Estimation of water yield in the hydrographic basins of southern Ecuador

Abstract. Humans greatly benefit from natural water resources, also known as hydrological ecosystem services. However, these services may be reduced by population growth, land use changes, and climate change. As these problems become more critical, the need to quantify water resources increases. The estimation of water yield and its distribution are of great importance for the management of water resources. In the present study, the average annual water yield of the hydrographic basins in the southern region of Ecuador was estimated for the 1970–2015 period using the InVEST water yield model based on the Budyko framework. The model estimates annual surface run-off at the pixel, sub-basin, and basin level considering the following variables: precipitation, actual evapotranspiration, land cover/use, soil depth, and available water content for plants. The model was calibrated by varying the ecohydrological parameter Z to reduce error between estimated and observed water yield. The results showed that the modeling of water yield in the majority of the hydrographic basins was satisfactory, allowing the basins to be ranked according to their importance for water production. The Mayo and Zamora basins had the highest water production, corresponding with 934 and 1218 mm per year, respectively, while the Alamor and Catamayo basins had the lowest water production, corresponding with 206 and 291 mm per year, respectively. The present study provides an initial estimate of water yield at the basin level in the southern region of Ecuador, and the results can be used to evaluate the impacts of land cover changes and climate change over time.

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Watershed Hydrological Response to Combined Land Use/Land Cover and Climate Change in Highland Ethiopia: Finchaa Catchment

Water ◽

10.3390/w12061801 ◽

2020 ◽

Vol 12 (6) ◽

pp. 1801 ◽

Cited By ~ 1

Author(s):

Wakjira Takala Dibaba ◽

Tamene Adugna Demissie ◽

Konrad Miegel

Keyword(s):

Climate Change ◽

Land Use ◽

Water Resources ◽

Land Cover ◽

Surface Runoff ◽

Regional Climate ◽

Water Yield ◽

Land Use Land Cover ◽

Ensemble Mean ◽

The Future

Land use/land cover (LULC) and climate change affect the availability of water resources by altering the magnitude of surface runoff, aquifer recharge, and river flows. The evaluation helps to identify the level of water resources exposure to the changes that could help to plan for potential adaptive capacity. In this research, Cellular Automata (CA)-Markov in IDRISI software was used to predict the future LULC scenarios and the ensemble mean of four regional climate models (RCMs) in the coordinated regional climate downscaling experiment (CORDEX)-Africa was used for the future climate scenarios. Distribution mapping was used to bias correct the RCMs outputs, with respect to the observed precipitation and temperature. Then, the Soil and Water Assessment Tool (SWAT) model was used to evaluate the watershed hydrological responses of the catchment under separate, and combined, LULC and climate change. The result shows the ensemble mean of the four RCMs reported precipitation decline and increase in future temperature under both representative concentration pathways (RCP4.5 and RCP8.5). The increases in both maximum and minimum temperatures are higher for higher emission scenarios showing that RCP8.5 projection is warmer than RCP4.5. The changes in LULC brings an increase in surface runoff and water yield and a decline in groundwater, while the projected climate change shows a decrease in surface runoff, groundwater and water yield. The combined study of LULC and climate change shows that the effect of the combined scenario is similar to that of climate change only scenario. The overall decline of annual flow is due to the decline in the seasonal flows under combined scenarios. This could bring the reduced availability of water for crop production, which will be a chronic issue of subsistence agriculture. The possibility of surface water and groundwater reduction could also affect the availability of water resources in the catchment and further aggravate water stress in the downstream. The highly rising demands of water, owing to socio-economic progress, population growth and high demand for irrigation water downstream, in addition to the variability temperature and evaporation demands, amplify prolonged water scarcity. Consequently, strong land-use planning and climate-resilient water management policies will be indispensable to manage the risks.

