-cost flumes for testing, training, and demonstration purposes.