ENVIRONMENTAL THRESHOLD FUNCTIONS FOR USER ORIENTED RESOURCE PLANNING AND MANAGEMENT1

ABSTRACT: Managers of water related outdoor recreation resources want to provide facilities and recreational opportunities of high quality that are attractive to recreationists. The reported research develops a relevant site quality assessment and measurement procedure called environmental threshold modeling. This modeling procedure is based upon the idea that individuals (i.e., recreationists) have specific, identifiable evaluative criteria which can be expressed as a mathematical function of various site characteristics. The function of interest is called a threshold function because it separates acceptable recreational settings from unacceptable settings. Individual specific threshold functions can be easily aggregated to form a population specific threshold function that estimates the proportion of a population that would find the recreational setting acceptable for some specific activity. Presented in this paper are illustrative calibration results based upon survey data collected from recreational canoeists using the Pine River in Michigan's Manistee National Forest.     

Using Landsat data to estimate evapotranspiration of winter wheat

An evapotranspiration (ET) model that accurately estimates daily water use and soil moisture on a regional basis is required for many agricultural and hydrological studies. The model should use meterological data that are readily available and crop information that is responsive to the changing vigor of the plants.We evaluated an ET model with a weighing lysimeter and then applied it to winter wheatfields at four Kansas locations. Model inputs are solar radiation, temperature, precipitation, and leaf area index (LAI); included in the outputs are estimates of transpiration, evaporation, and soil moisture. An equation was developed to estimate LAI from Landsat data. Because LAI can be estimated from satellites, the ET model can potentially be used on a regional basis.     

A METHODOLOGY FOR OUTDOOR RECREATION ANALYSIS IN A STATE WATER RESOURCES PLANNING STUDY1

ABSTRACT: The paper presents a methodology for outdoor recreation analysis in a comprehensive State water resources planning study. This methodology applies to determination of recreation participation desires among the population, allocation of those desires to areas of potential resources within which they must be satisfied, comparison of the areal potential resources against the allocated desires to identify areas having recreational resource deficits or needs, and exploration of alternative solutions to the identified needs. Major elements discussed are: market area, inflow-outflow, resource desire determination and projection, resource desire allocation, facility inventory, resource desire-resource analysis and alternative solutions to identified needs of water-oriented outdoor recreation.     

WATER QUALITY PERCEPTION BY USERS: CAN IT SUPPLEMENT OBJECTIVE WATER QUALITY MEASURES?1

ABSTRACT: Personal interviews were conducted with eighty campers in each of three Minnesota state parks to investigate the water quality perception of the recreationist. At the same time, water quality factors were measured or observed as an indication of conditions experienced by the interviewees. Most respondents perceived water pollution strictly on a visual basis. Sewage, public carelessness, industry, and farm fertilizers were “first choice selections” among major causes of water pollution in Minnesota. Seventy percent felt their recreational activities did not contribute to water pollution. Sixty-two percent said their life had not been affected by water pollution, while over two-thirds of the remaining thirty-eight percent listed curtailment of recreation as the primary result. Many mentioned an algal bloom at one park and the strong odor of rotten fish at a second park. On the basis of the senior author's observations, supported by the measurements taken, it was concluded that thèk were the only major problems in the three parks. Some incipient problems, such as nutrient enrichment and the presence of coliform bacteria, were indicated by the measurements. The type and degree of pollution identified by the recreationist could be important through its influence on user evaluations and space preferences. The establishment of relationships between water quality parameters and the perception of the recreationist will provide the manager with a tool to assist in evaluating participation in water-related outdoor recreation in terms of both user satisfaction and water quality.     

DEVELOPMENT OF AN INTERDISCIPLINARY PLANNING MODEL FOR WATER AND FISHERY MANAGEMENT1

ABSTRACT: This paper describes the development of an interdisciplinary model that analyzes the effects of resource management decisions on New Mexico fishery production, yield, sportfishing effort, and economic benefit to anglers. The model recreates river flows and materials transported through reservoirs and their tailwaters from 1974 through 1987. Solar radiation, water temperature, phosphorus, nitrogen, suspended solids, and water exchange rates determine primary production. Organic loads from watershed sources, added to primary production, form a trophic base for sportfish forage. Fish production is partitioned into biomass and growth of each age class in sportfish and forage fish groups by differential responses to food type, light, water-level fluctuation and predation. Fish biomass, with angler population distribution and site condition, contributes to determining angler effort and economic benefits. Model users can vary and analyze water level and quality, stocking, fishing regulations, site access, site facilities, and site entry fees. The model (on floppy disks with a user manual) is available for operation on MS DOS compatible computers with a hard disk. Contact R. M. Wilson, NMGF, State Capitol, Santa Fe, New Mexico, 87503.     

