共查询到9条相似文献,搜索用时 15 毫秒
1.
Peter Gripaios 《Journal of Environmental Planning and Management》1984,27(1):43-44
The recent central government paper on regional industrial development heralds a reduced role for regional policy, in contrast with the Regional Studies Association inquiry into regional problems in the U.K. A brief exploration of the central government views leads to the paper concluding with a call for an increase in regional planning and for regional planning authorities. 相似文献
2.
D. S. Gunby 《Journal of Environmental Planning and Management》1987,30(1):6-12
This paper analyses the currents which gave rise to the 1947 Town & Country Planning Act. It describes the main statutory events in the first half of the 20th century and considers the progress made in implementing the legislation. It is argued that, while the 1947 Act was a major advance on what went before, it is not a significant departure. 相似文献
3.
Frederick Steiner 《Environmental management》1991,15(4):519-529
This article is the first in a series of three. These articles were prepared to document the growth management process undertaken
in Teller County, Colorado, USA. In this article, an 11-step method for landscape planning is proposed. In step 1, an issue,
or set of related issues, is identified as posing a problem and/or opportunity to people and/or the environment. In step 2,
a goal, or several goals, is established to address the problem or opportunity. In steps 3 and 4, inventories and analyses
of biophysical and sociocultural processes are conducted, first at the regional level and then at the local level. Step 5
involves detailed studies (such as suitability analyses) that link the inventory and analysis information to the problems
or opportunities and goals. Detailed studies link regional and local information to specific sites. Thus, this method involves
a regional-local-specific site hierarchy. In step 6, concepts are developed that lead to a landscape plan in step 7. During
step 8, the plan is explained through a systematic educational and citizen involvement effort to the affected public. In step
9, detailed designs are developed that again are explained to the specific individuals who will be impacted by the designs.
It is in step 10 when the plan and designs are implemented. Step 11 involves the administration of the plan. The method is
illustrated through an example of growth management planning for Teller County and the city of Woodland Park, Colorado.
Paper 1 in a series of 3. 相似文献
4.
Five major management goals were identified for the upper Grande Ronde River Basin on the Wallowa-Whitman National Forest in northeastern Oregon: to produce high-quality fish habitat, to maintain elk habitat, to restore and maintain forest conditions within the natural range of viability, and to contribute to community economic stability. From the broad goals, specific goals for stream temperature, habitat effectiveness index (HEI), habitat corridors, maintenance of land in late or old seral stages, and a nondeclining even flow of timber were selected. A case study was undertaken in a small watershed that is under typical societal constraints to determine whether one decisionsupport tool, SNAP II+, could evaluate the selected goals in a single planning exercise. Three riparian management strategies and two forest road scenarios were used. The exclusion of harvest and road-building from riparian zones in order to increase habitat protection decreased harvest levels and net present value but maintained preactivity stream temperatures. Other resources were generally maintained within prescribed management levels. Although the technique has limitations (e.g., it does not account for riparian zones in calculations of forage and cover for HEI, and it can use the maximum but not minimum acreage goal for some resources), it shows promise for evaluating management tradeoffs in watershed analysis.This is Paper 3069 of the Forest Research Laboratory, Oregon State University, Corvallis, Oregon. 相似文献
5.
Linda A. Joyce Curtis H. Flather Patricia A. Flebbe Thomas W. Hoekstra Stan J. Ursic 《Environmental management》1990,14(4):489-500
The impact of timber management and land-use change on forage production, turkey and deer abundance, red-cockaded woodpecker
colonies, water yield, and trout abundance was projected as part of a policy study focusing on the southern United States.
The multiresource modeling framework used in this study linked extant timber management and land-area policy models with newly
developed models for forage, wildlife, fish, and water. Resource production was integrated through a commonly defined land
base that could be geographically partitioned according to individual resource needs. Resources were responsive to changes
in land use, particularly human-related, and timber management, particularly the harvest of older stands, and the conversion
to planted pine. 相似文献
6.
Securing sustainable livelihood conditions and reducing the risk of outmigration in savanna ecosystems hosted in the tropical semiarid regions is of fundamental importance for the future of humanity in general. Although precipitation in tropical drylands, or savannas, is generally more significant than one might expect, these regions are subject to considerable rainfall variability which causes frequent periods of water deficiency. This paper addresses the twin problems of “drought and desertification” from a water perspective, focusing on the soil moisture (green water) and plant water uptake deficiencies. It makes a clear distinction between long‐term climate change, meteorological drought, and agricultural droughts and dry spells caused by rainfall variability and land degradation. It then formulates recommendations to better cope with and to build resilience to droughts and dry spells. Coping with desertification requires a new conceptual framework based on green‐blue water resources to identify hydrological opportunities in a sea of constraints. This paper proposes an integrated land/water approach to desertification where ecosystem management supports agricultural development to build social‐ecological resilience to droughts and dry spells. This approach is based on the premise that to combat desertification, focus should shift from reducing trends of land degradation in agricultural systems to water resource management in savannas and to landscape‐wide ecosystem management. 相似文献
7.
