Hydrological Environmental Services Research Articles

Community Participation Provides Hydrological Environmental Services In the Watershed Area

The extent of critical and potential critical land in the Kambaniru watershed has encouraged community perceptions where management of land and forests in the watershed-based area of community empowerment is an important effort. To be able to achieve a good Kambaniru watershed condition, the behavior and activities of land and forest utilization by the community must comply with the principles of soil and water conservation. High population growth rate and followed by pressure on land has the potential to create new social problems in the form of poverty. On the other hand, the large potential of people who are willing to provide hydrological environmental services in watershed areas can be used as government investment. Therefore, opportunities for community participation need to be managed through an incentive approach through a cost-sharing mechanism. The overall objective of this study is to formulate a cost-sharing regression model of hydrological environmental services; to analyze the value of hydrological benefits for households at the upstream level in the Kambaniru watershed area, and assess the condition of community poverty levels based on pressure on land in the Kambaniru watershed area. This study concludes the formulation of the cost-sharing regression model of hydrological environmental services in the Kambaniru watershed area can explain the condition of the amount of water use and water requirements for households. The condition of population poverty is triggered by high pressure and dependence on land and forests. The recommendation is that farmer household should be given hydrological benefit compensation and lending without interest.

Forest Fires, Land Use Changes and Their Impact on Hydrological Balance in Temperate Forests of Central Mexico

Temperate forests play a fundamental role in the provision, regulation, and support of hydrological environmental services, but they are subject to constant changes in land use (clearing, overgrazing, deforestation, and forest fires) that upset the hydrological balance. Through scenarios simulated with the Water Evaluation and Planning (WEAP) hydrological model, the present study analyzes the effects of forest fires and land use changes on the hydrological balance in the microwatersheds of central Mexico. The land use changes that took place between 1995 and 2021 were estimated, and projections based on the current scenario were made. Two trend scenarios were proposed for 2047: one with a positive trend (forest permanence) and the other with a negative trend (loss of cover from forest fires). The results show that with permanence or an increase in forest area, the surface runoff would decrease by 48.2%, increasing the base flow by 37% and the soil moisture by 2.3%. If forest is lost, surface runoff would increase up to 454%, and soil moisture would decrease by 27%. If the current forest decline trends continue, then there will be negative alterations in hydrological processes: a reduction in the interception of precipitation by the canopy and an increase in the velocity and flow of surface runoff, among others. The final result will be a lower amount of water being infiltrated into the soil and stored in the subsoil. The provision of hydrological environmental services depends on the maintenance of forest cover.

Multicriterial Analysis for the Identification of Key Areas to Improve the Management in Piracicaba River Basin, Brazil

AbstractThe objective of the study was to identify areas subject to the implementation of payment for hydrological environmental services projects, aiming to provide solutions for planners and deci...

Changes in the constituents of the "Bosque de Agua" of the Sierra Cruces-Ajusco-Chichinautzín, Mexico, an area with payment for environmental services.

The “Bosque de Agua”, to the west and south of Mexico City, which is the fifth largest city in the world, has historically suffered disturbances in forest cover, with a consequent reduction in the environmental services provided. Changes in the state of the forests between 1994 and 2017 are here analyzed in terms of the annual net change in area of the different cover densities and the different change processes. In general, the net change was favorable in all cases: forest improvement vs. forest degradation, reforestation vs. deforestation, and afforestation vs. land use change. There were changes in 16.03% of the Bosque de Agua: recovery in 11.09% and disturbance in 4.94%. This marked recovery is the result of the protected status of two-thirds of the forest, the payment for hydrological environmental services in 29.33% of the forest, as of 2003, and the continuous programs of reforestation, fire control and surveillance by the local communities, circumstances that have allowed the recovery to exceed the disturbance in most of the Bosque de Agua. One-third of the forest disturbance is concentrated in six of the 35 municipalities in the southern region, caused by clandestine logging by organized gangs, due to the state of ungovernability that reigns in these municipalities.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12665-021-10025-w.