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Probable streamflow changes and its associated risk to the water resources of Abuan watershed, Philippines caused by climate change and land use changes

Stochastic Environmental Research and Risk Assessment ◽

10.1007/s00477-020-01953-3 ◽

2020 ◽

Author(s):

Arnan Araza ◽

Maricon Perez ◽

Rex Victor Cruz ◽

Larlyn Faith Aggabao ◽

Eugene Soyosa

Keyword(s):

Climate Change ◽

Land Use ◽

Water Resources ◽

Land Cover ◽

Crop Production ◽

Crop Yields ◽

Land Use Changes ◽

The Philippines ◽

Climate Projections ◽

Baseline Model

AbstractOne of the main impact areas of climate change (CC), and land use and land cover change (LULCC) is the hydrology of watersheds, which have negative implications to the water resources. Their impact can be indicated by changes on streamflow, which is quantifiable using process-based streamflow modelling of baseline and future scenarios. Here we include the uncertainty and associated risk of the streamflow changes for a robust impact assessment to agriculture. We created a baseline model and models of CC and LULCC “impact scenarios” that use: (1) the new climate projections until 2070 and (2) land cover scenarios worsened by forest loss, in a critical watershed in the Philippines. Simulations of peak flows by 26% and low flows by 63% from the baseline model improved after calibrating runoff, soil evaporation, and groundwater parameters. Using the calibrated model, impacts of both CC and LULCC in 2070 were indicated by water deficit (− 18.65%) from May to August and water surplus (12.79%) from November to December. Both CC and LULCC contributed almost equally to the deficit, but the surplus was more LULCC-driven. Risk from CC may affect 9.10% of the croplands equivalent to 0.31 million dollars, while both CC and LULCC doubled the croplands at risk (19.13%, 0.60 million dollars) in one cropping season. The findings warn for the inevitable cropping schedule adjustments in the coming decades, which both apply to irrigated and rainfed crops, and may have implications to crop yields. This study calls for better watershed management to mitigate the risk to crop production and even potential flood risks.

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ESTIMASI HASIL AIR DARI DAERAH TANGKAPAN AIR DANAU RAWA PENING DENGAN MENGGUNAKAN MODEL INVEST

MAJALAH ILMIAH GLOBE ◽

10.24895/mig.2017.19-2.578 ◽

2017 ◽

Vol 19 (2) ◽

pp. 157

Author(s):

Nunung Puji Nugroho

Keyword(s):