RIVER RECREATION EXPERIENCE OPPORTUNITIES IN TWO RECREATION OPPORTUNITY SPECTRUM (ROS) CLASSES1

The Recreation Opportunity Spectrum (ROS) system is used by the USDA Forest Service and USDI Bureau of Land Management for inventorying, classifying, and managing wildlands for recreation. Different ROS classes from the Colorado and Arkansas Rivers in Colorado were compared, using visitor survey data collected in 1979 and 1981, to see if the different classes offered different recreational experience opportunities. No difference between classes was found. Six possible reasons for not finding a difference are discussed. The usefulness of ROS at the broader levels of planning and the needs at more detailed levels of planning are noted.     

大都市郊区游憩开发与规划研究综述

从大都市区和大都市郊区的定义与特征、开发与规划研究的原则与方法、方向与模式、策略等方面总结了近年来国内的研究进展，评析了研究现状，指出未来重点要在理论建设、居民行为、市场营销、规划管理、规划影响等方面加深研究。     

RECREATION AT THE MC CLELLAN-KERR ARKANSAS RIVER NAVIGATION SYSTEM1

ABSTRACT: Recreation has produced substantial employment, incomes, economic development, and migration impacts since completion of the McCle-lan-Kerr Arkansas River Navigation System. These impacts support the influence of navigation, hydropower, flood control, and channel stabilization outputs on regional development. The marked success is not without substantial costs in public resources, including manpower which are devoted to recreational management. Increasing the share of financial resources obtained from recreational users and transfer of management responsibilities to nonfederal agencies, including private concessionaires is recommended.     

Modelling impacts of alternative farming management practices on greenhouse gas emissions from a winter wheat–maize rotation system in China

Agricultural production plays an important role in affecting atmospheric greenhouse gas concentrations. Field measurements were conducted in Quzhou County, Hebei Province in the North China Plains to quantify carbon dioxide (CO₂) and nitrous oxide (N₂O) emissions from a winter wheat–maize rotation field, a common cropping system across the Chinese agricultural regions. The observed flux data in conjunction with the local climate, soil and management information were utilized to test a process-based model, Denitrification–Decomposition or DNDC, for its applicability for the cropping system. The validated DNDC was then used for predicting impacts of three management alternatives (i.e., no-till, increased crop residue incorporation and reduced fertilizer application rate) on CO₂ and N₂O emissions from the target field. Results from the simulations indicated that (1) CO₂ emissions were significantly affected by temperature, initial SOC, tillage method, and quantity and quality of the organic matter added in the soils; (2) increases in temperature, initial SOC, total fertilizer N input, and manure amendment substantially increased N₂O emissions; and (3) temperature, initial SOC, tillage, and quantity and quality of the organic matter added in the soil all had significant effects on global warming. Finally, five 50-year scenarios were simulated with DNDC to predict their long-term impacts on crop yield, soil C dynamics, nitrate leaching losses, and N₂O emissions. The modelled results suggested that implementation of manure amendment or crop residue incorporation instead of increased fertilizer application rates would more efficiently mitigate GHG emissions from the tested agro-ecosystem. The multi-impacts provided a sound basis for comprehensive assessments on the management alternatives.     

Preferences and willingness to pay for close to home nature for outdoor recreation in Sweden

In Sweden there is a strong tradition of using nature areas for outdoor recreation. This paper reports on a study which explored preferences and willingness to pay for outdoor recreation close to home (≤100 km away from home and ≤24 hours stay at a recreation site) using the contingent valuation method. The data originated from a mail survey that involved Swedish residents who were randomly selected from a national register. An ordinary least squares regression model was used to account for factors influencing willingness to pay. The results showed that approximately 50% of the respondents used nature areas close to their home for recreation and their average frequency of visits to these areas was 74 times annually. Areas dominated by forests were the most preferred, followed by water. The respondents were willing to pay approximately 7200 SEK (US$1080) annually. Their willingness to pay was influenced by factors such as type of nature area, distance to and time spent at the recreation site and income. The results provide one input to the land use planning process by considering the demand for nature-based outdoor recreation close to home.