Reconstrucción de la precipitación y caudal medio del río Piaxtla mediante anillos de crecimiento de Pseudotsuga menziesii (Mirb.) Franco

La reconstrucción de variables hidroclimáticas es importante para comprender el funcionamiento de las cuencas forestales y tomar decisiones sobre su manejo. En este trabajo se reconstruyó la precipitación y el caudal medio a partir de información de anillos de crecimiento de Pseudostuga menziesii en la cuenca del río Piaxtla. Con la información de siete series dendrocronologías, se construyó una sola cronología regional. Se probó la correlación de la cronología regional con eventos de fenómenos océano-atmósfera como El Niño Oscilación del Sur, Oscilación Decadal del Pacífico, Oscilación Multidecadal del Atlántico e Índices de la Severidad de Sequía de Palmer. Los resultados mostraron que fue posible la reconstrucción de la precipitación de noviembre-abril y el caudal medio noviembre-agosto a partir de la serie de madera temprana con ecuaciones verificadas y validadas: Precipitación = -271.538 + 447.764*(índice de madera temprana), (r = 0.85, n = 49, p < 0.0001) y caudal medio = 5.123 + 0.623*log10(índice de madera temprana), (r = 0.68, n = 46, p < 0.001). Excepto por la Oscilación Multidecadal del Atlántico, todos los fenómenos globales mostraron correlación significativa con la información de los anillos de crecimiento. Este estudio confirma que los bosques de P. menziesii de la Sierra Madre Occidental son altamente sensibles al clima, lo que se refleja en la anchura de anillos de crecimiento y a su vez en la variabilidad del caudal medio de la cuenca. Por lo anterior se debe aprovechar el potencial de este tipo de trabajos para prever los cambios en la disponibilidad de recursos hídricos, así como ampliar su uso en la valoración de servicios ambientales hidrológicos.

VALORACIÓN SOCIOECONÓMICA DEL PAGO POR SERVICIOS AMBIENTALES HIDROLÓGICOS EN VERACRUZ (COATEPEC Y SAN ANDRES TUXTLA)


 
 
 Se trabajó en las poblaciones de San Andrés Tuxtla y Coatepec, en el estado de Veracruz, México, que representan zonas que han recibido pago por servicios ambientales hidrológicos (PSAH) desde el año 2004. El objetivo fue analizar el impacto socioeconómico del PSAH en función del mercado local de agua, obtener las percepciones sociales del valor del agua y el posible impacto de la aplicación del PSAH. Se utilizó análisis etnográfico, sociológico y valoración contingente en una muestra de 171 consumidores en Coatepec y 228 en San Andrés, así como 85 productores, 45 de ellos de Coatepec. Los resultados mostraron que la población privilegia los valores económicos de los paisajes que componen las zonas de pago. Existe un fuerte potencial para incorporar el reconocimiento social en la generación de servicios ambientales, lo que podría incrementar el pago a los productores para observar un impacto socioeconómico real del PSAH. Se identificaron diferencias entre los actores respecto a valor de un m3 de agua, tanto dentro como entre zonas, ya que los valores fiscales de referencia y del productor fueron mayores en Coatepec. Los programas de conservación y las políticas públicas inherentes deberán considerar la voluntad de todos los actores sociales para obtener un impacto visible.
 
 

Pago por servicios ambientales hidrológicos y dinámica de la cobertura arbórea en la región Iztaccíhuatl-Popocatépetl, Puebla, México