Many lakes have experienced a transition from a clear into a turbid state without macrophyte growth due to eutrophication.
There are several measures by which nitrogen (N) and phosphorus (P) concentrations in the surface water can be reduced. We
used the shallow lake model PCLake to evaluate the effects of three measures (reducing external nutrient loading, increasing
relative marsh area, and increasing exchange rate between open water and marsh) on water quality improvement. Furthermore,
the contribution of different retention processes was calculated. Settling and burial contributed more to nutrient retention
than denitrification. The model runs for a typical shallow lake in The Netherlands showed that after increasing relative marsh
area to 50%, total phosphorous (TP) concentration in the surface water was lower than the Maximum Admissible Risk (MAR, a
Dutch government water quality standard) level, in contrast to total nitrogen (TN) concentration. The MAR levels could also
be achieved by reducing N and P load. However, reduction of nutrient concentrations to MAR levels did not result in a clear
lake state with submerged vegetation. Only a combination of a more drastic reduction of the present nutrient loading, in combination
with a relatively large marsh cover (approximately 50%) would lead to such a clear state. We therefore concluded that littoral
marsh areas can make a small but significant contribution to lake recovery. 相似文献
8.
A Water Quality Index Applied to an International Shared River Basin: The Case of the Douro River 总被引:2,自引:0,他引:2
A Water Quality Index (WQI) is a numeric expression used to evaluate the quality of a given water body and to be easily understood
by managers. In this study, a modified nine-parameter Scottish WQI was used to assess the monthly water quality of the Douro
River during a 10-year period (1992–2001), scaled from zero (lowest) to 100% (highest). The 98,000 km2 of the Douro River international watershed is the largest in the Iberian Peninsula, split between upstream Spain (80%) and
downstream Portugal (20%). Three locations were surveyed: at the Portuguese–Spanish border, 350 km from the river mouth; 180
km from the mouth, where the river becomes exclusively Portuguese; and 21 km from the mouth. The water received by Portugal
from Spain showed the poorest quality (WQI 47.3 ± 0.7%); quality increased steadily downstream, up to 61.7 ± 0.7%. In general,
the water quality at all three sites was medium to poor. Seasonally, water quality decreased from winter to summer, but no
statistical relationship between quality and discharge rate could be established. Depending on the location, different parameters
were responsible for the episodic decline of quality: high conductivity and low oxygen content in the uppermost reservoir,
and fecal coliform contamination downstream. This study shows the need to enforce the existing international bilateral agreements
and to implement the European Water Quality Directive in order to improve the water quantity and quality received by the downstream
country of a shared watershed, especially because two million inhabitants use the water from the last river location as their
only source of drinking water. 相似文献
9.
Hannah M. Clilverd Daniel M. White Amy C. Tidwell Michael A. Rawlins 《Journal of the American Water Resources Association》2011,47(6):1228-1240
Clilverd, Hannah M., Daniel M. White, Amy C. Tidwell, and Michael A. Rawlins, 2011. The Sensitivity of Northern Groundwater Recharge to Climate Change: A Case Study in Northwest Alaska. Journal of the American Water Resources Association (JAWRA) 47(6):1228–1240. DOI: 10.1111/j.1752‐1688.2011.00569.x Abstract: The potential impacts of climate change on northern groundwater supplies were examined at a fractured‐marble mountain aquifer near Nome, Alaska. Well water surface elevations (WSE) were monitored from 2004‐2009 and analyzed with local meteorological data. Future aquifer response was simulated with the Pan‐Arctic Water Balance Model (PWBM) using forcings (air temperature and precipitation) derived from fifth‐generation European Centre Hamburg Model (ECHAM5) global circulation model climate scenarios for extreme and modest increases in greenhouse gases. We observed changes in WSE due to the onset of spring snowmelt, low intensity and high intensity rainfall events, and aquifer head recession during the winter freeze period. Observed WSE and snow depth compared well with PWBM‐simulated groundwater recharge and snow storage. Using ECHAM5‐simulated increases in mean annual temperature of 4‐8°C by 2099, the PWBM predicted that by 2099 later freeze‐up and earlier snowmelt will decrease seasonal snow cover by one to two months. Annual evapotranspiration and precipitation are predicted to increase 27‐40% (55‐81 mm) and 33‐42% (81‐102 mm), respectively, with the proportion of snowfall in annual precipitation decreasing on average 9‐25% (p < 0.05). The amount of snowmelt is not predicted to change significantly by 2099; however, a decreasing trend is evident from 2060 in the extreme ECHAM5 greenhouse gas scenario. Increases in effective precipitation were predicted to be great enough to sustain sufficient groundwater recharge. 相似文献