Calibration and Validation of SWAT for the Upper Maquoketa River Watershed, June 2005

A validation study has been performed using the Soil and Water Assessment Tool (SWAT) model with data collected for the Upper Maquoketa River Watershed (UMRW), which drains over 16,000 ha in northeast Iowa. This validation assessment builds on a previous study with nested modeling for the UMRW that required both the Agricultural Policy EXtender (APEX) model and SWAT. In the nested modeling approach, edge-offield flows and pollutant load estimates were generated for manure application fields with APEX and were then subsequently routed to the watershed outlet in SWAT, along with flows and pollutant loadings estimated for the rest of the watershed routed to the watershed outlet. In the current study, the entire UMRW cropland area was simulated in SWAT, which required translating the APEX subareas into SWAT hydrologic response units (HRUs). Calibration and validation of the SWAT output was performed by comparing predicted flow and NO3-N loadings with corresponding in-stream measurements at the watershed outlet from 1999 to 2001. Annual stream flows measured at the watershed outlet were greatly under-predicted when precipitation data collected within the watershed during the 1999-2001 period were used to drive SWAT. Selection of alternative climate data resulted in greatly improved average annual stream predictions, and also relatively strong r2 values of 0.73 and 0.72 for the predicted average monthly flows and NO3-N loads, respectively. The impact of alternative precipitation data shows that as average annual precipitation increases 19%, the relative change in average annual streamflow is about 55%. In summary, the results of this study show that SWAT can replicate measured trends for this watershed and that climate inputs are very important for validating SWAT and other water quality models.

Watershed Improvement Review Board Annual Report, 2005

The Iowa Watershed Improvement Review Board was created by the Iowa Legislature and signed into law by the Governor in 2005 as Senate File 200. This statute is now codified in Iowa Code Chapter 466A. The fifteen-member board was appointed with the initial meeting being held August 22, 2005. Subsequent Board meetings were held October 10, December 2, and December 19. Attachment 1 lists the board members and their organization affiliation. The Board created a five-member subcommittee to develop and submit to the Board the Request for Applications (RFA) documents and procedural guidelines. These RFA documents were approved as modified on October 10, 2005.

Transmission Fourier transform infrared microspectroscopy allows simultaneous assessment of cutin and cell-wall polysaccharides of Arabidopsis petals.

A procedure for the simultaneous analysis of cell-wall polysaccharides, amides and aliphatic polyesters by transmission Fourier transform infrared microspectroscopy (FTIR) has been established for Arabidopsis petals. The combination of FTIR imaging with spectra derivatization revealed that petals, in contrast to other organs, have a characteristic chemical zoning with high amount of aliphatic compounds and esters in the lamina and of polysaccharides in the stalk of the petal. The hinge region of petals was particular rich in amides as well as in vibrations potentially associated with hemicellulose. In addition, a number of other distribution patterns have been identified. Analyses of mutants in cutin deposition confirmed that vibrations of aliphatic compounds and esters present in the lamina were largely associated with the cuticular polyester. Calculation of spectrotypes, including the standard deviation of intensities, allowed detailed comparison of the spectral features of various mutants. The spectrotypes not only revealed differences in the amount of polyesters in cutin mutants, but also changes in other compound classes. For example, in addition to the expected strong deficiencies in polyester content, the long-chain acyl CoA synthase 2 mutant showed increased intensities of vibrations in a wavelength range that is typical for polysaccharides. Identical spectral features were observed in quasimodo2, a cell-wall mutant of Arabidopsis with a defect in pectin formation that exhibits increased cellulose synthase activity. FTIR thus proved to be a convenient method for the identification and characterization of mutants affected in the deposition of cutin in petals.

Watershed Improvement Review Board Calendar Year 2006 Annual Report, January 31, 2007

The Iowa Watershed Improvement Review Board (WIRB) was created by the Iowa Legislature and signed into law by the Governor in 2005 as Senate File 200. This statute is now codified in Iowa Code Chapter 466A. The fifteen-member Board conducted eight meetings throughout the year in-person or via teleconference. Meetings were held January 24, February 27, March 13, May 15, August 7, September 20, October 6, and December 18. Attachment 3 lists the board members and their organization affiliation. The Board appointed a five-member subcommittee to review and revise the Request For Applications (RFA) documents and submit recommendations to the full Board. The RFA documents were approved as modified at the May 15, 2006 Board meeting.

Cedar Lake Watershed Project, 2004

For years, Cedar Lake has been there for the Winterset community, providing drinking water, offering recreational opportunities, teaching students outdoors lessons and giving wildlife a home. With water quality a serious concern, it is now our turn to be there for the lake.