El pago por servicios ambientales hidrológicos es un instrumento de política ambiental aplicado en la mayoría de los países para promover la conservación de los ecosistemas, principalmente los forestales. En 2003, el gobierno de México, a través de la Comisión Nacional Forestal (CONAFOR), implementó el programa de Pago por Servicios Ambientales Hidrológicos (PSAH) para atender los problemas de agua y deforestación en el país. Un prerrequisito para que un área reciba el PSAH es que mantenga una cobertura vegetal mínima de 80%, o la aumente, durante los 5 años posteriores al inicio del contrato. Las evaluaciones de los impactos del Programa sobre la cobertura forestal consisten principalmente en estudios nacionales o regionales. En México no se tienen evaluaciones de los impactos a nivel comunitario, escala a la que el PSAH es ejecutado. En el presente estudio se evaluó el impacto del programa de PSAH en la dinámica de la cobertura arbórea en seis ejidos de la región Iztaccíhuatl-Popocatépetl, Puebla. Para realizar el estudio se utilizaron imágenes Quickbird y se realizó una clasificación supervisada. Los resultados indicaron que el Programa PSAH cumplió con su objetivo en cuatro de los seis núcleos agrarios analizados.

AVANCES Y LIMITANTES DEL PROGRAMA DE PAGO POR SERVICIOS AMBIENTALES HIDROLÓGICOS EN MÉXICO, 2003 - 2009


 
 
 En el presente estudio se analiza el proceso de implementación del programa de Pago por Servicios Ambientales Hidrológicos (PSAH) en México durante el periodo 2003 - 2009, que surge como instrumento de política pública nacional dirigida a la creación de nuevos esquemas de compensación económica, para los propietarios de terrenos que cuentan con cobertura forestal, por la conservación de los bosques y de los servicios ambientales que estos proveen, incluso el hidrológico. Con este fin se recurrió al marco teórico-conceptual de Servicios Ambientales y su aceptación histórica a nivel internacional. La revisión consecuente de diversos trabajos académicos publicados sobre el tema permitió fundamentar el propósito y la utilidad del estudio, que consiste en el primer esfuerzo sistemático de análisis de implementación del programa en el país, por medio de una comparación entre los esquemas federales de PSAH en México y Costa Rica (el caso más reconocido en América Latina). El apoyo documental de la investigación se realizó mediante el trabajo de campo con aplicación de entrevistas a los tomadores de decisión, los funcionarios y algunos beneficiarios en ambos países. Finalmente, con base en cuatro criterios predeterminados (la operatividad, la regulación ambiental, el marco político-institucional y el financiero) fue posible formular los principales avances y limitantes del programa en México y reflexionar sobre sus retos a futuro, como parte del ejercicio de evaluación de las políticas públicas, el cual está dedicado al mejoramiento de sus instrumentos.
 
 

Differentiated payments for environmental services schemes: Amethodology proposal

Payment schemes for environmental services face serious budget constraints in Mexico. Payments are equally distributed among forest owners, and the governmental agencies that make payments to beneficiaries do not evaluate the amount of environmental services produced by forested areas. This lack of evaluation could lead to economic and environmental deficiencies that restrict the possible benefits of such programmes. In general, these programmes do not achieve their conservation objectives, and local beneficiaries are not involved in the design or application of these programmes. Similarly, the Payments for Hydrological Environmental Services (PHES) programme of the State of Mexico, Mexico, makes equal payments to beneficiaries of forested areas considering tree density. The objective of the present work was to create a methodology for determining differentiated payments schemes for hydrological environmental services, prioritising areas that contribute the most to groundwater recharge and promote the participation of society. In the Nevado de Toluca Natural Protected Area, the environmental criteria of forest type, tree density and aquifer overexploitation as well as social participation were considered in a multi-criteria analysis implemented in a Geographic Information System. A methodology was developed to determine differentiated payments based on specific forest characteristics that influence the potential capacity of forests to recharge groundwater reserves in addition to the level of social participation. In particular, social participation is key as it could ensure the viability of PHES programmes as conservation alternatives in forested areas with high groundwater recharge potential.

