Overview of Studies and Workshops by Soil and Water Conservation ...

www.swcs.orgOverview of Studies andWorkshops by Soil andWater ConservationSociety that deal withGreat LakesGary Bowen TRCAMarch 3 and 4, 20091

Thus it appears that changes in the short duration intensity factor, as well aschanges in daily falls are affecting the “R” erosivity factor in the soil lossequation.Overall we could expect a combined EI30 factor (RUSLE and RUSLEFACequations) to increase by the order of 5 x 3 = 15% per decade, with thefuture rate of change to 2050 not significantly different from that experiencedin the 1970 to 2000 periodFrom an erosion perspective it should be noted from the studies byStone et al. (2000) and by Zhang et al. (2000) that the greatest one day(and probably shorter duration) increases have been in late Spring andearly Summer, with lesser but significant increases in the March to Mayperiod, and this is likely to continue.NONPOINT SOURCE POLLUTION LIKELY TO INCREASEThe magnitude of nonpoint source pollution is the result ofthe interaction between (1) the physical landscape, (2) thetype, intensity, and level of management of that landscape,and (3) the frequency, intensity, timing, and volume ofprecipitation.Therefore, it is highly likely that a precipitation regime withmore frequent, more intense, and/or larger storms willincrease the severity of nonpoint source pollution.MANAGING RISK AT THE WATERSHED SCALEThe most compelling advantage of working at the watershed scale is theability to “focus for effect” to direct conservation efforts at the mostvulnerable parts of the landscape and during the most vulnerable times ofthe year.Participants argued that working at the watershed or landscapescale is the only way to deal with the off-site effects in agriculturalwatersheds. Conservationists “have to connect the dots—makesure our work on farms adds up—that the sum of our efforts isgreater than the parts.”Working at the watershed scale opens up opportunities to planand implement different strategies that complement and increasethe benefits of in-field practices.Strategies to restore wetlands, repair stream channels, andenhance riparian corridors are best implemented at thewatershed scale and will reinforce the benefits of work at the farmscale if the efforts are effectively targeted and coordinatedPublic policy must ensure a long-term commitment ofpeople and resources to community-driven projects at thewatershed scale. The more traditional approach ofproviding short-term, three- to five-year grants tocommunities will not work.Sustained effort and support must be available to build thelocal infrastructure—leadership, technical support, andmonitoring systems— essential to making effectiveadaptive management possible.More effective conservation assessmentand planning tools will accomplish little,according to workshop participants,unless we find effective ways toincrease the use and implementation ofconservation systems and to targetimplementation at the most criticalportions of farms and watersheds.2