On the Relationship Between Flood and Contributing Area
Bibliographic record
Abstract
Abstract. While it is well known that the vast majority of the time only a portion of any watershed contributes runoff to the outlet, this extent is rarely documented. The power-law form of the streamflow and contributing area (Q-Ac) relationship has been known for a half century, but it is uncommon for it to be quantified or its controls evaluated. In this study a semi-distributed hydrological model (MESH-PDMROF) that can simulate contributing area and streamflow was employed to compare contributing area and flood frequency distributions in a southern Manitoba, Canada catchment and test the hypothesis that the relationship between a catchment’s floods and contributing area is a power function that influences the form of regional flood-area relationships. The model simulated streamflow reasonably well (Nash Sutcliffe values = 0.62). Modelled estimates of the area contributing to the mean annual flood were much lower (0.3) than those derived from independent topographic analysis (0.9) described in earlier literature, even after bias and error corrections. Estimates of the coefficient and exponent of the Q-Ac power law function ranged from 0.08–0.14 and 0.9–1.12, respectively. Lower exponent values of regional flood frequency curves suggest they are a construct of Q-Ac curves from individual basins. The non-linear nature of this relationship implies any contributing area change will have a profound impact on flood magnitude. The mean annual flood of the major river in this region, the Red, has increased 33 % since 1987. Applying the coefficient and exponent ranges above suggests this is associated with an expansion in contributing areas of 29–38 %. There are implications for the attribution of causes and mitigation of nutrient transport from regional watersheds. However, how physiography and land and water management could change Q-Ac power law exponents is poorly known and MESH-PDMROF does not provide explicit estimates of the spatial distribution of contributing area. These are areas encouraged for future research.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.006 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".