Evaluación ambiental integrada de áreas inscritas en el programa federal de Pago por Servicios Ambientales Hidrológicos. Caso de estudio: Ajusco, México

Since the specific problem of deforestation on an international level, they have created compensation mechanisms for ecosystem services, which have recently been increasing interest in the academic and government sectors, however, a lack of information on their potential effects is detected, especially from the aspects of integrative approach and spatial. Therefore, this work presents the case study of the community of San Miguel and Santo Tomas Ajusco, located on the suburbs of México City, because the community has participated in the federal program payments for hydrological environmental services (phes) since 2004. Based on the construction of longitudinal profiles (which are incorporated thematic geographic information layers) we analyzed if there is correspondence between the potential of ecosystem services and enrolled in the program areas. In addition, the effectiveness of the program regarding deforestation detected in the area was observed. For the profiling, it is noticed the exercise of combining the different layers selected for analysis, forming a two-dimensional model that allows us to appreciate the altitudinal gradient of the area with its biophysical components (vegetation and land use, soil science, geology and landforms highlights) with information environmental Services (ES). This facilitates the analysis of all these variables and has the advantage that it can be adapted to the number of variables we have, since they must only be incorporated to the profile (with pretreatment data).The profiles helped to identify whether registered in the phes program areas correspond to the most important areas for the provision of environmental services; however, a complementary work was developed consisting of a map which would bring together the most important areas for the contribution of es; This was generated by applying the statistical model of Jenks’ Natural Breaks “(which allows to discriminate classes by the similarity of values that compose them), in the layers of ES that it had (potential infiltration, carbon stock in forests, surface runoff and provision of habitat), establishing quantitative 5 for each category. The criterion model allow standardize classes; therefore, quantitative categories were matched to (very low, low, medium, high and very high) qualitative categories. Then the “high” and “very high” categories were selected and merged into a map with software tools Arc. map 10.1. denominating as “high priority areas for ecosystem services”.ES mapping was deployed with phes polygons and correspondence between sites on phes and areas with greatest potential for ES (except for an area of 236.7 hectares) was found. However, in many cases, the highest values of es not correspond to water resources, as they are more associated with vegetation and biodiversity (carbon stock in forestsand provision of habitat), which helps to conclude that the phes program should consider other variables and not be restricted to the es associated with hydrology. Two studies on quantifying forest cover were reviewed in the area (one covers from 1986 to 2010, with a projection to 2030 and the other from 2006 to 2014). The information regarding sites on phes Program and the result shows that deforestation has remained revised (although the rate decreased in the period 2006-2014) and deforested areas within enrolled in the program areas phes are greater than those who have not been. Although factors that could contribute to the process are identified, it is concluded that a program like phes implemented in an isolated manner, has no bearing on the problem of deforestation. Finally, the importance of obtaining the map “high priority areas for ecosystem services”, the most environmentally important areas are identified and this helps manage phes expanding areas and get other resources or protection status in areas with natural ecosystems.

Hydrochemical assessment of Hydrological Environmental Services in the recharge area in the Southwest of Mexico City

The aquifer recharge area that supplies water to Mexico City is being protected with the implementation of land use restrictions and with the use of payment schemes for maintaining environmental services (PES). In order to assess the effects of PES in the conservation soil area, the chemical and isotopic compositions of water from springs were characterized and the water baseline chemistry was established to provide a useful standard to monitor the water resources and to support the decision-making under current water management policies. A total of 32 water samples taken in four field surveys, during the dry and rainy season, and background chemical data from different information sources, were studied. The water salinity increases from southwest to northeast towards the urbanized area. The chemical composition of water is due to the occurrence of natural chemical interactions between water and rocks in aquifers and to the presence of effluents generated by human activities. In the forest area, water chemistry has not changed significantly over the past three decades and there are no major discernible trends in the compiled water chemistry data, suggesting that PES has contributed in part to maintain the initial condition in the aquifer recharge area. The natural reference levels proposed have allowed the current chemical conditions in the system to be understood and can be implemented to monitor water resources in the area of conservation soil in the Sierra de Las Cruces with an acceptable degree of reliability.