Soil and water conservation strategies and impact on sustainable livelihood in Cape Verde – Case study of Ribeira Seca watershed

Cape Verde, located off the coast of Senegal in western Africa, is a volcanic archipelago where a combination of human, climatic, geomorphologic and pedologic factors has led to extensive degradation of the soils. Like other Sahelian countries, Cape Verde has suffered the effects of desertification through the years, threatening the livelihood of the islands population and its fragile environment. In fact, the steep slopes in the ore agricultural islands, together with semi-arid and arid environments, characterized by an irregular and poorly distributed rainy season, with high intensity rainfall events, make dryland production a challenge. To survive in these fragile conditions, the stabilization of the farming systems and the maintenance of sustainable yields have become absolute priorities, making the islands an erosion control laboratory. Soil and water conservation strategies have been a centerpiece of the government0s agricultural policies for the last half century. Aiming to maintain the soil in place and the water inside the soil, the successive governments of Cape Verde have implemented a number of soil and water conservation techniques, the most common ones being terraces, half moons, live barriers, contour rock walls, contour furrows and microcatchments, check dams and reforestation with drought resistant species. The soil and water conservation techniques implemented have contributed to the improvement of the economical and environmental conditions of the treated landscape, making crop production possible, consequently, improving the livelihood of the people living on the islands. In this paper, we survey the existing soil and water conservation techniques, analyze their impact on the livelihood condition of the population through a thorough literature review and field monitoring using a semi-quantitative methodology and evaluate their effectiveness and impact on crop yield in the Ribeira Seca watershed. A brief discussion is given on the cost and effectiveness of the techniques to reduce soil erosion and to promote rainfall infiltration. Finally, we discuss the critical governance factors that lead to the successful implementation of such strategy in a country with scarce natural resources.

Bacteria Source Tracking in Lake Darling Watershed, 2005

Monitoring of Iowa's surface waters during the past five years has demonstrated the regular occurrence of fecel bacteria in surface water resources.

Intensive Watershed Investigations at Iowa Beaches, 2005

This monthly report from the Iowa Department of Transportation is about the water quality management of Iowa's rivers, streams and lakes.

Soil and Water Conservation Strategies in Cape Verde (Cabo Verde in Portuguese) and Their Impacts on Livelihoods - An Overview from the Ribeira Seca Watershed

Severe land degradation has strongly affected both people’s livelihood and the environment in Cape Verde (Cabo Verde in Portuguese), a natural resource poor country. Despite the enormous investment in soil and water conservation measures (SWC or SLM), which are visible throughout the landscape, and the recognition of their benefits, their biophysical and socioeconomic impacts have been poorly assessed and scientifically documented. This paper contributes to filling this gap, by bringing together insights from literature and policy review, field survey and participatory assessment in the Ribeira Seca Watershed through a concerted approach devised by the DESIRE project (the “Desire approach”). Specifically, we analyze government strategies towards building resilience against the harsh conditions, analyze the state of land degradation and its drivers, survey and map the existing SWC measures, and assess their effectiveness against land degradation, on crop yield and people’s livelihood. We infer that the relative success of Cape Verde in tackling desertification and rural poverty owes to an integrated governance strategy that comprises raising awareness, institutional framework development, financial resource allocation, capacity building, and active participation of rural communities. We recommend that specific, scientific-based monitoring and assessment studies be carried out on the biophysical and socioeconomic impact of SLM and that the “Desire approach” be scaled-up to other watersheds in the country.

Assessment and mapping the sensitive areas to desertification in an insular Sahelian mountain region Case study of the Ribeira Seca Watershed, Santiago Island - Cabo Verde

This paper presents the assessment and mapping of the Ribeira Seca catchment, an insular Sahelian mountain region sensitive to desertification, located on the island of Santiago, Cabo Verde. Desertification is a threat to the global environment, representing a serious ecological problemin Cabo Verde. To successfully combat desertification, an evaluation of desertification consequences is required and the building of cartography of the sensitivity for arid and semi-arid ecosystems is required as a first step. The MEDALUS model was the basis for this study in which six quality indicators were used: climate, soil, vegetation, land management, erosion and social factors. Several parameters were defined for each indicator with weights varying between 1 (very low) and 2 (very high). The geometric mean of each of the six quality indicators was employed to produce a map of areas sensitive to desertification. The results of this study show that more than 50% of the watershed show clear evidence of becoming a desertified area.