Spatial Distribution ◽

Ecosystem Services ◽

Water Resources ◽

High Water ◽

Water Yield ◽

Accurate Information ◽

Yield Model ◽

Catchment Areas ◽

Integrated Valuation ◽

Valuation Of Ecosystem Services

ABSTRAKInformasi hasil air dari suatu ekosistem sangat penting dalam pengelolaan sumber daya air. Dalam perencanaan kegiatan konservasi sumber daya air, informasi sebaran spasial hasil air diperlukan untuk menentukan prioritas wilayah terkait dengan alokasi anggaran. Hasil air dari suatu ekosistem atau daerah aliran sungai (DAS) dapat diestimasi dengan menggunakan model hidrologi. Penelitian ini bertujuan untuk mendapatkan informasi tentang hasil air, baik besaran maupun sebaran spasialnya, dari daerah tangkapan air (DTA) Danau Rawa Pening. Hasil air dari lokasi penelitian dihitung dengan menggunakan model hasil air pada InVEST (the Integrated Valuation of Ecosystem Services and Tradeoffs), yang didasarkan pada pendekatan neraca air. Hasil perhitungan menunjukkan bahwa volume hasil air di DTA Danau Rawa Pening pada tahun 2015 adalah sekitar 337 juta m3. SubDAS Galeh, sebagai subDAS terluas, merupakan penghasil air terbesar (72,4 juta m3) diikuti oleh subDAS Sraten (66,8 juta m3) dan Parat (62,4 juta m3). Secara spasial, hasil air di lokasi kajian mempunyai nilai antara 0 hingga 29.634,19 m3/ha. Wilayah hulu dan tengah subDAS Sraten secara umum mempunyai hasil air yang lebih tinggi, sedangkan wilayah danau dan sekitarnya serta hulu subDAS Galeh mempunyai hasil air yang lebih rendah dibandingkan dengan wilayah lainnya. Wilayah dengan hasil air tinggi dapat diprioritaskan dalam kegiatan konservasi sumber daya air untuk mendukung pasokan air ke Danau Rawa Pening.Kata kunci: hasil air, daerah tangkapan air, model InVEST, Danau Rawa PeningABSTRACTAccurate information on water yield from an ecosystem is very important in the management of water resources. In the planning of water resources conservation activities, the information on the spatial distribution of water yield is needed to determine regional priorities related to budget allocations. The water yield from an ecosystem or watershed can be estimated using a hydrological model. This study aimed to obtain information about the water yield, both the magnitude and their spatial distribution, from the catchment areas of Lake Rawa Pening. The water yield from the study area was calculated using the water yield model in InVEST (the Integrated Valuation of Ecosystem Services and Tradeoffs), which based on the water balance approach. The results indicated that the volume of water yield in Lake Rawa Pening for 2015 is approximately 337 million m3. Galeh subwatershed, as the largest subwatershed, is the largest water producer (72.4 million m3), followed by Sraten subwatershed (66.8 million m3) and Parat subwatershed (62.4 million m3). Spatially, the water yield at the study site has a value between 0 to 29,634.19 m3/ha. Upstream and middle areas of Sraten subwatershed generally have higher water yield, while the lake and its surrounding areas as well as the upstream of Galeh subwatershed have lower water yield compared to other regions. The regions with high water yield can be prioritized in water resource conservation activities to support the supply of water to Lake Rawa Pening.Keywords: water yield, catchment areas, InVEST model, Lake Rawa Pening

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Impact of Climate and Land Use/Land Cover Change on the Water Resources of a Tropical Inland Valley Catchment in Uganda, East Africa

Climate ◽

10.3390/cli8070083 ◽

2020 ◽

Vol 8 (7) ◽

pp. 83

Author(s):

Geofrey Gabiri ◽

Bernd Diekkrüger ◽

Kristian Näschen ◽

Constanze Leemhuis ◽

Roderick van der Linden ◽

...

Keyword(s):

Climate Change ◽

Land Use ◽

Water Resources ◽

Land Cover ◽

Rainy Season ◽

Hydrological Processes ◽

Land Use Land Cover ◽

Lulc Change ◽

Inland Valley ◽

Headwater Catchment

The impact of climate and land use/land cover (LULC) change continues to threaten water resources availability for the agriculturally used inland valley wetlands and their catchments in East Africa. This study assessed climate and LULC change impacts on the hydrological processes of a tropical headwater inland valley catchment in Uganda. The hydrological model Soil and Water Assessment Tool (SWAT) was applied to analyze climate and LULC change impacts on the hydrological processes. An ensemble of six regional climate models (RCMs) from the Coordinated Regional Downscaling Experiment for two Representative Concentration Pathways (RCPs), RCP4.5 and RCP8.5, were used for climate change assessment for historical (1976–2005) and future climate (2021–2050). Four LULC scenarios defined as exploitation, total conservation, slope conservation, and protection of headwater catchment were considered. The results indicate an increase in precipitation by 7.4% and 21.8% of the annual averages in the future under RCP4.5 and RCP8.5, respectively. Future wet conditions are more pronounced in the short rainy season than in the long rainy season. Flooding intensity is likely to increase during the rainy season with low flows more pronounced in the dry season. Increases in future annual averages of water yield (29.0% and 42.7% under RCP4.5 and RCP8.5, respectively) and surface runoff (37.6% and 51.8% under RCP4.5 and RCP8.5, respectively) relative to the historical simulations are projected. LULC and climate change individually will cause changes in the inland valley hydrological processes, but more pronounced changes are expected if the drivers are combined, although LULC changes will have a dominant influence. Adoption of total conservation, slope conservation and protection of headwater catchment LULC scenarios will significantly reduce climate change impacts on water resources in the inland valley. Thus, if sustainable climate-smart management practices are adopted, the availability of water resources for human consumption and agricultural production will increase.

