Predicting Opportunities for Greening and Patterns of Vegetation on Private Urban Lands

This paper examines predictors of vegetative cover on private lands in Baltimore, Maryland. Using high-resolution spatial data, we generated two measures: “possible stewardship,” which is the proportion of private land that does not have built structures on it and hence has the possibility of supporting vegetation, and “realized stewardship,” which is the proportion of possible stewardship land upon which vegetation is growing. These measures were calculated at the parcel level and averaged by US Census block group. Realized stewardship was further defined by proportion of tree canopy and grass. Expenditures on yard supplies and services, available by block group, were used to help understand where vegetation condition appears to be the result of current activity, past legacies, or abandonment. PRIZM™ market segmentation data were tested as categorical predictors of possible and realized stewardship and yard expenditures. PRIZM™ segmentations are hierarchically clustered into 5, 15, and 62 categories, which correspond to population density, social stratification (income and education), and lifestyle clusters, respectively. We found that PRIZM 15 best predicted variation in possible stewardship and PRIZM 62 best predicted variation in realized stewardship. These results were further analyzed by regressing each dependent variable against a set of continuous variables reflective of each of the three PRIZM groupings. Housing age, vacancy, and population density were found to be critical determinants of both stewardship metrics. A number of lifestyle factors, such as average family size, marriage rates, and percentage of single-family detached homes, were strongly related to realized stewardship. The percentage of African Americans by block group was positively related to realized stewardship but negatively related to yard expenditures.     

Susceptibility indexing method for irrigation water management planning: applications to K. Menderes river basin, Turkey

A susceptibility indexing method was developed based on vulnerability and quality indices. The contamination susceptibility index (SI) at a given location was calculated by taking the product of the vulnerability index (VI) and the quality index (QI): SI = VI × QI. This method incorporates both hydrogeological and hydrochemical data for a comprehensive index mapping. The DRASTIC index methodology was used for the hydrogeological data evaluations. The quality index calculation procedure based on a water quality classification scheme was introduced to evaluate hydrochemical data. The suggested susceptibility indexing method was applied to the Küçük Menderes river basin located in western Turkey. The susceptibility index map shows both hydrogeological and hydrochemical data related to the contamination problem including areas that should be taken into consideration during water management planning. The index map indicates that the most susceptible groundwater is located along the river channel between Kiraz and Tire towns, in the Selçuk area and along the Fertek stream channel to the north of Torbal? town. The results indicate that the incorporation of both hydrogeological and hydrochemical datasets enables more realistic evaluations than those of an individual dataset to estimate the groundwater contamination susceptibility of an aquifer. The numerical procedure applied could be extended further by including other parameters such as retardation, potential contaminant sources, etc. that affect the water quality in a given basin.     

SOIL MOISTURE SENSORS FOR CONTINUOUS MONITORING1

ABSTRACT: Certain physical and chemical properties of soil vary with soil water content. The relationship between these properties and water content is complex and involves both the pore structure and constituents of the soil solution. One of the most economical techniques to quantify soil water content involves the measurement of electrical resistance of a dielectric medium that is in equilibrium with the soil water content. The objective of this research was to test the reliability and accuracy of fiberglass soil-moisture electrical resistance sensors (ERS) as compared to gravimetric sampling and Time Domain Reflectometry (TDR). The response of the ERS was compared to gravimetric measurements at eight locations on the USDA-ABS Walnut Gulch Experimental Watershed. The comparisons with TDR sensors were made at three additional locations on the same watershed. The high soil rock content (≥45 percent) at seven locations resulted in consistent overestimation of soil water content by the ERS method. Where rock content was less than 10 percent, estimation of soil water was within 5 percent of the gravimetric soil water content. New methodology to calibrate the ERS sensors for rocky soils will need to be developed before soil water content values can be determined with these sensors.     

PROJECTED EFFECTS OF ENERGY POLICIES ON AGRICULTURAL WATER USE AND IRRIGATION1

ABSTRACT: A national and interregional programming model was used in projecting the impacts of alternative energy policies and prices on agricultural production, land use, and irrigation. The alternatives analyzed include (a) natural gas deregulation, (b) natural gas curtailment, (c) doubled energy prices, and (d) tripled energy prices. These alternatives are compared with a base alternative where prices and conditions are at normal levels. Restraints in the model control availability of water, land, nitrogen fertilizers, and energy. Water production functions were used to adjust water use to conform with projected energy prices and policies. Natural gas curtailment would have the largest effect on nitrogen use on irrigated land. Values or shadow prices for lands that remains in irrigation would increase under all of the alternatives because of reduced supply. Increased energy prices generally would increase use of surface water for irrigation and reduce use of ground water due to higher pumping costs. Reductions of 50 percent or more in ground water use would occur in the South Central and Western regions of the United States. Water supply prices increase under all of the alternatives; with the amount varying by regions and the policy or price situation.