Recommended
Recommended
More Related Content
What's hot
What's hot (20)
Similar to The impact of climate change and sustainable land management based adaptation on hydrology and soil erosion of a large semiarid catchment
Similar to The impact of climate change and sustainable land management based adaptation on hydrology and soil erosion of a large semiarid catchment (20)
Recently uploaded
Recently uploaded (20)
The impact of climate change and sustainable land management based adaptation on hydrology and soil erosion of a large semiarid catchment
- 1. The impact of climate change and sustainable land management based adaptation on hydrology and soil erosion of a large semiarid catchment Joris Eekhout (CEBAS-CSIC), Joris de Vente (CEBAS-CSIC), and Wilco Terink (FutureWater)
- 2. Segura River catchment Segura River catchment
- 3. Semi-arid climate Yearly precipitation: 350 mm Catchment size: 15900 km2
- 4. Analysis of 9 RCMs Catchment-averaged decrease of precipitation and increase of temperature
- 5. 51% of catchment used for agriculture 24% orchards (almond trees, fruit trees and olive trees)
- 6. 33 reservoirs Water is used for irrigation and drinking water
- 7. Main results: Ongoing field experiment since 2007 in almond orchard: • Conventional tillage (control) • Reduced tillage • Reduced tillage + green manure 60-70% decrease of soil erosion 15% increase in soil moisture 55% decrease in surface runoff
- 8. Main results: Ongoing field experiment since 2007 in almond orchard: • Conventional tillage (control) • Reduced tillage • Reduced tillage + green manure 60-70% decrease of soil erosion 15% increase in soil moisture 55% decrease in surface runoff Objective: To assess the catchment scale effect of SLM on water availability and soil erosion under current and future climate conditions
- 9. MUSLE Surface runoff Precipitation Evapotranspiration Infiltration Rootzone layer Subsoil layer Groundwater layer Terink et al. (2015) Geosci. Model Dev., 8 SPHY model PCRaster Transport Capacity TC = k qβ slope γ SY = 11.8 (Qsurf qpeak A)0.56 K C P LS CFRG Williams (1975) Proc. Sed. Yield Workshop Prosser & Rustomji (2000) Prog. in Phys. Geogr., 24 Model details • 200 m grid • Daily time step • 20-year model period (1981- 2000, 2031-2050, 2081-2100) • Calibration/validation in head waters • Nash–Sutcliffe: 0.67
- 10. Surface runoff Discharge Precipitation Actual evapo- transpiration Infiltration Soil moisture Crop stress RAW = p · TAW p = pcrop + 0.04 (5-ETp) Allen, et al. (1998) FAO report 56
- 11. +35.6%45 mm 790 Hm3 303 mm 256 mm 268 mm 105 mm 1981-2000 2031-2050 0.66 +29.7% +3.7% -2.6% -3.0% -1.5% +4.1% Impact future climate on water availability
- 12. Soil erosion Sediment yield Impact future climate on soil erosion 1981-2000 2031-2050
- 13. +51.0% 1.6 ton ha-1yr-1 1981-2000 2031-2050 +70.0% 8.4 ton ha-1yr-1 Impact future climate on soil erosion
- 14. Reduced Tillage Reduced Tillage + OM amendment Soil organic matter1,2 +17% +43% Bulk density1,2 -4% -4% C-factor3 -35% -35% Crop factor Increase in winter Increase in winter 1 Aguilera et al. (2013) Agric. Ecosyst. Environ.,168 2 Almagro et al. (2015) Mitig. adapt. strategies glob. chang., in press 3 Panagos et al. (2015) Land Use Policy, 48
- 15. -12.7% -2.9% +0% +2.3% +2.1% +1.7% +0.4% -29.4%45 mm 790 Hm3 303 mm 256 mm 268 mm 105 mm 1981-2000 / no 1981-2000 / RT 1981-2000 / 0.66 -6.1% +0% +4.9% +4.9% +5.2% -1.3 % Impact SLM on water availability
- 16. 1981-2000 / no -42.8%8.4 ton ha-1yr-1 -3.0% -54.0% -5.2%1.6 ton ha-1yr-1 1981-2000 / RT 1981-2000 / Impact SLM on soil erosion
- 17. +23.1% +27.1% +3.7% -0.6% -1.0% +0.3% +4.2% +6.0%+35.6% +29.7% +3.7% -2.6% -3.0% -1.5% 2031-2050 / no slm 2031-2050 / RT 2031-2050 / RT+OM +4.1% +23.7% +3.7% +2.1% +1.9% +4.0% +2.3% Impact SLM and climate change on water availability
- 18. 2031-2050 / no slm -11.8%+51.0% +70.0% +65.9% -27.1% +63.2% Impact SLM and climate change on soil erosion 2031-2050 / RT 2031-2050 / RT+OM
- 19. Conclusions Future precipitation decrease causes an increase in crop stress, which will affect crop yield Increase in intense precipitation causes an increase in surface runoff and soil erosion SLM may significantly mitigate these effects at the field scale RT may still lead to crop stress, while in combination with organic amendments, crop stress will decrease SLM can mitigate the catchment scale effect of CC by 3-7% We will continue… …to run the model forced with other RCM output and provide ensemble predictions …to implement SLM measures in cereal fields (13% catchment) …to evaluate the tempering effect of SLM on frequency and intensity of extreme discharge and soil erosion rates
- 20. Thank you for your attention! Twitter: @JorisEekhout & @CEBAS_SWC www.joriseekhout.com
Editor's Notes
- Today I will present the results of a model study on the impact of climate change and sustainable land management on a large-scale semi-arid catchment in SE Spain This study is a result of a colaboration between CEBAS-CSIC from Spain and FutureWater from the Netherlands First I will give a short introduction of the catchment characteristics
- The segura catchment is located in SE spain
- The segura catchment is a semi-arid catchment with an average yearly precipitation of 350 mm The precipitation is not evenly distributed over the catchment In the head waters the yearly precipitation amounts to 600 mm
- Future climate scenarios show a strong impact in the catchment We analysed 9 Regional Climate Models and averaged the yearly precipitation and temperature for the whole catchment The results show an overall decrease of precipitation, up to 100 mm in the period 2081-2100 And an overall increase of temperature, up to 4 degrees in the same period Besides most RCMs show an increase of intense precipitation events
- The main land use type in the catchment is agriculture, which amounts to 51% of the surface area of the catchment About half of this area is used for orchards, such as almond trees, fruit trees and olive trees With decreasing precipitation amounts and increasing temperature, these agricultural areas will be under pressure
