River Basin Water Research Articles

Is there enough water? How bearish and bullish outlooks are linked to decision maker perspectives on environmental flows

Policies that mandate environmental flows (e-flows) can be powerful tools for freshwater conservation, but implementation of these policies faces many hurdles. To better understand these challenges, we explored two key questions: (1) What additional data are needed to implement e-flows? and (2) What are the major socio-political barriers to implementing e-flows? We surveyed water and natural resource decision makers in the semi-arid Red River basin, Texas-Oklahoma, USA, and used social network analysis to analyze their communication patterns. Most respondents agreed that e-flows can provide important benefits and identified the same data needs. However, respondents sharply in their beliefs on other issues, and a clustering analysis revealed two distinct groups of decision makers. One cluster of decision makers tended to be bearish, or pessimistic, and believed that: current flow conditions are not adequate, there are many serious socio-political barriers to implementation, water conflicts will likely increase in the future, and climate change is likely to exacerbate these issues. The other cluster of respondents was bullish, or optimistic: they foresaw fewer future water conflicts and fewer socio-political barriers to implementation. Despite these differences, both clusters largely identified the same data needs and barriers to e-flows implementation. Our social network analysis revealed that the frequency of communication between clusters was not significantly different than the frequency of communication within clusters. Overall, our results suggest that the different perspectives of decision-makers could complicate efforts to implement e-flows and proactively plan for climate change. However, there are opportunities for collaboration on addressing common data needs and barriers to implementation. Overall, our study provides a key socio-environmental perspective on e-flows implementation from a semi-arid and socio-politically complex river basin and contextualizes the many challenges facing e-flows implementation in river basins globally.

Groundwater recharge in the oasis-desert areas of northern Tarim Basin, Northwest China

AbstractGroundwater is an important source for maintaining desert ecological processes in arid areas. With the increasing intensity of climate change and human activities, the rivers in Tarim Basin are severely dried-up. Aiming at the dried-up river, vegetation degradation and oasis maintenance in the middle and lower reaches of dried-up river basin, groundwater recharge and groundwater-surface water interaction have become hotspots, but are not well known. We examined spatial distributions and controlling factors of groundwater stable isotopes and recharge at oasis scale using data from 247 samples surveyed in the four headwaters in the northern Tarim Basin. Stable isotopes of surface water and groundwater were different from each other, and varied among sampling sites. Surface water and groundwater isotopes generally became enriched towards the east throughout the study area, while surface water isotopes showed enrichment towards the upstream direction within each catchment, mainly due to cultivated area expansion. Surface water mainly originated from precipitation, groundwater, and meltwater, while shallow groundwater derived from lateral groundwater flow, river and irrigated water infiltration, and little precipitation. The mainstream water was directly recharged by the headwaters. The results could provide a new insight into groundwater cycling in oases of dried-up river basins, which is helpful for regional groundwater management.

La hidropolítica y las relaciones exteriores de China en el complejo hídrico del Himalaya; los casos de Nepal e India

Los diez sistemas de ríos principales del continente asiático nacen en el Himalaya, la gran mayoría, en la enorme meseta tibetana. China es uno de los países con más ríos transfronterizos en el mundo, solo superado por Rusia y Argentina. La torre de agua de Asia se encuentra en una posición que le confiere un enorme poder e influencia, y las decisiones que adopte en el campo de sus relaciones hidráulicas con el resto de países tiene un alcance regional, continental y, posiblemente, global. La gestión de sus 16 ríos transfronterizos puede afectar la disponibilidad de agua de muchos países río abajo, con afectación directa al acceso a los recursos hídricos de 14 países en el continente asiático y de casi tres billones de personas, es decir casi la mitad de la población mundial El objetivo del presente artículo es analizar el comportamiento hidráulico chino en el complejo del Himalaya, a partir de dos casos de estudio: las relaciones de China con Nepal e India. Se pretende así contribuir al debate sobre, por una parte, los factores explicativos del comportamiento hídrico de la potencia asiática, prestando especial atención a la importancia de la meseta tibetana y, por el otro, al debate académico sobre la estrategia china en relación con uno de los recursos más apreciados del planeta, el agua. China cuenta hoy en día con unas 90.000 infraestructuras hidráulicas, contando presas, diques y proyectos de desvío de agua, y sus intereses hídricos abarcan tanto ríos internos —que acusan la escasez y la sequía con más gravedad, como el Amarillo o el Yangtzé— como los ríos transfronterizos internacionales, lo que conlleva de inmediato una amenaza para los países con los que comparte estos ríos —como el Brahmaputra. El principal argumento es que la política china en el Himalaya es un eslabón más en el intento chino de consolidar su presencia política y estratégica en diferentes partes del mundo. Las relaciones hídricas chinas se deben analizar en el contexto de la política exterior del gigante asiático en la última década, marcada por su expansionismo, su cristalización como gran potencia mundial, y su estilo de política exterior a escala global El artículo se estructura de la siguiente forma. El primer apartado contiene el marco teórico y analítico del articulado, empezando por el paraguas conceptual que nos ofrece la hidropolítica para entender el comportamiento en términos hídricos de China en el espacio del Himalaya, en base a dos conceptos principales: hidrohegemonía e hidrodominación. El segundo apartado contiene una disección analítica del Himalaya como complejo hídrico y el estudio de los casos relevantes para entender el comportamiento de China en el sistema himalayo; Nepal e India. El análisis de los factores explicativos de la política hídrica china, a nivel endógeno y exógeno, así como la estrategia seguida por Pekín, sustentan el tercer apartado del documento. Las conclusiones y consideraciones finales cierran el presente artículo.

