Self-supporting freshwater availability along the coastal zones in the Netherlands Spaarwater

Transcription

1 Self-supporting freshwater availability along the coastal zones in the Netherlands Spaarwater Implementing climate resilient water management projects to increase adaptive capacities, food security & avoid conflict over resources Jouke Velstra Han de Kreuk Contents Salinization in the Netherlands What can we expect in the future Enough water, but... Examples of succesfull solutions Concluding remarks 2 1

2 Fresh rain water lens Agriculture possible by the existence of fresh rain water lenses which float on saline water Expected risk to disappear, due to (1) sea level rise, (2) land subsidence and (3) climate change Fresh water geophysical cross-section Saline groundwater Depending heavily on inflow of fresh water Large areas with diffuse upward seepage of saline groundwater Water quality maintained by flushing with fresh water from the river Rhine, main source of irrigation water. State Rivers Rhine and Lake IJssel Water authorities Main water system in the region Farmers Small water courses and plot drainage Salt load from diffuse seepage (kg/ha/jr) Area provided with water from Rhine (July, dry year) 2

3 Enough water, but in the wrong place at the wrong time Increasing demand of fresh water for flushing Increase salinization surface water Increase evapo(transpi)ration Irrigation and maintaining water levels Shift towards high value crops High quality water Ambition increase crop yield by 2% per year River discharge becomes less reliable due to melting of glaciers Enough water, but in the wrong place at the wrong time availability demand water volume & quality surplus shortage time 3

4 Enough water, but in the wrong place at the wrong time Solution is in making water surplus available in times of shortage availability demand water volume & quality surplus shortage time Enough water, at the right place at the right time: Small scale solutions using: 4

5 Enough water, at the right place at the right time: Small scale solutions using: Tile drainage Open storage pond Surface drip irrigation Roof top Shallow subsurface storage Subsurface drip irrigation Paved surface Subsurface storage (ASR) Sprinkler irrigation Subirrigation (tile drainage) Fertigation 2 Self-supporting freshwater availability & Borgsweer - Groningen Seed potatoes Saline area and thus periodic scarcity in water availability Irrigation from surface water not allowed because of brown rot fungus Tile drainage Open storage pond Surface drip irrigation Roof top Shallow subsurface storage Subsurface drip irrigation Paved surface Subsurface storage (ASR) Sprinkler irrigation Subirrigation (tile drainage) Fertigation 5

6 2 Self-supporting freshwater availability & Source 1.5 ha tile drainage via collectordrain Tile drainage EC EC Filter ditch brakish water 2 Self-supporting freshwater availability & Storage Subsurface storage (10m 20m below surface) 1 infiltration well & 3 abstraction wells (2 filters each) to enhance removal of pathogenes Observed fresh water storage Subsurface storage Tile drainage EC EC Filter ditch fresh water -10m brakish water -20m 6

7 2 Self-supporting freshwater availability & Use 0.5 ha Subsurface drip irrigation More efficient Lower labour costs Suburface drip irrigation Moisture in the rootzone Drip lines Dry fresh water -10m brakish water -20m 2 Self-supporting freshwater availability & Benefits Self-supporting is feasible 10 ha source -> ca ha use Reduced risk of diseases (also other crop related diseases like erwinia in bulbs) Expected removal of brown rot fungus during subsurface storage Optimized crop yield > 20% increase Long life expectancy of subsurface drip lines Tile drainage Open storage pond Surface drip irrigation Roof top Shallow subsurface storage Subsurface drip irrigation Paved surface Subsurface storage (ASR) Sprinkler irrigation Subirrigation (tile drainage) Fertigation 7

8 3 Self-supporting freshwater availability & Source tile drainage via collectordrain and roof top Storage Open storage pond (>9000m3) Use Surface drip irrigation / fertigation Subirrigation (controlled drainage) to maintain groundwater level Roof top Tile drainage Open storage pond surface drip irrigation subirrigation 3 Self-supporting freshwater availability & Benefits Self-supporting is feasible 10 ha source -> ca. 35 ha use Optimized crop yield: >15% bulbs & >25% sugar beets Precision farming with fertigation (drip and fertilizer) Decrease in use water and nutrients Tile drainage Open storage pond Surface drip irrigation Roof top Shallow subsurface storage Subsurface drip irrigation Paved surface Subsurface storage (ASR) Sprinkler irrigation Subirrigation (tile drainage) Fertigation 8

9 International context Example Uganda area with high food insecurity Day 1 Day 2 Day 3 Succesfull smale scale local solutions Sand dams Kenia & Ethiopia Making safe water available Subsurface storage Bangladesh Making safe water available 9

10 Practical maps with small scale solutions Long term solutions!!! Water security Food security Disaster risk reduction Combine succesfull solutions and mapping suitable regions 19 Concluding remarks Self-supporting in water (drinking water + agricultural use) is within in reach using components from Source Storage Use Self-supporting is crucial for secure and safe drinking water and improved crop production Additional benefits (cost-benefit) are Improved water efficiency Reduced risk of diseases Reduced application of fertilizer Optimized crop yield SOURCE : USE 10 ha : 12 ha 35 ha 10

11 Thank you Jouke Velstra Acacia Water ( ) Jouke.velstra@acaciawater.com Han de Kreuk 21 1 (Remote) controlled drainage Hornhuizen Groningen Wheat and bulbs No fresh rainwater lens present 40m Saline groundwater ~ mg/l chloride 5m Tile drainage Open storage pond Surface drip irrigation Roof top Shallow subsurface storage Subsurface drip irrigation Paved surface Subsurface storage (ASR) Sprinkler irrigation Subirrigation (tile drainage) Fertigation 11

12 Before After 1 (Remote) controlled drainage Drainage depth changed from 1m depth to 1.6m depth Adjustable drainage level ( m depth) Real time monitoring (groundwater and salinity) Remote controlled drainage level autumn/winter summer 1 (Remote) controlled drainage Increase thickness rainwater lens (fresh water buffer) Prevent saline groundwater to reach root zone Maintain or improve dewatering by adjusting drainage level Decrease discharge of nutrients to surface water With controlled drainage Original situation Increase in 1 year 15cm 12