Demanda, disponibilidad de pago y costo de oportunidad hídrica en la Cuenca Tapalpa, Jalisco

Para conocer la factibilidad de la creación de un mercado de servicios ambientales hidrológicos, se requiere contar con información sobre la oferta y demanda hídrica del lugar. Este estudio pretende aportar información sobre el último aspecto, al estimar la demanda hídrica en la cuenca de Tapalpa, Jalisco, México, en cuya superficie de 21 000 ha, la mitad es forestal. Adicionalmente, se estimó la disponibilidad a pagar (DAP) por el recurso hídrico (RH), además de un análisis del costo de oportunidad del uso del suelo para “producción” de agua. El análisis indicó que el RH utilizado asciende a23 171 885 m3/año. El 93% de éste se utiliza en el sector agrícola, principalmente en la producción de hortalizas y cultivos básicos. La DAP calculada por el RH es mayor en el sector servicios (76,7% de los casos dijeron estar dispuestos), en comparación con los otros sectores encuestados. Sin embargo, la mayor participación monetaria en la DAP total estuvo dada por el sector doméstico, con 46 ,5% del total, con $3 064 301 pesos al año. Adicionalmente se determinó que la escolaridad tiene una relación directa con la DAP por RH, mientras que la edad presentó una relación inversa. El valor estimado de la DAP total fue menor que el costo de oportunidad para conservar la superficie boscosa de la cuenca, presentando un déficit anual de $27 201 313 pesos, y sólo cubre el 10% de dicho costo de oportunidad. Al agregar el costo asociado a la recuperación de la superficie forestal actualmente en otro uso (áreas en conflicto), el déficit anual se incrementaría a $45 130 988 pesos y la DAP se reduce a sólo 6% del costo de oportunidad total.

The Payment for Hydrological Environmental Services. Examining the Experiences of Costa Rica, Mexico, Ecuador and Colombia

Existe una crisis mundial en la gestión del agua, lo cual conlleva la necesidad de buscar alternativas sostenibles como lo son los mecanismos tipo pagos por servicios ambientales hidrológicos, instrumentos económicos que promueven la conservación de los cuerpos de agua a partir del cambio en el paradigma de uso y conservación en las comunidades. Se realizó una revisión documental sobre la aplicación de los PSAH en cuatro países latinoamericanos —Colombia, México, Costa Rica y Ecuador— para identificar instrumentos de gestión ambiental, con elobjetivo de proponer lineamientos que optimicen la aplicación del mecanismo en Colombia, a través de una recopilación de experiencias en su desarrollo y un análisis integral de los mecanismos dentro del contexto social, normativo, económico e institucional.

Valuation of Environmental Services of Catchment Forests Within Baubau Wonco Watershed

Catchment forests cover a total of 2.750, 11 Ha. This is about 31,85% of the total area of Baubau Wonco watershed. This forested land provides both tangible and intangible benefits of which some are perceived as environmental services. However, it has encountered high rate of deforestation and forests degradation [7]. A well managed catchment forests can bring about advantages to a wide range of stakeholders, normally far away from the forests in the form of water for domestic use, agriculture, industry, and preventing from flooding, erosion and landslide hazards. To this view, it is a logical assumption that these various stakeholders who are mostly living in the downstream area should provide costs for a good forest management as incentives to the local community who mostly occupy the upstream area. Therefore, the need of a model that regulates the upstream and downstream mechanism should be explored. The research is planned to be conducted for two years. The first year research has been carried out from July to October 2015. The study employed various methods of data analysis. Those are as follow: (i) Hedonic Price is used for estimating economic value of water for domestic and industrial use; (ii) Productivity approach used for analyzing economic value of water for agricultural use; (iii) Willingness to Pay (WTP) is used for analyzing economic value of catchment forests to preventing from erosion, flooding and landslide hazards. The results of the first year research show that the total volume of water domestic consumption reachs 6.163.488,50 m³ year^-1, which is used by 18.950 households with the economic value obtains of Rp. 40.062.668.750 year^-1, while the economic value of water for agricultural use achieves Rp. 30.199.167/ha year^-1. This research will be continued to the second year study to (i) estimate the economic value of industrial water, (ii) to analyze the Total Economic Value of hydrological environmental services provided by catchment forests of the watershed area, and (iii) to develop a model that can facilitate downstream-upstream mechanism of a payment for the hydrological environmental services.