Enabling improved water and environmental management in an irrigated river basin using multi-agent optimization of reservoir operations

In Colorado's Lower Arkansas River Basin (LARB), inefficient irrigation and canal seepage contribute to salinization and waterlogging of irrigated lands and to stream-aquifer pollution. The geographic information system (GIS)-based river basin management model River GeoDSS is applied to further explore best management practices (BMPs) earlier determined to remedy these agro-environmental impacts. Unfortunately, BMP benefits are offset by altered irrigation return flows which change historical downstream river flows, threatening compliance with water rights and the Arkansas River Compact. Compensation is possible through optimal sizing and operation of a dedicated reservoir storage account. Multi-agent optimization combines a metaheuristic mutation linear particle swarm optimization (MLPSO) with a fuzzy rule-based system to produce generalized operational policies along with optimal storage sizing, to enable BMPs while satisfying legal constraints. A storage account making up less than 5% of available reservoir capacity can be operated with rules that enable implementation of even the most aggressive BMPs.

Resolution matters when modeling climate change in headwaters of the Colorado River

The continued growth of Southwestern cities depends on reliable water export from Rocky Mountain headwaters, which provide ∼85% of Colorado River Basin (CRB) streamflow. Despite being more sensitive to warming temperatures, alpine systems are simplified in the regional-scale models currently in use to plan for future water supply. We used an integrated hydrologic model that couples groundwater and surface water with snow and vegetation processes to examine the effect of topographic simplifications as a result of grid coarsening in a representative CRB headwater basin. High-resolution (100 m) simulations predicted headwater streamflow losses of 16% by 2050 while coarse-resolution (1 km) simulations predict only 12%, suggesting that regional-scale models (coarser than 1 km) likely overestimate future Colorado River Basin water supplies.

Hydrological Tracking Model for Amazon Surface Waters

AbstractThis study presents an alternative model for hydrological tracking of surface waters designed to investigate multiyear storage and movement of water in large river basins. We coupled this model with a background solution from a large‐scale hydrological‐hydrodynamic model to study the fate of waters in the Amazon River basin (6 million km2) considering the following: (i) the surface water travel times, (ii) the role of large floodable areas (17% of the basin), and (iii) the relations between water composition and lithological sources. Through numerical experiments, we investigated the spatial distribution of in‐stream surface water travel time for the Amazon River Basin (relative to the outlet) and the role of floodplains in seasonal water storage. We estimate that surface water travel time is likely to be less than 90 days (median of 45 days), although about 20% of the flowing water passes through large floodplains. Our modeling exercises indicate that whole‐basin monthly water net balance between river and floodplain can reach up to magnitudes of 105 m3/s; the water exchanged with floodplains during the annual floods can represent a large portion (up to 40%) of the basin discharge during low waters season. Finally, we took advantage of the tracking approach to study the hydrograph composition based on parent river lithology quantifying the role of major tributaries. Parallel to the development of global hydrology databases, new modeling approaches are also required to push advances in the discussion of renewal and travel times of surface waters in large river basins.

