Samuel Sandoval-Solis

Sustainability Index for Water Resources Planning and Management

This paper presents a water resources sustainability index that makes it possible to evaluate and compare different water management policies with respect to their sustainability. The sustainability index identifies policies that preserve or improve the desired water management characteristics of the basin in the future. This index is based on a previous sustainability index with improvements in its structure, scale, and content to make it more flexible and adjustable to the requirements of each water user, type of use, and basin. The Rio Grande transboundary basin is used as a case study demonstrating the use of the index. Tailor-made sustainability indexes are defined for water users in Mexico, the United States, the environment, and for meeting system requirements (international treaty obligations). Group sustainability indexes are calculated to summarize the results for groups of water users of each country, the environment, and the basin as a whole. Sustainability indexes by subbasins are calculated ...

Integrated Water Management for Environmental Flows in the Rio Grande

In the Rio Grande transboundary basin, environmental flows have not been considered as an integral part of the water man- agement. This research focuses on the Big Bend, a reach located along the Rio Grande mainstem. Important natural regions of the Chihuahuan Desert are threatened due to the lack of environmental flows. In this paper is estimated the maximum volume of water available for environmental flows without affecting human and international water requirements, and without increasing the flood risk in Presidio-Ojinaga. Environmental flows are proposed based on an analysis of the prior reservoir alteration hydrology of the river. A planning model was built to simulate the water allocation system and evaluate alternative policies. A reservoir reoperation policy for Luis L. Leon reservoir is proposed to supply environmental flows without violating the system constraints. The policy that supplies the maximum water to the environment is two-thirds (66%) of the prior reservoir alteration conditions; it also improves human water supply, treaty obligations, and decreases flood risk. DOI: 10.1061/(ASCE)WR.1943-5452.0000331.

Groundwater Banking in the Rio Grande Basin

The water planning and management policies of the Rio Grande basin no longer respond to the sustainable needs of water users, environment, and international commitments of this transboundary basin between Mexico and the United States. This paper describes how groundwater banking through an in lieu method is one approach leading to better water management in this basin. In lieu groundwater banking is a conjunctive water allocation policy applicable to water users supplied from surface water and groundwater sources. A basin simulation model of the Rio Grande basin, built in the water evaluation and planning system (WEAP) software, was used to evaluate the groundwater banking policy. Two scenarios are discussed: a baseline scenario without new water allocation policies implemented and a groundwater banking scenario considering the in lieu groundwater banking method implemented in the Meoqui aquifer. Results show that groundwater banking can significantly improve water management in the basin, increasing syst...

Revealing the Diversity of Natural Hydrologic Regimes in California with Relevance for Environmental Flows Applications

Alterations to flow regimes for water management objectives have degraded river ecosystems worldwide. These alterations are particularly profound in Mediterranean climate regions such as California with strong climatic variability and riverine species highly adapted to the resulting flooding and drought disturbances. However, defining environmental flow targets for Mediterranean rivers is complicated by extreme hydrologic variability and often intensive water management legacies. Improved understanding of the diversity of natural streamflow patterns and their spatial arrangement across Mediterranean regions is needed to support the future development of effective flow targets at appropriate scales for management applications with minimal resource and data requirements. Our study addresses this need through the development of a spatially explicit reach-scale hydrologic classification for California. Dominant hydrologic regimes and their physio-climatic controls are revealed, using available unimpaired and naturalized streamflow time-series and generally publicly available geospatial datasets. This methodology identifies eight natural flow classes representing distinct flow sources, hydrologic characteristics, and catchment controls over rainfall-runoff response. The study provides a broad-scale hydrologic framework upon which flow-ecology relationships could subsequently be established towards reach-scale environmental flows applications in a complex, highly altered Mediterranean region.

Hydrological feasibility of environmental flows in the Rio Grande/bravo basin

Due to high water demand, the scarcity of water resources, and the complexity of water allocation in the Rio Grande/Bravo basin, environmental flows have not been considered as an integral part of the water management in this basin. Important environmental habitats such as the Big Bend National Park in the US, the Northern Chihuahuan desert, the Maderas del Carmen and the Canon de Santa Elena natural reserves in Mexico are ecologically threatened because of the lack of environmental water management policies in the basin. Several efforts have been undertaken by government agencies and non-governmental organizations in order to determine the environmental flows requirements for the basin. Even though environmental flows in several locations along the basin have been determined (e.g., the Rio Conchos tributary), the quantification and availability of the water necessary to provide these environmental flows has not been determined. In this paper we evaluate the hydrological feasibility of environmental flows in the Rio Conchos tributary to the Rio Grande. This evaluation is done in a basin model constructed in the Water Evaluation and Planning system (WEAP) software. An analysis of the available water has been defined to determine the amount of water required to provide the environmental flows. The description and evaluation of the environmental flows are presented along with a comparison against the current water management policies.