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Land Cover/ Land Use Change and Climate Change in Dhofar Governorate, Oman

International Journal of Geoinformatics ◽

10.52939/ijg.v17i4.1949 ◽

2021 ◽

pp. 41-47

Author(s):

E. Ramadan ◽

T. Al-Awadhi ◽

Y. Charabi

Keyword(s):

Climate Change ◽

Land Use ◽

Land Cover ◽

Land Cover Change ◽

Land Use Changes ◽

Spatial Differentiation ◽

Study Results ◽

Vegetation Activity ◽

The Status ◽

Landsat Satellite

The study of land cover/land use dynamics under climate change conditions is of great significance for improving sustainable ecological management. Understanding the relationships between land cover and land use changes and climate change is thus very important. Understanding the interactive and cumulative effects of climate and land-use changes are a priority for urban planners and policy makers. The present investigation is based on Landsat satellite imagery to explore changes in vegetation spatial distribution between the years from 2000 to2018 The methodology is focused on vegetation indexes tracking and algebraic overlay calculation to analyzed vegetation and their spatial differentiation, land cover change pattern, and the relationships between vegetation dynamics and land cover change in Dhofar Governorate. The study results have revealed that the vegetation vigor is lower in all years compared to 2000. The scene of 2010 shows the minimum vegetation vigor, overall. Besides, the investigation shows a statistical relationship between rainfall and the status of the health of vegetation. Monsoon rainfall has an impact of the growth of vegetation. Between 2012 and 2013, the vegetation activity shows a decreasing trend. The analysis diagnoses an area affected by the worst degree of aridity situated in the southeastern of Dhofar Mountains. Climate change is the main driving factor resulted from both human activities and rainfall fluctuation.

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Groundwater recharge and groundwater water resources under present and future climate over the Pyrenees (France, Spain, Andorre)

10.5194/egusphere-egu21-16471 ◽

2021 ◽

Author(s):

Yvan Caballero ◽

Sandra Lanini ◽

Pierre Le Cointe ◽

Stéphanie Pinson ◽

Guillaume Hevin ◽

...

Keyword(s):

Climate Change ◽

Water Resources ◽

Land Cover ◽

Groundwater Recharge ◽

Hot Spot ◽

Infiltration Capacity ◽

Mountain Areas ◽

Development Fund ◽

Effective Precipitation ◽

Potential Groundwater

Climate change is expected to have a significant impact on water resources in mountain areas, as it is the case of the Pyrenees range between France, Spain and Andorre. Independently of future changes on rainfall patterns, global temperature rise is likely to provoke larger and earlier snowmelt, and enhanced precipitation deficits during the dry summer season. Exploring the impacts of this future situation on groundwater is essential, as this resource is often important for drinking water, irrigation and breeding uses in mountain regions. However, studies on groundwater recharge in the context of climate change are relatively scarce, as compared to studies focusing on surface water resources.We assessed potential groundwater recharge (part of effective precipitation that infiltrates and potentially reach the aquifers) over the Pyrenean range in the framework of the PIRAGUA project, a collaborative multi-national effort funded by the EU&#8217;s Interreg POCTEFA program. Based on a gridded (5x5 km&#178;) meteorological dataset derived from observational data by the CLIMPY project, we estimated effective precipitation for each grid cell using a conceptual water balance scheme. The effect of the seasonal change of land cover / land use (based on the Corine Land Cover dataset) on the water budget model has been assessed, and showed the need to include this component for a more accurate simulation. Based on a spatial characterization of the land infiltration capacity, the potential groundwater recharge has been computed for homogeneous groundwater bodies. Results have been compared to the outputs of groundwater models applied on selected karstic catchments using the BALAN code, and to a general knowledge of groundwater recharge rates for different regions within the study zone. Finally, climate change impacts on future IDPR have been explored using scenarios provided by the CLIMPY project.The Pyrenees range is a hot-spot for water resources with a tremendous impact over a much broader region in SW Europe, as Pyrenean rivers are fundamental contributors to large systems such as those of the Adour and Garonne (France) or Ebro (Spain), as well as smaller systems in the western and eastern sectors such as the Bidasoa (Spanish Basque Country), Llobregat-Ter-Muga (Catalonia), or T&#234;t-Tech-Aude (France). Our results are relevant for the planning and management of water resources for this important transboundary region in the future, as changes in groundwater recharge will also affect water resources availability.Acknowledgments: the project PIRAGUA, is funded by the European Regional Development Fund (ERDF) through the Interreg V-A Spain France Andorra programme (POCTEFA 2014-2020).