A multivariate statistical approach in assessing the quality of potable and irrigation water environs of the Netravati River basin (India)

The current river basin monitoring study investigates the standards of the quality of the river and well water in a biodiversity-rich Netravati River basin in Karnataka state, India. Water samples were collected from 16 major sampling sites during pre-monsoon (April), monsoon (August) and post-monsoon (October) seasons in 2017 to ascertain its physico-chemical parameters. The results of the tests were compared with maximum permissible limits proposed by the World Health Organisation drinking water guidelines. The Water Quality Index (WQI) and the Irrigation Water Quality Index (IWQI) using parameters such as Sodium Percentage (Na %), Magnesium Hazard (MH), Permeability Index (PI), Sodium Absorption Ratio (SAR) and Residual Sodium Carbonate (RSC) have been determined to provide a better understanding of its drinking and irrigation water quality. The interpreted WQI values of the water in Netravati River vary from 33.21 to 298.66, which fall in the range of excellent to very poor drinking water quality. In the case of well water, 100% falls under the excellent category. Multiple statistical methods like Principal Component Analysis (PCA) and Pearson correlation analysis were used, and the results of PCA were found to be in a correlation with the results of the Pearson correlation analysis method. The study, as a whole, highlights the importance of the application of PCA, WQI and IWQI as standard methods to evaluate the quality of water. The results of the present study could be used to contemplate regulations to improve the water quality standard and help people living in and around the river basin to understand the current status of the water quality they use for various purposes.

Major Scientific Achievements of the First China-Japan Cooperative GAME/HUBEX Experiment: A Historical Review

In the summers of 1998 and 1999, Chinese and Japanese scientists cooperatively conducted the first large-scale energy and water cycle experiment (WCRP/GEWEX/GAME/HUBEX: World Climate Research Program/Global Energy and Water Cycle Experiment/Asian Monsoon Experiment/Huaihe River Basin Energy and Water Cycle Experiment) in the Huaihe River basin, Anhui Province of China. The main objective of this field experiment (HUBEX) was to investigate the multiple-scale structure characteristics, life cycles, and genesis and development mechanisms of the Meiyu system in East Asia as well as the cause of related flooding disasters. It was a joint China–Japan cooperative meteorological and hydrological observation experiment. On the basis of intensive observations, scientists from the two countries conducted follow-up investigations through collating and compiling data and performing scientific analysis during the following five years. It can be concluded that the HUBEX project has yielded comprehensive and remarkable achievements. This paper introduces the major scientific results derived from this field experiment and the ensuing investigations, and reassesses their merits and shortages for the purpose of providing useful experience and proposing new research targets as well as prospects for the initiation of a new joint scientific Meiyu experiment in the middle and lower Yangtze River basin.

Sediment deposition and distribution modelling in reservoirs: current trends and prospects

Global and regional challenges related to river basin water scarcity can effectively be managed through improved reservoir operations and reservoir sedimentation control. It is a well-known fact that increased sedimentation due to various reasons is adversely affecting reservoir capacities and threatening long-term water supplies; these implications are aggravated due to impact stresses such as climate change and other anthropogenic activities. The aim of this study was to gather the important concepts behind popularly applied models and approaches in the field of reservoir sedimentation modelling and assess their strengths and weaknesses. To describe the modelling concepts, different kinds of reservoir sedimentation applications were grouped into five categories: empirical approaches, numerical approaches, conceptual approaches, artificial intelligence approaches and alternative approaches. However, there are a significant number of studies on hydro-ecological models, erosion models and river sediment dynamics models. This article predominantly focuses on reservoir-based literature dealing with sediment deposition and distribution in reservoirs, along with some future perspectives on the need for advanced reservoir sedimentation management and modelling. The article provides practitioners with practical and useful information on the extent of the application of different models and approaches, along with their strengths and weaknesses.

A global dataset of surface water and groundwater salinity measurements from 1980\u20132019

Salinization of freshwater resources is a growing water quality challenge, which may negatively impact both sectoral water-use and food security, as well as biodiversity and ecosystem services. Although monitoring of salinity is relatively common compared to many other water quality parameters, no compilation and harmonisation of available datasets for both surface and groundwater components have been made yet at the global scale. Here, we present a new global salinity database, compiled from electrical conductivity (EC) monitoring data of both surface water (rivers, lakes/reservoirs) and groundwater locations over the period 1980–2019. The data were assembled from a range of sources, including local to global salinity databases, governmental organizations, river basin management commissions and water development boards. Our resulting database comprises more than 16.3 million measurements from 45,103 surface water locations and 208,550 groundwater locations around the world. This database could provide new opportunities for meta-analyses of salinity levels of water resources, as well as for addressing data and model-driven questions related to historic and future salinization patterns and impacts.