Evaluation of water conservation measures implemented in the Rio Grande/Bravo basin.

As part of a set of immediate and long-term actions taken in the drought of 1994–2003, on July 3 rd 2003, the Mexican and the U.S. sections of the International Boundary and Water Commission (IBWC) signed Minute 309; an amendment to the treaty of 1944 that specifies a set of water conservations measures implemented in the Rio Conchos basin and the conveyance of saved water to the main stream of the Rio Grande/Bravo on December and January. These water conservation measures include the reduction of conveyance losses and the increase in application efficiency on the farms in the basin, therefore, a substantial fraction of these savings are in the form of reductions in groundwater recharge, and not in the reduction of physical losses of the system. In this paper, we evaluate performance of the policy proposed in Minute 309 for aquifers, reservoirs, water users and the environment. This evaluation is done in a basin model constructed in the Water Evaluation and Planning system (WEAP) software. Additionally, a scenario where the water savings are delivered in environmental patterns is also presented. The description and evaluation of Minute 309 are presented along with a comparison against the current water management policies and the environmental pattern water savings delivery scenario.

Integrated analysis of flow, form, and function for river management and design testing

Author(s): Lane, BA; Pasternack, GB; Sandoval Solis, S | Abstract: Copyright

The role of topographic variability in river channel classification

To date, subreach-scale variations in flow width and bed elevation have rarely been included in channel classifications. Variability in topographic features of rivers, however, in conjunction with sediment supply and discharge produces a mosaic of channel forms that provides unique habitats for sensitive aquatic species. In this study we investigated the utility of topographic variability attributes (TVAs) in distinguishing channel types and dominant channel formation and maintenance processes in montane and lowland streams of the Sacramento River basin, California, USA. A stratified random survey of 161 stream sites was performed to ensure balanced sampling across groups of stream reaches with expected similar geomorphic settings. For each site surveyed, width and depth variability were measured at baseflow and bankfull stages, and then incorporated in a channel classification framework alongside traditional reach-averaged geomorphic attributes (e.g., channel slope, width-to-depth, confinement, and dominant substrate) to evaluate the significance of TVAs in differentiating channel types. In contrast to more traditional attributes such as slope and contributing area, which are often touted as the key indicators of hydrogeomorphic processes, bankfull width variance emerged as a first-order attribute for distinguishing channel types. A total of nine channel types were distinguished for the Sacramento Basin consisting of both previously identified and new channel types. The results indicate that incorporating TVAs in channel classification provides a quantitative basis for interpreting nonuniform as well as uniform geomorphic processes, which can improve our ability to distinguish linked channel forms and processes of geomorphic and ecological significance.

Food, water, and fault lines: Remote sensing opportunities for earthquake-response management of agricultural water.

Earthquakes often cause destructive and unpredictable changes that can affect local hydrology (e.g. groundwater elevation or reduction) and thus disrupt land uses and human activities. Prolific agricultural regions overlie seismically active areas, emphasizing the importance to improve our understanding and monitoring of hydrologic and agricultural systems following a seismic event. A thorough data collection is necessary for adequate post-earthquake crop management response; however, the large spatial extent of earthquakes impact makes challenging the collection of robust data sets for identifying locations and magnitude of these impacts. Observing hydrologic responses to earthquakes is not a novel concept, yet there is a lack of methods and tools for assessing earthquakes impacts upon the regional hydrology and agricultural systems. The objective of this paper is to describe how remote sensing imagery, methods and tools allow detecting crop responses and damage incurred after earthquakes because a change in the regional hydrology. Many remote sensing datasets are long archived with extensive coverage and with well-documented methods to assess plant-water relations. We thus connect remote sensing of plant water relations to its utility in agriculture using a post-earthquake agrohydrologic remote sensing (PEARS) framework; specifically in agro-hydrologic relationships associated with recent earthquake events that will lead to improved water management.

Simulation Modeling to Secure Environmental Flows in a Diversion Modified Flow Regime

AbstractThis paper describes the development and application of a spreadsheet model to evaluate effects of water management on diversion modified flow regimes, enabling the exploration of novel ways to meet proposed environmental flow standards. Mill Creek, a northern California river with an altered flow regime that impacts aquatic species, was used as a case study. Test cases examined how water management alternatives, such as groundwater pumping, water rights transfers, and water exchange agreements, can improve environmental flow allocations given irrigation water demands. Four test cases include passage flows for Chinook salmon and steelhead trout, a minimum instream flow, 80% of natural flow, and a spring recession flow with functional flow components. The model identified late October as consistently water-scarce, even in wet years. These analyses suggest that fall shortages for fish migration could be eliminated through a water exchange agreement combined with use of wells. All cases except the mi...