Dispersion of natural arsenic in the Malcantone watershed, Southern Switzerland: field evidence for repeated sorption-desorption and oxidation-reduction processes

In recent years, elevated arsenic concentrations have been found in waters and soils of many, countries, often resulting in a health threat for the local population. Switzerland is not an exception and this paper deals with the release and subsequent fate of arsenic in a 200-km(2) mountainous watershed, characterized by crystalline silicate rocks (gneisses, schists, amphibolites) that contain abundant As-bearing sulfide ore deposits, some of which have been mined for iron and gold in the past. Using analytical methods common for mineralogical, ground water and soil studies (XRD, XRF, XAS-XANES and -EXAFS, electron microprobe, extraction, ICP, AAS with hydride generator, ion chromatography), seven different field situations and related dispersion processes of natural arsenic have been studied: (1) release by rock weathering, (2) transport and deposition by water and ice; (3) release of As to the ground and surface water due to increasing pH; (4) accumulation in humic soil horizons; (5) remobilization by reduction in water-saturated soils and stagnant ground waters; (6) remobilization by using P-rich fertilizers or dung and (7) oxidation, precipitation and dilution in surface waters. Comparison of the results with experimental adsorption studies and speciation diagrams from the literature allows us to reconstruct and identify the typical behavior of arsenic in a natural environment under temperate climatic conditions. The main parameters identified are: (a) once liberated from the primary minerals, sorption processes on Fe-oxy-hydroxides dominate over Al-phases, such as Al-hydroxides or clay minerals and limit the As concentrations in the spring and well waters between 20 and 300 mug/l. (b) Precipitation as secondary minerals is limited to the weathering domain, where the As concentrations are still high and not yet too diluted by rain and soils waters. (c) Although neutral and alkaline pH conditions clearly increase the mobility of As, the main factor to mobilize As is a low redox potential (Eh close or below 0 mV), which favors the dissolution of the Fe-oxy-hydroxides on which the As is sorbed. (d) X-ray absorption spectroscopy (XAS) of As in water-logged humic forest soils indicates that the reduction to As III only occurs at the solid-water interface and that the solid contains As as As V (e) A and Bh horizons of humic cambisols can effectively capture As when As-rich waters flow through them. Complex spatial and temporal variation of the various parameters in a watershed results in repeated mobilization and immobilization of As, which continuously transports As from the upper to the lower part of a watershed and ultimately to the ocean. (C) 2004 Elsevier B.V. All rights reserved.

Land Ownership Guide for Watershed Cleanups, March 2006

A river can wander through the land in any way it pleases. People, however, face a few legal restrictions when following rivers, lakes, and streams through privately owned land. Care must be taken not to trespass on private property.

Runoff measurement and prediction for a watershed under natural vegetation in central Brazil

This work aimed to measure and analyze total rainfall (P), rainfall intensity and five-day antecedent rainfall effects on runoff (R); to compare measured and simulated R values using the Soil Conservation Service Curve Number method (CN) for each rainfall event; and to establish average R/P ratios for observed R values. A one-year (07/01/96 to 06/30/97) rainfall-runoff data study was carried out in the Capetinga watershed (962.4 ha), located at the Federal District of Brazil, 47° 52' longitude West and 15° 52' latitude South. Soils of the watershed were predominantly covered by natural vegetation. Total rainfall and runoff for the period were 1,744 and 52.5 mm, respectively, providing R/P of 3% and suggesting that watershed physical characteristics favored water infiltration into the soil. A multivariate regression analysis for 31 main rainfall-runoff events totaling 781.9 and 51.0 mm, respectively, indicated that the amount of runoff was only dependent upon rainfall volume. Simulated values of total runoff were underestimated about 15% when using CN method and an area-weighted average of the CN based on published values. On the other hand, when average values of CN were calculated for the watershed, total runoff was overestimated about 39%, suggesting that CN method shoud be used with care in areas under natural vegetation.

Hydrologic Simulations of the Maquoketa River Watershed Using SWAT Working Paper 09-WP 49,June 2009

This paper describes the application of the Soil and Water Assessment Tool (SWAT) model to the Maquoketa River watershed, located in northeast Iowa. The inputs to the model were obtained from the Environmental Protection Agency’s geographic information/database system called Better Assessment Science Integrating Point and Nonpoint Sources (BASINS). Climatic data from six weather stations located in and around the watershed, and measured streamflow data from a U.S. Geological Survey gage station at the watershed outlet were used in the sensitivity analysis of SWAT model parameters as well as its calibration and validation for watershed hydrology and streamflow. A sensitivity analysis was performed using an influence coefficient method to evaluate surface runoff and base flow variations in response to changes in model input hydrologic parameters. The curve number, evaporation compensation factor, and soil available water capacity were found to be the most sensitive parameters among eight selected parameters when applying SWAT to the Maquoketa River watershed. Model calibration, facilitated by the sensitivity analysis, was performed for the period 1988 through 1993, and validation was performed for 1982 through 1987. The model performance was evaluated by well-established statistical methods and was found to explain at least 86% and 69% of the variability in the measured stream flow data for the calibration and validation periods, respectively. This initial hydrologic modeling analysis will facilitate future applications of SWAT to the Maquoketa River watershed for various watershed analysis, including water quality.