Application of Back Propagation (BP) Neural Network in Water Quality Assessment: A Case Study of Ashi River Basin

Wang, H., 2020. Application of back propagation (BP) neural network in water quality assessment: A case study of Ashi River Basin. In: Gong, D.; Zhang, M., and Liu, R. (eds.), Advances in Coastal Research: Engineering, Industry, Economy, and Sustainable Development. Journal of Coastal Research, Special Issue No. 106, pp. 377–380. Coconut Creek (Florida), ISSN 0749-0208.The artificial neural network (ANN) theory and method was adopted to establish a back propagation (BP) neural network model for the assessment of water quality. Considering the water quality in the Ashi River basin as an example, a comparative analysis between the obtained results and the results from the Nemerow index method shows that the BP neural network model is applicable to evaluate the river basin water quality, and the model has a good reliability. By simulating the human brain in the thought process and analysis mode, the accuracy of water quality assessment is greatly improved, which means that the model can provide a reliable basis for assessing the water quality of the river basin.

Study on the variation in evapotranspiration in different period of the Genhe River Basin in China

Evapotranspiration is an important component and key link of river basin water cycles and plant hydrological processes, and is a core issue in global climate change research. It is not only an important way to understand the energy and water consumption of permafrost regions, but also is an important channel to master the water cycle and energy balance in cold regions. In this paper, multiple linear regression analysis method and weighted comprehensive analysis of major factors method were used to investigate the variation characteristics and impact factors of evapotranspiration in the Genhe River Basin. The results showed the following: (1) The monthly average evapotranspiration in the Genhe River Basin during the freezing-thawing periods in 1980–2017 was 28.29 mm. Compared with the freezing-thawing periods, the total evapotranspiration in the growing seasons was much higher than that in the freezing-thawing periods, with monthly average evapotranspiration of 67.71 mm; (2) The main factors affecting evapotranspiration in the Genhe River Basin were precipitation and temperature. During the freezing-thawing periods, the variation in evapotranspiration in May was mainly determined by temperature. In the growing season, precipitation was the main factors affecting evapotranspiration in June. This will lay a foundation for clarifying the relationship between permafrost–climate change–hydrologic cycle in the permafrost active layer during the land surface process, so as to provide some basic data and important scientific basis for the comprehensive study of the hydrologic process and its impact on climate, ecology, water resources and environment in the permafrost area.

A systematic approach of determining compensation and allocation for river basin water environment based on total pollutants control

The compensation of upstream protective area should be determined carefully. This paper provides a comprehensive evaluation framework for economic assessments on the treatment of wastewater discharged into a river basin. We explore the rational costs of compensation and the funding allocation in the Xin'an River basin based on rate agreements. The compensation is determined in accordance with the total compensation model based on the opportunity cost method and allocated by the method of information entropy. In this study, we identify the total compensation payment and distribution of funds in each district and county in the upstream area (Huangshan). Results show that the She county can receive the highest compensation, and the Tunxi district deserves the lowest compensation. In addition, this paper demonstrates that the existing compensation is insufficient for the reduction of water pollutants in the upstream area. Our findings contribute to the existing schemes of ecosystem services payment and improve the environmental decision-making.

Growth diffusion-limited aggregation for basin fractal river network evolution model

Diffusion-limited aggregation (DLA) model has been widely used to simulate fractal aggregation processes. This DLA model and its improved model growth diffusion-limited aggregation (GDLA) can reasonably plan and manage rivers within the basin scale. In this paper, the growth and evolution of the river network at the basin scale were simulated using the Northwest China Basin as the study area. To achieve this research goal, this paper used gas injection system image processing technology and data analysis methods for overall processing and distributed processing of river basin remote sensing data. A new growth method, unit-gradient growth, was added to the standard DLA model, and a combination of the extracted Daxia River Basin geomorphological features and DEM data was used to optimize the Brownian motion of the model particle growth method. A computational model was proposed: GDLA model to predict the river network growth in the study area. The fractal dimension of the river network in the study area was extracted and corrected by the box-counting method. Finally, the predicted river network was compared with the extracted actual river network. The included angle cosine method was used for modeling evaluation and analysis. The results showed that the fractal dimension of the Daxia River Basin and sub-basin water systems was less than 1.6, indicating that the basin geomorphology was in its infancy. The structural similarity degrees were greater than 0.99, indicating that the GDLA model had a better simulation on fractal river networks, which can successfully reproduce and predict different morphological two-dimensional river networks. Studies showed that using GDLA to model fractal river networks can better predict the river network growth and evolution, ultimately promoting sustainable development of river basin water management.

