scholarly journals Study on Potential Influence of Runoff on Observatory-Based Watershed in Japan

2019 ◽  
Vol 12 (4) ◽  
pp. 19
Author(s):  
Donglai Ma ◽  
Seiko Yoshikawa ◽  
Yoshiaki Ohsawa ◽  
Tadamasa Saito ◽  
Masahiro Kobayashi ◽  
...  

Land use shows the interaction between human and nature, and its impacts especially on runoff have received global attention and required more research studies. However, watershed database is generally available only for very large scales and not yet adapted to small scales. This paper presents a methodology for watershed delineation and potential influence assessment of runoff on the small watersheds in Japan based on the locations of the official observatory point data. Flow direction, flow accumulation, snap pour point and watershed recognition were analyzed by using the D8 algorithm and 10 m × 10 m DEM data of Japan. Totally 3831 watersheds were delineated by defining snapping pour point distance of 50 m as the input value, and the nation-wide watershed database was established. According to the suggestion of Notification No. 521 from the Ministry of Land, Infrastructure and Transport of Japan and land use/land cover data from JAXA satellite Alos-2, comprehensive runoff coefficient (CRC) was calculated by the weighted average method and divided into 10 levels by the equal interval method using ArcGIS. The obtained watershed boundary lines were almost identical to the ridge lines in the mountain area which accounts for more than half of Japan. The CRC values in the biggest cities such as Tokyo and Osaka were the highest, indicating these cities would receive the highest impacts of runoff. These results can provide the technical support for the decision-making on watershed management. The creation of small-scale watershed database would provide basic materials for the subsequent research such as flood prevention, water shortage and biogeochemical cycle of the sustainable regional development.

Hydrology ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 102
Author(s):  
Frauke Kachholz ◽  
Jens Tränckner

Land use changes influence the water balance and often increase surface runoff. The resulting impacts on river flow, water level, and flood should be identified beforehand in the phase of spatial planning. In two consecutive papers, we develop a model-based decision support system for quantifying the hydrological and stream hydraulic impacts of land use changes. Part 1 presents the semi-automatic set-up of physically based hydrological and hydraulic models on the basis of geodata analysis for the current state. Appropriate hydrological model parameters for ungauged catchments are derived by a transfer from a calibrated model. In the regarded lowland river basins, parameters of surface and groundwater inflow turned out to be particularly important. While the calibration delivers very good to good model results for flow (Evol =2.4%, R = 0.84, NSE = 0.84), the model performance is good to satisfactory (Evol = −9.6%, R = 0.88, NSE = 0.59) in a different river system parametrized with the transfer procedure. After transferring the concept to a larger area with various small rivers, the current state is analyzed by running simulations based on statistical rainfall scenarios. Results include watercourse section-specific capacities and excess volumes in case of flooding. The developed approach can relatively quickly generate physically reliable and spatially high-resolution results. Part 2 builds on the data generated in part 1 and presents the subsequent approach to assess hydrologic/hydrodynamic impacts of potential land use changes.


Author(s):  
Jane J. Aggrey ◽  
Mirjam A. F. Ros-Tonen ◽  
Kwabena O. Asubonteng

AbstractArtisanal and small-scale mining (ASM) in sub-Saharan Africa creates considerable dynamics in rural landscapes. Many studies addressed the adverse effects of mining, but few studies use participatory spatial tools to assess the effects on land use. Hence, this paper takes an actor perspective to analyze how communities in a mixed farming-mining area in Ghana’s Eastern Region perceive the spatial dynamics of ASM and its effects on land for farming and food production from past (1986) to present (2018) and toward the future (2035). Participatory maps show how participants visualize the transformation of food-crop areas into small- and large-scale mining, tree crops, and settlement in all the communities between 1986 and 2018 and foresee these trends to continue in the future (2035). Participants also observe how a mosaic landscape shifts toward a segregated landscape, with simultaneous fragmentation of their farming land due to ASM. Further segregation is expected in the future, with attribution to the expansion of settlements being an unexpected outcome. Although participants expect adverse effects on the future availability of food-crop land, no firm conclusions can be drawn about the anticipated effect on food availability. The paper argues that, if responsibly applied and used to reveal community perspectives and concerns about landscape dynamics, participatory mapping can help raise awareness of the need for collective action and contribute to more inclusive landscape governance. These findings contribute to debates on the operationalization of integrated and inclusive landscape approaches and governance, particularly in areas with pervasive impacts of ASM.


2019 ◽  
Vol 34 ◽  
pp. 15-24
Author(s):  
Sebastian Kepfer-Rojas ◽  
Kris Verheyen ◽  
An De Schrijver ◽  
Jonas Morsing ◽  
Inger Kappel Schmidt

2008 ◽  
Vol 310 (1-2) ◽  
pp. 103-112 ◽  
Author(s):  
Zhiyong Zhou ◽  
Osbert Jianxin Sun ◽  
Zhongkui Luo ◽  
Hongmei Jin ◽  
Quansheng Chen ◽  
...  

2021 ◽  
Author(s):  
Mohammad A. Alam

This research focuses on the waste and environmental damage caused by mining activities and the impact that this has on settlement pattern of adjacent areas. This research identifies that mining cities are unique in their land use dynamics due to the physical attributes of mining sites and there impacts on human and nature. Using a method of three sequential approaches to understand the land use dynamics of mining cities the first study examines the physical attributes of mining sites, through the creation of a new data set that combines existing and abandoned sites from existing separate datasets, outlining production, proximity to settlement areas and water bodies to identify their degree of threat to human and nature. Secondly, a single case study of Copper Cliff, ON is used to investigate how mining activities and its changes interact with surrounding land uses through a Land mosaic-function-land change feedback model adapted from Richard T.T. Forman’s theory of land mosaic. The analysis then investigates the policy responses that are enacted to mitigate the mining activities with other land uses. The analysis identifies that the potential impact of mining activities is more prominent where mining waste production is higher and located at close proximity to settlement areas. However, although the growth pattern of settlement areas are often guided by the physical characteristics of mining sites, effective response of land use policies may stimulate positive changes of land use pattern.


