Create Presentation
Download Presentation

Download Presentation
## Planning with water - an overview

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -

**Planning with water - an overview**Paul van Walsum**Overview**• introduction • regional influencing through GW & SW • methods for decision support • influence matrix method • embedding method**Regional influencing through GW & SW**• pressure wave • droplet movement**Methods for decision support**• simulation models • optimization models • linked optimization-simulation models**Planning with water, ‘conventional style’**Stakeholders suggest measures communication simulation effects on objectives**Planning with water, ‘inverse approach’**measures communication optimization Stakeholders: • targets on objectives • options for measures**Integrated model**simple reduction verification complex economy ecology hydrology Multi-level modelling**Optimization model using LP**• x1, x2,... vector of decision variables x xi = 0 : no, you do not do it xi = 1 : yes, you do it • g1x1 + g2x2 + .. objective function gx --> max • a11x1 + a12x2 + .. <b1 constraints Ax < b • a21x1 + a22x2 + .. <b2**Non-linear programming**• non-linear constraints and/or non-linear objective • optimality not guaranteed (lowest point potato field?) • if optimality is guaranteed, then you can probably do it with LP (piece-wise linear)**Non-linear programming (ctd)**• non-linear constraints and/or non-linear objective • optimality not guaranteed (lowest point potato field?) • if optimality is guaranteed, then you can probably do it with LP (piece-wise linear) • if not guaranteed, then with integer programming you can construct non-linear functions using special sets**Use of special sets for constructing non-convex piece-wise**linear functions**Approximation of quantity*quality**• (a+ x1)*(b+x2) ab + ax2 + bx1**Building of simplified groundmodel**• Boundary condition of nature area in terms of • Mean Spring Watertable MSW • Mean Lowest Watertable MLW • seepage that reaches the rootzone**Analytical solution for spatial interaction**• steady-state • homogeneous geohydrology • radial flow • analytical solution (Groenendijk) i j Unit rise of head 0 Calculated effect 1**‘Walking’ measure**• Influence matrix IM for spatial interaction through groundwater Bovenaanzicht Modelcel (i) j j i IM = a(i)/p(j) a(i)/p(j)**K**1 eenheidsverhoging k 2 fre a berekend effect Combination with simulation model • Sensitivity analyses with SIMGRO (uniform measure) • 2) MHW, MSW, MLW (phreatic level agricultural land) • 4) MSWa en MLWa (aquifer under nature area) 1) maatregelen 6) effecten op k k landbouwgebied natuurgebied 1 2 2) grondwaterstand 5) grondwaterstand- veranderingen veranderingen 4) stijghoogte- 3) superpositie effecten veranderingen op stijghoogten**Regression model MSWa (1)**• MSWa = fMSW · [IM]• MSW**Regressiemodel MSWa (2)**• MSWa = fMSW · [IM]• MSW • MSWa = fMSW · [IM]• MSW + fMHW · [IM]• MHW**SNCc(r)**fltir,l flhir, rp, l r rp GNCr,l flbir,l Embedding approach using mixing cells**Software**• Xpress package of DASH • interior point algorithm (not ‘Simplex”) • integer extensions (also binary variables) • use of special sets for nonlinear functions implemented with integer variables**What are we talking about ?**1. Problem definition**What are the stakeholder objectives ?**1. Problem definition 2. Objectives - stakeholders - authorities**Objectives**• reduce flood risk / climate change • reduce desiccation of nature areas • reduce nitrogen and phosphorous loading on groundwater & surface water • minimize loss of income from agriculture**Where are we now ?**1. Problem definition 2. Objectives 3. Actual situation - authorities - stakeholders - now**grassland**arable land tree nurseries water built-up area nature area Situation Now land use**AlterrAqua: GIS-shell for regional hydrology**waterways culverts weirs subcatchments Land use DTM top10 vector sewerage systems**Metamodel for leaching of nutrients**Pload =f(Soiltype,Landuse,P-surplus, MHW)**NO3-N aquifer 2 (mg/l)**Situation NowNitrate concentration(in the long-term,after endlessly repeating manuring)**470 kg/ha/year**Situation Now : N-loading on surface waternitrogen surplus**Where are we heading ?**1. Problem definition 2. Objectives 3. Actual situation - authorities - stakeholders - now - autonomous developments**Autonomous developments + climate scenario**Discharge (m3/s) Situation Now Pwinter +17% Autonomous dev.**Autonomous developments: drainage & nature**Current Situation Autonomous development**What should we focus on ?**1. Problem definition 2. Objectives 3. Actual situation compare - authorities - stakeholders - now - autonomous developments 4. Focal points**What are the options ?**1. Problem definition 2. Objectives 3. Actual situation compare - authorities - stakeholders - now - autonomous developments 4. Focal points 5. Measures (options)**Measures(options)**• land use • water management**What is the best strategy ?**1. Problem definition 2. Objectives 3. Actual situation compare - authorities - stakeholders - now - autonomous developments 4. Focal points 5. Measures (options) 6. Strategies**Planning with water, ‘inverse approach’**measures communication optimization Stakeholders: • targets on objectives • options for measures**DRAM**Waterwijs market prices (elasticity) 15 Integration with agricultural model DRAM**Optimisation-model (Beerze-Reusel)**• 60 000 constraints • 200 000 continuous decision variables • 2 million non-zero coefficients in de matrix • CPU-time ~0.5 hour on a P4-2.4**Strategy 1 : flood risk **Discharge (m3/s) Situation Now Pwinter +17% Autonomous dev. Strategy 1