Hugo Loaiciga

University of California, Santa Barbara | UCSB · Department of Geography

Inter-basin water transfers are implemented to counter the uneven geographical distribution of natural water sources. This paper’s novelty consists of providing a system-dynamics framework to evaluate inter-basin water transfers based on integrated water governance. The Big Karun Basin, Iran, has long been of interest to water managers due to its d...

This paper presents a statistical approach based on data mining to estimate the riverine environmental water demand (EWD). A river’s environmental water demand defines the quantity, timing, and quality of streamflow that are required to sustain riverine ecosystems and human activities. Genetic programming (GP), artificial neural network (ANN), and...

The scarcity of global water resources has been exacerbated by a variety of factors, including population growth, the impacts of climate change, and mismanagement. Policymakers face a challenge in managing tradeoffs between human water demands and maintaining the world’s water resources. This study investigates water resource management strategies...

The pressing issue of the impact of changing agricultural policies on the water, food, and energy nexus is of utmost importance in today’s world. This issue is particularly critical in countries currently grappling with a severe water crisis. This work develops a national-level water, food, and energy (WFE) nexus model using a combination of system...

This work projects the long-term energy demand and assesses the effects of using renewable-energy technologies on greenhouse gas (GHG) emissions in the Marun Basin, Iran. Energy projections are made with the Low Emissions Analysis Platform (LEAP) model. Demographic and macro-economic data, per capita energy use in the urban and agricultural sectors...

Accurate drought forecasting is necessary for effective agricultural and water resource management and for early risk warning. Various machine learning models have been developed for drought forecasting. This work developed and tested a fusion-based ensemble model, namely, the stacking (ST) model, that integrates extreme gradient boosting (XGBoost)...

Optimal reservoir operation involves complex decision making. The marine predators algorithm (MPA) is herein applied and evaluated with several mathematical functions and with the optimized operation of the Aydogmush reservoir (East Azerbaijan province, Iran) that minimizes the deficit of agricultural water supplied to downstream lands. Reservoir o...

This study presents a method to address the issue of burdensome computations in water resources optimization based on a hybrid algorithm derived from the firefly algorithm (FA) and the K-nearest neighbor (KNN) algorithm, herein named the FA-KNN algorithm. The FA-KNN algorithm introduced in this work is tested with three standard test problems (the...

This work simulates rainfall using the GFDL-ESM2G large-scale model (from the Intergovernmental Panel on Climate Change-Fifth Assessment Report (IPCC-AR5)) and the change-factor method to downscale rainfall under three emission scenarios: RCP 2.6, RCP 4.5, and RCP 8.5. The Storm Water Management Model (SWMM) is applied to simulate stormwater driven...

Thorough evaluations of satellite precipitation products are necessary for accurately detecting meteorological drought. A comprehensive assessment of 15 state-of-the-art precipitation products (i.e., IMERG_cal, IMERG_uncal, GSMaP-G, CPC-Global, TRMM3B42, CMORPH-CRT, PERSIANN-CDR, PERSIANN, PERSIANN-CCS, SM2RAIN, CHIRPS, ERA5, ERA-Interim, MERRA-2,...

Floods inflict financial and human losses worldwide. The importance of assessing the effectiveness of flood management policies rises as the frequency and severity of floods increase. This study presents a novel forensic engineering framework for assessing the role of reservoir operation in achieving objectives under flood conditions. Specifically,...

In this issue paper, the authors refine the definition of water sustainability to account for temporal dynamics and spatial variability, identify specific challenges that must be resolved in the very near future to avoid catastrophic outcomes on levels ranging from economic disruption to survival of mankind, discuss related policy changes and poten...

International organizations constitute the basis to increase water co-operation, prevent or reduce the possibility of conflicts between countries, and, were they to occur, achieve co-operation to resolve them. The proliferation of water-related conflicts, especially involving transboundary watersheds, the need for stakeholder co-operation, and the...

The Colorado River delta is a sedimentary alluvial formation that embodies the Lower Colorado River transboundary aquifer. The Mexicali Valley overlies the Mexican part of the aquifer, and the Imperial Valley the aquifer’s portion north of the Mexico–U.S. border. Mexico receives an annual water allocation from the Colorado River stipulated by an in...