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Hydrological Alteration Index as an Indicator of the Calibration Complexity of Water Quantity and Quality Modeling in the Context of Global Change

Water ◽

10.3390/w12010115 ◽

2019 ◽

Vol 12 (1) ◽

pp. 115 ◽

Cited By ~ 3

Author(s):

Roxelane Cakir ◽

Mélanie Raimonet ◽

Sabine Sauvage ◽

Javier Paredes-Arquiola ◽

Youen Grusson ◽

...

Keyword(s):

Climate Change ◽

Water Quality ◽

Water Resources ◽

Stream Water ◽

Swat Model ◽

Water Yield ◽

Observation Data ◽

Hydrological Alteration ◽

Water Quality And Quantity ◽

The Impact

Modeling is a useful way to understand human and climate change impacts on the water resources of agricultural watersheds. Calibration and validation methodologies are crucial in forecasting assessments. This study explores the best calibration methodology depending on the level of hydrological alteration due to human-derived stressors. The Soil and Water Assessment Tool (SWAT) model is used to evaluate hydrology in South-West Europe in a context of intensive agriculture and water scarcity. The Index of Hydrological Alteration (IHA) is calculated using discharge observation data. A comparison of two SWAT calibration methodologies are done; a conventional calibration (CC) based on recorded in-stream water quality and quantity and an additional calibration (AC) adding crop managements practices. Even if the water quality and quantity trends are similar between CC and AC, water balance, irrigation and crop yields are different. In the context of rainfall decrease, water yield decreases in both CC and AC, while crop productions present opposite trends (+33% in CC and −31% in AC). Hydrological performance between CC and AC is correlated to IHA: When the level of IHA is under 80%, AC methodology is necessary. The combination of both calibrations appears essential to better constrain the model and to forecast the impact of climate change or anthropogenic influences on water resources.

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Drought Risk under Climate and Land Use Changes: Implication to Water Resource Availability at Catchment Scale

Water ◽

10.3390/w11091790 ◽

2019 ◽

Vol 11 (9) ◽

pp. 1790 ◽

Cited By ~ 1

Author(s):

Muhammad Afzal ◽

Ragab Ragab

Keyword(s):

Climate Change ◽

Land Use ◽

Water Resources ◽

Groundwater Recharge ◽

Land Use Changes ◽

Future Climate Change ◽

Emission Scenarios ◽

Catchment Scale ◽

High Emission ◽

The Impact

Although the climate change projections are produced by global models, studying the impact of climatic change on water resources is commonly investigated at catchment scale where the measurements are taken, and water management decisions are made. For this study, the Frome catchment in the UK was investigated as an example of midland England. The DiCaSM model was applied using the UKCP09 future climate change scenarios. The climate projections indicate that the greatest decrease in groundwater recharge and streamflow was projected under high emission scenarios in the 2080s. Under the medium and high emission scenarios, model results revealed that the frequency and severity of drought events would be the highest. The drought indices, the Reconnaissance Drought Index, RDI, Soil Moisture Deficit, SMD and Wetness Index, WI, predicted an increase in the severity of future drought events under the high emission scenarios. Increasing broadleaf forest area would decrease streamflow and groundwater recharge. Urban expansion could increase surface runoff. Decreasing winter barley and grass and increasing oil seed rape, would increase SMD and slightly decrease river flow. Findings of this study are helpful in the planning and management of the water resources considering the impact of climate and land use changes on variability in the availability of surface and groundwater resources.

