Common use of Model Results Clause in Contracts

Model Results. Before the results are presented, the scenarios modelled will be defined. For the baseline scenario, the most up-to-date data are used that were available. Monthly recorded rainfall from within the study area for the years 1995-1997 was used, the latest years of data available. For canal inflows, data for eight local water supply canals at monthly resolution for the years 2008-2010 were used. For domestic and industrial use, and for treated wastewater reuse, only a single annual value for 2009 was available. In the absence of better data, it was assumed that these demands were evenly distributed through the year, and the annual cycle was repeated three times. For agriculture, data were available for nine crops in the study area: alfalfa, cotton, maize, rice, tree crops, summer vegetables, winter vegetables, wheat and 'other'. For each crop, the data available were: crop planted area, monthly crop water requirement per unit area, crop productivity (yield) per unit area and crop economic value per unit area. Two 2050 scenarios were simulated: a best case and a worst case, both defined with ECRI. The best case scenario, on top of decreasing rainfall totals, assumes a 10% increase to canal inflows (a proxy for changes to Nile flows), significant increases in treated waste-water volumes, and mitigation measures put in place to prevent inundation due to sea-level rise. The worst case scenario assumes decreases to canal flows, that sea- level rise results in a 13% loss to agricultural land (assumption from ECRI), that water consumption increases generally and that treated waste-water volumes do not improve on the present day. Both scenarios assume increases in domestic and industrial demand, thereby accounting for population increase and improving living standards. There are two main areas of considerable uncertainty with respect to the 2050 scenarios: a) the proportion of land that could be lost to sea-level rise. Because of the uncertainty in the actual level of sea-level rise predicted by global climate models, and because it is not known how much effort will be put into local mitigation efforts, values between 2-20% land loss were chosen to represent various levels of sea level rise and/or investment in mitigation measures. b) the direction and magnitude of changes in Nile flows. The results of numerous modelling studies have not converged to agree on either the direction or magnitude of change to Nile flows, with the current range of predictions from -50 to +60% (▇▇▇▇▇▇, 2005). This full range was tested during sensitivity analysis. In order to examine the potential impacts of changing cropping patterns (potentially due to policy instruments or market drivers) on local water availability, crop yield and economic output, a suite of 22 crop scenarios were simulated. All the scenarios were conducted on baseline data due to lower uncertainty in this dataset. The scenarios were developed with ECRI who provided data on potential changes to crop water requirements and crop productivity in 2050 for four crops (wheat, maize, rice and cotton). No estimates were available for future economic output so baseline values were used. Initially, changes were implemented to crop water requirements and crop yield only, with no alterations to the area planted by each crop type. This formed Scenario 1. For all the other Scenarios (2 to 8), planted crop areas were altered according to one of three 'pathways': a) food security, b) economic security, and c) a balanced pathway. For scenarios 2 to 8, the crops that had their areas altered were: wheat, rice, cotton and vegetables (winter and summer). In each of the scenarios from 2 to 8, the area of rice (baseline = 7096 feddans) was decreased by 1000 feddans except in Scenario 8, when it was reduced to zero. As such, in Scenario 2, the area of rice was reduced by 1000 feddans, in Scenario 3 it was reduced by 2000 feddans and so on. This 'recovered' land was partitioned according to each of the three pathways as follows: a) food security: 50% new land to wheat, 25% to cotton and 25% to vegetables; b) economic security: 50% to vegetables, 25% to cotton and 25% to wheat; c) 'balanced': 33.3% to each. As an example, Scenario 2a denotes the food security pathway with a rice reduction of 1000 feddans, while 4c denotes the balanced pathway with a rice reduction of 3000 feddans. The 3000 feddans was then split equally between wheat, cotton and vegetables. It is noted that these scenarios are hypothetical, and do not reflect any current or proposed policy measured being implemented in the Rosetta region. Under baseline conditions, the model simulation suggests an average local annual water deficit of c. 133 x 106 m3 (Figure 14). At present, it is reported that water is being over-exploited in the area, although this is the first time that a figure has been put on the over-exploitation, giving local and regional policy-makers a handle on the size of the problem being faced. Because there are some assumptions in the baseline data set, and because it is unlikely that the simulation is comprehensive (i.e. some system aspects have probably been neglected), this number gives a first-order approximation of the deficit, rather than an accurate definition. Total current agricultural yield in the study area is c. 536 000 t yr-1, and economic output is c. 567 x 106 Egyptian Pounds (LE) yr-1. Under the best case 2050 scenario, the water balance situation is shown to improve by c. 35%. While still over- exploited, the average annual deficit is c. -74 x 106 m3 yr-1. Because no changes were made to cropping patterns and no land was lost to sea-level rise, there are no apparent changes to agricultural yield or economic output. This is of course is unlikely to be the case in reality. Under the worst case scenario, the situation becomes worse than the present day, with a water deficit of -122 x 106 m3 yr-1. Because agricultural land is lost to sea level rise in this scenario, the economic output and crop productivity values also decrease by 13% with respect to the baseline (a linear relationship with land loss is assumed due to a lack of better data). From the canal inflow sensitivity tests (Figure 15), it is shown that if canal inflows increase by more than 30% with respect to the present day flows, then the region will have surplus water, assuming all other parameters remain as today. If inflows increase by 60%, then this surplus is considerable (127 x 106 m3 yr-1). However, if inflows decrease by 30% with respect to today, then the average annual water deficit is over twice as much as the baseline, and if inflows reduce by 50%, then the situation is critical, with a deficit of over 340 x 106 m3 yr-1. With regard to the land loss sensitivity tests (Figure 16), the results are somewhat counter-intuitive in that the water balance situation improves as more land is lost to inundation. This is because it is assumed that the total agricultural water requirement is linearly proportional to land loss. Therefore, if land loss is 10%, total crop water requirements decrease by 10% and so on. If 20% of the land in the study is lost, and if all other parameters remain unchanged, then the water deficit is only -2 x 106 m3 yr-1. However, increased land loss is viewed a negative impact because agriculture is the largest economy in the region. Thus, a slow-down in agricultural output could hinder local development, and mitigation efforts are being explored despite the fact that this will impact water saving efforts. The 22 cropping scenarios tested examine the effects of changes to the crop water requirements, crop productivity and cropping patterns in the area. Figure 6 shows the absolute change in total annual agricultural water requirement, agricultural yield and economic output when compared with the baseline for all 22 scenarios. Figure 17 indicates that improvements to economic output only can be made with relatively little change to the current cropping regime, however water consumption increases and yield decreases at these small changes. However, by the Scenario 4 suite of tests (in which the rice area is reduced by 3000 feddans), the total water requirement starts to decrease with respect to the baseline and total yield and economic output increase. As one moves through the scenarios, the improvements get more desirable, peaking at Scenario 8b, under which the total annual water requirement is 22 x 106 m3 yr-1 less than at present, while the yield and economic output increase by 24 000 t yr-1 and 13 x 106 LE yr-1 respectively. Somewhat surprisingly, the 'economic security' pathways modelled in a Scenario produce a better improvement to agricultural yield than the corresponding 'food' security pathways, and are generally more favourable than the balanced pathways. Upon close inspection this was found to be due to the 9% estimated decrease to the yield of wheat (which is important for the food security pathway) by 2050 coupled with the 17% increase in the yield of cotton and a very high yield for vegetables (which are important in the economic security pathway) and the interaction of these changes with changes to the cropping regime. These factors were not taken into account when deriving the pathways with ECRI, but have proved to have subtle, unexpected but important implications on the final results.