The uneven temporal and spatial distribution of water has led to water crises in many countries. The virtual water trade constitutes a means of dealing with such crises. The virtual water trade uncovers the hidden flow of water in traded commodities between countries. This work proposes a multi-objective optimization model that maximizes the revenu...

This work proposes a method to evaluate the performance of water supply systems under climate change with reservoir efficiency indexes. The method projects rainfall and surface air temperature with the GFDL-ESM2M and MIROC-ESM climate models, respectively, under the Representative Concentration Pathways RCP2.6 and RCP8.5 for greenhouse gas concentr...

This paper evaluates several efficiency indexes of hydropower energy generation in Iran’s Karkheh Basin water reservoir system (i.e., Seymareh and Karkheh Rivers) under climate change based on the system dynamics approach. The climate change effects are investigated with simulations of surface temperature and rainfall driven by downscaled climate p...

This paper presents a multipurpose optimization algorithm (MOA) to optimize crop patterns under climate change, minimizing water use and maximizing crop revenue while enforcing food security and regional water security constraints. An application of the MOA yields a total of 12 Pareto fronts for 20-year horizons centered on 2030, 2050, 2070, and 20...

The water evaluation and planning (WEAP) approach and the invasive weed optimization algorithm (IWOA) are herein employed to determine the optimal operating policies in conjunctive (surface water/groundwater) systems for water supply in agricultural municipal/industrial (M&I) sectors under climate change. Climatic variables are simulated with atmos...

Sustainable water resources management aims at increasing the efficient use of water and achieving food security. This work proposes a generalized novel spatial fuzzy strategic planning (SFSP) in combination with multi-criteria decision making (MCDM) and a conceptual agricultural water use model for determining sustainable agricultural water manage...

Based on the available evidence and studies, freshwater resources can be intensely affected by climate change, with extensive consequences for human communities and ecosystems. Climate change has immediate and long-term effects on water resources such as floods, droughts, rising sea levels in estuaries, drying up of rivers, poor water quality in su...

Sustainable water resources management involves social, economic, environmental, water use, and resources factors. This study proposes a new framework of strategic planning with multi-criteria decision-making to develop sustainable water management alternatives for large scale water resources systems. A fuzzy multi-criteria decision-making model is...

This study assesses the feedbacks between water, food, and energy nexus at the national level with a dynamic-system model, taking into account the qualitative and quantitative environmental water needs. Surface and groundwater resources are considered jointly in the water resources subsystem of this dynamic system. The developed model considers the...

Lake Urmia, the twentieth largest lake in the world, is the most valuable aquatic ecosystem in Iran. The lake water level has decreased in recent years due to human activities and climate change. Several studies have highlighted the significant roles of climatic and anthropogenic factors on the shrinkage of the lake. Management policies for water r...

Efficient water allocation in a transboundary river basin is a complex issue in water resources management. This work develops a framework for the allocation of transboundary river water between the countries located in the river basin to evaluate the characteristics of allocation approaches. The allocation of river water is obtained based on initi...

There is substantial evidence suggesting climate change is having an adverse impact on the world’s water resources. One must remember, however, that climate change is beset by uncertainty. It is therefore meaningful for climate change impact assessments to be conducted with stochastic-based frameworks. The degree of uncertainty about the nature of...

This study develops a multi-criteria decision-making framework for optimizing the ranking of wastewater reuse allocation alternatives in a water/wastewater supply system. The method of stepwise weight assessment ratio analysis is used for weighting economic, socio-cultural, environmental, and technologic criteria and their 15 sub-criteria. The opti...

This paper develops and applies algorithms for optimally merging satellite precipitation products with rain-gauge precipitation for accurate rainfall estimation. The satellite-based precipitation products (SBPs) PERSIANN-CDR, TMPA-3B42, GPM-IMERG, and GSMaP MKV are combined and evaluated to generate accurate rainfall estimates. Daily satellite prec...

Abstract This paper develops and applies algorithms for optimally merging satellite precipitation products with rain-gauge precipitation for accurate rainfall estimation. The satellite-based precipitation products (SBPs) PERSIANN-CDR, TMPA-3B42, GPM- IMERG, and GSMaP MKV are combined and evaluated to generate accurate rainfall estimates. Daily sat...

