Timber harvest and flood impacts on sediment yield in a postglacial, mixed-forest watershed, Maine, USA

The variability in fluvial yield of clastic sediment is a useful metric of the upstream basin's geomorphic response to natural and anthropogenic landscape disturbances. It reflects an integrated signal of sediment mobilization and connectivity, that is the efficiency with which the mobilized material is evacuated by the sediment routing system. Average clastic sediment yield has also been used as a measure of mechanical denudation rates, although material storage along the routing system necessitates caution in such inferences.Insight into the geomorphic responses to disturbances, provided by sediment yield analysis, is crucial for the understanding and management of river ecosystems. In the context of ongoing environmental change, intermediate-term system responses (spanning decades-to-centuries) to shifting disturbance regimes are of particular interest. Because of non-stationary conditions and high variability in fluvial sediment transport, knowledge developed based on short-term records of instrumented measurements is not readily transferrable to such longer time-scales. As a result, there is a need for more research focused on multi-decadal sediment yield patterns.&#160;This research addresses such a research need, by estimating clastic sediment yield from a forested mountain basin in NE Washington (USA) during a period of 107 years. To this end, we use historical aerial imagery and track, at the decadal resolution, sedimentation associated with delta growth following the construction of a dam. We interpret these data in the context of available records of streamflow and timber harvest operations, which constitute primary natural and anthropogenic disturbances.&#160;Preliminary results suggest relatively low sediment yield from the study basin, almost an order of magnitude lower than those reported from the coastal Pacific Northwest. We interpret inter-decadal variation in sediment yield estimates as indicative of interactive effects of flow forcing and land cover disturbance magnitude. We also believe that, because of variations of connectivity within the routing system, the sensitivity of sediment yield to disturbance at this time-scale is modulated by the location within the basin relative to its outlet.

Download Full-text

Forest disturbance frequency and patch structure from pre-European settlement to present in the Mixed Forest Province of Minnesota, USA

Canadian Journal of Forest Research ◽

10.1139/x08-065 ◽

2008 ◽

Vol 38 (8) ◽

pp. 2212-2226 ◽

Cited By ~ 23

Author(s):

M. A. White ◽

G. E. Host

Keyword(s):

Spatial Pattern ◽

Tree Mortality ◽

Management Practices ◽

Forest Disturbance ◽

Mixed Forest ◽

Strong Relationship ◽

Timber Harvest ◽

Study Region ◽

Disturbance Frequency ◽

Disturbance Factor

We used General Land Office survey data (1860–1890) and interpreted aerial photography from the 1930s, 1970s, and 1990s to quantify forest disturbance frequency and spatial patterns for four time periods in the Mixed Forest Province of Minnesota. The study region included eight subsections within the Mixed Forest Province of Minnesota’s Ecological Classification System. Presettlement disturbance and spatial pattern estimates varied across the eight subsections indicating a strong relationship to soil and landform characteristics. Land surveyors primarily recorded higher severity disturbances that resulted in significant tree mortality. The 1900–1940 era was characterized by a short-term increase in fire frequency that was relatively uniform across the study region, in contrast to the variability of the presettlement (1860–1890) landscape. In the postsettlement period (1940–1995), timber harvest replaced fire as the dominant disturbance factor. Similar management practices among subsections created similar harvest rates throughout the study region. These management practices imposed a more homogeneous pattern dominated by small (10–25 ha) patches. Management practices now have a greater influence than natural processes in the generation of landscape pattern in the Mixed Forest Province of Minnesota. Information on presettlement forest conditions and subsequent changes can be used by land managers to restore spatial pattern variability in managed forest landscapes.

Download Full-text

EMERGY-based environmental systems assessment of a multi-purpose temperate mixed-forest watershed of the southern Appalachian Mountains, USA

Journal of Environmental Management ◽

10.1016/j.jenvman.2003.08.002 ◽

2003 ◽

Vol 69 (3) ◽

pp. 213-227 ◽

Cited By ~ 63

Author(s):

David Rogers Tilley ◽

Wayne T. Swank

Keyword(s):

Appalachian Mountains ◽

Mixed Forest ◽

Southern Appalachian Mountains ◽

Southern Appalachian ◽

Environmental Systems ◽

Forest Watershed ◽

Temperate Mixed Forest

Download Full-text

Impact of Multiple Vegetation Covers on Surface Runoff and Sediment Yield in the Small Basin of Nverzhai, Hunan Province, China

Forests ◽

10.3390/f11030329 ◽

2020 ◽

Vol 11 (3) ◽

pp. 329 ◽

Cited By ~ 3

Author(s):

Jia Luo ◽

Xiaoling Zhou ◽

Matteo Rubinato ◽

Guijing Li ◽

Yuxin Tian ◽

...