Discharge areas as a useful tool for understanding recharge areas, study case: Mexico Catchment

At present, demographic growth is a significant issue related to environmental damage due to an excessive use of water and forest. Governments are now interested in formulating new strategies that might help to reach a sustainable development. Thus, the Mexican Federal Government initiated an Environmental Hydrological Services Payment Programme in 2003 to preserve its forest territory, specifically to keep its groundwater recharge potential. However, the application of this programme was not supported by hydrogeological studies defining the physical media, rainwater and groundwater flows through proper identification of recharge areas as well as probable impacts to groundwater or to other components of the environment. Wide-view system studies still need to be incorporated. This work highlights the importance of including groundwater flow system investigations as a basis to support environmental projects where a clear understanding of groundwater functioning in relation to a zone receiving payment for hydrological environmental services is required. Stable isotopes and chemical characteristics of non-evaporated groundwater in discharge areas allow the computation of the altitude of recharging precipitation from where possible recharge area location is proposed. Finally, this paper puts forward groundwater flow system definition as a basic tool to support recommendation for an adequate water and environmental management.

The Federal Program of Payment for Hydrological Environmental Services as an Alternative Instrument for Integrated Water Resources Management in Mexico City

This paper discusses the possibility of considering the federal program of Payment for Hydrological Environmental Services, implemented by the National Forest Commission in Mexico since 2003, as an alternative instrument of the environmental public policy in order to contribute to the Integrated Water Resources Management, based on the territorial concept of basin. As a case study we present Mexico City, which is the most important urban area of the country that faces serious problems in providing water to its population. The used methodology consists of cabinet work with the analysis of scientific papers, data bases, public material, and the field work with the application of proof structured interviews and one questionnaire to the principal groups of participants (authorities and communities). In the final part we compare the points of view of these actors and review the idea of the viability through a combination of two theoretical concepts into the application of one environmental policy program.

CONDESAN: Two Decades of Innovation for the Sustainable Development of the Andean Ecoregion

In almost 2 decades of existence the Consorcio para el Desarrollo Sostenible de la Ecorregión Andina (CONDESAN) has experienced institutional innovations in response to the economic, social, environmental, and institutional dynamics of Andean countries and territories. As a result, interinstitutional interventions have been promoted in strategic spaces of the Andean region through local and regional projects in order to contribute to knowledge about the Andes, its provision of natural resources, and the strategies of Andean inhabitants to profit from these resources in a sustainable fashion.In this context, the “Encuentro CONDESAN 2010” marked CONDESAN's first biannual meeting with researchers, decision-makers, and various organizations, providing a space for analysis and discussion on climate change, innovation in agricultural systems, hydrological environmental services, and the importance of collective action for managing natural resources, among other topics (Figure 1).The approval of CONDESAN's new Road Map 2011–2015 is the conclusion of its latest evolution process: CONDESAN today is an independent regional research for development platform, disengaged from the Consultative Group on International Agricultural Research (CGIAR) and its host center, the International Potato Center (CIP). The Road Map marks the strategic route for CONDESAN's next 5 years of work as of 2011, with a view to continue contributing to knowledge and sustainable development of the Andes as a multistakeholder platform, with regional research for development initiatives.

Modelling the hydrological behaviour of a coffee agroforestry basin in Costa Rica