Hydrogeological controls on ammonium enrichment in shallow groundwater in the central Yangtze River Basin

The controlling processes of excessive ammonium in surface water and groundwater in the central Yangtze River Basin remain unclear. In this study, monitoring of water levels and temporal-spatial distributions of major N compounds were implemented at the large Jiangshan plain and at the local site scale in the central Yangtze River Basin. The results indicate that the recharge, movement and transformation of ammonium were controlled by hydrogeological conditions. Manure and sewage from anthropogenic activities were identified as the main source of nitrogen compounds. The nitrogen loading into aquifers were governed by water table and groundwater flow. After entering subsurface soils, nitrification and dissimilatory nitrate reduction to ammonium (DNRA) were proposed as the ammonium consumption and production mechanisms, respectively, by combining the concentrations of ammonium‑nitrogen and nitrate‑nitrogen with the corresponding isotopic compositions. These microbially mediated processes controlling transport and transformation of nitrogen compounds were influenced by the seasonally varying groundwater flow regime that changed the redox conditions in the aquifers. In the subsurface environments, ammonium was converted to nitrate when sufficient oxygen supply was available, and this process was reversed under anoxic conditions along the groundwater flow path. A conceptual model for the reactive transport of nitrogen compounds jointly controlled by the vertical groundwater flows and biogeochemical processes was proposed, which provides new insights into the genesis of high ammonium groundwater.

Estimation of the measurement uncertainty, including the contribution arising from sampling, of water quality parameters in surface waters of the Loire-Bretagne river basin, France

A specific study was designed and carried out at the Loire River Basin in France, in order to estimate the measurement uncertainty, including the contribution of sampling. Following recommendations from the Eurachem Guide on Uncertainty arising from sampling, the duplicate method was selected. The study was conducted in 2017 under routine and operational conditions with the accredited laboratories selected by the Loire-Bretagne Water Agency. In overall, 35 monitoring stations were chosen for estimating the spatial variability, and among them 11 monitoring stations were singled out for estimating the temporal variability from April to December. To reduce both the number of analysis and the costs of this study, an unbalanced design was used. Finally, a robust analysis of variance was used to evaluate the measurement uncertainty by means of RANOVA2 software. For some parameters (e.g., calcium, dissolved organic carbon, nitrates, phosphates, suspended matter, metals), the expanded measurement uncertainty estimated using robust ANOVA was found to be lower than 20 % and was thus used to calculate the lower and upper confidence interval limits at 95 %. For parameters having an expanded measurement uncertainty greater than 20 % (e.g., most pesticides, chlorophyll a, biochemical oxygen demand, ammonium, nitrites, Kjeldahl nitrogen), the lower and upper confidence interval limits at 95 % were established using an alternative approach: the expanded uncertainty factor (FU) derived from log-transformed data.

Identifying Nitrate Sources in a Typical Karst Underground River Basin

Underground rivers are an important source of groundwater in karst area. Recently, nitrate pollution of underground rivers has become a serious issue. To identify the sources of nitrate in Guancun typical karst underground river basin, stable isotope techniques (δ15N-NO3-, δ18O-NO3-, and δ18O-H2O) were applied in this study. The contribution rates of different nitrate sources in groundwater were quantitatively identified based on the stable isotope analysis in R (SIAR) model, and the influence of land use type on nitrate distribution and source in watershed water was clarified. The results showed that ① nitrate mainly came from fertilizers, soil organic nitrogen, and manure/sewage based to the isotopic composition of nitrate nitrogen and oxygen isotopes. It was revealed that non-point sources significantly contributed to nitrate in waters of the Guancun underground river basin. ② Nitrification dominated the formation process of nitrate in groundwater, and the initial values of nitrogen and oxygen isotopes were not affected by fractionation. ③ Based on SIAR, the contribution of different sources to nitrate in water in the basin varied seasonally, and the contributions of fertilizer, soil organic nitrogen, and manure/sewage to nitrate were 57.07%, 34.06%, and 8.87% in the wet season and 34.14%, 33.02%, and 32.84% in the dry season, respectively. Overall, the present study quantitatively evaluated the temporal variations of nitrate sources in a typical karst groundwater river basin and provided a theoretical foundation for prevention and control management of non-point source pollution and watershed management in karst areas.