Keyword(s):

Soil Erosion ◽

Sediment Yield ◽

Water Conservation ◽

Surface Runoff ◽

Mixed Forest ◽

Ground Cover ◽

Hunan Province ◽

Vegetation Types ◽

Runoff And Sediment Yield ◽

Small Basin

Vegetation plays a significant role in controlling soil erosion. However, the effects of each vegetation type on soil erosion have not been fully investigated. In order to explore the influence of multiple vegetation covers on soil erosion and surface runoff generation, 10 different vegetation types, typical of the Nverzhai small basin, have been selected for this study. Regional precipitation, surface runoff, and sediment yield were measured from 2007 to 2018. The wettest year recorded was 2012. Recorded data confirmed that July was the wettest month in this region while January and December were the driest months. Furthermore, surface runoff and sediment yield associated with different vegetation types gradually decreased after 2013, which is the quantification of the consequences due to afforestation processes started in this area. Surface runoff and sediment content recorded for the configuration of sloping farmland were the largest between the different investigated vegetation types. The smallest were the broad-leaved mixed forest, the coniferous mixed forest, and shrubs. Finally, a significant linear positive correlation was found between rainfall and surface runoff, as well as sediment yield (R2 = 0.75). This suggests that climate change implications could be limited by using the more efficient vegetation covering. This research indicates that the ground cover is a key element in controlling soil and water loss, as well as vegetation measures, with high ground cover (i.e., broad-leaved trees). These measures should be strongly recommended for soil erosion control and surface runoff reduction. Moreover, these outcomes can be very helpful for vegetation restoration and water conservation strategies if implemented by local authorities.

Download Full-text

Modeling Climate Change Impacts on the Water Balance of a Medium-Scale Mixed-Forest Watershed, SE USA

Southeastern Geographer ◽

10.1353/sgo.2019.0011 ◽

2019 ◽

Vol 59 (2) ◽

pp. 110-129

Author(s):

C. Andrew Day ◽

D. A. Howarth

Keyword(s):

Climate Change ◽

Water Balance ◽

Mixed Forest ◽

Climate Change Impacts ◽

Medium Scale ◽

Forest Watershed

Download Full-text

KAJIAN EROSI LAHAN DI KAWASAN AIR STRIP RUNWAY 2600 BANDARA DEPATI AMIR (PGK) BERDASARKAN TATA GUNA LAHAN MASTERPLAN ULTIMATE

FROPIL (Forum Profesional Teknik Sipil) ◽

10.33019/fropil.v7i2.1627 ◽

2019 ◽

Vol 7 (2) ◽

pp. 100-111

Author(s):

Miskar Maini ◽

Junita Eka Susanti

Keyword(s):

Sediment Yield ◽

Soil Loss ◽

Universal Soil Loss Equation ◽

Delivery Ratio ◽

Sediment Delivery Ratio ◽

Sediment Delivery ◽

Soil Loss Equation

Standar permintaan engineering pesawat agar desain bangunan infrastruktur di area Air Strip Runway 2600 yang ada dapat mempunyai fungsi lain. Sedangkan kondisi lain sangat menentukan keselamatan karena lahan di sekitar Air Strip Runway 2600 Bandara Depati Amir (PGK) jika tidak ditutupi vegetasi seperti rumput, kondisi lain lahan yang belum ditutupi vegetasi di sekitar Air Strip Runway 2600 berpotensi akan mengalami erosi lahan, kemudian hasil erosi lahan ini akan terbawa oleh aliran air sehingga akan masuk ke saluran drainase yang akan menyebabkan sedimentasi pada saluran drainase tersebut, akhirnya akan berkurang efektifitas kinerja saluran drainase tersebut. Metode yang digunakan untuk memprediksi laju rata-rata erosi di area Air Strip Runway 2600 dengan memperhitungkan faktor erosivitas hujan, erodibilitas tanah, kemiringan lereng atau panjang lereng, pengelolaan tanaman dan konservasi tanah, yang masing masing tata guna lahan tersebut mengacu pada Masterplan Ultimate Bandara Depati Amir (PGK). Perhitungan dilakukan menggunakan persamaan USLE (Universal Soil Loss Equation) yang dikembangkan oleh Wischmeier dan Smith (1965, 1978), kemudian Sediment Delivery Ratio (SDR) dan Sediment Yield.Hasil penelitian ini, prediksi laju erosi permukaan pada area Air Strip Runway 2600 Bandara Depati Amir (PGK) tahun pertama yang mencapai 5,60 mm/tahun atau 100,76 Ton/Ha/tahun, laju erosi tahun kedua mencapai 3,38 mm/tahun atau 60,84 Ton/Ha/tahun dapat diklasifikasikan ke dalam kelas bahaya erosi sedang (kelas III) dan nilai SDR adalah sebesar 56,3%, nilai sediment yield (SR) pada tahun pertama sebesar 5.887,59 Ton/Tahun, pada tahun kedua ketika rumput pada area Air Strip telah tumbuh dengan sempurna terjadi penurunan hasil sediment yield yaitu nilai SR sebesar 3.554,85 Ton/Tahun.

Download Full-text