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The Impact of Land Use/Land Cover Change (LULCC) on Water Resources in a Tropical Catchment in Tanzania under Different Climate Change Scenarios

Sustainability ◽

10.3390/su11247083 ◽

2019 ◽

Vol 11 (24) ◽

pp. 7083 ◽

Cited By ~ 4

Author(s):

Kristian Näschen ◽

Bernd Diekkrüger ◽

Mariele Evers ◽

Britta Höllermann ◽

Stefanie Steinbach ◽

...

Keyword(s):

Climate Change ◽

Land Use ◽

Water Resources ◽

Land Cover ◽

Water Balance ◽

Land Cover Change ◽

Sub Saharan Africa ◽

Climate Change Scenarios ◽

Land Use Land Cover ◽

The Impact

Many parts of sub-Saharan Africa (SSA) are prone to land use and land cover change (LULCC). In many cases, natural systems are converted into agricultural land to feed the growing population. However, despite climate change being a major focus nowadays, the impacts of these conversions on water resources, which are essential for agricultural production, is still often neglected, jeopardizing the sustainability of the socio-ecological system. This study investigates historic land use/land cover (LULC) patterns as well as potential future LULCC and its effect on water quantities in a complex tropical catchment in Tanzania. It then compares the results using two climate change scenarios. The Land Change Modeler (LCM) is used to analyze and to project LULC patterns until 2030 and the Soil and Water Assessment Tool (SWAT) is utilized to simulate the water balance under various LULC conditions. Results show decreasing low flows by 6–8% for the LULC scenarios, whereas high flows increase by up to 84% for the combined LULC and climate change scenarios. The effect of climate change is stronger compared to the effect of LULCC, but also contains higher uncertainties. The effects of LULCC are more distinct, although crop specific effects show diverging effects on water balance components. This study develops a methodology for quantifying the impact of land use and climate change and therefore contributes to the sustainable management of the investigated catchment, as it shows the impact of environmental change on hydrological extremes (low flow and floods) and determines hot spots, which are critical for environmental development.

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Hydrological Responses to Climate and Land Use Changes in a Watershed of the Loess Plateau, China

Sustainability ◽

10.3390/su11051443 ◽

2019 ◽

Vol 11 (5) ◽

pp. 1443 ◽

Cited By ~ 10

Author(s):

Rui Yan ◽

Yanpeng Cai ◽

Chunhui Li ◽

Xuan Wang ◽

Qiang Liu

Keyword(s):

Climate Change ◽

Land Use ◽

Water Balance ◽

Loess Plateau ◽

Climate Changes ◽

Land Use Changes ◽

Water Yield ◽

The Loess Plateau ◽

Runoff Water ◽

Lulc Change

This study researched the individual and combined impacts of future LULC and climate changes on water balance in the upper reaches of the Beiluo River basin on the Loess Plateau of China, using the scenarios of RCP4.5 and 8.5 of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). The climate data indicated that both precipitation and temperature increased at seasonal and annual scales from 2020 to 2050 under RCP4.5 and 8.5 scenarios. The future land use changes were predicted through the CA-Markov model. The land use predictions of 2025, 2035, and 2045 indicated rising forest areas with decreased agricultural land and grassland. In this study, three scenarios including only LULC change, only climate change, and combined climate and LULC change were established. The SWAT model was calibrated, validated, and used to simulate the water balance under the three scenarios. The results showed that increased rainfall and temperature may lead to increased runoff, water yield, and ET in spring, summer, and autumn and to decreased runoff, water yield, and ET in winter from 2020 to 2050. However, LULC change, compared with climate change, may have a smaller impact on the water balance. On an annual scale, runoff and water yield may gradually decrease, but ET may increase. The combined effects of both LULC and climate changes on water balance in the future were similar to the variation trend of climate changes alone at both annual and seasonal scales. The results obtained in this study provide further insight into the availability of future streamflow and can aid in water resource management planning in the study area.

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