2021 ◽  
Vol 13 (1) ◽  
pp. 1-20
Author(s):  
Abdelwassie Hussien ◽  
Tesfamichael Gebreyohannes ◽  
Miruts Hagos ◽  
Gebremedhin Berhane ◽  
Kassa Amare ◽  
...  

Due to the ever-increasing demand for water in Aynalem catchment and its surrounding, there has been an increased pressure on the Aynalem well field putting the sustainability of water supply from the aquifer under continuous threat. Thus, it is vital to understand the water balance of the catchment to ensure sustainable utilization of the groundwater resource. This in turn requires proper quantification of the components of water balance among which recharge estimation is the most important. This paper estimates the groundwater recharge of the Aynalem catchment using high-resolution hydro-meteorological data. Daily precipitation and temperature measurement data for years 2001-2018; groundwater level fluctuation records collected at every 30 minutes; and soil and land use maps were used to make recharge estimations. In the groundwater level fluctuation, three boreholes were monitored, but only two were utilized for the analysis because the third was under operation and does not represent the natural hydrologic condition. Thornthwaite soil moisture balance and groundwater level fluctuation methods were applied to determine the groundwater recharge of the Aynalem catchment. Accordingly, the annual rate of groundwater recharge estimated based on the soil-water balance ranges between 7mm/year and 138.5 mm/year with the weighted average value of 89.04 mm/year. The weighted average value is considered to represent the catchment value because the diverse soil and land use/cover types respond differently to allow the precipitation to recharge the groundwater. On the other hand, the groundwater recharge estimated using the groundwater level fluctuation method showed yearly groundwater recharge of 91 to 93 mm/year. The similarity in the groundwater recharge result obtained from both methods strengthens the acceptability of the estimate. It also points out that the previously reported estimate is much lower (36 to 66 mm/year).


Author(s):  
Verónica Iñiguez-Gallardo ◽  
Renato Serrano-Barbecho ◽  
Fabián René Reyes Bueno

La regulación de uso del suelo es un continuo debate en el proceso de planificación territorial, sobre todo en Ecuador, donde la agricultura a pequeña escala es uno de los pilares de la economía familiar para un amplio porcentaje de habitantes del sector rural. Por esta razón, identificar las variables requeridas para mantener la actividad agrícola es una necesidad y obligación. El objetivo principal de este artículo es identificar las variables espaciales que inciden sobre la probabilidad de mantener la actividad agrícola, de acuerdo con las expectativas de la gente y las características del territorio. Para ello, se comparan datos de percepción de los pobladores sobre variables tales como superficie predial, distancia a carretera, a canales de riego y a mercados, con datos espaciales de estas mismas variables. El área de estudio es la Parroquia Chuquiribamba, perteneciente al cantón Loja, al sur del Ecuador, por ser una de las principales fuentes agrícolas del sector. Los resultados sugieren convergencias entre las percepciones de la gente y las variables espaciales necesarias para asegurar la actividad agrícola, así como divergencias respecto a la normativa que regula el tamaño mínimo predial.  Abstract Land-use regulation is an ongoing debate in the process of land-use planning. This is particularly true for a country such as Ecuador, where small-scale agriculture is one of the pillars of the family economy for a large percentage of inhabitants of the rural sector.  In this context, identifying the necessary variables for ensuring agricultural activities is a need and an obligation. The main objective of this article is to identify the spatial variables that affect the probability of maintaining agricultural activity, according to the expectations of the people and the characteristics of the territory. We compare data regarding the perceptions of the people of variables such as parcel size, road, irrigation and market proximity, with spatial data of the same variables. The area of study is the Chuquiribamba Parish, located in Canton Loja, in southern Ecuador. We selected it due to its agricultural importance in the Canton. The results suggest convergences between the perceptions of the people and the spatial variables necessary to safeguard agriculture, as well as divergences with the normative regulating the minimum parcel-size. 


10.26458/1845 ◽  
2018 ◽  
Vol 18 (4) ◽  
pp. 75-93
Author(s):  
Viorica Jelev

 This paper presents the existing situation at national and world level considering the available water resources, their vulnerability especially in the mountains areas, the impact of climate changes, the possible conflicts regarding the intensification of water shortage in some regions of the world. I also present a case study on forests in Romania. Beginning with the general data mentioned above, we point out the specific peculiarities of the mountain area hydrology for identifying some aspects which are specific to the mountain water relationship. The analysis is necessary as no specifications regarding the mountain hilly or plain areas are done in the activity regarding waters management. Waters are managed unitary on river basins considering some general principles, unanimously recognized, well reflected into the national and international regulations. As a first stage, traditional economic activities are identified in the relationship of the mountain areas inhabitants with water but also some present approaches. The way the mountain areas inhabitants knew how to live together and capitalize water resources represents a model and impulse for coming back to such sustainable solutions but capitalizing the advantages of modern technologies. Each of these activities referring to waters which take place in the mountains area can represent ways for the research activity and future thorough studies from the technical, economic, social, cultural-traditional point of view and also for environment protection. A main preoccupation might have connection with the evolution of agricultural activities in the mountains area considering the climate changes and a possible “migration” towards higher areas of some agricultural practices specific to lower areas. The paper also shows a small example of the regaining by the locals of a community of an important resource for their lives in the hands of corporations: the forests defaced by HOLZINDUSTRIE SCHWEIGHOFER and stop flooding villages. 


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