Water is stored in reservoirs for various purposes, including regular distribution, flood control, hydropower generation, and meeting the environmental demands of downstream habitats and ecosystems. However, these objectives are often in conflict with each other and make the operation of reservoirs a complex task, particularly during flood periods....

Water use by the agricultural sector along with inefficient irrigation methods and climate change has led to the depletion and insecurity of water resources and consequent instability of the agricultural system. Defining benchmarks and comparing them is essential for sustainable system management performance. The sustainability performance of an ag...

Water use by the agricultural sector along with inefficient irrigation methods and climate change has led to the depletion and insecurity of water resources and consequent instability of the agricultural system. Defining benchmarks and comparing them is essential for sustainable system management performance. The sustainability performance of an ag...

Water use by the agricultural sector along with inefficient irrigation methods and climate change has led to the depletion and insecurity of water resources and consequent instability of the agricultural system. Defining benchmarks and comparing them is essential for sustainable system management performance. The sustainability performance of an ag...

The worsening water scarcity has imposed a significant stress on food production in many parts of the world. This stress becomes more critical when countries seek self-sufficiency. A literature review shows that food self-sufficiency has not been assessed as the main factor in determining the optimal cultivation patterns. However, food self-suffici...

Transboundary river basins give rise to complex water-sharing decision making that can be analyzed as a game in the sense of dynamic game theory, as done in this work. The sharing of transboundary water resources depends on the long-term shifting interactions between upstream and downstream countries, which has received limited research attention i...

Metaheuristics are widely applied to solve optimization problems. Numerous metaheuristic algorithms inspired by natural processes have been introduced in the past years. Studying and comparing the convergence of metaheuristics is helpful in future algorithmic development and applications. This study focuses on bee-inspired metaheuristics and identi...

Hydropower is a low-carbon energy source, which may be adversely impacted by climate change. This work applies the Grasshopper Optimization Algorithm (GOA) to optimize hydropower multi-reservoir systems. Performance of GOA is compared with that of particle swarm optimization (PSO). GOA is applied to hydropower, three-reservoir system (Seymareh, Saz...

Increasing population and water use, rising pollution of water resources, and climate change affect the quantity and quality of water resources. Reservoir operation is an important tool for water supply that can be optimized by simulation-optimization considering the impact of climate change on water quality. This study presents a simulation-optimi...

Environmental Impact Assessments (EIAs) of development projects are necessary to minimize negative impacts and maximize benefits. The objective of this paper is to determine the best strategy to mitigate the adverse effects of dam construction with Multi-Criteria Decision-Making (MCDM) method based on results of EIAs. For this purpose, a group of e...

Water is a vital element that plays a central role in human life. This study assesses the status of indicators based on water resources availability relying on hydro-social analysis. The assessment involves countries exhibiting decreasing trends in per capita renewable water during 2005–2017. Africa, America, Asia, Europe, and Oceania encompass res...

The Muskingum model is a popular hydrologic flood routing technique; however, the accurate estimation of model parameters challenges the effective, precise, and rapid-response operation of flood routing. Evolutionary and metaheuristic optimization algorithms (EMOAs) are well suited for parameter estimation task associated with a wide range of compl...

Inter-basin water transfers are widely implemented to counter the uneven geographical distribution of natural water sources. The Big Karun Basin, Iran, has long been of interest to water managers due to its discharge potential, and where several water transfer projects are operated or are under study. This study implements system dynamics modeling...

The application of neural networks (NN) in groundwater (GW) level prediction has been shown promising by previous works. Yet, previous works have relied on a variety of inputs, such as air temperature, pumping rates, precipitation, service population, and others. This work presents a long short-term memory neural network (LSTM-NN) for GW level fore...

The existence of uncertainties in decision-making has given rise to multicriteria decision-making to achieve results that weigh in the effects of uncertainty. This study presents a method for selecting the best alternative for treated wastewater reuse based on gray system theory (GST). Alternatives and appropriate decision criteria for wastewater r...