Abstract. The profitability of hydropower in Costa Rica is affected by soil erosion and sedimentation in dam reservoirs, which are in turn influenced by land use, infiltration and aquifer interactions with surface water. In order to foster the provision and payment for Hydrological Environmental Services (HES), a quantitative assessment of the impact of specific land uses on the functioning of drainage-basins is required. The present paper aims to study the water balance partitioning in a volcanic coffee agroforestry micro-basin (1 km2, steep slopes) in Costa Rica, as a first step towards evaluating sediment or contaminant loads. The main hydrological processes were monitored during one year, using flume, eddy-covariance flux tower, soil water profiles and piezometers. A new Hydro-SVAT lumped model is proposed, that balances SVAT (Soil Vegetation Atmosphere Transfer) and basin-reservoir routines. The purpose of such a coupling was to achieve a trade-off between the expected performance of ecophysiological and hydrological models, which are often employed separately and at different spatial scales, either the plot or the basin. The calibration of the model to perform streamflow yielded a Nash-Sutcliffe (NS) coefficient equal to 0.89 for the year 2009, while the validation of the water balance partitioning was consistent with the independent measurements of actual evapotranspiration (R2 = 0.79, energy balance closed independently), soil water content (R2 = 0.35) and water table level (R2 = 0.84). Eight months of data from 2010 were used to validate modelled streamflow, resulting in a NS = 0.75. An uncertainty analysis showed that the streamflow modelling was precise for nearly every time step, while a sensitivity analysis revealed which parameters mostly affected model precision, depending on the season. It was observed that 64% of the incident rainfall R flowed out of the basin as streamflow and 25% as evapotranspiration, while the remaining 11% is probably explained by deep percolation, measurement errors and/or inter-annual changes in soil and aquifer water stocks. The model indicated an interception loss equal to 4% of R, a surface runoff of 4% and an infiltration component of 92%. The modelled streamflow was constituted by 87% of baseflow originating from the aquifer, 7% of subsurface non-saturated runoff and 6% of surface runoff. Given the low surface runoff observed under the current physical conditions (andisol) and management practices (no tillage, planted trees, bare soil kept by weeding), this agroforestry system on a volcanic soil demonstrated potential to provide valuable HES, such as a reduced superficial displacement-capacity for fertilizers, pesticides and sediments, as well as a streamflow regulation function provided by the highly efficient mechanisms of aquifer recharge and discharge. The proposed combination of experimentation and modelling across ecophysiological and hydrological approaches proved to be useful to account for the behaviour of a given basin, so that it can be applied to compare HES provision for different regions or management alternatives.

Adaptación a la Degradación de los Recursos Naturales en la Zona Semiárida Mexicana

La investigación hidrológica y edafológica en la zona semiárida mexicana ha puesto en evidencia un proceso de erosión hídrica exacerbado por el cambio climático y el cambio de uso del suelo. Los resultados de investigación han inspirado un programa de adaptación exitoso con una visión ambiental, económica y social. El Programa de Servicios Ambientales Hidrológicos (PSAH) consiste en el pago de mano de obra local para la construcción de obras de conservación del suelo y del agua en áreas susceptibles de proporcionar servicios ambientales hidrológicos. Sus resultados cualitativos saltan a la vista: retención del suelo y del agua, mantenimiento de la cobertura vegetal, retención de pobladores en sus comunidades y bienestar social, entre otros. El PSAH como estrategia de adaptación AL impacto del cambio climático deberá encontrar eco en otros lugares de México con el fin de replicar sus beneficios en el medio físico y humano de la zona semiárida.

Paying for the hydrological services of Mexico's forests: Analysis, negotiations and results

Mexico faces both high deforestation and severe water scarcity. The Payment for Hydrological Environmental Services (PSAH) Program was designed to complement other policy responses to the crisis at the interface of these problems. Through the PSAH, the Mexican federal government pays participating forest owners for the benefits of watershed protection and aquifer recharge in areas where commercial forestry is not currently competitive. Funding comes from fees charged to water users, from which nearly US$18 million are earmarked for payments of environmental services. Applicants are selected according to several criteria that include indicators of the value of water scarcity in the region. This paper describes the process of policy design of the PSAH, the main actors involved in the program, its operating rules, and provides a preliminary evaluation. One of the main findings is that many of the program's payments have been in areas with low deforestation risk. Selection criteria need to be modified to better target the areas where benefits to water users are highest and behavior modification has the least cost, otherwise the program main gains will be distributive, but without bringing a Pareto improvement in overall welfare.