A multimetric index for assessment of aquatic ecosystem health based on macroinvertebrates for the Zio river basin in Togo

The use of multimetric indices as tools for assessing aquatic ecosystem health in most of the developing countries such as Togo is still lacking. To fill this gap, we developed a macroinvertebrates-based multimetric index for the Zio river basin of Togo. Forty-two sites were assessed for the development and the validation of the Multimetric Index of Zio River Basin (MMIZB). Thirty-nine candidate metrics belonging to four categories (composition metrics, functional feeding metrics, diversity metrics and tolerance measure metrics) were evaluated. After comprehensive multiple selection procedure, six core metrics were retained to provide the final MMIZB. The results showed that the MMIZB responded to a set of organic pollution (chemical oxygen demand, ammonium, total suspended solid) and hydromorphological alterations, which corresponded to a set of gradients of human pressures affecting the ecological integrity of Zio river basin water bodies (r = 0.78, p < 0.001). The final macroinvertebrate index well distinguished the reference sites and impaired sites of a validation data set (p < 0.001) and showed a significant relationship between water and habitat quality based on Prati’s index (r = 0.73, p < 0.001) and Multimetric Macroinvertebrates Index of Vietnam (MMI_Vietnam) (r = 0.88, p < 0.001). This work underlines the relevance of the MMIZB as an effective tool for biological monitoring and decision making in water management of Zio river basin.

\u2018Sub-Prime\u2019 Water, Low-Security Entitlements and Policy Challenges in Over-Allocated River Basins: the Case of the Murray\u2013Darling Basin

Environmental policy is often implemented using market instruments. In some cases, including carbon taxing, the links between financial products and the environmental objectives, are transparent. In other cases, including water markets, the links are less transparent. In Australia’s Murray–Darling Basin (MDB), financial water products are known as ‘entitlements’, and are similar to traditional financial products, such as shares. The Australian water market includes ‘Low Security’ entitlements, which are similar to ‘sub-prime’ mortgage bonds because they are unlikely to yield an amount equal to their financial worth. Nearly half the water purchased under the Murray–Darling Basin Plan for environmental purposes is ‘Low Security’. We suggest that the current portfolio of water held by the Australian Government for environmental purposes reflects the mortgage market in the lead-up to the global financial crisis. Banks assumed that the future value of the mortgage market would reflect past trends. Similarly, it is assumed that the future value of water products will reflect past trends, without considering climate change. Historic records of allocations to ‘Low Security’ entitlements in the MDB suggest that, in the context of climate change, the Basin Plan water portfolio may fall short of the target annual average yield of 2075 GL by 511 GL. We recommend adopting finance sector methods including ‘hedging’ ‘Low Security’ entitlements by purchasing an additional 322–2755 GL of ‘Low Security’, or 160–511 GL of ‘High Security’ entitlements. Securing reliable environmental water is a global problem. Finance economics present opportunities for increasing the reliability of environmental flows.

Valores y principios bioéticos que identifican las comunidades en los servicios ecosistémicos que prestan los ríos y quebradas

Este artículo tiene como propósito analizar los valores y principios bioéticos que identifican las comunidades sobre los servicios ecosistémicos que prestan los ríos y quebradas en los municipios de la cuenca del Río Apulo, en el Departamento de Cundinamarca, Colombia. En este artículo se trabaja alrededor de la idea de la coexistencia armoniosa de los seres humanos y los ríos, como fundamento para lograr un uso sostenible de los servicios que nos prestan estos ecosistemas. Metodológicamente el proyecto consta de dos partes: en la primera se trabajó desde el paradigma positivista de la investigación, a través de metodologías cuantitativas de campo y de laboratorio, en la segunda parte se trabajó desde el paradigma interpretativo de la investigación a través de talleres de cartografía social. Por el análisis de los datos cuantitativos, se encontró de que las aguas de los ríos de la cuenca estaban contaminadas en todas las estaciones de muestreo, entre otras, con materia fecal. La identificación de los valores de los servicios ecosistémicos que prestan estos ríos y quebradas mostraron una fuerte influencia de la concepción productivista, localista y antropocéntrica. Debido a que la contaminación afecta al ambiente, tanto presente como futuro, es necesario acudir a los principios de precaución, de responsabilidad y de justicia.