Nowadays, novel water resources management strategies have been developed and applied by borrowing new concepts to overcome the water shortage crisis and balance the distribution of water resources. Therefore, this book has been categorized in four main sections as follows. It should be added that all of these concepts have been integrated into thi...

Selecting the flow accumulation threshold (FAT) plays a central role in extracting drainage networks from Digital Elevation Models (DEMs). This work presents the MR-AP (Multiple Regression and Adaptive Power) method for choosing suitable FAT when extracting drainage from DEMs. This work employs 36 sample sub-basins in Hubei (China) province. Firstl...

In March 2019, the Iranian meteorological organization warned of the formation of several dense precipitation systems throughout the country. This was followed by a chain of storm events that ended up with three major floods with heavy damages, including at least 78 fatalities. Reportedly, within the first 48 h of the storm, the cumulative rainfall...

About 40% of the global cultivable land practices dryland farming. An improvement of dryland farming is imperative to ensure food security for expanding populations in the developing world. This paper presents a method to assess the impact of precipitation variability on the annual yield of dryland farmed crops. All probable periods of precipitatio...

A coupled simulation-optimization model (SOM) is developed in this work that links the US Environmental Protection Agency’s Storm Water Management Model (SWMM) with a genetic algorithm. The SOM simulates rainfall-runoff processes in urban watersheds and optimizes the implementation of drywells (DWs), bio-retention cells (BCs), and permeable pavemen...

A Handbook on Multi-Attribute Decision-Making Methods describes multi-attribute decision-making (MADM) methods and provides step-by-step guidelines for applying them. The authors describe the most important MADM methods and provide an assessment of their performance in solving problems across disciplines. After offering an overview of decision-maki...

The impacts of climate change on the conjunctive use of surface water and groundwater resources of the Khorramabad basin were evaluated. Monthly temperature and rainfall modelled using HadCM3 and CGCM2 under greenhouse gas emissions scenarios (GHGESs) A2 and B2 were downscaled to baseline (1971–2000) and future periods (2040–2069 and 2070–2099). Si...

This chapter is dedicated to a family of outranking‐oriented techniques, namely, preference ranking organization methods for enrichment evaluation (PROMETHEE). The chapter begins with a brief discussion over the basic principles on which these methods are founded upon, followed by a description of the mathematical framework and the stepwise procedu...

The technique for order preferences by similarity to an ideal solution (TOPSIS) method, which is based on the foundations of the reference‐dependent theory, identifies a feasible alternative with the shortest distance to the ideal alternative, and the greatest distance from the inferior alternative. This chapter presents the basic principles of thi...

The best–worst method (BWM) is a compensatory, pairwise, comparison‐oriented MADM method described in this chapter following a brief literature review.

This chapter is dedicated to one the most popular MADM methods, namely the analytic hierarchy process (AHP). This chapter first reviews two of the main characteristics of the AHP method, namely, the pairwise comparison and the hierarchical structure, which makes the AHP an ideal tool to deal with complex MADM problems. Thereafter, the mathematical...

This chapter is dedicated to the Elimination et choix traduisant la realité (ELECTRE) family. The chapter begins with brief review of the history of this outranking‐oriented family of MADM methods followed by a stepwise description of the main members of the family, namely, ELECTRE I, II, III, and IV.

The philosophical foundations and the mathematical procedures behind one of the well‐known MADM methods, namely the analytic network process (ANP), are presented in this chapter.

This chapter is dedicated to a relatively new outranking‐oriented MADM method called superiority and inferiority ranking (SIR). This chapter begins with a brief review of this method's background and applications, followed by a summary of the mathematical and logical foundations of the method, a stepwise description of SIR, and ends with a conclusi...

This chapter introduces the basic principles of the MADM procedure and presents two widely used MADM methods, namely, the weighted sum method (WSM) and the weighted product method (WPM).

Gray system theory is a mathematical approach to address the uncertainties that are caused by lack of information and/or inaccuracy in data sets. Gray relational analysis is a branch of gray system theory that is dedicated to decision‐making under the aforementioned circumstances. This chapter presents a brief literature review of the application o...

A Benchmark Example and a Comparison between Objective‐ and Subjective‐Based MADM Methods