- A total of 33 reservoirs are located in the catchment Water in these reservoirs is used for irrigation and drinking water It is therefore important that the capacity of these reservoirs are maintained, under current and future climate conditions Although the RCMs show a decrease of precipitation, soil erosion may increase as a result of an increase in intense rainfall We hypothesise that under future climate conditions the capacity of these reservoirs will be under pressure due to an increase in soil erosion
- Sustainable land management is a promising technique to increase soil moisture and decrease soil erosion and surface runoff and mitigate climate change effects In an ongoing field experiment in an almond orchard located in the catchment, two types of SLM have been implemented: reduced tillage and reduced tillage and green manure amendment The main results of this field experiment are a decrease of soil erosion and an increase in soil moisture Our study aims to upscale the application of SLM to all orchards in the catchment and to asses the catchment scale effect of SLM on water availability and soil erosion under current and future climate conditions
- Sustainable land management is a promising technique to increase soil moisture and decrease soil erosion and surface runoff and mitigate climate change effects In an ongoing field experiment in an almond orchard located in the catchment, two types of SLM have been implemented: reduced tillage and reduced tillage and green manure amendment The main results of this field experiment are a decrease of soil erosion and an increase in soil moisture Our study aims to upscale the application of SLM to all orchards in the catchment and to asses the catchment scale effect of SLM on water availability and soil erosion under current and future climate conditions
- To achieve this, we applied the SPHY model (Spatial Processes in Hydrology), which is a leaky bucket type of model This diagram shows the main processes of the model The model makes use of the PCRaster framework We coupled the model with MUSLE equation and included a transport capacity formula in the channel cells
- In this presentation I will show the results of one RCM and will focus on the processes that may occur under future climate conditions, which are shown in this diagram The diagram consists of two parts, the upper part concentrates on the plot-scale impact and consists of the average values from all orchard cells The lower part focusses on the catchment-scale impact All processes are directly obtained from the model, apart from the crop stress index We define the crop stress as follows (pointing at crop stress figure)
- The values shown in the diagram are those under current climate conditions It is important to emphasize that in the area where SLM is proposed to be implemented, the precipitation amounts to only 300 mm per year Under future conditions a small increase of precipitation is observed, even though, soil moisture will decrease and crop stress will increase This is for a large part the consequence of an increase in intense precipitation, which causes an increase of surface runoff
- So how will this affect soil erosion?
- Under current climate conditions, the specific sediment yield in orchards amounts to 8.4 ton per ha per year and on catchment scale to 1.6 ton per ha per year The increase in intense precipitation and surface runoff will cause an increase in soil erosion of 51% on plot scale and to 70% on catchment-scale
- Our results have shown that future climate conditions may result in a decrease in soil moisture and an increase in soil erosion The field experiment and other results obtained from the literature have shown SLM may have a positive impact on soil moisture and soil erosion We implemented SLM measures to all orchard cells according to this table We applied two types of SLM: reduced tillage and reduced tillage plus organic matter amendment
- First I will show the results of the impact of SLM under current climate conditions The diagram on the left shows the same reference model runs as shown before The other two diagrams will show the results of the reduced tillage and reduced tillage plus OM amendment model runs When reduced tillage is applied, surface runoff will decrease and soil moisture will increase The decrease of surface runoff will cause a decrease of discharge, the opposite effect as we saw before under future climate conditions When OM amendment is also applied, the surface runoff will decrease and soil moisture will increase even more
- The impact on soil erosion is as expected: a decrease in soil erosion On plot-scale, the effect is comparable to the effect from the field experiment On catchment-scale, the impact will be a decrease of 5% of specific sediment yield
- This slide shows the results when SLM measures are applied under future climate conditions, the values that are shown are percentages with respect to the scenario under current climate condtions without SLM When only reduced tillage is applied to the orchard cells, the surface runoff will decrease compared to the reference scenario without SLM Similar to the results under current climate conditions, OM amendment increases the impact with an increase of soil moisture of 4% with respect to the reference run This will cause a decrease of crop stress
- When focussing on soil erosion, on plot-scale SLM may reduce soil erosion, even under future climate conditions On catchment-scale the impact of climate change seems to predominate, although a decrease of 7% specific sediment yield is achieved with respect to the future scenario without SLM
- Future precipitation decrease causes an increase in crop stress, which will affect crop yield Increase in intense precipitation causes an increase in surface runoff and soil erosion SLM may significantly mitigate these effects at the field scale… RT positively affects soil water content, but may still lead to crop stress, while in combination with organic amendments, crop stress will also decrease At the catchment scale, SLM in orchards (24% of the catchment) can mitigate the effect of climate change on discharge and sediment yield by 3-7% We will continue… …to run the model forced with other RCM output and provide ensemble predictions …to implement SLM measures in cereal fields (13% of the catchment) …to evaluate the tempering effect of SLM on frequency and intensity of extreme discharge and soil erosion rates